Sample records for single-photon sensitive detector

  1. Single photon detector with high polarization sensitivity.

    PubMed

    Guo, Qi; Li, Hao; You, LiXing; Zhang, WeiJun; Zhang, Lu; Wang, Zhen; Xie, XiaoMing; Qi, Ming

    2015-04-15

    Polarization is one of the key parameters of light. Most optical detectors are intensity detectors that are insensitive to the polarization of light. A superconducting nanowire single photon detector (SNSPD) is naturally sensitive to polarization due to its nanowire structure. Previous studies focused on producing a polarization-insensitive SNSPD. In this study, by adjusting the width and pitch of the nanowire, we systematically investigate the preparation of an SNSPD with high polarization sensitivity. Subsequently, an SNSPD with a system detection efficiency of 12% and a polarization extinction ratio of 22 was successfully prepared.

  2. Frequency-multiplexed bias and readout of a 16-pixel superconducting nanowire single-photon detector array

    NASA Astrophysics Data System (ADS)

    Doerner, S.; Kuzmin, A.; Wuensch, S.; Charaev, I.; Boes, F.; Zwick, T.; Siegel, M.

    2017-07-01

    We demonstrate a 16-pixel array of microwave-current driven superconducting nanowire single-photon detectors with an integrated and scalable frequency-division multiplexing architecture, which reduces the required number of bias and readout lines to a single microwave feed line. The electrical behavior of the photon-sensitive nanowires, embedded in a resonant circuit, as well as the optical performance and timing jitter of the single detectors is discussed. Besides the single pixel measurements, we also demonstrate the operation of a 16-pixel array with a temporal, spatial, and photon-number resolution.

  3. Photocurrent spectrum study of a quantum dot single-photon detector based on resonant tunneling effect with near-infrared response

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Weng, Q. C.; Key Laboratory of Polar Materials and Devices, Ministry of Education, East China Normal University, Shanghai 200241; An, Z. H., E-mail: anzhenghua@fudan.edu.cn, E-mail: luwei@mail.sitp.ac.cn

    We present the photocurrent spectrum study of a quantum dot (QD) single-photon detector using a reset technique which eliminates the QD's “memory effect.” By applying a proper reset frequency and keeping the detector in linear-response region, the detector's responses to different monochromatic light are resolved which reflects different detection efficiencies. We find the reset photocurrent tails up to 1.3 μm wavelength and near-infrared (∼1100 nm) single-photon sensitivity is demonstrated due to interband transition of electrons in QDs, indicating the device a promising candidate both in quantum information applications and highly sensitive imaging applications operating in relative high temperatures (>80 K).

  4. Demonstration of a superconducting nanowire single photon detector with an ultrahigh polarization extinction ratio over 400.

    PubMed

    Xu, Ruiying; Li, Yongchao; Zheng, Fan; Zhu, Guanghao; Kang, Lin; Zhang, Labao; Jia, Xiaoqing; Tu, Xuecou; Zhao, Qingyuan; Jin, Biaobing; Xu, Weiwei; Chen, Jian; Wu, Peiheng

    2018-02-19

    Polarization sensitive photo-detectors are the key to the implementation of the polarimetric imaging systems, which are proved to have superior performance than their traditional counterparts based on intensity discriminations. In this article, we report the demonstration of a superconducting nanowire single photon detector (SNSPD) of which the response is ultra-sensitive to the polarization state of the incident photons. Measurements carried out on a fabricated SNSPD show that a device efficiency of ~48% can be achieved at 1550 nm for the case of parallel polarization, which is ~420 times larger than that for the case of perpendicular polarization. While the reported polarization ultra-sensitive technique is demonstrated on a single-pixel SNSPD, it is also fully compatible with the multi-pixel SNSPD array platforms that emerged recently.

  5. Ultrafast time measurements by time-correlated single photon counting coupled with superconducting single photon detector

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Shcheslavskiy, V., E-mail: vis@becker-hickl.de; Becker, W.; Morozov, P.

    Time resolution is one of the main characteristics of the single photon detectors besides quantum efficiency and dark count rate. We demonstrate here an ultrafast time-correlated single photon counting (TCSPC) setup consisting of a newly developed single photon counting board SPC-150NX and a superconducting NbN single photon detector with a sensitive area of 7 × 7 μm. The combination delivers a record instrument response function with a full width at half maximum of 17.8 ps and system quantum efficiency ∼15% at wavelength of 1560 nm. A calculation of the root mean square value of the timing jitter for channels withmore » counts more than 1% of the peak value yielded about 7.6 ps. The setup has also good timing stability of the detector–TCSPC board.« less

  6. Isolated nanoinjection photo detectors for high-speed and high-sensitivity single-photon detection

    NASA Astrophysics Data System (ADS)

    Fathipour, V.; Memis, O. G.; Jang, S. J.; Khalid, F.; Brown, R. L.; Hassaninia, I.; Gelfand, R.; Mohseni, H.

    2013-09-01

    Our group has designed and developed a new SWIR single photon detector called the nano-injection detector that is conceptually designed with biological inspirations taken from the rod cells in human eye. The detector couples a nanoscale sensory region with a large absorption volume to provide avalanche free internal amplification while operating at linear regime with low bias voltages. The low voltage operation makes the detector to be fully compatible with available CMOS technologies. Because there is no photon reemission, detectors can be formed into high-density single-photon detector arrays. As such, the nano injection detectors are viable candidates for SPD and imaging at the short-wave infrared band. Our measurements in 2007 proved a high SNR and a stable excess noise factor of near unity. We are reporting on a high speed version of the detector with 4 orders of magnitude enhancement in speed as well as 2 orders of magnitude reduction in dark current (30nA vs. 10 uA at 1.5V).

  7. Linewidth Narrowing and Purcell Enhancement in Photonic Crystal Cavities on an Er-Doped Silicon Nitride Platform

    DTIC Science & Technology

    2010-02-01

    Low noise superconducting single photon detectors on silicon,” Appl. Phys. Lett. 93, 131101 (2008). 20. M. T. Tanner, C. M. Natarajan, V. K... wavelength sensitivity in NbTiN superconducting nanowire single-photon detectors fabricated on oxidized silicon substrates,” Proceedings of Single...cavity resonance wavelength and Q-factor for the PC cavity are shown in Figure 3. The data are taken both at low (0.050 mW) pump power and high (30 mW

  8. First Dark Matter Constraints from SuperCDMS Single-Charge Sensitive Detectors

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Agnese, R.; et al.

    We present the first limits on inelastic electron-scattering dark matter and dark photon absorption using a prototype SuperCDMS detector having a charge resolution of 0.1 electron-hole pairs (CDMS HVeV, a 0.93 gram CDMS HV device). These electron-recoil limits significantly improve experimental constraints on dark matter particles with masses as low as 1 MeV/more » $$\\mathrm{c^2}$$. We demonstrate a sensitivity to dark photons competitive with other leading approaches but using substantially less exposure (0.49 gram days). These results demonstrate the scientific potential of phonon-mediated semiconductor detectors that are sensitive to single electronic excitations.« less

  9. Negative Avalanche Feedback Detectors for Photon-Counting Optical Communications

    NASA Technical Reports Server (NTRS)

    Farr, William H.

    2009-01-01

    Negative Avalanche Feedback photon counting detectors with near-infrared spectral sensitivity offer an alternative to conventional Geiger mode avalanche photodiode or phototube detectors for free space communications links at 1 and 1.55 microns. These devices demonstrate linear mode photon counting without requiring any external reset circuitry and may even be operated at room temperature. We have now characterized the detection efficiency, dark count rate, after-pulsing, and single photon jitter for three variants of this new detector class, as well as operated these uniquely simple to use devices in actual photon starved free space optical communications links.

  10. Sensitivity booster for DOI-PET scanner by utilizing Compton scattering events between detector blocks

    NASA Astrophysics Data System (ADS)

    Yoshida, Eiji; Tashima, Hideaki; Yamaya, Taiga

    2014-11-01

    In a conventional PET scanner, coincidence events are measured with a limited energy window for detection of photoelectric events in order to reject Compton scatter events that occur in a patient, but Compton scatter events caused in detector crystals are also rejected. Scatter events within the patient causes scatter coincidences, but inter crystal scattering (ICS) events have useful information for determining an activity distribution. Some researchers have reported the feasibility of PET scanners based on a Compton camera for tracing ICS into the detector. However, these scanners require expensive semiconductor detectors for high-energy resolution. In the Anger-type block detector, single photons interacting with multiple detectors can be obtained for each interacting position and complete information can be gotten just as for photoelectric events in the single detector. ICS events in the single detector have been used to get coincidence, but single photons interacting with multiple detectors have not been used to get coincidence. In this work, we evaluated effect of sensitivity improvement using Compton kinetics in several types of DOI-PET scanners. The proposed method promises to improve the sensitivity using coincidence events of single photons interacting with multiple detectors, which are identified as the first interaction (FI). FI estimation accuracy can be improved to determine FI validity from the correlation between Compton scatter angles calculated on the coincidence line-of-response. We simulated an animal PET scanner consisting of 42 detectors. Each detector block consists of three types of scintillator crystals (LSO, GSO and GAGG). After the simulation, coincidence events are added as information for several depth-of-interaction (DOI) resolutions. From the simulation results, we concluded the proposed method promises to improve the sensitivity considerably when effective atomic number of a scintillator is low. Also, we showed that FI estimate accuracy is improved, as DOI resolution is high.

  11. Single-Photon-Sensitive HgCdTe Avalanche Photodiode Detector

    NASA Technical Reports Server (NTRS)

    Huntington, Andrew

    2013-01-01

    The purpose of this program was to develop single-photon-sensitive short-wavelength infrared (SWIR) and mid-wavelength infrared (MWIR) avalanche photodiode (APD) receivers based on linear-mode HgCdTe APDs, for application by NASA in light detection and ranging (lidar) sensors. Linear-mode photon-counting APDs are desired for lidar because they have a shorter pixel dead time than Geiger APDs, and can detect sequential pulse returns from multiple objects that are closely spaced in range. Linear-mode APDs can also measure photon number, which Geiger APDs cannot, adding an extra dimension to lidar scene data for multi-photon returns. High-gain APDs with low multiplication noise are required for efficient linear-mode detection of single photons because of APD gain statistics -- a low-excess-noise APD will generate detectible current pulses from single photon input at a much higher rate of occurrence than will a noisy APD operated at the same average gain. MWIR and LWIR electron-avalanche HgCdTe APDs have been shown to operate in linear mode at high average avalanche gain (M > 1000) without excess multiplication noise (F = 1), and are therefore very good candidates for linear-mode photon counting. However, detectors fashioned from these narrow-bandgap alloys require aggressive cooling to control thermal dark current. Wider-bandgap SWIR HgCdTe APDs were investigated in this program as a strategy to reduce detector cooling requirements.

  12. Graphene-Based Josephson-Junction Single-Photon Detector

    NASA Astrophysics Data System (ADS)

    Walsh, Evan D.; Efetov, Dmitri K.; Lee, Gil-Ho; Heuck, Mikkel; Crossno, Jesse; Ohki, Thomas A.; Kim, Philip; Englund, Dirk; Fong, Kin Chung

    2017-08-01

    We propose to use graphene-based Josephson junctions (GJJs) to detect single photons in a wide electromagnetic spectrum from visible to radio frequencies. Our approach takes advantage of the exceptionally low electronic heat capacity of monolayer graphene and its constricted thermal conductance to its phonon degrees of freedom. Such a system could provide high-sensitivity photon detection required for research areas including quantum information processing and radio astronomy. As an example, we present our device concepts for GJJ single-photon detectors in both the microwave and infrared regimes. The dark count rate and intrinsic quantum efficiency are computed based on parameters from a measured GJJ, demonstrating feasibility within existing technologies.

  13. Fabrication of superconducting nanowire single-photon detectors by nonlinear femtosecond optical lithography

    NASA Astrophysics Data System (ADS)

    Minaev, N. V.; Tarkhov, M. A.; Dudova, D. S.; Timashev, P. S.; Chichkov, B. N.; Bagratashvili, V. N.

    2018-02-01

    This paper describes a new approach to the fabrication of superconducting nanowire single-photon detectors from ultrathin NbN films on SiO2 substrates. The technology is based on nonlinear femtosecond optical lithography and includes direct formation of the sensitive element of the detector (the meander) through femtosecond laser exposure of the polymethyl methacrylate resist at a wavelength of 525 nm and subsequent removal of NbN using plasma-chemical etching. The nonlinear femtosecond optical lithography method allows the formation of planar structures with a spatial resolution of ~50 nm. These structures were used to fabricate single-photon superconducting detectors with quantum efficiency no worse than 8% at a wavelength of 1310 nm and dark count rate of 10 s-1 at liquid helium temperature.

  14. Single photon detection of 1.5 THz radiation with the quantum capacitance detector

    NASA Astrophysics Data System (ADS)

    Echternach, P. M.; Pepper, B. J.; Reck, T.; Bradford, C. M.

    2018-01-01

    Far-infrared spectroscopy can reveal secrets of galaxy evolution and heavy-element enrichment throughout cosmic time, prompting astronomers worldwide to design cryogenic space telescopes for far-infrared spectroscopy. The most challenging aspect is a far-infrared detector that is both exquisitely sensitive (limited by the zodiacal-light noise in a narrow wavelength band, λ/Δλ 1,000) and array-able to tens of thousands of pixels. We present the quantum capacitance detector, a superconducting device adapted from quantum computing applications in which photon-produced free electrons in a superconductor tunnel into a small capacitive island embedded in a resonant circuit. The quantum capacitance detector has an optically measured noise equivalent power below 10-20 W Hz-1/2 at 1.5 THz, making it the most sensitive far-infrared detector ever demonstrated. We further demonstrate individual far-infrared photon counting, confirming the excellent sensitivity and suitability for cryogenic space astrophysics.

  15. Hybrid photodetector for single-molecule spectroscopy and microscopy

    PubMed Central

    Michalet, X.; Cheng, Adrian; Antelman, Joshua; Suyama, Motohiro; Arisaka, Katsushi; Weiss, Shimon

    2011-01-01

    We report benchmark tests of a new single-photon counting detector based on a GaAsP photocathode and an electron-bombarded avalanche photodiode developed by Hamamatsu Photonics. We compare its performance with those of standard Geiger-mode avalanche photodiodes. We show its advantages for FCS due to the absence of after-pulsing and for fluorescence lifetime measurements due to its excellent time resolution. Its large sensitive area also greatly simplifies setup alignment. Its spectral sensitivity being similar to that of recently introduced CMOS SPADs, this new detector could become a valuable tool for single-molecule fluorescence measurements, as well as for many other applications. PMID:21822361

  16. Characterization of Geiger mode avalanche photodiodes for fluorescence decay measurements

    NASA Astrophysics Data System (ADS)

    Jackson, John C.; Phelan, Don; Morrison, Alan P.; Redfern, R. Michael; Mathewson, Alan

    2002-05-01

    Geiger mode avalanche photodiodes (APD) can be biased above the breakdown voltage to allow detection of single photons. Because of the increase in quantum efficiency, magnetic field immunity, robustness, longer operating lifetime and reduction in costs, solid-state detectors capable of operating at non-cryogenic temperatures and providing single photon detection capabilities provide attractive alternatives to the photomultiplier tube (PMT). Shallow junction Geiger mode APD detectors provide the ability to manufacture photon detectors and detector arrays with CMOS compatible processing steps and allows the use of novel Silicon-on-Insulator(SoI) technology to provide future integrated sensing solutions. Previous work on Geiger mode APD detectors has focused on increasing the active area of the detector to make it more PMT like, easing the integration of discrete reaction, detection and signal processing into laboratory experimental systems. This discrete model for single photon detection works well for laboratory sized test and measurement equipment, however the move towards microfluidics and systems on a chip requires integrated sensing solutions. As we move towards providing integrated functionality of increasingly nanoscopic sized emissions, small area detectors and detector arrays that can be easily integrated into marketable systems, with sensitive small area single photon counting detectors will be needed. This paper will demonstrate the 2-dimensional and 3-dimensional simulation of optical coupling that occurs in Geiger mode APDs. Fabricated Geiger mode APD detectors optimized for fluorescence decay measurements were characterized and preliminary results show excellent results for their integration into fluorescence decay measurement systems.

  17. Room temperature single-photon detectors for high bit rate quantum key distribution

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Comandar, L. C.; Patel, K. A.; Engineering Department, Cambridge University, 9 J J Thomson Ave., Cambridge CB3 0FA

    We report room temperature operation of telecom wavelength single-photon detectors for high bit rate quantum key distribution (QKD). Room temperature operation is achieved using InGaAs avalanche photodiodes integrated with electronics based on the self-differencing technique that increases avalanche discrimination sensitivity. Despite using room temperature detectors, we demonstrate QKD with record secure bit rates over a range of fiber lengths (e.g., 1.26 Mbit/s over 50 km). Furthermore, our results indicate that operating the detectors at room temperature increases the secure bit rate for short distances.

  18. High quantum efficiency and low dark count rate in multi-layer superconducting nanowire single-photon detectors

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Jafari Salim, A., E-mail: ajafaris@uwaterloo.ca; Eftekharian, A.; University of Waterloo, Waterloo, Ontario N2L 3G1

    In this paper, we theoretically show that a multi-layer superconducting nanowire single-photon detector (SNSPD) is capable of approaching characteristics of an ideal SNSPD in terms of the quantum efficiency, dark count, and band-width. A multi-layer structure improves the performance in two ways. First, the potential barrier for thermally activated vortex crossing, which is the major source of dark counts and the reduction of the critical current in SNSPDs is elevated. In a multi-layer SNSPD, a vortex is made of 2D-pancake vortices that form a stack. It will be shown that the stack of pancake vortices effectively experiences a larger potentialmore » barrier compared to a vortex in a single-layer SNSPD. This leads to an increase in the experimental critical current as well as significant decrease in the dark count rate. In consequence, an increase in the quantum efficiency for photons of the same energy or an increase in the sensitivity to photons of lower energy is achieved. Second, a multi-layer structure improves the efficiency of single-photon absorption by increasing the effective optical thickness without compromising the single-photon sensitivity.« less

  19. Photon Counting System for High-Sensitivity Detection of Bioluminescence at Optical Fiber End.

    PubMed

    Iinuma, Masataka; Kadoya, Yutaka; Kuroda, Akio

    2016-01-01

    The technique of photon counting is widely used for various fields and also applicable to a high-sensitivity detection of luminescence. Thanks to recent development of single photon detectors with avalanche photodiodes (APDs), the photon counting system with an optical fiber has become powerful for a detection of bioluminescence at an optical fiber end, because it allows us to fully use the merits of compactness, simple operation, highly quantum efficiency of the APD detectors. This optical fiber-based system also has a possibility of improving the sensitivity to a local detection of Adenosine triphosphate (ATP) by high-sensitivity detection of the bioluminescence. In this chapter, we are introducing a basic concept of the optical fiber-based system and explaining how to construct and use this system.

  20. Photon-Counting Kinetic Inductance Detectors (KID) for Far/Mid-Infrared Space Spectroscopy with the Origins Space Telescope (OST)

    NASA Astrophysics Data System (ADS)

    Noroozian, Omid; Barrentine, Emily M.; Stevenson, Thomas R.; Brown, Ari D.; Moseley, Samuel Harvey; Wollack, Edward; Pontoppidan, Klaus Martin; U-Yen, Konpop; Mikula, Vilem

    2018-01-01

    Photon-counting detectors are highly desirable for reaching the ~ 10-20 W/√Hz power sensitivity permitted by the Origins Space Telescope (OST). We are developing unique Kinetic Inductance Detectors (KIDs) with photon counting capability in the far/mid-IR. Combined with an on-chip far-IR spectrometer onboard OST these detectors will enable a new data set for exploring galaxy evolution and the growth of structure in the Universe. Mid-IR spectroscopic surveys using these detectors will enable mapping the composition of key volatiles in planet-forming material around protoplanetary disks and their evolution into solar systems. While these OST science objectives represent a well-organized community agreement they are impossible to reach without a significant leap forward in detector technology, and the OST is likely not to be recommended if a path to suitable detectors does not exist.To reach the required sensitivity we are experimenting with superconducting resonators made from thin aluminum films on single-crystal silicon substrates. Under the right conditions, small-volume inductors made from these films can become ultra-sensitive to single photons >90 GHz. Understanding the physics of these superconductor-dielectric systems is critical to performance. We achieved a very high quality factor of 0.5 x 106 for a 10-nm Al resonator at n ~ 1 microwave photon drive power, by far the highest value for such thin films in the literature. We measured a residual electron density of < 5 /µm3 and extremely long lifetime of ~ 6.0 ms, both within requirements for photon-counting. To realize an optically coupled device, we are integrating these films with our on-chip spectrometer (μ-Spec) fabrication process. Using a detailed model we simulated the detector when illuminated with randomly arriving photon events. Our results show that photon counting with >95% efficiency at 0.5 - 1.0 THz is achievable.We report on these developments and discuss plans to test in our facility through funding from our recently awarded ROSES-APRA grant and Roman Technology Fellowship award.

  1. The TORCH detector R&D: Status and perspectives

    NASA Astrophysics Data System (ADS)

    Gys, T.; Brook, N.; García, L. Castillo; Cussans, D.; Föhl, K.; Forty, R.; Frei, C.; Gao, R.; Harnew, N.; Piedigrossi, D.; Rademacker, J.; García, A. Ros; van Dijk, M.

    2017-12-01

    TORCH (Timing Of internally Reflected CHerenkov photons) is a time-of-flight detector for particle identification at low momentum. It has been originally proposed for the LHCb experiment upgrade. TORCH is using plates of quartz radiator in a modular design. A fraction of the Cherenkov photons produced by charged particles passing through this radiator propagate by total internal reflection, they emerge at the edges and are subsequently focused onto fast, position-sensitive single-photon detectors. The recorded position and arrival time of the photons are used to precisely reconstruct their trajectory and propagation time in the quartz. The on-going R&D programme aims at demonstrating the TORCH basic concept through the realization of a full detector module and has been organized on the following main development lines: micro-channel plate photon detectors featuring the required granularity and lifetime, dedicated fast front-end electronics preserving the picosecond timing information provided by single photons, and high-quality quartz radiator and focussing optics minimizing photon losses. The present paper reports on the TORCH results successfully achieved in the laboratory and in charged particle beam tests. It will also introduce the latest developments towards a final full-scale module prototype.

  2. A 64-pixel NbTiN superconducting nanowire single-photon detector array for spatially resolved photon detection.

    PubMed

    Miki, Shigehito; Yamashita, Taro; Wang, Zhen; Terai, Hirotaka

    2014-04-07

    We present the characterization of two-dimensionally arranged 64-pixel NbTiN superconducting nanowire single-photon detector (SSPD) array for spatially resolved photon detection. NbTiN films deposited on thermally oxidized Si substrates enabled the high-yield production of high-quality SSPD pixels, and all 64 SSPD pixels showed uniform superconducting characteristics within the small range of 7.19-7.23 K of superconducting transition temperature and 15.8-17.8 μA of superconducting switching current. Furthermore, all of the pixels showed single-photon sensitivity, and 60 of the 64 pixels showed a pulse generation probability higher than 90% after photon absorption. As a result of light irradiation from the single-mode optical fiber at different distances between the fiber tip and the active area, the variations of system detection efficiency (SDE) in each pixel showed reasonable Gaussian distribution to represent the spatial distributions of photon flux intensity.

  3. Performance and Characterization of a Modular Superconducting Nanowire Single Photon Detector System for Space-to-Earth Optical Communications Links

    NASA Technical Reports Server (NTRS)

    Vyhnalek, Brian E.; Tedder, Sarah A.; Nappier, Jennifer M.

    2018-01-01

    Space-to-ground photon-counting optical communication links supporting high data rates over large distances require enhanced ground receiver sensitivity in order to reduce the mass and power burden on the spacecraft transmitter. Superconducting nanowire single-photon detectors (SNSPDs) have been demonstrated to offer superior performance in detection efficiency, timing resolution, and count rates over semiconductor photodetectors, and are a suitable technology for high photon efficiency links. Recently photon detectors based on superconducting nanowires have become commercially available, and we have assessed the characteristics and performance of one such commercial system as a candidate for potential utilization in ground receiver designs. The SNSPD system features independent channels which can be added modularly, and we analyze the scalability of the system to support different data rates, as well as consider coupling concepts and issues as the number of channels increases.

  4. Single-Electron and Single-Photon Sensitivity with a Silicon Skipper CCD

    DOE PAGES

    Tiffenberg, Javier; Sofo-Haro, Miguel; Drlica-Wagner, Alex; ...

    2017-09-26

    Here, we have developed ultralow-noise electronics in combination with repetitive, nondestructive readout of a thick, fully depleted charge-coupled device (CCD) to achieve an unprecedented noise level of 0.068 e - rms/pixel. This is the first time that discrete subelectron readout noise has been achieved reproducible over millions of pixels on a stable, large-area detector. This enables the contemporaneous, discrete, and quantized measurement of charge in pixels, irrespective of whether they contain zero electrons or thousands of electrons. Thus, the resulting CCD detector is an ultra-sensitive calorimeter. It is also capable of counting single photons in the optical and near-infrared regime.more » Implementing this innovative non-destructive readout system has a negligible impact on CCD design and fabrication, and there are nearly immediate scientific applications. As a particle detector, this CCD will have unprecedented sensitivity to low-mass dark matter particles and coherent neutrino-nucleus scattering, while future astronomical applications may include direct imaging and spectroscopy of exoplanets.« less

  5. Single-Electron and Single-Photon Sensitivity with a Silicon Skipper CCD

    NASA Astrophysics Data System (ADS)

    Tiffenberg, Javier; Sofo-Haro, Miguel; Drlica-Wagner, Alex; Essig, Rouven; Guardincerri, Yann; Holland, Steve; Volansky, Tomer; Yu, Tien-Tien

    2017-09-01

    We have developed ultralow-noise electronics in combination with repetitive, nondestructive readout of a thick, fully depleted charge-coupled device (CCD) to achieve an unprecedented noise level of 0.068 e- rms /pixel . This is the first time that discrete subelectron readout noise has been achieved reproducible over millions of pixels on a stable, large-area detector. This enables the contemporaneous, discrete, and quantized measurement of charge in pixels, irrespective of whether they contain zero electrons or thousands of electrons. Thus, the resulting CCD detector is an ultra-sensitive calorimeter. It is also capable of counting single photons in the optical and near-infrared regime. Implementing this innovative non-destructive readout system has a negligible impact on CCD design and fabrication, and there are nearly immediate scientific applications. As a particle detector, this CCD will have unprecedented sensitivity to low-mass dark matter particles and coherent neutrino-nucleus scattering, while future astronomical applications may include direct imaging and spectroscopy of exoplanets.

  6. Single-Electron and Single-Photon Sensitivity with a Silicon Skipper CCD.

    PubMed

    Tiffenberg, Javier; Sofo-Haro, Miguel; Drlica-Wagner, Alex; Essig, Rouven; Guardincerri, Yann; Holland, Steve; Volansky, Tomer; Yu, Tien-Tien

    2017-09-29

    We have developed ultralow-noise electronics in combination with repetitive, nondestructive readout of a thick, fully depleted charge-coupled device (CCD) to achieve an unprecedented noise level of 0.068  e^{-} rms/pixel. This is the first time that discrete subelectron readout noise has been achieved reproducible over millions of pixels on a stable, large-area detector. This enables the contemporaneous, discrete, and quantized measurement of charge in pixels, irrespective of whether they contain zero electrons or thousands of electrons. Thus, the resulting CCD detector is an ultra-sensitive calorimeter. It is also capable of counting single photons in the optical and near-infrared regime. Implementing this innovative non-destructive readout system has a negligible impact on CCD design and fabrication, and there are nearly immediate scientific applications. As a particle detector, this CCD will have unprecedented sensitivity to low-mass dark matter particles and coherent neutrino-nucleus scattering, while future astronomical applications may include direct imaging and spectroscopy of exoplanets.

  7. Performance optimization of detector electronics for millimeter laser ranging

    NASA Technical Reports Server (NTRS)

    Cova, Sergio; Lacaita, A.; Ripamonti, Giancarlo

    1993-01-01

    The front-end electronic circuitry plays a fundamental role in determining the performance actually obtained from ultrafast and highly sensitive photodetectors. We deal here with electronic problems met working with microchannel plate photomultipliers (MCP-PMTs) and single photon avalanche diodes (SPADs) for detecting single optical photons and measuring their arrival time with picosecond resolution. The performance of available fast circuits is critically analyzed. Criteria for selecting the most suitable electronics are derived and solutions for exploiting the detector performance are presented and discussed.

  8. Measurements of wavelength-dependent double photoelectron emission from single photons in VUV-sensitive photomultiplier tubes

    NASA Astrophysics Data System (ADS)

    Faham, C. H.; Gehman, V. M.; Currie, A.; Dobi, A.; Sorensen, P.; Gaitskell, R. J.

    2015-09-01

    Measurements of double photoelectron emission (DPE) probabilities as a function of wavelength are reported for Hamamatsu R8778, R8520, and R11410 VUV-sensitive photomultiplier tubes (PMTs). In DPE, a single photon strikes the PMT photocathode and produces two photoelectrons instead of a single one. It was found that the fraction of detected photons that result in DPE emission is a function of the incident photon wavelength, and manifests itself below ~250 nm. For the xenon scintillation wavelength of 175 nm, a DPE probability of 18-24% was measured depending on the tube and measurement method. This wavelength-dependent single photon response has implications for the energy calibration and photon counting of current and future liquid xenon detectors such as LUX, LZ, XENON100/1T, Panda-X and XMASS.

  9. Ion photon emission microscope

    DOEpatents

    Doyle, Barney L.

    2003-04-22

    An ion beam analysis system that creates microscopic multidimensional image maps of the effects of high energy ions from an unfocussed source upon a sample by correlating the exact entry point of an ion into a sample by projection imaging of the ion-induced photons emitted at that point with a signal from a detector that measures the interaction of that ion within the sample. The emitted photons are collected in the lens system of a conventional optical microscope, and projected on the image plane of a high resolution single photon position sensitive detector. Position signals from this photon detector are then correlated in time with electrical effects, including the malfunction of digital circuits, detected within the sample that were caused by the individual ion that created these photons initially.

  10. Quantum correlation enhanced super-resolution localization microscopy enabled by a fibre bundle camera

    PubMed Central

    Israel, Yonatan; Tenne, Ron; Oron, Dan; Silberberg, Yaron

    2017-01-01

    Despite advances in low-light-level detection, single-photon methods such as photon correlation have rarely been used in the context of imaging. The few demonstrations, for example of subdiffraction-limited imaging utilizing quantum statistics of photons, have remained in the realm of proof-of-principle demonstrations. This is primarily due to a combination of low values of fill factors, quantum efficiencies, frame rates and signal-to-noise characteristic of most available single-photon sensitive imaging detectors. Here we describe an imaging device based on a fibre bundle coupled to single-photon avalanche detectors that combines a large fill factor, a high quantum efficiency, a low noise and scalable architecture. Our device enables localization-based super-resolution microscopy in a non-sparse non-stationary scene, utilizing information on the number of active emitters, as gathered from non-classical photon statistics. PMID:28287167

  11. Multiparameter estimation with single photons—linearly-optically generated quantum entanglement beats the shotnoise limit

    NASA Astrophysics Data System (ADS)

    You, Chenglong; Adhikari, Sushovit; Chi, Yuxi; LaBorde, Margarite L.; Matyas, Corey T.; Zhang, Chenyu; Su, Zuen; Byrnes, Tim; Lu, Chaoyang; Dowling, Jonathan P.; Olson, Jonathan P.

    2017-12-01

    It was suggested in (Motes et al 2015 Phys. Rev. Lett. 114 170802) that optical networks with relatively inexpensive overheads—single photon Fock states, passive optical elements, and single photon detection—can show significant improvements over classical strategies for single-parameter estimation, when the number of modes in the network is small (n< 7). A similar case was made in (Humphreys et al 2013 Phys. Rev. Lett. 111 070403) for multi-parameter estimation, where measurement is instead made using photon-number resolving detectors. In this paper, we analytically compute the quantum Cramér-Rao bound to show these networks can have a constant-factor quantum advantage in multi-parameter estimation for even large number of modes. Additionally, we provide a simplified measurement scheme using only single-photon (on-off) detectors that is capable of approximately obtaining this sensitivity for a small number of modes.

  12. On the measurement of intensity correlations from laboratory and astronomical sources with SPADs and SNSPDs

    NASA Astrophysics Data System (ADS)

    Schroeder, Edward; Mauskopf, Philip; Pilyavsky, Genady; Sinclair, Adrian; Smith, Nathan; Bryan, Sean; Mani, Hamdi; Morozov, Dmitry; Berggren, Karl; Zhu, Di; Smirnov, Konstantin; Vakhtomin, Yuriy

    2016-08-01

    We describe the performance of detector modules containing silicon single photon avalanche photodiodes (SPADs) and superconducting nanowire single photon detectors (SNSPDs) to be used for intensity interferometry. The SPADs are mounted in fiber-coupled and free-space coupled packages. The SNSPDs are mounted in a small liquid helium cryostat coupled to single mode fiber optic cables which pass through a hermetic feed-through. The detectors are read out with microwave amplifiers and FPGA-based coincidence electronics. We present progress on measurements of intensity correlations from incoherent sources including gas-discharge lamps and stars with these detectors. From the measured laboratory performance of the correlation system, we estimate the sensitivity to intensity correlations from stars using commercial telescopes and larger existing research telescopes.

  13. Fluorescence lifetime microscopy with a time- and space-resolved single-photon counting detector

    PubMed Central

    Michalet, X.; Siegmund, O.H.W.; Vallerga, J.V.; Jelinsky, P.; Pinaud, F. F.; Millaud, J.E.; Weiss, S.

    2017-01-01

    We have recently developed a wide-field photon-counting detector (the H33D detector) having high-temporal and high-spatial resolutions and capable of recording up to 500,000 photons per sec. Its temporal performance has been previously characterized using solutions of fluorescent materials with different lifetimes, and its spatial resolution using sub-diffraction objects (beads and quantum dots). Here we show its application to fluorescence lifetime imaging of live cells and compare its performance to a scanning confocal TCSPC approach. With the expected improvements in photocathode sensitivity and increase in detector throughput, this technology appears as a promising alternative to the current lifetime imaging solutions. PMID:29449756

  14. Proposed Ultra-High Sensitivity High-Frequency Gravitational Wave Detector

    NASA Astrophysics Data System (ADS)

    Baker, Robert M. L.; Stephenson, Gary V.; Li, Fangyu

    2008-01-01

    The paper discusses the proposed improvement of a High-Frequency Relic Gravitational Wave (HFRGW) detector designed by Li, Baker, Fang, Stephenson and Chen in order to greatly improve its sensitivity. The improved detector is inspired by the Laser Interferometer Gravitational Observatory or LIGO, but is sensitive to the high-frequency end of the gravitational-wave spectrum. As described in prior papers it utilizes the Gertsenshtein effect, which introduces the conversion of gravitational waves to electromagnetic (EM) waves in the presence of a static magnetic field. Such a conversion, if it leads to photons moving in a direction perpendicular to the plane of the EM waves and the magnetic field, will allow for ultra-high sensitivity HFRGW detection. The use of sensitive microwave, single photon detectors such as a circuit QED and/or the Rydberg Atom Cavity Detector, or off-the-shelf detectors, could lead to such detection. When the EM-detection photons are focused at the microwave detectors by fractal-membrane reflectors sensitivity is also improved. Noise sources external to the HFRGW detector will be eliminated by placing a tight mosaic of superconducting tiles (e.g., YBCO) and/or fractal membranes on the interior surface of the detector's cryogenic containment vessel in order to provide a perfect Faraday cage. Internal thermal noise will be eliminated by means of a microwave absorbing (or reflecting) interior enclosure shaped to conform to a high-intensity continuous microwave Gaussian beam (GB), will reduce any background photon flux (BPF) noise radiated normal to the GB's axis. Such BPF will be further attenuated by a series of microwave absorbing baffles forming tunnels to the sensitive microwave detectors on each side of the GB and at right angles to the static magnetic field. A HFGW detector of bandwidth of 1 KHz to 10 KHz or less in the GHz band has been selected. It is concluded that the utilization of the new ultra-high-sensitivity microwave detectors, together with the increased microwave power and magnet intensity will allow for a detection of high-frequency gravitational waves (HFGWs) exhibiting amplitudes, A, of the time-varying spacetime strains on the order of 10-30 to 10-34.

  15. Enhanced ν-optical time domain reflectometry using gigahertz sinusoidally gated InGaAs/InP single-photon avalanche detector

    NASA Astrophysics Data System (ADS)

    Zhang, Xuping; Shi, Yuanlei; Shan, Yuanyuan; Sun, Zhenhong; Qiao, Weiyan; Zhang, Yixin

    2016-09-01

    Optical time domain reflectometry (OTDR) is one of the most successful diagnostic tools for nondestructive attenuation measurement of a fiber link. To achieve better sensitivity, spatial resolution, and avoid dead-zone in conversional OTDR, a single-photon detector has been introduced to form the photon-counting OTDR (ν-OTDR). We have proposed a ν-OTDR system using a gigahertz sinusoidally gated InGaAs/InP single-photon avalanche detector (SPAD). Benefiting from the superior performance of a sinusoidal gated SPAD on dark count probability, gating frequency, and gate duration, our ν-OTDR system has achieved a dynamic range (DR) of 33.4 dB with 1 μs probe pulse width after an equivalent measurement time of 51 s. This obtainable DR corresponds to a sensing length over 150 km. Our system has also obtained a spatial resolution of 5 cm at the end of a 5-km standard single-mode fiber. By employing a sinusoidal gating technique, we have improved the ν-OTDR spatial resolution and significantly reduced the measurement time.

  16. Silicon Photomultiplier Performance in High ELectric Field

    NASA Astrophysics Data System (ADS)

    Montoya, J.; Morad, J.

    2016-12-01

    Roughly 27% of the universe is thought to be composed of dark matter. The Large Underground Xenon (LUX) relies on the emission of light from xenon atoms after a collision with a dark matter particle. After a particle interaction in the detector, two things can happen: the xenon will emit light and charge. The charge (electrons), in the liquid xenon needs to be pulled into the gas section so that it can interact with gas and emit light. This allows LUX to convert a single electron into many photons. This is done by applying a high voltage across the liquid and gas regions, effectively ripping electrons out of the liquid xenon and into the gas. The current device used to detect photons is the photomultiplier tube (PMT). These devices are large and costly. In recent years, a new technology that is capable of detecting single photons has emerged, the silicon photomultiplier (SiPM). These devices are cheaper and smaller than PMTs. Their performance in a high electric fields, such as those found in LUX, are unknown. It is possible that a large electric field could introduce noise on the SiPM signal, drowning the single photon detection capability. My hypothesis is that SiPMs will not observe a significant increase is noise at an electric field of roughly 10kV/cm (an electric field within the range used in detectors like LUX). I plan to test this hypothesis by first rotating the SiPMs with no applied electric field between two metal plates roughly 2 cm apart, providing a control data set. Then using the same angles test the dark counts with the constant electric field applied. Possibly the most important aspect of LUX, is the photon detector because it's what detects the signals. Dark matter is detected in the experiment by looking at the ratio of photons to electrons emitted for a given interaction in the detector. Interactions with a low electron to photon ratio are more like to be dark matter events than those with a high electron to photon ratio. The ability to distinguish these ratios relies on the high sensitivity to single photons. To achieve a similar sensitivity to dark matter interactions as LUX, the new SiPM devices need to operate in the same conditions without any loss in sensitivity to single photons. Knowing that this new type of technology operates in high electric field without issues, could save hundreds of thousands of dollars and valuable space.

  17. A new detector for mass spectrometry: direct detection of low energy ions using a multi-pixel photon counter.

    PubMed

    Wilman, Edward S; Gardiner, Sara H; Nomerotski, Andrei; Turchetta, Renato; Brouard, Mark; Vallance, Claire

    2012-01-01

    A new type of ion detector for mass spectrometry and general detection of low energy ions is presented. The detector consists of a scintillator optically coupled to a single-photon avalanche photodiode (SPAD) array. A prototype sensor has been constructed from a LYSO (Lu(1.8)Y(0.2)SiO(5)(Ce)) scintillator crystal coupled to a commercial SPAD array detector. As proof of concept, the detector is used to record the time-of-flight mass spectra of butanone and carbon disulphide, and the dependence of detection sensitivity on the ion kinetic energy is characterised.

  18. Detecting Axion Dark Matter with Superconducting Qubits

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Dixit, Akash; Chou, Aaron; Schuster, David

    Axion dark matter haloscopes aim to detect dark matter axions converting to single photons in resonant cavities bathed in a uniform magnetic field. A qubit (two level system) operating as a single microwave photon detector is a viable readout system for such detectors and may offer advantages over the quantum limited amplifiers currently used. When weakly coupled to the detection cavity, the qubit transition frequency is shifted by an amount proportional to the cavity photon number. Through spectroscopy of the qubit, the frequency shift is measured and the cavity occupation number is extracted. At low enough temperatures, this would allowmore » sensitivities exceeding that of the standard quantum limit.« less

  19. A scalable multi-photon coincidence detector based on superconducting nanowires.

    PubMed

    Zhu, Di; Zhao, Qing-Yuan; Choi, Hyeongrak; Lu, Tsung-Ju; Dane, Andrew E; Englund, Dirk; Berggren, Karl K

    2018-06-04

    Coincidence detection of single photons is crucial in numerous quantum technologies and usually requires multiple time-resolved single-photon detectors. However, the electronic readout becomes a major challenge when the measurement basis scales to large numbers of spatial modes. Here, we address this problem by introducing a two-terminal coincidence detector that enables scalable readout of an array of detector segments based on superconducting nanowire microstrip transmission line. Exploiting timing logic, we demonstrate a sixteen-element detector that resolves all 136 possible single-photon and two-photon coincidence events. We further explore the pulse shapes of the detector output and resolve up to four-photon events in a four-element device, giving the detector photon-number-resolving capability. This new detector architecture and operating scheme will be particularly useful for multi-photon coincidence detection in large-scale photonic integrated circuits.

  20. Physical effects of mechanical design parameters on photon sensitivity and spatial resolution performance of a breast-dedicated PET system.

    PubMed

    Spanoudaki, V C; Lau, F W Y; Vandenbroucke, A; Levin, C S

    2010-11-01

    This study aims to address design considerations of a high resolution, high sensitivity positron emission tomography scanner dedicated to breast imaging. The methodology uses a detailed Monte Carlo model of the system structures to obtain a quantitative evaluation of several performance parameters. Special focus was given to the effect of dense mechanical structures designed to provide mechanical robustness and thermal regulation to the minuscule and temperature sensitive detectors. For the energies of interest around the photopeak (450-700 keV energy window), the simulation results predict a 6.5% reduction in the single photon detection efficiency and a 12.5% reduction in the coincidence photon detection efficiency in the case that the mechanical structures are interspersed between the detectors. However for lower energies, a substantial increase in the number of detected events (approximately 14% and 7% for singles at a 100-200 keV energy window and coincidences at a lower energy threshold of 100 keV, respectively) was observed with the presence of these structures due to backscatter. The number of photon events that involve multiple interactions in various crystal elements is also affected by the presence of the structures. For photon events involving multiple interactions among various crystal elements, the coincidence photon sensitivity is reduced by as much as 20% for a point source at the center of the field of view. There is no observable effect on the intrinsic and the reconstructed spatial resolution and spatial resolution uniformity. Mechanical structures can have a considerable effect on system sensitivity, especially for systems processing multi-interaction photon events. This effect, however, does not impact the spatial resolution. Various mechanical structure designs are currently under evaluation in order to achieve optimum trade-off between temperature stability, accurate detector positioning, and minimum influence on system performance.

  1. Physical effects of mechanical design parameters on photon sensitivity and spatial resolution performance of a breast-dedicated PET system

    PubMed Central

    Spanoudaki, V. C.; Lau, F. W. Y.; Vandenbroucke, A.; Levin, C. S.

    2010-01-01

    Purpose: This study aims to address design considerations of a high resolution, high sensitivity positron emission tomography scanner dedicated to breast imaging. Methods: The methodology uses a detailed Monte Carlo model of the system structures to obtain a quantitative evaluation of several performance parameters. Special focus was given to the effect of dense mechanical structures designed to provide mechanical robustness and thermal regulation to the minuscule and temperature sensitive detectors. Results: For the energies of interest around the photopeak (450–700 keV energy window), the simulation results predict a 6.5% reduction in the single photon detection efficiency and a 12.5% reduction in the coincidence photon detection efficiency in the case that the mechanical structures are interspersed between the detectors. However for lower energies, a substantial increase in the number of detected events (approximately 14% and 7% for singles at a 100–200 keV energy window and coincidences at a lower energy threshold of 100 keV, respectively) was observed with the presence of these structures due to backscatter. The number of photon events that involve multiple interactions in various crystal elements is also affected by the presence of the structures. For photon events involving multiple interactions among various crystal elements, the coincidence photon sensitivity is reduced by as much as 20% for a point source at the center of the field of view. There is no observable effect on the intrinsic and the reconstructed spatial resolution and spatial resolution uniformity. Conclusions: Mechanical structures can have a considerable effect on system sensitivity, especially for systems processing multi-interaction photon events. This effect, however, does not impact the spatial resolution. Various mechanical structure designs are currently under evaluation in order to achieve optimum trade-off between temperature stability, accurate detector positioning, and minimum influence on system performance. PMID:21158296

  2. Which role does multiphoton interference play in small phase estimation in quantum Fourier transform interferometers?

    NASA Astrophysics Data System (ADS)

    Zimmermann, Olaf; Tamma, Vincenzo

    Recently, quantum Fourier transform interferometers have been demonstrated to allow a quantum metrological enhancement in phase sensitivity for a small number n of identical input single photons [J. P. Olson, K. R. Motes, P. M. Birchall, N. M. Studer, M. LaBorde, T. Moulder, P. P. Rohde and J. P. Dowling, Phys. Rev. A 96 (2017) 013810; K. R. Motes, J. P. Olson, E. J. Rabeaux, J. P. Dowling, S. J. Olson and P. P. Rohde, Phys. Rev. Lett. 114 (2015) 170802; O. Zimmermann, Bachelor Thesis (Ulm University, 2015) arXiv: 1710.03805.]. However, multiphoton distinguishability at the detectors can play an important role from an experimental point of view [V. Tamma and S. Laibacher, Phys. Rev. Lett. 114 (2015) 243601.]. This raises a fundamental question: How is the phase sensitivity affected when the photons are completely distinguishable at the detectors and therefore do not interfere? In other words, which role does multiphoton interference play in these schemes? Here, we show that for small phase values, the phase sensitivity achievable in the proposed schemes with indistinguishable photons is enhanced only by a constant factor with respect to the case of completely distinguishable photons at the detectors. Interestingly, this enhancement arises from the interference of only a polynomial number (in n) of the total n! multiphoton path amplitudes in the n-port interferometer. These results are independent of the number n of single photons and of the phase weight factors employed at each interferometer channel.

  3. Detectors for single-molecule fluorescence imaging and spectroscopy

    PubMed Central

    MICHALET, X.; SIEGMUND, O.H.W.; VALLERGA, J.V.; JELINSKY, P.; MILLAUD, J.E.; WEISS, S.

    2010-01-01

    Single-molecule observation, characterization and manipulation techniques have recently come to the forefront of several research domains spanning chemistry, biology and physics. Due to the exquisite sensitivity, specificity, and unmasking of ensemble averaging, single-molecule fluorescence imaging and spectroscopy have become, in a short period of time, important tools in cell biology, biochemistry and biophysics. These methods led to new ways of thinking about biological processes such as viral infection, receptor diffusion and oligomerization, cellular signaling, protein-protein or protein-nucleic acid interactions, and molecular machines. Such achievements require a combination of several factors to be met, among which detector sensitivity and bandwidth are crucial. We examine here the needed performance of photodetectors used in these types of experiments, the current state of the art for different categories of detectors, and actual and future developments of single-photon counting detectors for single-molecule imaging and spectroscopy. PMID:20157633

  4. Low-Timing-Jitter Near-Infrared Single-Photon-Sensitive 16-Channel Intensified-Photodiode Detector

    NASA Technical Reports Server (NTRS)

    Krainak, Michael A.; Lu, Wei; Yang, Guangning; Sun, Xiaoli; Sykora, Derek; Jurkovic, Mike; Aebi, Verle; Costello, Ken; Burns, Richard

    2011-01-01

    We developed a 16-channel InGaAsP photocathode intensified-photodiode (IPD) detector with 78 ps (1-sigma) timing-jitter, less than 500 ps FWHM impulse response, greater than 15% quantum efficiency at 1064 nm wavelength with 131 kcps dark counts at 15 C.

  5. Quantum detector tomography of a time-multiplexed superconducting nanowire single-photon detector at telecom wavelengths.

    PubMed

    Natarajan, Chandra M; Zhang, Lijian; Coldenstrodt-Ronge, Hendrik; Donati, Gaia; Dorenbos, Sander N; Zwiller, Val; Walmsley, Ian A; Hadfield, Robert H

    2013-01-14

    Superconducting nanowire single-photon detectors (SNSPDs) are widely used in telecom wavelength optical quantum information science applications. Quantum detector tomography allows the positive-operator-valued measure (POVM) of a single-photon detector to be determined. We use an all-fiber telecom wavelength detector tomography test bed to measure detector characteristics with respect to photon flux and polarization, and hence determine the POVM. We study the SNSPD both as a binary detector and in an 8-bin, fiber based, Time-Multiplexed (TM) configuration at repetition rates up to 4 MHz. The corresponding POVMs provide an accurate picture of the photon number resolving capability of the TM-SNSPD.

  6. On-chip detection of non-classical light by scalable integration of single-photon detectors

    PubMed Central

    Najafi, Faraz; Mower, Jacob; Harris, Nicholas C.; Bellei, Francesco; Dane, Andrew; Lee, Catherine; Hu, Xiaolong; Kharel, Prashanta; Marsili, Francesco; Assefa, Solomon; Berggren, Karl K.; Englund, Dirk

    2015-01-01

    Photonic-integrated circuits have emerged as a scalable platform for complex quantum systems. A central goal is to integrate single-photon detectors to reduce optical losses, latency and wiring complexity associated with off-chip detectors. Superconducting nanowire single-photon detectors (SNSPDs) are particularly attractive because of high detection efficiency, sub-50-ps jitter and nanosecond-scale reset time. However, while single detectors have been incorporated into individual waveguides, the system detection efficiency of multiple SNSPDs in one photonic circuit—required for scalable quantum photonic circuits—has been limited to <0.2%. Here we introduce a micrometer-scale flip-chip process that enables scalable integration of SNSPDs on a range of photonic circuits. Ten low-jitter detectors are integrated on one circuit with 100% device yield. With an average system detection efficiency beyond 10%, and estimated on-chip detection efficiency of 14–52% for four detectors operated simultaneously, we demonstrate, to the best of our knowledge, the first on-chip photon correlation measurements of non-classical light. PMID:25575346

  7. Waveguide-Coupled Superconducting Nanowire Single-Photon Detectors

    NASA Technical Reports Server (NTRS)

    Beyer, Andrew D.; Briggs, Ryan M.; Marsili, Francesco; Cohen, Justin D.; Meenehan, Sean M.; Painter, Oskar J.; Shaw, Matthew D.

    2015-01-01

    We have demonstrated WSi-based superconducting nanowire single-photon detectors coupled to SiNx waveguides with integrated ring resonators. This photonics platform enables the implementation of robust and efficient photon-counting detectors with fine spectral resolution near 1550 nm.

  8. Real-time computational photon-counting LiDAR

    NASA Astrophysics Data System (ADS)

    Edgar, Matthew; Johnson, Steven; Phillips, David; Padgett, Miles

    2018-03-01

    The availability of compact, low-cost, and high-speed MEMS-based spatial light modulators has generated widespread interest in alternative sampling strategies for imaging systems utilizing single-pixel detectors. The development of compressed sensing schemes for real-time computational imaging may have promising commercial applications for high-performance detectors, where the availability of focal plane arrays is expensive or otherwise limited. We discuss the research and development of a prototype light detection and ranging (LiDAR) system via direct time of flight, which utilizes a single high-sensitivity photon-counting detector and fast-timing electronics to recover millimeter accuracy three-dimensional images in real time. The development of low-cost real time computational LiDAR systems could have importance for applications in security, defense, and autonomous vehicles.

  9. High-speed and high-efficiency travelling wave single-photon detectors embedded in nanophotonic circuits

    PubMed Central

    Pernice, W.H.P.; Schuck, C.; Minaeva, O.; Li, M.; Goltsman, G.N.; Sergienko, A.V.; Tang, H.X.

    2012-01-01

    Ultrafast, high-efficiency single-photon detectors are among the most sought-after elements in modern quantum optics and quantum communication. However, imperfect modal matching and finite photon absorption rates have usually limited their maximum attainable detection efficiency. Here we demonstrate superconducting nanowire detectors atop nanophotonic waveguides, which enable a drastic increase of the absorption length for incoming photons. This allows us to achieve high on-chip single-photon detection efficiency up to 91% at telecom wavelengths, repeatable across several fabricated chips. We also observe remarkably low dark count rates without significant compromise of the on-chip detection efficiency. The detectors are fully embedded in scalable silicon photonic circuits and provide ultrashort timing jitter of 18 ps. Exploiting this high temporal resolution, we demonstrate ballistic photon transport in silicon ring resonators. Our direct implementation of a high-performance single-photon detector on chip overcomes a major barrier in integrated quantum photonics. PMID:23271658

  10. Photon-Counting Kinetic Inductance Detectors for the Origins Space Telescope

    NASA Astrophysics Data System (ADS)

    Noroozian, Omid

    We propose to develop photon-counting Kinetic Inductance Detectors (KIDs) for the Origins Space Telescope (OST) and any predecessor missions, with the goal of producing background-limited photon-counting sensitivity, and with a preliminary technology demonstration in time to inform the Decadal Survey planning process. The OST, a midto far- infrared observatory concept, is being developed as a major NASA mission to be considered by the next Decadal Survey with support from NASA Headquarters. The objective of such a facility is to allow rapid spectroscopic surveys of the high redshift universe at 420-800 μm, using arrays of integrated spectrometers with moderate resolutions (R=λ/Δλ 1000), to create a powerful new data set for exploring galaxy evolution and the growth of structure in the Universe. A second objective of OST is to perform higher resolution (R 10,000-100,000) spectroscopic surveys at 20-300 µm, a uniquely powerful tool for exploring the evolution of protoplanetary disks into fledgling solar systems. Finally the OST aims to obtain sensitive mid-infrared (5-40 µm) spectroscopy of thermal emission from rocky planets in the habitable zone using the transit method. These OST science objectives are very exciting and represent a wellorganized community agreement. However, they are all impossible to reach without new detector technology, and the OST can’t be recommended or approved if suitable detectors do not exist. In all of the above instrument concepts, photon-counting direct detectors are mission-enabling and essential for reaching the sensitivity permitted by the cryogenic Origins Space Telescope and the performance required for its important science programs. Our group has developed an innovative design for an optically-coupled KID that can reach the photon-counting sensitivity required by the ambitious science goals of the OST mission. A KID is a planar microwave resonator patterned from a superconducting thin film, which responds to incident photons with a change in its resonance frequency and dissipation. This detector response is intrinsically frequency multiplexed, and consequently KIDs at different resonance frequencies can be read out using standard digital radio techniques, which enables multiplexing of 10,000s of detectors. In our photon-counting KID design we employ a small-volume (and thin) superconducting Al inductor to enhance the per-photon responsivity, and large parallel-plate NbTiN capacitors on single-crystal silicon-on-insulator (SOI) substrates to eliminate frequency noise. We have developed a comprehensive design demonstrating that photon-counting sensitivity is possible in a small-volume Al KID. In addition, we have already demonstrated ultra-high quality factors in resonators made of very thin ( 10 nm) Al films with long electron lifetimes. These are the critical material parameters for reaching photon-counting sensitivity levels. In our proposed work plan our objective is to implement these high quality films into our optically-coupled small-volume KID design and demonstrate photon-counting sensitivity. The successful development of our photon-counting technology will significantly increase the sensitivity of the OST mission, making it more scientifically competitive than one based on power detectors. Photon-counting at the background limit provides a x4 increase in observation speed over that of background-limited power detection, since there is no need to measure and subtract a zero point. Photon-counting detectors will enable an instrument on the OST to observe the fine structure lines of galaxies which are currently only observable at redshifts of z 1, out to redshifts of z=6, probing the early stages of galaxy, star and planet formation. Our photon-counting detectors will also enable entirely new science, including the mapping of the composition and evolution of water and other key volatiles in planet-forming materials around large samples of nearby young stars.

  11. Fabrication of Tunnel Junctions For Direct Detector Arrays With Single-Electron Transistor Readout Using Electron-Beam Lithography

    NASA Technical Reports Server (NTRS)

    Stevenson, T. R.; Hsieh, W.-T.; Li, M. J.; Stahle, C. M.; Rhee, K. W.; Teufel, J.; Schoelkopf, R. J.

    2002-01-01

    This paper will describe the fabrication of small aluminum tunnel junctions for applications in astronomy. Antenna-coupled superconducting tunnel junctions with integrated single-electron transistor readout have the potential for photon-counting sensitivity at sub-millimeter wavelengths. The junctions for the detector and single-electron transistor can be made with electron-beam lithography and a standard self-aligned double-angle deposition process. However, high yield and uniformity of the junctions is required for large-format detector arrays. This paper will describe how measurement and modification of the sensitivity ratio in the resist bilayer was used to greatly improve the reliability of forming devices with uniform, sub-micron size, low-leakage junctions.

  12. An efficient computational approach to model statistical correlations in photon counting x-ray detectors

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Faby, Sebastian; Maier, Joscha; Sawall, Stefan

    2016-07-15

    Purpose: To introduce and evaluate an increment matrix approach (IMA) describing the signal statistics of energy-selective photon counting detectors including spatial–spectral correlations between energy bins of neighboring detector pixels. The importance of the occurring correlations for image-based material decomposition is studied. Methods: An IMA describing the counter increase patterns in a photon counting detector is proposed. This IMA has the potential to decrease the number of required random numbers compared to Monte Carlo simulations by pursuing an approach based on convolutions. To validate and demonstrate the IMA, an approximate semirealistic detector model is provided, simulating a photon counting detector inmore » a simplified manner, e.g., by neglecting count rate-dependent effects. In this way, the spatial–spectral correlations on the detector level are obtained and fed into the IMA. The importance of these correlations in reconstructed energy bin images and the corresponding detector performance in image-based material decomposition is evaluated using a statistically optimal decomposition algorithm. Results: The results of IMA together with the semirealistic detector model were compared to other models and measurements using the spectral response and the energy bin sensitivity, finding a good agreement. Correlations between the different reconstructed energy bin images could be observed, and turned out to be of weak nature. These correlations were found to be not relevant in image-based material decomposition. An even simpler simulation procedure based on the energy bin sensitivity was tested instead and yielded similar results for the image-based material decomposition task, as long as the fact that one incident photon can increase multiple counters across neighboring detector pixels is taken into account. Conclusions: The IMA is computationally efficient as it required about 10{sup 2} random numbers per ray incident on a detector pixel instead of an estimated 10{sup 8} random numbers per ray as Monte Carlo approaches would need. The spatial–spectral correlations as described by IMA are not important for the studied image-based material decomposition task. Respecting the absolute photon counts and thus the multiple counter increases by a single x-ray photon, the same material decomposition performance could be obtained with a simpler detector description using the energy bin sensitivity.« less

  13. Single-photon sensitive fast ebCMOS camera system for multiple-target tracking of single fluorophores: application to nano-biophotonics

    NASA Astrophysics Data System (ADS)

    Cajgfinger, Thomas; Chabanat, Eric; Dominjon, Agnes; Doan, Quang T.; Guerin, Cyrille; Houles, Julien; Barbier, Remi

    2011-03-01

    Nano-biophotonics applications will benefit from new fluorescent microscopy methods based essentially on super-resolution techniques (beyond the diffraction limit) on large biological structures (membranes) with fast frame rate (1000 Hz). This trend tends to push the photon detectors to the single-photon counting regime and the camera acquisition system to real time dynamic multiple-target tracing. The LUSIPHER prototype presented in this paper aims to give a different approach than those of Electron Multiplied CCD (EMCCD) technology and try to answer to the stringent demands of the new nano-biophotonics imaging techniques. The electron bombarded CMOS (ebCMOS) device has the potential to respond to this challenge, thanks to the linear gain of the accelerating high voltage of the photo-cathode, to the possible ultra fast frame rate of CMOS sensors and to the single-photon sensitivity. We produced a camera system based on a 640 kPixels ebCMOS with its acquisition system. The proof of concept for single-photon based tracking for multiple single-emitters is the main result of this paper.

  14. Properties of GaAs:Cr-based Timepix detectors

    NASA Astrophysics Data System (ADS)

    Smolyanskiy, P.; Bergmann, B.; Chelkov, G.; Kotov, S.; Kruchonak, U.; Kozhevnikov, D.; Mora Sierra, Y.; Stekl, I.; Zhemchugov, A.

    2018-02-01

    The hybrid pixel detector technology brought to the X-ray imaging a low noise level at a high spatial resolution, thanks to the single photon counting. However, silicon as the most widespread detector material is marginally sensitive to photons with energies above 30 keV. Therefore, the high-Z alternatives to silicon such as gallium arsenide and cadmium telluride are increasingly attracting attention of the community for the development of X-ray imaging systems. The results of our investigations of the Timepix detectors bump bonded to sensors made of gallium arsenide compensated by chromium (GaAs:Cr) are presented in this work. The following properties are most important from the practical point of view: the IV characteristics, the charge transport characteristics, photon detection efficiency, operational stability, homogeneity, temperature dependence, as well as energy and spatial resolution are considered. The applicability of these detectors for spectroscopic X-ray imaging is discussed.

  15. Time and position sensitive single photon detector for scintillator read-out

    NASA Astrophysics Data System (ADS)

    Schössler, S.; Bromberger, B.; Brandis, M.; Schmidt, L. Ph H.; Tittelmeier, K.; Czasch, A.; Dangendorf, V.; Jagutzki, O.

    2012-02-01

    We have developed a photon counting detector system for combined neutron and γ radiography which can determine position, time and intensity of a secondary photon flash created by a high-energy particle or photon within a scintillator screen. The system is based on a micro-channel plate photomultiplier concept utilizing image charge coupling to a position- and time-sensitive read-out anode placed outside the vacuum tube in air, aided by a standard photomultiplier and very fast pulse-height analyzing electronics. Due to the low dead time of all system components it can cope with the high throughput demands of a proposed combined fast neutron and dual discrete energy γ radiography method (FNDDER). We show tests with different types of delay-line read-out anodes and present a novel pulse-height-to-time converter circuit with its potential to discriminate γ energies for the projected FNDDER devices for an automated cargo container inspection system (ACCIS).

  16. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Shanks, Katherine S.; Philipp, Hugh T.; Weiss, Joel T.

    Experiments at storage ring light sources as well as at next-generation light sources increasingly require detectors capable of high dynamic range operation, combining low-noise detection of single photons with large pixel well depth. XFEL sources in particular provide pulse intensities sufficiently high that a purely photon-counting approach is impractical. The High Dynamic Range Pixel Array Detector (HDR-PAD) project aims to provide a dynamic range extending from single-photon sensitivity to 10{sup 6} photons/pixel in a single XFEL pulse while maintaining the ability to tolerate a sustained flux of 10{sup 11} ph/s/pixel at a storage ring source. Achieving these goals involves themore » development of fast pixel front-end electronics as well as, in the XFEL case, leveraging the delayed charge collection due to plasma effects in the sensor. A first prototype of essential electronic components of the HDR-PAD readout ASIC, exploring different options for the pixel front-end, has been fabricated. Here, the HDR-PAD concept and preliminary design will be described.« less

  17. Waveguide integrated low noise NbTiN nanowire single-photon detectors with milli-Hz dark count rate

    PubMed Central

    Schuck, Carsten; Pernice, Wolfram H. P.; Tang, Hong X.

    2013-01-01

    Superconducting nanowire single-photon detectors are an ideal match for integrated quantum photonic circuits due to their high detection efficiency for telecom wavelength photons. Quantum optical technology also requires single-photon detection with low dark count rate and high timing accuracy. Here we present very low noise superconducting nanowire single-photon detectors based on NbTiN thin films patterned directly on top of Si3N4 waveguides. We systematically investigate a large variety of detector designs and characterize their detection noise performance. Milli-Hz dark count rates are demonstrated over the entire operating range of the nanowire detectors which also feature low timing jitter. The ultra-low dark count rate, in combination with the high detection efficiency inherent to our travelling wave detector geometry, gives rise to a measured noise equivalent power at the 10−20 W/Hz1/2 level. PMID:23714696

  18. 1.5- μm single photon counting using polarization-independent up-conversion detector

    NASA Astrophysics Data System (ADS)

    Takesue, Hiroki; Diamanti, Eleni; Langrock, Carsten; Fejer, M. M.; Yamamoto, Yoshihisa

    2006-12-01

    We report a 1.5- μm band polarization independent single photon detector based on frequency up-conversion in periodically poled lithium niobate (PPLN) waveguides. To overcome the polarization dependence of the PPLN waveguides, we employed a polarization diversity configuration composed of two up-conversion detectors connected with a polarization beam splitter. We experimentally confirmed polarization independent single photon counting using our detector. We undertook a proof-of-principle differential phase shift quantum key distribution experiment using the detector, and confirmed that the sifted key rate and error rate remained stable when the polarization state was changed during single photon transmission.

  19. Cryogenic photodetectors

    NASA Astrophysics Data System (ADS)

    Chardin, G.

    2000-03-01

    Some of the most significant developments in cryogenic photodetectors are presented. In particular, the main characteristics of microbolometers involving Transition Edge- and NTD-sensors and offering resolutions of a few eV in the keV range, superconducting tunnel junction detectors with resolutions of the order of 10 eV or offering position sensitivity, and infrared bolometers with recent developments towards matrix detectors are discussed. Some of the recent achievements using large mass bolometers for gamma and neutron discriminating detectors, and future prospects of single photon detection in the far infrared using Single Electron Transistor devices are also presented.

  20. Single photon detection using Geiger mode CMOS avalanche photodiodes

    NASA Astrophysics Data System (ADS)

    Lawrence, William G.; Stapels, Christopher; Augustine, Frank L.; Christian, James F.

    2005-10-01

    Geiger mode Avalanche Photodiodes fabricated using complementary metal-oxide-semiconductor (CMOS) fabrication technology combine high sensitivity detectors with pixel-level auxiliary circuitry. Radiation Monitoring Devices has successfully implemented CMOS manufacturing techniques to develop prototype detectors with active diameters ranging from 5 to 60 microns and measured detection efficiencies of up to 60%. CMOS active quenching circuits are included in the pixel layout. The actively quenched pixels have a quenching time less than 30 ns and a maximum count rate greater than 10 MHz. The actively quenched Geiger mode avalanche photodiode (GPD) has linear response at room temperature over six orders of magnitude. When operating in Geiger mode, these GPDs act as single photon-counting detectors that produce a digital output pulse for each photon with no associated read noise. Thermoelectrically cooled detectors have less than 1 Hz dark counts. The detection efficiency, dark count rate, and after-pulsing of two different pixel designs are measured and demonstrate the differences in the device operation. Additional applications for these devices include nuclear imaging and replacement of photomultiplier tubes in dosimeters.

  1. Measurement of the lifetime of the 7 s 1/2 2S state in atomic cesium using asynchronous gated detection

    NASA Astrophysics Data System (ADS)

    Toh, George; Jaramillo-Villegas, Jose A.; Glotzbach, Nathan; Quirk, Jonah; Stevenson, Ian C.; Choi, J.; Weiner, Andrew M.; Elliott, D. S.

    2018-05-01

    We report a measurement of the lifetime of the cesium 7 s 1/2 2S state using time-correlated single-photon counting spectroscopy in a vapor cell. We excite the atoms using a Doppler-free two-photon transition from the 6 s 1/2 2S ground state, and detect the 1.47 -μ m photons from the spontaneous decay of the 7 s 1/2 2S to the 6 p 3/2 2P state. We use a gated single-photon detector in an asynchronous mode, allowing us to capture the fluorescence profile for a window much larger than the detector gate length. Analysis of the exponential decay of the photon count yields a 7 s 1/2 2S lifetime of 48.28 ±0.07 ns, an uncertainty of 0.14%. These measurements provide sensitive tests of theoretical models of the Cs atom, which play a central role in parity violation measurements.

  2. Critical Current Statistics of a Graphene-Based Josephson Junction Infrared Single Photon Detector

    NASA Astrophysics Data System (ADS)

    Walsh, Evan D.; Lee, Gil-Ho; Efetov, Dmitri K.; Heuck, Mikkel; Crossno, Jesse; Taniguchi, Takashi; Watanabe, Kenji; Ohki, Thomas A.; Kim, Philip; Englund, Dirk; Fong, Kin Chung

    Graphene is a promising material for single photon detection due to its broadband absorption and exceptionally low specific heat. We present a photon detector using a graphene sheet as the weak link in a Josephson junction (JJ) to form a threshold detector for single infrared photons. Calculations show that such a device could experience temperature changes of a few hundred percent leading to sub-Hz dark count rates and internal efficiencies approaching unity. We have fabricated the graphene-based JJ (gJJ) detector and measure switching events that are consistent with single photon detection under illumination by an attenuated laser. We study the physical mechanism for these events through the critical current behavior of the gJJ as a function of incident photon flux.

  3. Un-collimated single-photon imaging system for high-sensitivity small animal and plant imaging.

    PubMed

    Walker, Katherine L; Judenhofer, Martin S; Cherry, Simon R; Mitchell, Gregory S

    2015-01-07

    In preclinical single-photon emission computed tomography (SPECT) system development the primary objective has been to improve spatial resolution by using novel parallel-hole or multi-pinhole collimator geometries. However, such high-resolution systems have relatively poor sensitivity (typically 0.01-0.1%). In contrast, a system that does not use collimators can achieve very high-sensitivity. Here we present a high-sensitivity un-collimated detector single-photon imaging (UCD-SPI) system for the imaging of both small animals and plants. This scanner consists of two thin, closely spaced, pixelated scintillator detectors that use NaI(Tl), CsI(Na), or BGO. The performance of the system has been characterized by measuring sensitivity, spatial resolution, linearity, detection limits, and uniformity. With (99m)Tc (140 keV) at the center of the field of view (20 mm scintillator separation), the sensitivity was measured to be 31.8% using the NaI(Tl) detectors and 40.2% with CsI(Na). The best spatial resolution (FWHM when the image formed as the geometric mean of the two detector heads, 20 mm scintillator separation) was 19.0 mm for NaI(Tl) and 11.9 mm for CsI(Na) at 140 keV, and 19.5 mm for BGO at 1116 keV, which is somewhat degraded compared to the cm-scale resolution obtained with only one detector head and a close source. The quantitative accuracy of the system's linearity is better than 2% with detection down to activity levels of 100 nCi. Two in vivo animal studies (a renal scan using (99m)Tc MAG-3 and a thyroid scan with (123)I) and one plant study (a (99m)TcO4(-) xylem transport study) highlight the unique capabilities of this UCD-SPI system. From the renal scan, we observe approximately a one thousand-fold increase in sensitivity compared to the Siemens Inveon SPECT/CT scanner. UCD-SPI is useful for many imaging tasks that do not require excellent spatial resolution, such as high-throughput screening applications, simple radiotracer uptake studies in tumor xenografts, dynamic studies where very good temporal resolution is critical, or in planta imaging of radioisotopes at low concentrations.

  4. Un-collimated single-photon imaging system for high-sensitivity small animal and plant imaging

    DOE PAGES

    Walker, Katherine L.; Judenhofer, Martin S.; Cherry, Simon R.; ...

    2014-12-12

    In preclinical single-photon emission computed tomography (SPECT) system development the primary objective has been to improve spatial resolution by using novel parallel-hole or multi-pinhole collimator geometries. Furthermore, such high-resolution systems have relatively poor sensitivity (typically 0.01% to 0.1%). In contrast, a system that does not use collimators can achieve very high-sensitivity. Here we present a high-sensitivity un-collimated detector single-photon imaging (UCD-SPI) system for the imaging of both small animals and plants. This scanner consists of two thin, closely spaced, pixelated scintillator detectors that use NaI(Tl), CsI(Na), or BGO. The performance of the system has been characterized by measuring sensitivity, spatialmore » resolution, linearity, detection limits, and uniformity. With 99mTc (140 keV) at the center of the field of view (20 mm scintillator separation), the sensitivity was measured to be 31.8% using the NaI(Tl) detectors and 40.2% with CsI(Na). The best spatial resolution (FWHM when the image formed as the geometric mean of the two detector heads, 20 mm scintillator separation) was 19.0 mm for NaI(Tl) and 11.9 mm for CsI(Na) at 140 keV, and 19.5 mm for BGO at 1116 keV, which is somewhat degraded compared to the cm-scale resolution obtained with only one detector head and a close source. The quantitative accuracy of the system’s linearity is better than 2% with detection down to activity levels of 100 nCi. Two in vivo animal studies (a renal scan using 99mTc MAG-3 and a thyroid scan with 123I) and one plant study (a 99mTcO 4- xylem transport study) highlight the unique capabilities of this UCD-SPI system. From the renal scan, we observe approximately a one thousand-fold increase in sensitivity compared to the Siemens Inveon SPECT/CT scanner. In conclusion, UCD-SPI is useful for many imaging tasks that do not require excellent spatial resolution, such as high-throughput screening applications, simple radiotracer uptake studies in tumor xenografts, dynamic studies where very good temporal resolution is critical, or in planta imaging of radioisotopes at low concentrations.« less

  5. Un-collimated single-photon imaging system for high-sensitivity small animal and plant imaging

    NASA Astrophysics Data System (ADS)

    Walker, Katherine L.; Judenhofer, Martin S.; Cherry, Simon R.; Mitchell, Gregory S.

    2015-01-01

    In preclinical single-photon emission computed tomography (SPECT) system development the primary objective has been to improve spatial resolution by using novel parallel-hole or multi-pinhole collimator geometries. However, such high-resolution systems have relatively poor sensitivity (typically 0.01-0.1%). In contrast, a system that does not use collimators can achieve very high-sensitivity. Here we present a high-sensitivity un-collimated detector single-photon imaging (UCD-SPI) system for the imaging of both small animals and plants. This scanner consists of two thin, closely spaced, pixelated scintillator detectors that use NaI(Tl), CsI(Na), or BGO. The performance of the system has been characterized by measuring sensitivity, spatial resolution, linearity, detection limits, and uniformity. With 99mTc (140 keV) at the center of the field of view (20 mm scintillator separation), the sensitivity was measured to be 31.8% using the NaI(Tl) detectors and 40.2% with CsI(Na). The best spatial resolution (FWHM when the image formed as the geometric mean of the two detector heads, 20 mm scintillator separation) was 19.0 mm for NaI(Tl) and 11.9 mm for CsI(Na) at 140 keV, and 19.5 mm for BGO at 1116 keV, which is somewhat degraded compared to the cm-scale resolution obtained with only one detector head and a close source. The quantitative accuracy of the system’s linearity is better than 2% with detection down to activity levels of 100 nCi. Two in vivo animal studies (a renal scan using 99mTc MAG-3 and a thyroid scan with 123I) and one plant study (a 99mTcO4- xylem transport study) highlight the unique capabilities of this UCD-SPI system. From the renal scan, we observe approximately a one thousand-fold increase in sensitivity compared to the Siemens Inveon SPECT/CT scanner. UCD-SPI is useful for many imaging tasks that do not require excellent spatial resolution, such as high-throughput screening applications, simple radiotracer uptake studies in tumor xenografts, dynamic studies where very good temporal resolution is critical, or in planta imaging of radioisotopes at low concentrations.

  6. Quantum interference in heterogeneous superconducting-photonic circuits on a silicon chip.

    PubMed

    Schuck, C; Guo, X; Fan, L; Ma, X; Poot, M; Tang, H X

    2016-01-21

    Quantum information processing holds great promise for communicating and computing data efficiently. However, scaling current photonic implementation approaches to larger system size remains an outstanding challenge for realizing disruptive quantum technology. Two main ingredients of quantum information processors are quantum interference and single-photon detectors. Here we develop a hybrid superconducting-photonic circuit system to show how these elements can be combined in a scalable fashion on a silicon chip. We demonstrate the suitability of this approach for integrated quantum optics by interfering and detecting photon pairs directly on the chip with waveguide-coupled single-photon detectors. Using a directional coupler implemented with silicon nitride nanophotonic waveguides, we observe 97% interference visibility when measuring photon statistics with two monolithically integrated superconducting single-photon detectors. The photonic circuit and detector fabrication processes are compatible with standard semiconductor thin-film technology, making it possible to implement more complex and larger scale quantum photonic circuits on silicon chips.

  7. Pulse shape discrimination for background rejection in germanium gamma-ray detectors

    NASA Technical Reports Server (NTRS)

    Feffer, P. T.; Smith, D. M.; Campbell, R. D.; Primbsch, J. H.; Lin, R. P.

    1989-01-01

    A pulse-shape discrimination (PSD) technique is developed to reject the beta-decay background resulting from activation of Ge gamma-ray detectors by cosmic-ray secondaries. These beta decays are a major source of background at 0.2-2 MeV energies in well shielded Ge detector systems. The technique exploits the difference between the detected current pulse shapes of single- and multiple-site energy depositions within the detector: beta decays are primarily single-site events, while photons at these energies typically Compton scatter before being photoelectrically absorbed to produce multiple-site events. Depending upon the amount of background due to sources other than beta decay, PSD can more than double the detector sensitivity.

  8. Silicon photon-counting avalanche diodes for single-molecule fluorescence spectroscopy

    PubMed Central

    Michalet, Xavier; Ingargiola, Antonino; Colyer, Ryan A.; Scalia, Giuseppe; Weiss, Shimon; Maccagnani, Piera; Gulinatti, Angelo; Rech, Ivan; Ghioni, Massimo

    2014-01-01

    Solution-based single-molecule fluorescence spectroscopy is a powerful experimental tool with applications in cell biology, biochemistry and biophysics. The basic feature of this technique is to excite and collect light from a very small volume and work in a low concentration regime resulting in rare burst-like events corresponding to the transit of a single molecule. Detecting photon bursts is a challenging task: the small number of emitted photons in each burst calls for high detector sensitivity. Bursts are very brief, requiring detectors with fast response time and capable of sustaining high count rates. Finally, many bursts need to be accumulated to achieve proper statistical accuracy, resulting in long measurement time unless parallelization strategies are implemented to speed up data acquisition. In this paper we will show that silicon single-photon avalanche diodes (SPADs) best meet the needs of single-molecule detection. We will review the key SPAD parameters and highlight the issues to be addressed in their design, fabrication and operation. After surveying the state-of-the-art SPAD technologies, we will describe our recent progress towards increasing the throughput of single-molecule fluorescence spectroscopy in solution using parallel arrays of SPADs. The potential of this approach is illustrated with single-molecule Förster resonance energy transfer measurements. PMID:25309114

  9. Novel Photon-Counting Detectors for Free-Space Communication

    NASA Technical Reports Server (NTRS)

    Krainak, Michael A.; Yang, Guan; Sun, Xiaoli; Lu, Wei; Merritt, Scott; Beck, Jeff

    2016-01-01

    We present performance data for novel photon counting detectors for free space optical communication. NASA GSFC is testing the performance of three novel photon counting detectors 1) a 2x8 mercury cadmium telluride avalanche array made by DRS Inc. 2) a commercial 2880 silicon avalanche photodiode array and 3) a prototype resonant cavity silicon avalanche photodiode array. We will present and compare dark count, photon detection efficiency, wavelength response and communication performance data for these detectors. We discuss system wavelength trades and architectures for optimizing overall communication link sensitivity, data rate and cost performance. The HgCdTe APD array has photon detection efficiencies of greater than 50 were routinely demonstrated across 5 arrays, with one array reaching a maximum PDE of 70. High resolution pixel-surface spot scans were performed and the junction diameters of the diodes were measured. The junction diameter was decreased from 31 m to 25 m resulting in a 2x increase in e-APD gain from 470 on the 2010 array to 1100 on the array delivered to NASA GSFC. Mean single photon SNRs of over 12 were demonstrated at excess noise factors of 1.2-1.3.The commercial silicon APD array has a fast output with rise times of 300ps and pulse widths of 600ps. Received and filtered signals from the entire array are multiplexed onto this single fast output. The prototype resonant cavity silicon APD array is being developed for use at 1 micron wavelength.

  10. Optimizing Floating Guard Ring Designs for FASPAX N-in-P Silicon Sensors

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Shin, Kyung-Wook; Bradford, Robert; Lipton, Ronald

    2016-10-06

    FASPAX (Fermi-Argonne Semiconducting Pixel Array X-ray detector) is being developed as a fast integrating area detector with wide dynamic range for time resolved applications at the upgraded Advanced Photon Source (APS.) A burst mode detector with intendedmore » $$\\mbox{13 $$MHz$}$ image rate, FASPAX will also incorporate a novel integration circuit to achieve wide dynamic range, from single photon sensitivity to $$10^{\\text{5}}$$ x-rays/pixel/pulse. To achieve these ambitious goals, a novel silicon sensor design is required. This paper will detail early design of the FASPAX sensor. Results from TCAD optimization studies, and characterization of prototype sensors will be presented.« less

  11. Optimization of single photon detection model based on GM-APD

    NASA Astrophysics Data System (ADS)

    Chen, Yu; Yang, Yi; Hao, Peiyu

    2017-11-01

    One hundred kilometers high precision laser ranging hopes the detector has very strong detection ability for very weak light. At present, Geiger-Mode of Avalanche Photodiode has more use. It has high sensitivity and high photoelectric conversion efficiency. Selecting and designing the detector parameters according to the system index is of great importance to the improvement of photon detection efficiency. Design optimization requires a good model. In this paper, we research the existing Poisson distribution model, and consider the important detector parameters of dark count rate, dead time, quantum efficiency and so on. We improve the optimization of detection model, select the appropriate parameters to achieve optimal photon detection efficiency. The simulation is carried out by using Matlab and compared with the actual test results. The rationality of the model is verified. It has certain reference value in engineering applications.

  12. Enhancing the Linear Dynamic Range in Multi-Channel Single Photon Detector beyond 7OD

    PubMed Central

    Gudkov, Dmytro; Gudkov, George; Gorbovitski, Boris; Gorfinkel, Vera

    2015-01-01

    We present design, implementation, and characterization of a single photon detector based on 32-channel PMT sensor [model H7260-20, Hamamatsu]. The developed high speed electronics enables the photon counting with linear dynamic range (LDR) up to 108count/s per detector's channel. The experimental characterization and Monte-Carlo simulations showed that in the single photon counting mode the LDR of the PMT sensor is limited by (i) “photon” pulse width (current pulse) of 900ps and (ii) substantial decrease of amplitudes of current pulses for count rates exceeding 108 count/s. The multi-channel architecture of the detector and the developed firm/software allow further expansion of the dynamic range of the device by 32-fold by using appropriate beam shaping. The developed single photon counting detector was tested for the detection of fluorescence labeled microbeads in capillary flow. PMID:27087788

  13. A space- and time-resolved single photon counting detector for fluorescence microscopy and spectroscopy

    PubMed Central

    Michalet, X.; Siegmund, O.H.W.; Vallerga, J.V.; Jelinsky, P.; Millaud, J.E.; Weiss, S.

    2017-01-01

    We have recently developed a wide-field photon-counting detector having high-temporal and high-spatial resolutions and capable of high-throughput (the H33D detector). Its design is based on a 25 mm diameter multi-alkali photocathode producing one photo electron per detected photon, which are then multiplied up to 107 times by a 3-microchannel plate stack. The resulting electron cloud is proximity focused on a cross delay line anode, which allows determining the incident photon position with high accuracy. The imaging and fluorescence lifetime measurement performances of the H33D detector installed on a standard epifluorescence microscope will be presented. We compare them to those of standard single-molecule detectors such as single-photon avalanche photodiode (SPAD) or electron-multiplying camera using model samples (fluorescent beads, quantum dots and live cells). Finally, we discuss the design and applications of future generation of H33D detectors for single-molecule imaging and high-throughput study of biomolecular interactions. PMID:29479130

  14. Mid-infrared coincidence measurements on twin photons at room temperature

    PubMed Central

    Mancinelli, M.; Trenti, A.; Piccione, S.; Fontana, G.; Dam, J. S.; Tidemand-Lichtenberg, P.; Pedersen, C.; Pavesi, L.

    2017-01-01

    Quantum measurements using single-photon detectors are opening interesting new perspectives in diverse fields such as remote sensing, quantum cryptography and quantum computing. A particularly demanding class of applications relies on the simultaneous detection of correlated single photons. In the visible and near infrared wavelength ranges suitable single-photon detectors do exist. However, low detector quantum efficiency or excessive noise has hampered their mid-infrared (MIR) counterpart. Fast and highly efficient single-photon detectors are thus highly sought after for MIR applications. Here we pave the way to quantum measurements in the MIR by the demonstration of a room temperature coincidence measurement with non-degenerate twin photons at about 3.1 μm. The experiment is based on the spectral translation of MIR radiation into the visible region, by means of efficient up-converter modules. The up-converted pairs are then detected with low-noise silicon avalanche photodiodes without the need for cryogenic cooling. PMID:28504244

  15. Background in X-ray astronomy proportional counters

    NASA Technical Reports Server (NTRS)

    Bower, C. R.; Dietz, K. L.; Ramsey, B. D.; Weisskopf, M. C.

    1991-01-01

    The authors report the results of an investigation into the nature of background events in proportional counters sensitive to X-ray photons having energy of less than 150 keV. Even with the use of thick shields composed of high-atomic-number material, a significant flux background in the detector's energy region can result from multiple Compton scattering in the mass surrounding the active region of the detector. The importance of the selection of detector components in the reduction of the background by more than an order of magnitude is emphasized. Experimental results are shown to agree qualitatively with Monte Carlo simulations. It is concluded that escape gating is a powerful means of determining the nature of background in flight detectors: the single/pair ratios reveal whether the detected events are charged particles or photons.

  16. Nanobridge SQUIDs as calorimetric inductive particle detectors

    NASA Astrophysics Data System (ADS)

    Gallop, John; Cox, David; Hao, Ling

    2015-08-01

    Superconducting transition edge sensors (TESs) have made dramatic progress since their invention some 65 years ago (Andrews et al 1949 Phys. Rev. 76 154-155 Irwin and Hilton 2005 Topics Appl. Phys. 99 63-149) until now there are major imaging arrays of TESs with as many as 7588 separate sensors. These are extensively used by astronomers for some ground-breaking observations (Hattori et al 2013 Nucl. Instrum. Methods Phys. Res. A 732 299-302). The great success of TES systems has tended to overshadow other superconducting sensor developments. However there are other types (Sobolewski et al 2003 IEEE Trans. Appl. Supercond. 13 1151-7 Hadfield 2009 Nat. Photonics 3 696-705) which are discussed in papers within this special edition of the journal. Here we describe a quite different type of detector, also applicable to single photon detection but possessing possible advantages (higher sensitivity, higher operating temperature) over the conventional TES, at least for single detectors.

  17. Quantum interference in heterogeneous superconducting-photonic circuits on a silicon chip

    PubMed Central

    Schuck, C.; Guo, X.; Fan, L.; Ma, X.; Poot, M.; Tang, H. X.

    2016-01-01

    Quantum information processing holds great promise for communicating and computing data efficiently. However, scaling current photonic implementation approaches to larger system size remains an outstanding challenge for realizing disruptive quantum technology. Two main ingredients of quantum information processors are quantum interference and single-photon detectors. Here we develop a hybrid superconducting-photonic circuit system to show how these elements can be combined in a scalable fashion on a silicon chip. We demonstrate the suitability of this approach for integrated quantum optics by interfering and detecting photon pairs directly on the chip with waveguide-coupled single-photon detectors. Using a directional coupler implemented with silicon nitride nanophotonic waveguides, we observe 97% interference visibility when measuring photon statistics with two monolithically integrated superconducting single-photon detectors. The photonic circuit and detector fabrication processes are compatible with standard semiconductor thin-film technology, making it possible to implement more complex and larger scale quantum photonic circuits on silicon chips. PMID:26792424

  18. Upconversion single-microbelt photodetector via two-photon absorption simultaneous

    NASA Astrophysics Data System (ADS)

    Lou, Guanlin; Wu, Yanyan; Zhu, Hai; Li, Jinyu; Chen, Anqi; Chen, Zhiyang; Liang, Yunfeng; Ren, Yuhao; Gui, Xuchun; Zhong, Dingyong; Qiu, Zhiren; Tang, Zikang; Su, Shi C.

    2018-05-01

    Single microbelt (MB) photodetectors with metal–semiconductor-metal structure have been demonstrated and characterized comprehensively. For single-photon absorption, the maximum responsivity of ZnO-MB photodetector can reach as high as 1.4  ×  105 A W‑1 at 20 V bias. The results about photoresponse of MB-detector reveals that two relaxation mechanisms contribute to the carrier decay time. Moreover, the two-photon absorption upconversion photoresponsivity in the single-MB detector has also been realized, which is the first report about the two-photon absorption detector to the best of our knowledge. The excellent two-photon absorption photoresponsivity characteristic of the MB device can be available not only for detector but also for solar cell and biomedical imaging. The above results present a significant step towards future fabrication of single micro/nano-structure based multiphoton excitation optoelectronic devices.

  19. Investigation of the Effect of Temperature and Light Emission from Silicon Photomultiplier Detectors

    NASA Astrophysics Data System (ADS)

    Ruiz Castruita, Daniel; Ramos, Daniel; Hernandez, Victor; Niduaza, Rommel; Konx, Adrian; Fan, Sewan; Fatuzzo, Laura; Ritt, Stefan

    2015-04-01

    The silicon photomultiplier (SiPM) is an extremely sensitive light detector capable of measuring very dim light and operates as a photon-number resolving detector. Its high gain comes from operating at slightly above the breakdown voltage, which is also accompanied by a high dark count rate. At this conference poster session we describe our investigation of using SiPMs, the multipixel photon counters (MPPC) from Hamamatsu, as readout detectors for development in a cosmic ray scintillating detector array. Our research includes implementation of a novel design that automatically adjusts for the bias voltage to the MPPC detectors to compensate for changes in the ambient temperature. Furthermore, we describe our investigations for the MPPC detector characteristics at different bias voltages, temperatures and light emission properties. To measure the faint light emitted from the MPPC we use a photomultiplier tube capable of detecting single photons. Our data acquisition setup consists of a 5 Giga sample/second waveform digitizer, the DRS4, triggered to capture the MPPC detector waveforms. Analysis of the digitized waveforms, using the CERN package PAW, would be discussed and presented. US Department of Education Title V Grant PO31S090007.

  20. Theory of single-photon detectors employing smart strategies of detection

    NASA Astrophysics Data System (ADS)

    Silva, João Batista Rosa; Ramos, Rubens Viana

    2005-11-01

    Single-photon detectors have become more important with the advent of set-ups for optical communication using single-photon pulses, mainly quantum key distribution. The performance of quantum key distribution systems depends strongly on the performance of single-photon detectors. In this paper, aiming to overcome the afterpulsing that limits strongly the maximal transmission rate of quantum key distribution systems, three smart strategies for single-photon detection are discussed using analytical and numerical procedures. The three strategies are: hold-off time conditioned to avalanche presence, termed the Norwegian strategy, using one avalanche photodiode, using two raffled avalanche photodiodes and using two switched avalanche photodiodes. Finally we give examples using these strategies in a quantum key distribution set-up.

  1. Rise time of voltage pulses in NbN superconducting single photon detectors

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Smirnov, K. V.; CJSC “Superconducting Nanotechnology”; National Research University Higher School of Economics, Moscow Institute of Electronics and Mathematics, 34 Tallinskaya St., 109028 Moscow

    2016-08-01

    We have found experimentally that the rise time of voltage pulse in NbN superconducting single photon detectors increases nonlinearly with increasing the length of the detector L. The effect is connected with dependence of resistance of the detector R{sub n}, which appears after photon absorption, on its kinetic inductance L{sub k} and, hence, on the length of the detector. This conclusion is confirmed by our calculations in the framework of two temperature model.

  2. Tracking capabilities of SPADs for laser ranging

    NASA Technical Reports Server (NTRS)

    Zappa, F.; Ripamonti, Giancarlo; Lacaita, A.; Cova, Sergio; Samori, C.

    1993-01-01

    The spatial sensitivity of Single-Photon Avalanche Diodes (SPADs) can be exploited in laser ranging measurements to finely tune the laser spot in the center of the detector sensitive area. We report the performance of a SPAD with l00 micron diameter. It features a time resolution better than 80 ps rms when operated 4V above V(b) at minus 30 C, and a spatial sensitivity better than 20 microns to radial displacements of the laser spot. New SPAD structures with auxiliary delay detectors are proposed. These improved devices could allow a two dimensional sensitivity, that could be employed for the design of pointing servos.

  3. Single-Shot Quantum Nondemolition Detection of Individual Itinerant Microwave Photons

    NASA Astrophysics Data System (ADS)

    Besse, Jean-Claude; Gasparinetti, Simone; Collodo, Michele C.; Walter, Theo; Kurpiers, Philipp; Pechal, Marek; Eichler, Christopher; Wallraff, Andreas

    2018-04-01

    Single-photon detection is an essential component in many experiments in quantum optics, but it remains challenging in the microwave domain. We realize a quantum nondemolition detector for propagating microwave photons and characterize its performance using a single-photon source. To this aim, we implement a cavity-assisted conditional phase gate between the incoming photon and a superconducting artificial atom. By reading out the state of this atom in a single shot, we reach an external (internal) photon-detection fidelity of 50% (71%), limited by transmission efficiency between the source and the detector (75%) and the coherence properties of the qubit. By characterizing the coherence and average number of photons in the field reflected off the detector, we demonstrate its quantum nondemolition nature. We envisage applications in generating heralded remote entanglement between qubits and for realizing logic gates between propagating microwave photons.

  4. Single photon detection and signal analysis for high sensitivity dosimetry based on optically stimulated luminescence with beryllium oxide

    NASA Astrophysics Data System (ADS)

    Radtke, J.; Sponner, J.; Jakobi, C.; Schneider, J.; Sommer, M.; Teichmann, T.; Ullrich, W.; Henniger, J.; Kormoll, T.

    2018-01-01

    Single photon detection applied to optically stimulated luminescence (OSL) dosimetry is a promising approach due to the low level of luminescence light and the known statistical behavior of single photon events. Time resolved detection allows to apply a variety of different and independent data analysis methods. Furthermore, using amplitude modulated stimulation impresses time- and frequency information into the OSL light and therefore allows for additional means of analysis. Considering the impressed frequency information, data analysis by using Fourier transform algorithms or other digital filters can be used for separating the OSL signal from unwanted light or events generated by other phenomena. This potentially lowers the detection limits of low dose measurements and might improve the reproducibility and stability of obtained data. In this work, an OSL system based on a single photon detector, a fast and accurate stimulation unit and an FPGA is presented. Different analysis algorithms which are applied to the single photon data are discussed.

  5. JUNGFRAU 0.2: prototype characterization of a gain-switching, high dynamic range imaging system for photon science at SwissFEL and synchrotrons

    NASA Astrophysics Data System (ADS)

    Jungmann-Smith, J. H.; Bergamaschi, A.; Cartier, S.; Dinapoli, R.; Greiffenberg, D.; Johnson, I.; Maliakal, D.; Mezza, D.; Mozzanica, A.; Ruder, Ch; Schaedler, L.; Schmitt, B.; Shi, X.; Tinti, G.

    2014-12-01

    JUNGFRAU (adJUstiNg Gain detector FoR the Aramis User station) is a two-dimensional pixel detector for photon science applications at free electron lasers and synchrotron light sources. It is developed for the SwissFEL currently under construction at the Paul Scherrer Institute, Switzerland. Characteristics of this application-specific integrating circuit readout chip include single photon sensitivity and low noise over a dynamic range of over four orders of magnitude of photon input signal. These characteristics are achieved by a three-fold gain-switching preamplifier in each pixel, which automatically adjusts its gain to the amount of charge deposited on the pixel. The final JUNGFRAU chip comprises 256 × 256 pixels of 75 × 75 μm2 each. Arrays of 2 × 4 chips are bump-bonded to monolithic detector modules of about 4 × 8 cm2. Multi-module systems up to 16 Mpixels are planned for the end stations at SwissFEL. A readout rate in excess of 2 kHz is anticipated, which serves the readout requirements of SwissFEL and enables high count rate synchrotron experiments with a linear count rate capability of > 20 MHz/pixel. Promising characterization results from a 3.6 × 3.6 mm2 prototype (JUNGFRAU 0.2) with fluorescence X-ray, infrared laser and synchrotron irradiation are shown. The results include an electronic noise as low as 100 electrons root-mean-square, which enables single photon detection down to X-ray energies of about 2 keV. Noise below the Poisson fluctuation of the photon number and a linearity error of the pixel response of about 1% are demonstrated. First imaging experiments successfully show automatic gain switching. The edge spread function of the imaging system proves to be comparable in quality to single photon counting hybrid pixel detectors.

  6. Infrared engineering for the advancement of science: A UK perspective

    NASA Astrophysics Data System (ADS)

    Baker, Ian M.

    2017-02-01

    Leonardo MW (formerly Selex ES) has been developing infrared sensors and cameras for over 62 years at two main sites at Southampton and Basildon. Funding mainly from UK MOD has seen the technology progress from single element PbSe sensors to advanced, high definition, HgCdTe cameras, widely deployed in many fields today. However, in the last 10 years the major challenges and research funding has come from projects within the scientific sphere, particularly: astronomy and space. Low photon flux, high resolution spectroscopy and fast frame rates are the motivation to drive the sensitivity of infrared detectors to the single photon level. These detectors make use of almost noiseless avalanche gain in HgCdTe to achieve the sensitivity and speed of response. Metal Organic Vapour Phase Epitaxy, MOVPE, grown on low-cost GaAs substrates, provides the capability for crucial bandgap engineering to suppress breakdown currents and allow high avalanche gain even in very low background conditions. This paper describes the progress so far and provides a glimpse of the future.

  7. Single photon ranging system using two wavelengths laser and analysis of precision

    NASA Astrophysics Data System (ADS)

    Chen, Yunfei; He, Weiji; Miao, Zhuang; Gu, Guohua; Chen, Qian

    2013-09-01

    The laser ranging system based on time correlation single photon counting technology and single photon detector has the feature of high precision and low emergent energy etc. In this paper, we established a single photon laser ranging system that use the supercontinuum laser as light source, and two wavelengths (532nm and 830nm) of echo signal as the stop signal. We propose a new method that is capable to improve the single photon ranging system performance. The method is implemented by using two single-photon detectors to receive respectively the two different wavelength signals at the same time. We extracted the firings of the two detectors triggered by the same laser pulse at the same time and then took mean time of the two firings as the combined detection time-of-flight. The detection by two channels using two wavelengths will effectively improve the detection precision and decrease the false alarm probability. Finally, an experimental single photon ranging system was established. Through a lot of experiments, we got the system precision using both single and two wavelengths and verified the effectiveness of the method.

  8. Single Microwave-Photon Detector using an Artificial Lambda-type Three-Level System

    DTIC Science & Technology

    2016-01-11

    Single microwave-photon detector using an artificial Λ-type three- level system Kunihiro Inomata,1∗†, Zhirong Lin,1†, Kazuki Koshino,2, William D...three- level system Kunihiro Inomata,1∗† Zhirong Lin,1† Kazuki Koshino,2 William D. Oliver,3,4 Jaw-Shen Tsai,1 Tsuyoshi Yamamoto,5 Yasunobu Nakamura...single-microwave-photon detector based on the deterministic switching in an artificial Λ-type three- level system implemented using the dressed states of a

  9. Prototype readout system for a multi Mpixels UV single-photon imaging detector capable of space flight operation

    NASA Astrophysics Data System (ADS)

    Seljak, A.; Cumming, H. S.; Varner, G.; Vallerga, J.; Raffanti, R.; Virta, V.

    2018-02-01

    Our collaboration works on the development of a large aperture, high resolution, UV single-photon imaging detector, funded through NASA's Strategic Astrophysics Technology (SAT) program. The detector uses a microchannel plate for charge multiplication, and orthogonal cross strip (XS) anodes for charge readout. Our target is to make an advancement in the technology readiness level (TRL), which enables real scale prototypes to be tested for future NASA missions. The baseline detector has an aperture of 50×50 mm and requires 160 low-noise charge-sensitive channels, in order to extrapolate the incoming photon position with a spatial resolution of about 20 μm FWHM. Technologies involving space flight require highly integrated electronic systems operating at very low power. We have designed two ASICs which enable the construction of such readout system. First, a charge sensitive amplifier (CSAv3) ASIC provides an equivalent noise charge (ENC) of around 600 e-, and a baseline gain of 10 mV/fC. The second, a Giga Sample per Second (GSPS) ASIC, called HalfGRAPH, is a 12-bit analog to digital converter. Its architecture is based on waveform sampling capacitor arrays and has about 8 μs of analog storage memory per channel. Both chips encapsulate 16 measurement channels. Using these chips, a small scale prototype readout system has been constructed on a FPGA Mezzanine Board (FMC), equipped with 32 measurement channels for system evaluation. We describe the construction of HalfGRAPH ASIC, detector's readout system concept and obtained results from the prototype system. As part of the space flight qualification, these chips were irradiated with a Cobalt gamma-ray source, to verify functional operation under ionizing radiation exposure.

  10. Quantum dot single-photon switches of resonant tunneling current for discriminating-photon-number detection

    PubMed Central

    Weng, Qianchun; An, Zhenghua; Zhang, Bo; Chen, Pingping; Chen, Xiaoshuang; Zhu, Ziqiang; Lu, Wei

    2015-01-01

    Low-noise single-photon detectors that can resolve photon numbers are used to monitor the operation of quantum gates in linear-optical quantum computation. Exactly 0, 1 or 2 photons registered in a detector should be distinguished especially in long-distance quantum communication and quantum computation. Here we demonstrate a photon-number-resolving detector based on quantum dot coupled resonant tunneling diodes (QD-cRTD). Individual quantum-dots (QDs) coupled closely with adjacent quantum well (QW) of resonant tunneling diode operate as photon-gated switches- which turn on (off) the RTD tunneling current when they trap photon-generated holes (recombine with injected electrons). Proposed electron-injecting operation fills electrons into coupled QDs which turn “photon-switches” to “OFF” state and make the detector ready for multiple-photons detection. With proper decision regions defined, 1-photon and 2-photon states are resolved in 4.2 K with excellent propabilities of accuracy of 90% and 98% respectively. Further, by identifying step-like photon responses, the photon-number-resolving capability is sustained to 77 K, making the detector a promising candidate for advanced quantum information applications where photon-number-states should be accurately distinguished. PMID:25797442

  11. Quantum dot single-photon switches of resonant tunneling current for discriminating-photon-number detection.

    PubMed

    Weng, Qianchun; An, Zhenghua; Zhang, Bo; Chen, Pingping; Chen, Xiaoshuang; Zhu, Ziqiang; Lu, Wei

    2015-03-23

    Low-noise single-photon detectors that can resolve photon numbers are used to monitor the operation of quantum gates in linear-optical quantum computation. Exactly 0, 1 or 2 photons registered in a detector should be distinguished especially in long-distance quantum communication and quantum computation. Here we demonstrate a photon-number-resolving detector based on quantum dot coupled resonant tunneling diodes (QD-cRTD). Individual quantum-dots (QDs) coupled closely with adjacent quantum well (QW) of resonant tunneling diode operate as photon-gated switches- which turn on (off) the RTD tunneling current when they trap photon-generated holes (recombine with injected electrons). Proposed electron-injecting operation fills electrons into coupled QDs which turn "photon-switches" to "OFF" state and make the detector ready for multiple-photons detection. With proper decision regions defined, 1-photon and 2-photon states are resolved in 4.2 K with excellent propabilities of accuracy of 90% and 98% respectively. Further, by identifying step-like photon responses, the photon-number-resolving capability is sustained to 77 K, making the detector a promising candidate for advanced quantum information applications where photon-number-states should be accurately distinguished.

  12. Coherent photon scattering background in sub- GeV / c 2 direct dark matter searches

    DOE PAGES

    Robinson, Alan E.

    2017-01-18

    Here, proposed dark matter detectors with eV-scale sensitivities will detect a large background of atomic (nuclear) recoils from coherent photon scattering of MeV-scale photons. This background climbs steeply below ~10 eV, far exceeding the declining rate of low-energy Compton recoils. The upcoming generation of dark matter detectors will not be limited by this background, but further development of eV-scale and sub-eV detectors will require strategies, including the use of low nuclear mass target materials, to maximize dark matter sensitivity while minimizing the coherent photon scattering background.

  13. SiC-based Photo-detectors for UV, VUV, EUV and Soft X-ray Detection

    NASA Technical Reports Server (NTRS)

    Yan, Feng

    2006-01-01

    A viewgraph presentation describing an ideal Silicon Carbide detector for ultraviolet, vacuum ultraviolet, extreme ultraviolet and soft x-ray detection is shown. The topics include: 1) An ideal photo-detector; 2) Dark current density of SiC photodiodes at room temperature; 3) Dark current in SiC detectors; 4) Resistive and capacitive feedback trans-impedance amplifier; 5) Avalanche gain; 6) Excess noise; 7) SNR in single photon counting mode; 8) Structure of SiC single photon counting APD and testing structure; 9) Single photon counting waveform and testing circuit; 10) Amplitude of SiC single photon counter; 11) Dark count of SiC APD photon counters; 12) Temperature-dependence of dark count rate; 13) Reduce the dark count rate by reducing the breakdown electric field; 14) Spectrum range for SiC detectors; 15) QE curves of Pt/4H-SiC photodiodes; 16) QE curve of SiC; 17) QE curves of SiC photodiode vs. penetration depth; 18) Visible rejection of SiC photodiodes; 19) Advantages of SiC photodiodes; 20) Competitors of SiC detectors; 21) Extraterrestrial solar spectra; 22) Visible-blind EUV detection; 23) Terrestrial solar spectra; and 24) Less than 1KeV soft x-ray detection.

  14. Design and characterization of free-running InGaAsP single-photon detector with active-quenching technique

    NASA Astrophysics Data System (ADS)

    Liu, Junliang; Zhang, Tingfa; Li, Yongfu; Ding, Lei; Tao, Junchao; Wang, Ying; Wang, Qingpu; Fang, Jiaxiong

    2017-07-01

    A free-running single-photon detector for 1.06 μm wavelength based on an InGaAsP/InP single-photon avalanche diode is presented. The detector incorporates an ultra-fast active-quenching technique to greatly lessen the afterpulsing effects. An improved method for avalanche characterization using electroluminescence is proposed, and the performance of the detector is evaluated. The number of avalanche carriers is as low as 1.68 ×106 , resulting in a low total afterpulse probability of 4% at 233 K, 10% detection efficiency, and 1 μs hold-off time.

  15. Methods for Reducing Singly Reflected Rays on the Wolter-I Focusing Figures of the FOXSI Rocket Experiment

    NASA Technical Reports Server (NTRS)

    Buitrago-Casas, Juan Camilo; Glesener, Lindsay; Christe, Steven; Elsner, Ronald; Ramsey, Brian; Courtade, Sasha; Ishikawa, Shin-nosuke; Narukage, Noriyuki; Vievering, Juliana; Subramania, Athiray; hide

    2017-01-01

    In high energy solar astrophysics, imaging hard X-rays by direct focusing offers higher dynamic range and greater sensitivity compared to past techniques that used indirect imaging. The Focusing Optics X-ray Solar Imager (FOXSI) is a sounding rocket payload which uses seven sets of nested Wolter-I figured mirrors that, together with seven high-sensitivity semiconductor detectors, observes the Sun in hard X-rays by direct focusing. The FOXSI rocket has successfully flown twice and is funded to fly a third time in Summer 2018. The Wolter-I geometry consists of two consecutive mirrors, one paraboloid, and one hyperboloid, that reflect photons at grazing angles. Correctly focused X-rays reflect twice, once per mirror segment. For extended sources, like the Sun, off-axis photons at certain incident angles can reflect on only one mirror and still reach the focal plane, generating a pattern of single-bounce photons that can limit the sensitivity of the observation of faint focused X-rays. Understanding and cutting down the singly reflected rays on the FOXSI optics will maximize the instrument's sensitivity of the faintest solar sources for future flights. We present an analysis of the FOXSI singly reflected rays based on ray-tracing simulations, as well as the effectiveness of different physical strategies to reduce them.

  16. Recent advances in superconducting nanowire single photon detectors for single-photon imaging

    NASA Astrophysics Data System (ADS)

    Verma, V. B.; Allman, M. S.; Stevens, M.; Gerrits, T.; Horansky, R. D.; Lita, A. E.; Marsili, F.; Beyer, A.; Shaw, M. D.; Stern, J. A.; Mirin, R. P.; Nam, S. W.

    2016-05-01

    We demonstrate a 64-pixel free-space-coupled array of superconducting nanowire single photon detectors optimized for high detection efficiency in the near-infrared range. An integrated, readily scalable, multiplexed readout scheme is employed to reduce the number of readout lines to 16. The cryogenic, optical, and electronic packaging to read out the array, as well as characterization measurements are discussed.

  17. Fill-factor improvement of Si CMOS single-photon avalanche diode detector arrays by integration of diffractive microlens arrays.

    PubMed

    Intermite, Giuseppe; McCarthy, Aongus; Warburton, Ryan E; Ren, Ximing; Villa, Federica; Lussana, Rudi; Waddie, Andrew J; Taghizadeh, Mohammad R; Tosi, Alberto; Zappa, Franco; Buller, Gerald S

    2015-12-28

    Single-photon avalanche diode (SPAD) detector arrays generally suffer from having a low fill-factor, in which the photo-sensitive area of each pixel is small compared to the overall area of the pixel. This paper describes the integration of different configurations of high efficiency diffractive optical microlens arrays onto a 32 × 32 SPAD array, fabricated using a 0.35 µm CMOS technology process. The characterization of SPAD arrays with integrated microlens arrays is reported over the spectral range of 500-900 nm, and a range of f-numbers from f/2 to f/22. We report an average concentration factor of 15 measured for the entire SPAD array with integrated microlens array. The integrated SPAD and microlens array demonstrated a very high uniformity in overall efficiency.

  18. A miniaturized 4 K platform for superconducting infrared photon counting detectors

    NASA Astrophysics Data System (ADS)

    Gemmell, Nathan R.; Hills, Matthew; Bradshaw, Tom; Rawlings, Tom; Green, Ben; Heath, Robert M.; Tsimvrakidis, Konstantinos; Dobrovolskiy, Sergiy; Zwiller, Val; Dorenbos, Sander N.; Crook, Martin; Hadfield, Robert H.

    2017-11-01

    We report on a miniaturized platform for superconducting infrared photon counting detectors. We have implemented a fibre-coupled superconducting nanowire single photon detector in a Stirling/Joule-Thomson platform with a base temperature of 4.2 K. We have verified a cooling power of 4 mW at 4.7 K. We report 20% system detection efficiency at 1310 nm wavelength at a dark count rate of 1 kHz. We have carried out compelling application demonstrations in single photon depth metrology and singlet oxygen luminescence detection.

  19. 32-channel single photon counting module for ultrasensitive detection of DNA sequences

    NASA Astrophysics Data System (ADS)

    Gudkov, Georgiy; Dhulla, Vinit; Borodin, Anatoly; Gavrilov, Dmitri; Stepukhovich, Andrey; Tsupryk, Andrey; Gorbovitski, Boris; Gorfinkel, Vera

    2006-10-01

    We continue our work on the design and implementation of multi-channel single photon detection systems for highly sensitive detection of ultra-weak fluorescence signals, for high-performance, multi-lane DNA sequencing instruments. A fiberized, 32-channel single photon detection (SPD) module based on single photon avalanche diode (SPAD), model C30902S-DTC, from Perkin Elmer Optoelectronics (PKI) has been designed and implemented. Unavailability of high performance, large area SPAD arrays and our desire to design high performance photon counting systems drives us to use individual diodes. Slight modifications in our quenching circuit has doubled the linear range of our system from 1MHz to 2MHz, which is the upper limit for these devices and the maximum saturation count rate has increased to 14 MHz. The detector module comprises of a single board computer PC-104 that enables data visualization, recording, processing, and transfer. Very low dark count (300-1000 counts/s), robust, efficient, simple data collection and processing, ease of connectivity to any other application demanding similar requirements and similar performance results to the best commercially available single photon counting module (SPCM from PKI) are some of the features of this system.

  20. High-fidelity frequency down-conversion of visible entangled photon pairs with superconducting single-photon detectors

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ikuta, Rikizo; Kato, Hiroshi; Kusaka, Yoshiaki

    We experimentally demonstrate a high-fidelity visible-to-telecommunicationwavelength conversion of a photon by using a solid-state-based difference frequency generation. In the experiment, one half of a pico-second visible entangled photon pair at 780 nm is converted to a 1522-nm photon. Using superconducting single-photon detectors with low dark count rates and small timing jitters, we observed a fidelity of 0.93±0.04 after the wavelength conversion.

  1. Cadmium Telluride Semiconductor Detector for Improved Spatial and Energy Resolution Radioisotopic Imaging

    PubMed Central

    Abbaspour, Samira; Mahmoudian, Babak; Islamian, Jalil Pirayesh

    2017-01-01

    The detector in single-photon emission computed tomography has played a key role in the quality of the images. Over the past few decades, developments in semiconductor detector technology provided an appropriate substitution for scintillation detectors in terms of high sensitivity, better energy resolution, and also high spatial resolution. One of the considered detectors is cadmium telluride (CdTe). The purpose of this paper is to review the CdTe semiconductor detector used in preclinical studies, small organ and small animal imaging, also research in nuclear medicine and other medical imaging modalities by a complete inspect on the material characteristics, irradiation principles, applications, and epitaxial growth method. PMID:28553175

  2. A universal setup for active control of a single-photon detector

    NASA Astrophysics Data System (ADS)

    Liu, Qin; Lamas-Linares, Antía; Kurtsiefer, Christian; Skaar, Johannes; Makarov, Vadim; Gerhardt, Ilja

    2014-01-01

    The influence of bright light on a single-photon detector has been described in a number of recent publications. The impact on quantum key distribution (QKD) is important, and several hacking experiments have been tailored to fully control single-photon detectors. Special attention has been given to avoid introducing further errors into a QKD system. We describe the design and technical details of an apparatus which allows to attack a quantum-cryptographic connection. This device is capable of controlling free-space and fiber-based systems and of minimizing unwanted clicks in the system. With different control diagrams, we are able to achieve a different level of control. The control was initially targeted to the systems using BB84 protocol, with polarization encoding and basis switching using beamsplitters, but could be extended to other types of systems. We further outline how to characterize the quality of active control of single-photon detectors.

  3. A universal setup for active control of a single-photon detector

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Liu, Qin; Skaar, Johannes; Lamas-Linares, Antía

    2014-01-15

    The influence of bright light on a single-photon detector has been described in a number of recent publications. The impact on quantum key distribution (QKD) is important, and several hacking experiments have been tailored to fully control single-photon detectors. Special attention has been given to avoid introducing further errors into a QKD system. We describe the design and technical details of an apparatus which allows to attack a quantum-cryptographic connection. This device is capable of controlling free-space and fiber-based systems and of minimizing unwanted clicks in the system. With different control diagrams, we are able to achieve a different levelmore » of control. The control was initially targeted to the systems using BB84 protocol, with polarization encoding and basis switching using beamsplitters, but could be extended to other types of systems. We further outline how to characterize the quality of active control of single-photon detectors.« less

  4. Improving the counting efficiency in time-correlated single photon counting experiments by dead-time optimization

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Peronio, P.; Acconcia, G.; Rech, I.

    Time-Correlated Single Photon Counting (TCSPC) has been long recognized as the most sensitive method for fluorescence lifetime measurements, but often requiring “long” data acquisition times. This drawback is related to the limited counting capability of the TCSPC technique, due to pile-up and counting loss effects. In recent years, multi-module TCSPC systems have been introduced to overcome this issue. Splitting the light into several detectors connected to independent TCSPC modules proportionally increases the counting capability. Of course, multi-module operation also increases the system cost and can cause space and power supply problems. In this paper, we propose an alternative approach basedmore » on a new detector and processing electronics designed to reduce the overall system dead time, thus enabling efficient photon collection at high excitation rate. We present a fast active quenching circuit for single-photon avalanche diodes which features a minimum dead time of 12.4 ns. We also introduce a new Time-to-Amplitude Converter (TAC) able to attain extra-short dead time thanks to the combination of a scalable array of monolithically integrated TACs and a sequential router. The fast TAC (F-TAC) makes it possible to operate the system towards the upper limit of detector count rate capability (∼80 Mcps) with reduced pile-up losses, addressing one of the historic criticisms of TCSPC. Preliminary measurements on the F-TAC are presented and discussed.« less

  5. Antenna-Coupled Superconducting Tunnel Junctions with Single-Electron Transistor Readout for Detection of Sub-mm Radiation

    NASA Technical Reports Server (NTRS)

    Stevenson, T. R.; Hsieh, W.-T.; Li, M. J.; Stahle, C. M.; Wollack, E. J.; Schoelkopf, R. J.; Teufel, J.; Krebs, Carolyn (Technical Monitor)

    2002-01-01

    Antenna-coupled superconducting tunnel junction detectors have the potential for photon-counting sensitivity at sub-mm wavelengths. The device consists of an antenna structure to couple radiation into a small superconducting volume and cause quasiparticle excitations, and a single-electron transistor to measure currents through tunnel junction contacts to the absorber volume. We will describe optimization of device parameters, and recent results on fabrication techniques for producing devices with high yield for detector arrays. We will also present modeling of expected saturation power levels, antenna coupling, and rf multiplexing schemes.

  6. Non-Geiger-Mode Single-Photon Avalanche Detector with Low Excess Noise

    NASA Technical Reports Server (NTRS)

    Zhao, Kai; Lo, YuHwa; Farr, William

    2010-01-01

    This design constitutes a self-resetting (gain quenching), room-temperature operational semiconductor single-photon-sensitive detector that is sensitive to telecommunications optical wavelengths and is scalable to large areas (millimeter diameter) with high bandwidth and efficiencies. The device can detect single photons at a 1,550-nm wavelength at a gain of 1 x 10(exp 6). Unlike conventional single photon avalanche detectors (SPADs), where gain is an extremely sensitive function to the bias voltage, the multiplication gain of this device is stable at 1 x 10(exp 6) over a wide range of bias from 30.2 to 30.9 V. Here, the multiplication gain is defined as the total number of charge carriers contained in one output pulse that is triggered by the absorption of a single photon. The statistics of magnitude of output signals also shows that the device has a very narrow pulse height distribution, which demonstrates a greatly suppressed gain fluctuation. From the histograms of both pulse height and pulse charge, the equivalent gain variance (excess noise) is between 1.001 and 1.007 at a gain of 1 x 10(exp 6). With these advantages, the device holds promise to function as a PMT-like photon counter at a 1,550- nm wavelength. The epitaxial layer structure of the device allows photons to be absorbed in the InGaAs layer, generating electron/hole (e-h) pairs. Driven by an electrical field in InGaAs, electrons are collected at the anode while holes reach the multiplication region (InAlAs p-i-n structure) and trigger the avalanche process. As a result, a large number of e-h pairs are created, and the holes move toward the cathode. Holes created by the avalanche process gain large kinetic energy through the electric field, and are considered hot. These hot holes are cooled as they travel across a p -InAlAs low field region, and are eventually blocked by energy barriers formed by the InGaAsP/ InAlAs heterojunctions. The composition of the InGaAsP alloy was chosen to have an 80 meV valance band offset with InAlAs, which is high enough to hinder the transport of the already cooled holes. Being stopped by the energy barrier, holes are accumulated at the junctions to shield the electric field, resulting in a decrease of the electric field in the multiplication region. Because the impact ionization rate is extremely sensitive to the magnitude of the electric field, the field-screening effect drastically reduces the impact ionization rate and quenches the output signals. After the avalanche pulse signal is self-quenched, the accumulated holes at the InGaAsP/ InAlAs interface escape the energy barrier through thermal excitation and tunneling and finally leave the device. The device is thus reset and ready for subsequent photon detection. This recovery time is controlled by the height of the energy barrier and the hole-cooling rate.

  7. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Robinson, Alan E.

    Here, proposed dark matter detectors with eV-scale sensitivities will detect a large background of atomic (nuclear) recoils from coherent photon scattering of MeV-scale photons. This background climbs steeply below ~10 eV, far exceeding the declining rate of low-energy Compton recoils. The upcoming generation of dark matter detectors will not be limited by this background, but further development of eV-scale and sub-eV detectors will require strategies, including the use of low nuclear mass target materials, to maximize dark matter sensitivity while minimizing the coherent photon scattering background.

  8. An efficient fluorescent single-particle position tracking system for long-term pulsed measurements of nitrogen-vacancy centers in diamond

    NASA Astrophysics Data System (ADS)

    Kim, Kiho; Yun, Jiwon; Lee, Donghyuck; Kim, Dohun

    2018-02-01

    A simple and convenient design enables real-time three-dimensional position tracking of nitrogen-vacancy (NV) centers in diamond. The system consists entirely of commercially available components (a single-photon counter, a high-speed digital-to-analog converter, a phase-sensitive detector-based feedback device, and a piezo stage), eliminating the need for custom programming or rigorous optimization processes. With a large input range of counters and trackers combined with high sensitivity of single-photon counting, high-speed position tracking (upper bound recovery time of 0.9 s upon 250 nm of step-like positional shift) not only of bright ensembles, but also of low-photon-collection-efficiency single to few NV centers (down to 103 s-1) is possible. The tracking requires position modulation of only 10 nm, which allows simultaneous position tracking and pulsed measurements in the long term. Therefore, this tracking system enables measuring a single-spin magnetic resonance and Rabi oscillations at a very high resolution even without photon collection optimization. The system is widely applicable to various fields related to NV center quantum manipulation research such as NV optical trapping, NV tracking in fluid dynamics, and biological sensing using NV centers inside a biological cell.

  9. Comparison of 16-Channel Laser Photoreceivers for Topographic Mapping

    NASA Technical Reports Server (NTRS)

    Krainak, Michael A.; Yang, Guangning; Sun, XiaoIi; Lu, Wei; Bai, Xiaogang; Yuan, Ping; McDonald, Paul; Boisvert, Joseph; Woo, Robyn; Wan, Kam; hide

    2011-01-01

    Topographic mapping lidar instruments must be able to detect extremely weak laser return signals from high altitudes including orbital distance. The signals have a wide dynamic range caused by the variability in atmospheric transmission and surface reflectance under a fast moving spacecraft. Ideally, lidar detectors should be able to detect laser signal return pulses at the single photon level and produce linear output for multiple photon events. Silicon avalanche photodiode (APO) detectors have been used in most space lidar receivers to date. Their sensitivity is typically hundreds of photons per pulse, and is limited by the quantum efficiency, APO gain noise, dark current, and preamplifier noise. NASA is pursuing three approaches for a 16-channel laser photoreceiver for use on the next generation direct-detection airborne and spacebome lidars. We present our measurement results and a comparison of their performance.

  10. Fast time-domain measurements on telecom single photons

    NASA Astrophysics Data System (ADS)

    Allgaier, Markus; Vigh, Gesche; Ansari, Vahid; Eigner, Christof; Quiring, Viktor; Ricken, Raimund; Brecht, Benjamin; Silberhorn, Christine

    2017-09-01

    Direct measurements on the temporal envelope of quantum light are a challenging task and not many examples are known because most classical pulse characterisation methods do not work on the single-photon level. Knowledge of both spectrum and timing can, however, give insights on properties that cannot be determined by the spectral intensity alone. While temporal measurements on single photons on timescales of tens of picoseconds are possible with superconducting photon detectors, and picosecond measurements have been performed using streak cameras, there are no commercial single-photon sensitive devices with femtosecond resolution available. While time-domain sampling using sum-frequency generation has already been exploited for such a measurement, inefficient conversion has necessitated long integration times to build the temporal profile. We demonstrate a highly efficient waveguided sum-frequency generation process in Lithium Niobate to measure the temporal envelope of single photons with femtosecond resolution with short enough acquisition time to provide a live-view of the measurement. We demonstrate the measurement technique and combine it with spectral measurements using a dispersive-fibre time-of-flight spectrometer to determine upper and lower bounds for the spectral purity of heralded single photons. The approach complements the joint spectral intensity measurements as a measure on the purity can be given without knowledge of the spectral phase.

  11. Studies of Avalanche Photodiodes (APDS) as Readout Devices for Scintillating Fibers for High Energy Gamma-Ray Astronomy Telescopes

    NASA Technical Reports Server (NTRS)

    Vasile, Stefan; Shera, Suzanne; Shamo, Denis

    1998-01-01

    New gamma ray and charged particle telescope designs based on scintillating fiber arrays could provide low cost, high resolution, lightweight, very large area and multi radiation length instrumentation for planned NASA space exploration. The scintillating fibers low visible light output requires readout sensors with single photon detection sensitivity and low noise. The sensitivity of silicon Avalanche Photodiodes (APDS) matches well the spectral output of the scintillating fibers. Moreover, APDs have demonstrated single photon capability. The global aim of our work is to make available to NASA a novel optical detector concept to be used as scintillating fiber readouts and meeting the requirements of the new generations of space-borne gamma ray telescopes. We proposed to evaluate the feasibility of using RMD's small area APDs ((mu)APD) as scintillating fiber readouts and to study possible alternative (mu)APD array configurations for space borne readout scintillating fiber systems, requiring several hundred thousand to one million channels. The evaluation has been conducted in accordance with the task description and technical specifications detailed in the NASA solicitation "Studies of Avalanche Photodiodes (APD as readout devices for scintillating fibers for High Energy Gamma-Ray Astronomy Telescopes" (#8-W-7-ES-13672NAIS) posted on October 23, 1997. The feasibility study we propose builds on recent developments of silicon APD arrays and light concentrators advances at RMD, Inc. and on more than 5 years of expertise in scintillating fiber detectors. In a previous program we carried out the initial research to develop a high resolution, small pixel, solid-state, silicon APD array which exhibited very high sensitivity in the UV-VIS spectrum. This (mu)APD array is operated in Geiger mode and results in high gain (greater than 10(exp 8)), extremely low noise, single photon detection capability, low quiescent power (less than 10 (mu)W/pixel for 30 micrometers sensitive area diameter) and output in the 1-5 volt range. If successful, this feasibility study will make possible the development of a scintillating fiber detector with unsurpassed sensitivity, extremely low power usage, a crucial factor of merit for space based sensors and telescopes.

  12. Timing resolution and time walk in super low K factor single-photon avalanche diode-measurement and optimization

    NASA Astrophysics Data System (ADS)

    Fong, Bernicy S.; Davies, Murray; Deschamps, Pierre

    2018-01-01

    Timing resolution (or timing jitter) and time walk are separate parameters associated with a detector's response time. Studies have been done mostly on the time resolution of various single-photon detectors. As the designer and manufacturer of the ultra-low noise (ƙ-factor) silicon avalanche photodiode the super low K factor (SLiK) single-photon avalanche diode (SPAD), which is used in many single-photon counting applications, we often get inquiries from customers to better understand how this detector behaves under different operating conditions. Hence, here, we will be focusing on the study of these time-related parameters specifically for the SLiK SPAD, as a way to provide the most direct information for users of this detector to help with its use more efficiently and effectively. We will be providing the study data on how these parameters can be affected by temperature (both intrinsic to the detector chip and environmental input based on operating conditions), operating voltage, photon wavelength, as well as light spot size. How these parameters can be optimized and the trade-offs from optimization from the desired performance will be presented?

  13. Chem/bio sensing with non-classical light and integrated photonics.

    PubMed

    Haas, J; Schwartz, M; Rengstl, U; Jetter, M; Michler, P; Mizaikoff, B

    2018-01-29

    Modern quantum technology currently experiences extensive advances in applicability in communications, cryptography, computing, metrology and lithography. Harnessing this technology platform for chem/bio sensing scenarios is an appealing opportunity enabling ultra-sensitive detection schemes. This is further facilliated by the progress in fabrication, miniaturization and integration of visible and infrared quantum photonics. Especially, the combination of efficient single-photon sources together with waveguiding/sensing structures, serving as active optical transducer, as well as advanced detector materials is promising integrated quantum photonic chem/bio sensors. Besides the intrinsic molecular selectivity and non-destructive character of visible and infrared light based sensing schemes, chem/bio sensors taking advantage of non-classical light sources promise sensitivities beyond the standard quantum limit. In the present review, recent achievements towards on-chip chem/bio quantum photonic sensing platforms based on N00N states are discussed along with appropriate recognition chemistries, facilitating the detection of relevant (bio)analytes at ultra-trace concentration levels. After evaluating recent developments in this field, a perspective for a potentially promising sensor testbed is discussed for reaching integrated quantum sensing with two fiber-coupled GaAs chips together with semiconductor quantum dots serving as single-photon sources.

  14. SiPM electro-optical detection system noise suppression method

    NASA Astrophysics Data System (ADS)

    Bi, Xiangli; Yang, Suhui; Hu, Tao; Song, Yiheng

    2014-11-01

    In this paper, the single photon detection principle of Silicon Photomultipliers (SiPM) device is introduced. The main noise factors that infect the sensitivity of the electro-optical detection system are analyzed, including background light noise, detector dark noise, preamplifier noise and signal light noise etc. The Optical, electrical and thermodynamic methods are used to suppress the SiPM electro-optical detection system noise, which improved the response sensitivity of the detector. Using SiPM optoelectronic detector with a even high sensitivity, together with small field large aperture optical system, high cutoff narrow bandwidth filters, low-noise operational amplifier circuit, the modular design of functional circuit, semiconductor refrigeration technology, greatly improved the sensitivity of optical detection system, reduced system noise and achieved long-range detection of weak laser radiation signal. Theoretical analysis and experimental results show that the proposed methods are reasonable and efficient.

  15. Lead salt room-temperature MWIR FPA

    NASA Astrophysics Data System (ADS)

    Murphy, Paul F.; Jost, Steven R.; Barrett, John L.; Reese, Dan; Winn, Michael L.

    2001-10-01

    The development of low-cost uncooled thermal LWIR FPAs is resulting in the emergence of a new generation of infrared sensors for applications where affordability is the prerequisite for volume production. Both ferroelectric detector arrays and silicon-based microbolometers are finding numerous applications from gun sights to automotive FLIRs. There would be significant interest in a similar uncooled offering in the MWIR, but to date, thermal detectors have lacked sufficient sensitivity. The existing uncooled MWIR photon detector technology, based on polycrystalline lead salts, has been relegated to single-element detectors and relatively small linear arrays due to the high dark current and the stigma of being a 50-year-old technology.

  16. Photon-number-resolving SSPDs with system detection efficiency over 50% at telecom range

    NASA Astrophysics Data System (ADS)

    Zolotov, P.; Divochiy, A.; Vakhtomin, Yu.; Moshkova, M.; Morozov, P.; Seleznev, V.; Smirnov, K.

    2018-02-01

    We used technology of making high-efficiency superconducting single-photon detectors as a basis for improvement of photon-number-resolving devices. By adding optical cavity and using an improved NbN superconducting film, we enhanced previously reported system detection efficiency at telecom range for such detectors. Our results show that implementation of optical cavity helps to develop four-section device with quantum efficiency over 50% at 1.55 µm. Performed experimental studies of detecting multi-photon optical pulses showed irregularities over defining multi-photon through single-photon quantum efficiency.

  17. Detection of non-classical space-time correlations with a novel type of single-photon camera.

    PubMed

    Just, Felix; Filipenko, Mykhaylo; Cavanna, Andrea; Michel, Thilo; Gleixner, Thomas; Taheri, Michael; Vallerga, John; Campbell, Michael; Tick, Timo; Anton, Gisela; Chekhova, Maria V; Leuchs, Gerd

    2014-07-14

    During the last decades, multi-pixel detectors have been developed capable of registering single photons. The newly developed hybrid photon detector camera has a remarkable property that it has not only spatial but also temporal resolution. In this work, we apply this device to the detection of non-classical light from spontaneous parametric down-conversion and use two-photon correlations for the absolute calibration of its quantum efficiency.

  18. High-dynamic-range coherent diffractive imaging: ptychography using the mixed-mode pixel array detector

    PubMed Central

    Giewekemeyer, Klaus; Philipp, Hugh T.; Wilke, Robin N.; Aquila, Andrew; Osterhoff, Markus; Tate, Mark W.; Shanks, Katherine S.; Zozulya, Alexey V.; Salditt, Tim; Gruner, Sol M.; Mancuso, Adrian P.

    2014-01-01

    Coherent (X-ray) diffractive imaging (CDI) is an increasingly popular form of X-ray microscopy, mainly due to its potential to produce high-resolution images and the lack of an objective lens between the sample and its corresponding imaging detector. One challenge, however, is that very high dynamic range diffraction data must be collected to produce both quantitative and high-resolution images. In this work, hard X-ray ptychographic coherent diffractive imaging has been performed at the P10 beamline of the PETRA III synchrotron to demonstrate the potential of a very wide dynamic range imaging X-ray detector (the Mixed-Mode Pixel Array Detector, or MM-PAD). The detector is capable of single photon detection, detecting fluxes exceeding 1 × 108 8-keV photons pixel−1 s−1, and framing at 1 kHz. A ptychographic reconstruction was performed using a peak focal intensity on the order of 1 × 1010 photons µm−2 s−1 within an area of approximately 325 nm × 603 nm. This was done without need of a beam stop and with a very modest attenuation, while ‘still’ images of the empty beam far-field intensity were recorded without any attenuation. The treatment of the detector frames and CDI methodology for reconstruction of non-sensitive detector regions, partially also extending the active detector area, are described. PMID:25178008

  19. High-dynamic-range coherent diffractive imaging: ptychography using the mixed-mode pixel array detector.

    PubMed

    Giewekemeyer, Klaus; Philipp, Hugh T; Wilke, Robin N; Aquila, Andrew; Osterhoff, Markus; Tate, Mark W; Shanks, Katherine S; Zozulya, Alexey V; Salditt, Tim; Gruner, Sol M; Mancuso, Adrian P

    2014-09-01

    Coherent (X-ray) diffractive imaging (CDI) is an increasingly popular form of X-ray microscopy, mainly due to its potential to produce high-resolution images and the lack of an objective lens between the sample and its corresponding imaging detector. One challenge, however, is that very high dynamic range diffraction data must be collected to produce both quantitative and high-resolution images. In this work, hard X-ray ptychographic coherent diffractive imaging has been performed at the P10 beamline of the PETRA III synchrotron to demonstrate the potential of a very wide dynamic range imaging X-ray detector (the Mixed-Mode Pixel Array Detector, or MM-PAD). The detector is capable of single photon detection, detecting fluxes exceeding 1 × 10(8) 8-keV photons pixel(-1) s(-1), and framing at 1 kHz. A ptychographic reconstruction was performed using a peak focal intensity on the order of 1 × 10(10) photons µm(-2) s(-1) within an area of approximately 325 nm × 603 nm. This was done without need of a beam stop and with a very modest attenuation, while `still' images of the empty beam far-field intensity were recorded without any attenuation. The treatment of the detector frames and CDI methodology for reconstruction of non-sensitive detector regions, partially also extending the active detector area, are described.

  20. Amplitude distributions of dark counts and photon counts in NbN superconducting single-photon detectors integrated with the HEMT readout

    NASA Astrophysics Data System (ADS)

    Kitaygorsky, J.; Słysz, W.; Shouten, R.; Dorenbos, S.; Reiger, E.; Zwiller, V.; Sobolewski, Roman

    2017-01-01

    We present a new operation regime of NbN superconducting single-photon detectors (SSPDs) by integrating them with a low-noise cryogenic high-electron-mobility transistor and a high-load resistor. The integrated sensors are designed to get a better understanding of the origin of dark counts triggered by the detector, as our scheme allows us to distinguish the origin of dark pulses from the actual photon pulses in SSPDs. The presented approach is based on a statistical analysis of amplitude distributions of recorded trains of the SSPD photoresponse transients. It also enables to obtain information on energy of the incident photons, as well as demonstrates some photon-number-resolving capability of meander-type SSPDs.

  1. Evaluation of ion-implanted-silicon detectors for use in intraoperative positron-sensitive probes.

    PubMed

    Raylman, R R; Wahl, R L

    1996-11-01

    The continuing development of probes for use with beta (positron and electron) emitting radionuclides may result in more complete excision of tracer-avid tumors. Perhaps one of the most promising radiopharmaceuticals for this task is 18F-labeled-Fluoro-2-Deoxy-D-Glucose (FDG). This positron-emitting agent has been demonstrated to be avidly and rapidly absorbed by many human cancers. We have investigated the use of ion-implanted-silicon detectors in intraoperative positron-sensitive surgical probes for use with FDG. These detectors possess very high positron detection efficiency, while the efficiency for 511 keV photon detection is low. The spatial resolution, as well as positron and annihilation photon detection sensitivity, of an ion-implanted-silicon detector used with 18F was measured at several energy thresholds. In addition, the ability of the device to detect the presence of relatively small amounts of FDG during surgery was evaluated by simulating a surgical field in which some tumor was left intact following lesion excision. The performance of the ion-implanted-silicon detector was compared to the operating characteristics of a positron-sensitive surgical probe which utilizes plastic scintillator. In all areas of performance the ion-implanted-silicon detector proved superior to the plastic scintillator-based probe. At an energy threshold of 14 keV positron sensitivity measured for the ion-implanted-silicon detector was 101.3 cps/kBq, photon sensitivity was 7.4 cps/kBq. In addition, spatial resolution was found to be relatively unaffected by the presence of distant sources of annihilation photon flux. Finally, the detector was demonstrated to be able to localize small amounts of FDG in a simulated tumor bed; indicating that this device has promise as a probe to aid in FDG-guided surgery.

  2. Multiplexed single-mode wavelength-to-time mapping of multimode light

    PubMed Central

    Chandrasekharan, Harikumar K; Izdebski, Frauke; Gris-Sánchez, Itandehui; Krstajić, Nikola; Walker, Richard; Bridle, Helen L.; Dalgarno, Paul A.; MacPherson, William N.; Henderson, Robert K.; Birks, Tim A.; Thomson, Robert R.

    2017-01-01

    When an optical pulse propagates along an optical fibre, different wavelengths travel at different group velocities. As a result, wavelength information is converted into arrival-time information, a process known as wavelength-to-time mapping. This phenomenon is most cleanly observed using a single-mode fibre transmission line, where spatial mode dispersion is not present, but the use of such fibres restricts possible applications. Here we demonstrate that photonic lanterns based on tapered single-mode multicore fibres provide an efficient way to couple multimode light to an array of single-photon avalanche detectors, each of which has its own time-to-digital converter for time-correlated single-photon counting. Exploiting this capability, we demonstrate the multiplexed single-mode wavelength-to-time mapping of multimode light using a multicore fibre photonic lantern with 121 single-mode cores, coupled to 121 detectors on a 32 × 32 detector array. This work paves the way to efficient multimode wavelength-to-time mapping systems with the spectral performance of single-mode systems. PMID:28120822

  3. Interferometric Quantum-Nondemolition Single-Photon Detectors

    NASA Technical Reports Server (NTRS)

    Kok, Peter; Lee, Hwang; Dowling, Jonathan

    2007-01-01

    Two interferometric quantum-nondemolition (QND) devices have been proposed: (1) a polarization-independent device and (2) a polarization-preserving device. The prolarization-independent device works on an input state of up to two photons, whereas the polarization-preserving device works on a superposition of vacuum and single- photon states. The overall function of the device would be to probabilistically generate a unique detector output only when its input electromagnetic mode was populated by a single photon, in which case its output mode would also be populated by a single photon. Like other QND devices, the proposed devices are potentially useful for a variety of applications, including such areas of NASA interest as quantum computing, quantum communication, detection of gravity waves, as well as pedagogical demonstrations of the quantum nature of light. Many protocols in quantum computation and quantum communication require the possibility of detecting a photon without destroying it. The only prior single- photon-detecting QND device is based on quantum electrodynamics in a resonant cavity and, as such, it depends on the photon frequency. Moreover, the prior device can distinguish only between one photon and no photon. The proposed interferometric QND devices would not depend on frequency and could distinguish between (a) one photon and (b) zero or two photons. The first proposed device is depicted schematically in Figure 1. The input electromagnetic mode would be a superposition of a zero-, a one-, and a two-photon quantum state. The overall function of the device would be to probabilistically generate a unique detector output only when its input electromagnetic mode was populated by a single photon, in which case its output mode also would be populated by a single photon.

  4. Thermal detectors for high resolution spectroscopy

    NASA Technical Reports Server (NTRS)

    Mccammon, D.; Juda, M.; Zhang, J.; Kelley, R. L.; Moseley, S. H.; Szymkowiak, A. E.

    1986-01-01

    Cryogenic microcalorimeters can be made sensitive enough to measure the energy deposited by a single particle or X-ray photon with an accuracy of about one electron volt. It may also be possible to construct detectors of several-kilograms mass whose resolution is only a few times worse than this. Data from relatively crude test devices are in good agreement with thermal performance calculations, and a total system noise of 11 eV FWHM has been obtained for a silicon detector operating at 98 mK. Observations of 35 eV FWHM for 6-keV X-rays with a different device have been made.

  5. Study of a GaAs:Cr-based Timepix detector using synchrotron facility

    NASA Astrophysics Data System (ADS)

    Smolyanskiy, P.; Kozhevnikov, D.; Bakina, O.; Chelkov, G.; Dedovich, D.; Kuper, K.; Leyva Fabelo, A.; Zhemchugov, A.

    2017-11-01

    High resistivity gallium arsenide compensated by chromium fabricated by Tomsk State University has demonstrated a good suitability as a sensor material for hybrid pixel detectors used in X-ray imaging systems with photon energies up to 60 keV. The material is available with a thickness up to 1 mm and due to its Z number a high absorption efficiency in this energy region is provided. However, the performance of thick GaAs:Cr-based detectors in spectroscopic applications is limited by readout electronics with relatively small pixels due to the charge sharing effect. In this paper, we present the experimental investigation of the charge sharing effect contribution in the GaAs:Cr-based Timepix detector. By means of scanning the detector with a pencil photon beam generated by the synchrotron facility, the geometrical mapping of pixel sensitivity is obtained, as well as the energy resolution of a single pixel. The experimental results are supported by numerical simulations. The observed limitation of the GaAs:Cr-based Timepix detector for the high flux X-ray imaging is discussed.

  6. New cardiac cameras: single-photon emission CT and PET.

    PubMed

    Slomka, Piotr J; Berman, Daniel S; Germano, Guido

    2014-07-01

    Nuclear cardiology instrumentation has evolved significantly in the recent years. Concerns about radiation dose and long acquisition times have propelled developments of dedicated high-efficiency cardiac SPECT scanners. Novel collimator designs, such as multipinhole or locally focusing collimators arranged in geometries that are optimized for cardiac imaging, have been implemented to enhance photon-detection sensitivity. Some of these new SPECT scanners use solid-state photon detectors instead of photomultipliers to improve image quality and to reduce the scanner footprint. These new SPECT devices allow dramatic up to 7-fold reduction in acquisition times or similar reduction in radiation dose. In addition, new hardware for photon attenuation correction allowing ultralow radiation doses has been offered by some vendors. To mitigate photon attenuation artifacts for the new SPECT scanners not equipped with attenuation correction hardware, 2-position (upright-supine or prone-supine) imaging has been proposed. PET hardware developments have been primarily driven by the requirements of oncologic imaging, but cardiac imaging can benefit from improved PET image quality and improved sensitivity of 3D systems. The time-of-flight reconstruction combined with resolution recovery techniques is now implemented by all major PET vendors. These new methods improve image contrast and image resolution and reduce image noise. High-sensitivity 3D PET without interplane septa allows reduced radiation dose for cardiac perfusion imaging. Simultaneous PET/MR hybrid system has been developed. Solid-state PET detectors with avalanche photodiodes or digital silicon photomultipliers have been introduced, and they offer improved imaging characteristics and reduced sensitivity to electromagnetic MR fields. Higher maximum count rate of the new PET detectors allows routine first-pass Rb-82 imaging, with 3D PET acquisition enabling clinical utilization of dynamic imaging with myocardial flow measurements for this tracer. The availability of high-end CT component in most PET/CT configurations enables hybrid multimodality cardiac imaging protocols with calcium scoring or CT angiography or both. Copyright © 2014. Published by Elsevier Inc.

  7. Graphene Josephson Junction Single Photon Detector

    NASA Astrophysics Data System (ADS)

    Walsh, Evan D.; Lee, Gil-Ho; Efetov, Dmitri K.; Heuck, Mikkel; Crossno, Jesse; Taniguchi, Takashi; Watanabe, Kenji; Ohki, Thomas A.; Kim, Philip; Englund, Dirk; Fong, Kin Chung

    Single photon detectors (SPDs) have found use across a wide array of applications depending on the wavelength to which they are sensitive. Graphene, because of its linear, gapless dispersion near the Dirac point, has a flat, wide bandwidth absorption that can be enhanced to near 100 % through the use of resonant structures making it a promising candidate for broadband SPDs. Upon absorbing a photon in the optical to mid-infrared range, a small (~10 μm2) sheet of graphene at cryogenic temperatures can experience a significant increase in electronic temperature due to its extremely low heat capacity. At 1550 nm, for example, calculations show that the temperature could rise by as much as 500 %. This temperature increase could be detected with near perfect quantum efficiency by making the graphene the weak link in a Josephson junction (JJ). We present a theoretical model demonstrating that such a graphene JJ SPD could operate at the readily achievable temperature of 3 K with near zero dark count, sub-50 ps timing jitter, and sub-5 ns dead time and report on the progress toward experimentally realizing the device.

  8. A Flight Photon Counting Camera for the WFIRST Coronagraph

    NASA Astrophysics Data System (ADS)

    Morrissey, Patrick

    2018-01-01

    A photon counting camera based on the Teledyne-e2v CCD201-20 electron multiplying CCD (EMCCD) is being developed for the NASA WFIRST coronagraph, an exoplanet imaging technology development of the Jet Propulsion Laboratory (Pasadena, CA) that is scheduled to launch in 2026. The coronagraph is designed to directly image planets around nearby stars, and to characterize their spectra. The planets are exceedingly faint, providing signals similar to the detector dark current, and require the use of photon counting detectors. Red sensitivity (600-980nm) is preferred to capture spectral features of interest. Since radiation in space affects the ability of the EMCCD to transfer the required single electron signals, care has been taken to develop appropriate shielding that will protect the cameras during a five year mission. In this poster, consideration of the effects of space radiation on photon counting observations will be described with the mitigating features of the camera design. An overview of the current camera flight system electronics requirements and design will also be described.

  9. Multiple-Event, Single-Photon Counting Imaging Sensor

    NASA Technical Reports Server (NTRS)

    Zheng, Xinyu; Cunningham, Thomas J.; Sun, Chao; Wang, Kang L.

    2011-01-01

    The single-photon counting imaging sensor is typically an array of silicon Geiger-mode avalanche photodiodes that are monolithically integrated with CMOS (complementary metal oxide semiconductor) readout, signal processing, and addressing circuits located in each pixel and the peripheral area of the chip. The major problem is its single-event method for photon count number registration. A single-event single-photon counting imaging array only allows registration of up to one photon count in each of its pixels during a frame time, i.e., the interval between two successive pixel reset operations. Since the frame time can t be too short, this will lead to very low dynamic range and make the sensor merely useful for very low flux environments. The second problem of the prior technique is a limited fill factor resulting from consumption of chip area by the monolithically integrated CMOS readout in pixels. The resulting low photon collection efficiency will substantially ruin any benefit gained from the very sensitive single-photon counting detection. The single-photon counting imaging sensor developed in this work has a novel multiple-event architecture, which allows each of its pixels to register as more than one million (or more) photon-counting events during a frame time. Because of a consequently boosted dynamic range, the imaging array of the invention is capable of performing single-photon counting under ultra-low light through high-flux environments. On the other hand, since the multiple-event architecture is implemented in a hybrid structure, back-illumination and close-to-unity fill factor can be realized, and maximized quantum efficiency can also be achieved in the detector array.

  10. Photon catalysis acting as noiseless linear amplification and its application in coherence enhancement

    NASA Astrophysics Data System (ADS)

    Zhang, Shengli; Zhang, Xiangdong

    2018-04-01

    Photon catalysis is an intriguing quantum mechanical operation during which no photon is added to or subtracted from the relevant optical system. However, we prove that photon catalysis is in essence equivalent to the simpler but more efficient noiseless linear amplifier. This provides a simple and zero-energy-input method for enhancing quantum coherence. We show that the coherence enhancement holds both for a coherent state and a two-mode squeezed vacuum (TMSV) state. For the TMSV state, biside photon catalysis is shown to be equivalent to two times the single-side photon catalysis, and two times the photon catalysis does not provide a substantial enhancement of quantum coherence compared with single-side catalysis. We further extend our investigation to the performance of coherence enhancement with a more realistic photon catalysis scheme where a heralded approximated single-photon state and an on-off detector are exploited. Moreover, we investigate the influence of an imperfect photon detector and the result shows that the amplification effect of photon catalysis is insensitive to the detector inefficiency. Finally, we apply the coherence measure to quantum illumination and see the same trend of performance improvement as coherence enhancement is identified in practical quantum target detection.

  11. On the passive probing of fiber optic quantum communication channels

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Korol'kov, A. V., E-mail: sergei.kulik@gmail.co; Katamadze, K. G.; Kulik, S. P.

    2010-04-15

    Avalanche photodetectors based on InGaAs:P are the most sensitive and only detectors operating in the telecommunication wavelength range 1.30-1.55 {mu}m in the fiber optic quantum cryptography systems that can operate in the single photon count mode. In contrast to the widely used silicon photodetectors for wavelengths up to 1 {mu}m operating in a waiting mode, these detectors always operate in a gated mode. The production of an electron-hole pair in the process of the absorption of a photon and the subsequent appearance of an avalanche of carriers can be accompanied by the inverse processes of the recombination and emission ofmore » photons. Such a backward emission can present a potential serious problem for the stability of fiber optic quantum cryptography systems against passive probing. The results of analyzing the detection of backscattered radiation are reported. The probability of such an emission has been estimated.« less

  12. Medipix2 based CdTe microprobe for dental imaging

    NASA Astrophysics Data System (ADS)

    Vykydal, Z.; Fauler, A.; Fiederle, M.; Jakubek, J.; Svestkova, M.; Zwerger, A.

    2011-12-01

    Medical imaging devices and techniques are demanded to provide high resolution and low dose images of samples or patients. Hybrid semiconductor single photon counting devices together with suitable sensor materials and advanced techniques of image reconstruction fulfil these requirements. In particular cases such as the direct observation of dental implants also the size of the imaging device itself plays a critical role. This work presents the comparison of 2D radiographs of tooth provided by a standard commercial dental imaging system (Gendex 765DC X-ray tube with VisualiX scintillation detector) and two Medipix2 USB Lite detectors one equipped with a Si sensor (300 μm thick) and one with a CdTe sensor (1 mm thick). Single photon counting capability of the Medipix2 device allows virtually unlimited dynamic range of the images and thus increases the contrast significantly. The dimensions of the whole USB Lite device are only 15 mm × 60 mm of which 25% consists of the sensitive area. Detector of this compact size can be used directly inside the patients' mouth.

  13. Inexpensive electronics and software for photon statistics and correlation spectroscopy.

    PubMed

    Gamari, Benjamin D; Zhang, Dianwen; Buckman, Richard E; Milas, Peker; Denker, John S; Chen, Hui; Li, Hongmin; Goldner, Lori S

    2014-07-01

    Single-molecule-sensitive microscopy and spectroscopy are transforming biophysics and materials science laboratories. Techniques such as fluorescence correlation spectroscopy (FCS) and single-molecule sensitive fluorescence resonance energy transfer (FRET) are now commonly available in research laboratories but are as yet infrequently available in teaching laboratories. We describe inexpensive electronics and open-source software that bridges this gap, making state-of-the-art research capabilities accessible to undergraduates interested in biophysics. We include a discussion of the intensity correlation function relevant to FCS and how it can be determined from photon arrival times. We demonstrate the system with a measurement of the hydrodynamic radius of a protein using FCS that is suitable for the undergraduate teaching laboratory. The FPGA-based electronics, which are easy to construct, are suitable for more advanced measurements as well, and several applications are described. As implemented, the system has 8 ns timing resolution, can control up to four laser sources, and can collect information from as many as four photon-counting detectors.

  14. Inexpensive electronics and software for photon statistics and correlation spectroscopy

    PubMed Central

    Gamari, Benjamin D.; Zhang, Dianwen; Buckman, Richard E.; Milas, Peker; Denker, John S.; Chen, Hui; Li, Hongmin; Goldner, Lori S.

    2016-01-01

    Single-molecule-sensitive microscopy and spectroscopy are transforming biophysics and materials science laboratories. Techniques such as fluorescence correlation spectroscopy (FCS) and single-molecule sensitive fluorescence resonance energy transfer (FRET) are now commonly available in research laboratories but are as yet infrequently available in teaching laboratories. We describe inexpensive electronics and open-source software that bridges this gap, making state-of-the-art research capabilities accessible to undergraduates interested in biophysics. We include a discussion of the intensity correlation function relevant to FCS and how it can be determined from photon arrival times. We demonstrate the system with a measurement of the hydrodynamic radius of a protein using FCS that is suitable for the undergraduate teaching laboratory. The FPGA-based electronics, which are easy to construct, are suitable for more advanced measurements as well, and several applications are described. As implemented, the system has 8 ns timing resolution, can control up to four laser sources, and can collect information from as many as four photon-counting detectors. PMID:26924846

  15. Cherenkov radiation-based three-dimensional position-sensitive PET detector: A Monte Carlo study.

    PubMed

    Ota, Ryosuke; Yamada, Ryoko; Moriya, Takahiro; Hasegawa, Tomoyuki

    2018-05-01

    Cherenkov radiation has recently received attention due to its prompt emission phenomenon, which has the potential to improve the timing performance of radiation detectors dedicated to positron emission tomography (PET). In this study, a Cherenkov-based three-dimensional (3D) position-sensitive radiation detector was proposed, which is composed of a monolithic lead fluoride (PbF 2 ) crystal and a photodetector array of which the signals can be readout independently. Monte Carlo simulations were performed to estimate the performance of the proposed detector. The position- and time resolution were evaluated under various practical conditions. The radiator size and various properties of the photodetector, e.g., readout pitch and single photon timing resolution (SPTR), were parameterized. The single photon time response of the photodetector was assumed to be a single Gaussian for the simplification. The photo detection efficiency of the photodetector was ideally 100% for all wavelengths. Compton scattering was included in simulations, but partly analyzed. To estimate the position at which a γ-ray interacted in the Cherenkov radiator, the center-of-gravity (COG) method was employed. In addition, to estimate the depth-of-interaction (DOI) principal component analysis (PCA), which is a multivariate analysis method and has been used to identify the patterns in data, was employed. The time-space distribution of Cherenkov photons was quantified to perform PCA. To evaluate coincidence time resolution (CTR), the time difference of two independent γ-ray events was calculated. The detection time was defined as the first photon time after the SPTR of the photodetector was taken into account. The position resolution on the photodetector plane could be estimated with high accuracy, by using a small number of Cherenkov photons. Moreover, PCA showed an ability to estimate the DOI. The position resolution heavily depends on the pitch of the photodetector array and the radiator thickness. If the readout pitch were ideally 0 and practically 3 mm, a full-width at half-maximum (FWHM) of 0.348 and 1.92 mm was achievable with a 10-mm-thick PbF 2 crystal, respectively. Furthermore, first-order correlation could be observed between the primary principal component and the true DOI. To obtain a coincidence timing resolution better than 100-ps FWHM with a 20-mm-thick PbF 2 crystal, a photodetector with SPTR of better than σ = 30 ps was necessary. From these results, the improvement of SPTR allows us to achieve CTR better than 100-ps FWHM, even in the case where a 20-mm-thick radiator is used. Our proposed detector has the potential to estimate the 3D interaction position of γ-rays in the radiator, using only time and space information of Cherenkov photons. © 2018 American Association of Physicists in Medicine.

  16. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Walker, Katherine L.; Judenhofer, Martin S.; Cherry, Simon R.

    In preclinical single-photon emission computed tomography (SPECT) system development the primary objective has been to improve spatial resolution by using novel parallel-hole or multi-pinhole collimator geometries. Furthermore, such high-resolution systems have relatively poor sensitivity (typically 0.01% to 0.1%). In contrast, a system that does not use collimators can achieve very high-sensitivity. Here we present a high-sensitivity un-collimated detector single-photon imaging (UCD-SPI) system for the imaging of both small animals and plants. This scanner consists of two thin, closely spaced, pixelated scintillator detectors that use NaI(Tl), CsI(Na), or BGO. The performance of the system has been characterized by measuring sensitivity, spatialmore » resolution, linearity, detection limits, and uniformity. With 99mTc (140 keV) at the center of the field of view (20 mm scintillator separation), the sensitivity was measured to be 31.8% using the NaI(Tl) detectors and 40.2% with CsI(Na). The best spatial resolution (FWHM when the image formed as the geometric mean of the two detector heads, 20 mm scintillator separation) was 19.0 mm for NaI(Tl) and 11.9 mm for CsI(Na) at 140 keV, and 19.5 mm for BGO at 1116 keV, which is somewhat degraded compared to the cm-scale resolution obtained with only one detector head and a close source. The quantitative accuracy of the system’s linearity is better than 2% with detection down to activity levels of 100 nCi. Two in vivo animal studies (a renal scan using 99mTc MAG-3 and a thyroid scan with 123I) and one plant study (a 99mTcO 4- xylem transport study) highlight the unique capabilities of this UCD-SPI system. From the renal scan, we observe approximately a one thousand-fold increase in sensitivity compared to the Siemens Inveon SPECT/CT scanner. In conclusion, UCD-SPI is useful for many imaging tasks that do not require excellent spatial resolution, such as high-throughput screening applications, simple radiotracer uptake studies in tumor xenografts, dynamic studies where very good temporal resolution is critical, or in planta imaging of radioisotopes at low concentrations.« less

  17. Uncooled infrared photon detector and multicolor infrared detection using microoptomechanical sensors

    DOEpatents

    Datskos, Panagiotis G.; Rajic, Solobodan; Datskou, Irene C.

    1999-01-01

    Systems and methods for infrared detection are described. An optomechanical photon detector includes a semiconductor material and is based on measurement of a photoinduced lattice strain. A multicolor infrared sensor includes a stack of frequency specific optomechanical detectors. The stack can include one, or more, of the optomechanical photon detectors that function based on the measurement of photoinduced lattice strain. The systems and methods provide advantages in that rapid, sensitive multicolor infrared imaging can be performed without the need for a cooling subsystem.

  18. Secure detection in quantum key distribution by real-time calibration of receiver

    NASA Astrophysics Data System (ADS)

    Marøy, Øystein; Makarov, Vadim; Skaar, Johannes

    2017-12-01

    The single-photon detectionefficiency of the detector unit is crucial for the security of common quantum key distribution protocols like Bennett-Brassard 1984 (BB84). A low value for the efficiency indicates a possible eavesdropping attack that exploits the photon receiver’s imperfections. We present a method for estimating the detection efficiency, and calculate the corresponding secure key generation rate. The estimation is done by testing gated detectors using a randomly activated photon source inside the receiver unit. This estimate gives a secure rate for any detector with non-unity single-photon detection efficiency, both inherit or due to blinding. By adding extra optical components to the receiver, we make sure that the key is extracted from photon states for which our estimate is valid. The result is a quantum key distribution scheme that is secure against any attack that exploits detector imperfections.

  19. Fluorescence lifetime imaging system with nm-resolution and single-molecule sensitivity

    NASA Astrophysics Data System (ADS)

    Wahl, Michael; Rahn, Hans-Juergen; Ortmann, Uwe; Erdmann, Rainer; Boehmer, Martin; Enderlein, Joerg

    2002-03-01

    Fluorescence lifetime measurement of organic fluorophores is a powerful tool for distinguishing molecules of interest from background or other species. This is of interest in sensitive analysis and Single Molecule Detection (SMD). A demand in many applications is to provide 2-D imaging together with lifetime information. The method of choice is then Time-Correlated Single Photon Counting (TCSPC). We have devloped a compact system on a single PC board that can perform TCSPC at high throughput, while synchronously driving a piezo scanner holding the immobilized sample. The system allows count rates up to 3 MHz and a resolution down to 30 ps. An overall Instrument Response Function down to 300ps is achieved with inexpensive detectors and diode lasers. The board is designed for the PCI bus, permitting high throughput without loss of counts. It is reconfigurable to operate in different modes. The Time-Tagged Time-Resolved (TTTR) mode permits the recording of all photon events with a real-time tag allowing data analysis with unlimited flexibility. We use the Time-Tag clock for an external piezo scanner that moves the sample. As the clock source is common for scanning and tagging, the individual photons can be matched to pixels. Demonstrating the capablities of the system we studied single molecule solutions. Lifetime imaging can be performed at high resolution with as few as 100 photons per pixel.

  20. HiFi-MBQC High Fidelitiy Measurement-Based Quantum Computing using Superconducting Detectors

    DTIC Science & Technology

    2016-04-04

    superconducting nanowire single photon detectors (SNSPDs) which allowed support of quantum photonics experiments leading to 14 peer-reviewed...sampling, and several other areas. 15. SUBJECT TERMS EOARD, photonics, cryostat, superconducting nanowire , SNSPD 16. SECURITY CLASSIFICATION OF: 17...quantum simulations. The main budget contribution was dedicated to develop superconducting nanowire detectors with efficiencies above 93% at telecom

  1. Photon-HDF5: an open file format for single-molecule fluorescence experiments using photon-counting detectors

    DOE PAGES

    Ingargiola, A.; Laurence, T. A.; Boutelle, R.; ...

    2015-12-23

    We introduce Photon-HDF5, an open and efficient file format to simplify exchange and long term accessibility of data from single-molecule fluorescence experiments based on photon-counting detectors such as single-photon avalanche diode (SPAD), photomultiplier tube (PMT) or arrays of such detectors. The format is based on HDF5, a widely used platform- and language-independent hierarchical file format for which user-friendly viewers are available. Photon-HDF5 can store raw photon data (timestamp, channel number, etc) from any acquisition hardware, but also setup and sample description, information on provenance, authorship and other metadata, and is flexible enough to include any kind of custom data. Themore » format specifications are hosted on a public website, which is open to contributions by the biophysics community. As an initial resource, the website provides code examples to read Photon-HDF5 files in several programming languages and a reference python library (phconvert), to create new Photon-HDF5 files and convert several existing file formats into Photon-HDF5. As a result, to encourage adoption by the academic and commercial communities, all software is released under the MIT open source license.« less

  2. A Review of Some Superconducting Technologies for AtLAST: Parametric Amplifiers, Kinetic Inductance Detectors, and On-Chip Spectrometers

    NASA Astrophysics Data System (ADS)

    Noroozian, Omid

    2018-01-01

    The current state of the art for some superconducting technologies will be reviewed in the context of a future single-dish submillimeter telescope called AtLAST. The technologies reviews include: 1) Kinetic Inductance Detectors (KIDs), which have now been demonstrated in large-format kilo-pixel arrays with photon background-limited sensitivity suitable for large field of view cameras for wide-field imaging. 2) Parametric amplifiers - specifically the Traveling-Wave Kinetic Inductance (TKIP) amplifier - which has enormous potential to increase sensitivity, bandwidth, and mapping speed of heterodyne receivers, and 3) On-chip spectrometers, which combined with sensitive direct detectors such as KIDs or TESs could be used as Multi-Object Spectrometers on the AtLAST focal plane, and could provide low-medium resolution spectroscopy of 100 objects at a time in each field of view.

  3. Simulation results of Pulse Shape Discrimination (PSD) for background reduction in INTEGRAL Spectrometer (SPI) germanium detectors

    NASA Technical Reports Server (NTRS)

    Slassi-Sennou, S. A.; Boggs, S. E.; Feffer, P. T.; Lin, R. P.

    1997-01-01

    Pulse Shape Discrimination (PSD) for background reduction will be used in the INTErnational Gamma Ray Astrophysics Laboratory (INTEGRAL) imaging spectrometer (SPI) to improve the sensitivity from 200 keV to 2 MeV. The observation of significant astrophysical gamma ray lines in this energy range is expected, where the dominant component of the background is the beta(sup -) decay in the Ge detectors due to the activation of Ge nuclei by cosmic rays. The sensitivity of the SPI will be improved by rejecting beta(sup -) decay events while retaining photon events. The PSD technique will distinguish between single and multiple site events. Simulation results of PSD for INTEGRAL-type Ge detectors using a numerical model for pulse shape generation are presented. The model was shown to agree with the experimental results for a narrow inner bore closed end cylindrical detector. Using PSD, a sensitivity improvement factor of the order of 2.4 at 0.8 MeV is expected.

  4. Observation of 67 keV x-rays with a scintillation detector using proportional-mode silicon avalanche photodiode

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Inoue, Keisuke; Kishimoto, Shunji, E-mail: syunji.kishimoto@kek.jp; Inst. of Materials Structure Science, KEK, 1-1 Oho, Tsukuba, Ibaraki 305-0801

    2016-07-27

    We developed a scintillation X-ray detector using a proportional-mode silicon avalanche photodiode (Si-APD). We report a prototype detector using a lead-loaded plastic scintillator mounted on a proportional-mode Si-APD (active area size: 3 mm in diameter), which is operated at a low temperature. Using 67.41 keV X-rays, we could measure pulse-height spectra of scintillation light with a charge-sensitive preamplifier at 20, 0, and −35°C. Time spectra of the X-ray bunch structure were successfully recorded using a wideband and 60-dB-gain amplifier in hybrid-mode operation of the Photon Factory ring. We obtained a better time resolution of 0.51 ns (full width at half-maximum)more » for the single-bunch X-ray peak at −35°C. We were also able to observe a linear response of the scintillation pulses up to 8 Mcps for input photon rates up to 1.4 × 10{sup 8} photons/s.« less

  5. Effect of Detector Dead Time on the Performance of Optical Direct-Detection Communication Links

    NASA Technical Reports Server (NTRS)

    Chen, C.-C.

    1988-01-01

    Avalanche photodiodes (APDs) operating in the Geiger mode can provide a significantly improved single-photon detect ion sensitivity over conventional photodiodes. However, the quenching circuit required to remove the excess charge carriers after each photon event can introduce an undesirable dead time into the detection process. The effect of this detector dead time on the performance of a binary pulse-position-modulted (PPM) channel is studied by analyzing the error probability. It is shown that, when back- ground noise is negligible, the performance of the detector with dead time is similar to that o f a quantum-limited receiver. For systems with increasing background intensities, the error rate of the receiver starts to degrade rapidly with increasing dead time. The power penalty due to detector dead time is also evaluated and shown to depend critically on background intensity as well as dead time. Given the expected background strength in an optical channel, therefore, a constraint must be placed on the bandwidth of the receiver to limit the amount of power penalty due to detector dead time.

  6. Investigation of Self Triggered Cosmic Ray Detectors using Silicon Photomultiplier

    NASA Astrophysics Data System (ADS)

    Knox, Adrian; Niduaza, Rommel; Hernandez, Victor; Ruiz, Daniel; Ramos, Daniel; Fan, Sewan; Fatuzzo, Laura; Ritt, Stefan

    2015-04-01

    The silicon photomultiplier (SiPM) is a highly sensitive light detector capable of measuring single photons. It costs a fraction of the photomultiplier tube and operates slightly above the breakdown voltage. At this conference we describe our investigation of SiPM, the multipixel photon counters (MPPC) from Hamamatsu as readout detectors for plastic scintillators working for detecting cosmic ray particles. Our setup consists of scintillator sheets embedded with blue to green wavelength shifting fibers optically coupled to MPPCs to detect scintillating light. Four detector assemblies would be constructed and arranged to work in self triggered mode. Using custom matching tee boxes, the amplified MPPC signals are fed to discriminators with threshold set to give a reasonable coincidence count rate. Moreover, the detector waveforms are digitized using a 5 Giga Samples per second waveform digitizer, the DRS4, and triggered with the coincidence logic to capture the MPPC waveforms. Offline analysis of the digitized waveforms is accomplished using the CERN package PAW and results of our experiments and the data analysis would also be discussed. US Department of Education Title V Grant Number PO31S090007.

  7. Effect of detector dead time on the performance of optical direct-detection communication links

    NASA Astrophysics Data System (ADS)

    Chen, C.-C.

    1988-05-01

    Avalanche photodiodes (APDs) operating in the Geiger mode can provide a significantly improved single-photon detection sensitivity over conventional photodiodes. However, the quenching circuit required to remove the excess charge carriers after each photon event can introduce an undesirable dead time into the detection process. The effect of this detector dead time on the performance of a binary pulse-position-modulated (PPM) channel is studied by analyzing the error probability. It is shown that, when background noise is negligible, the performance of the detector with dead time is similar to that of a quantum-limited receiver. For systems with increasing background intensities, the error rate of the receiver starts to degrade rapidly with increasing dead time. The power penalty due to detector dead time is also evaluated and shown to depend critically on badkground intensity as well as dead time. Given the expected background strength in an optical channel, therefore, a constraint must be placed on the bandwidth of the receiver to limit the amount of power penalty due to detector dead time.

  8. Negative feedback avalanche diode

    NASA Technical Reports Server (NTRS)

    Itzler, Mark Allen (Inventor)

    2010-01-01

    A single-photon avalanche detector is disclosed that is operable at wavelengths greater than 1000 nm and at operating speeds greater than 10 MHz. The single-photon avalanche detector comprises a thin-film resistor and avalanche photodiode that are monolithically integrated such that little or no additional capacitance is associated with the addition of the resistor.

  9. Calibration of a time-resolved hard-x-ray detector using radioactive sources

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Stoeckl, C., E-mail: csto@lle.rochester.edu; Theobald, W.; Regan, S. P.

    A four-channel, time-resolved, hard x-ray detector (HXRD) has been operating at the Laboratory for Laser Energetics for more than a decade. The slope temperature of the hot-electron population in direct-drive inertial confinement fusion experiments is inferred by recording the hard x-ray radiation generated in the interaction of the electrons with the target. Measuring the energy deposited by hot electrons requires an absolute calibration of the hard x-ray detector. A novel method to obtain an absolute calibration of the HXRD using single photons from radioactive sources was developed, which uses a thermoelectrically cooled, low-noise, charge-sensitive amplifier.

  10. Development of new photon-counting detectors for single-molecule fluorescence microscopy.

    PubMed

    Michalet, X; Colyer, R A; Scalia, G; Ingargiola, A; Lin, R; Millaud, J E; Weiss, S; Siegmund, Oswald H W; Tremsin, Anton S; Vallerga, John V; Cheng, A; Levi, M; Aharoni, D; Arisaka, K; Villa, F; Guerrieri, F; Panzeri, F; Rech, I; Gulinatti, A; Zappa, F; Ghioni, M; Cova, S

    2013-02-05

    Two optical configurations are commonly used in single-molecule fluorescence microscopy: point-like excitation and detection to study freely diffusing molecules, and wide field illumination and detection to study surface immobilized or slowly diffusing molecules. Both approaches have common features, but also differ in significant aspects. In particular, they use different detectors, which share some requirements but also have major technical differences. Currently, two types of detectors best fulfil the needs of each approach: single-photon-counting avalanche diodes (SPADs) for point-like detection, and electron-multiplying charge-coupled devices (EMCCDs) for wide field detection. However, there is room for improvements in both cases. The first configuration suffers from low throughput owing to the analysis of data from a single location. The second, on the other hand, is limited to relatively low frame rates and loses the benefit of single-photon-counting approaches. During the past few years, new developments in point-like and wide field detectors have started addressing some of these issues. Here, we describe our recent progresses towards increasing the throughput of single-molecule fluorescence spectroscopy in solution using parallel arrays of SPADs. We also discuss our development of large area photon-counting cameras achieving subnanosecond resolution for fluorescence lifetime imaging applications at the single-molecule level.

  11. Development of new photon-counting detectors for single-molecule fluorescence microscopy

    PubMed Central

    Michalet, X.; Colyer, R. A.; Scalia, G.; Ingargiola, A.; Lin, R.; Millaud, J. E.; Weiss, S.; Siegmund, Oswald H. W.; Tremsin, Anton S.; Vallerga, John V.; Cheng, A.; Levi, M.; Aharoni, D.; Arisaka, K.; Villa, F.; Guerrieri, F.; Panzeri, F.; Rech, I.; Gulinatti, A.; Zappa, F.; Ghioni, M.; Cova, S.

    2013-01-01

    Two optical configurations are commonly used in single-molecule fluorescence microscopy: point-like excitation and detection to study freely diffusing molecules, and wide field illumination and detection to study surface immobilized or slowly diffusing molecules. Both approaches have common features, but also differ in significant aspects. In particular, they use different detectors, which share some requirements but also have major technical differences. Currently, two types of detectors best fulfil the needs of each approach: single-photon-counting avalanche diodes (SPADs) for point-like detection, and electron-multiplying charge-coupled devices (EMCCDs) for wide field detection. However, there is room for improvements in both cases. The first configuration suffers from low throughput owing to the analysis of data from a single location. The second, on the other hand, is limited to relatively low frame rates and loses the benefit of single-photon-counting approaches. During the past few years, new developments in point-like and wide field detectors have started addressing some of these issues. Here, we describe our recent progresses towards increasing the throughput of single-molecule fluorescence spectroscopy in solution using parallel arrays of SPADs. We also discuss our development of large area photon-counting cameras achieving subnanosecond resolution for fluorescence lifetime imaging applications at the single-molecule level. PMID:23267185

  12. Quantum optics with nanowires (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Zwiller, Val

    2017-02-01

    Nanowires offer new opportunities for nanoscale quantum optics; the quantum dot geometry in semiconducting nanowires as well as the material composition and environment can be engineered with unprecedented freedom to improve the light extraction efficiency. Quantum dots in nanowires are shown to be efficient single photon sources, in addition because of the very small fine structure splitting, we demonstrate the generation of entangled pairs of photons from a nanowire. By doping a nanowire and making ohmic contacts on both sides, a nanowire light emitting diode can be obtained with a single quantum dot as the active region. Under forward bias, this will act as an electrically pumped source of single photons. Under reverse bias, an avalanche effect can multiply photocurrent and enables the detection of single photons. Another type of nanowire under study in our group is superconducting nanowires for single photon detection, reaching efficiencies, time resolution and dark counts beyond currently available detectors. We will discuss our first attempts at combining semiconducting nanowire based single photon emitters and superconducting nanowire single photon detectors on a chip to realize integrated quantum circuits.

  13. Quantum Computers

    DTIC Science & Technology

    2010-03-04

    and their sensitivity to charge and flux fluctuations. The first type of superconducting qubit , the charge qubit , omits the inductance . There is no...nanostructured NbN superconducting nanowire detectors have achieved high efficiency and photon number resolution16,17. One approach to a high-efficiency single...resemble classical high- speed integrated circuits and can be readily fabricated using existing technologies. The basic physics behind superconducting qubits

  14. Single-photon semiconductor photodiodes for distributed optical fiber sensors: state of the art and perspectives

    NASA Astrophysics Data System (ADS)

    Ripamonti, Giancarlo; Lacaita, Andrea L.

    1993-03-01

    The extreme sensitivity and time resolution of Geiger-mode avalanche photodiodes (GM- APDs) have already been exploited for optical time domain reflectometry (OTDR). Better than 1 cm spatial resolution in Rayleigh scattering detection was demonstrated. Distributed and quasi-distributed optical fiber sensors can take advantage of the capabilities of GM-APDs. Extensive studies have recently disclosed the main characteristics and limitations of silicon devices, both commercially available and developmental. In this paper we report an analysis of the performance of these detectors. The main characteristics of GM-APDs of interest for distributed optical fiber sensors are briefly reviewed. Command electronics (active quenching) is then introduced. The detector timing performance sets the maximum spatial resolution in experiments employing OTDR techniques. We highlight that the achievable time resolution depends on the physics of the avalanche spreading over the device area. On the basis of these results, trade-off between the important parameters (quantum efficiency, time resolution, background noise, and afterpulsing effects) is considered. Finally, we show first results on Germanium devices, capable of single photon sensitivity at 1.3 and 1.5 micrometers with sub- nanosecond time resolution.

  15. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Cernoch, Antonin; Soubusta, Jan; Celechovska, Lucie

    We report on experimental implementation of the optimal universal asymmetric 1->2 quantum cloning machine for qubits encoded into polarization states of single photons. Our linear-optical machine performs asymmetric cloning by partially symmetrizing the input polarization state of signal photon and a blank copy idler photon prepared in a maximally mixed state. We show that the employed method of measurement of mean clone fidelities exhibits strong resilience to imperfect calibration of the relative efficiencies of single-photon detectors used in the experiment. Reliable characterization of the quantum cloner is thus possible even when precise detector calibration is difficult to achieve.

  16. Dijet cross sections in photoproduction at HERA

    NASA Astrophysics Data System (ADS)

    Derrick, M.; Krakauer, D.; Magill, S.; Mikunas, D.; Musgrave, B.; Repond, J.; Stanek, R.; Talaga, R. L.; Zhang, H.; Ayad, R.; Bari, G.; Basile, M.; Bellagamba, L.; Boscherini, D.; Bruni, A.; Bruni, G.; Bruni, P.; Cara Romeo, G.; Castellini, G.; Chiarini, M.; Cifarelli, L.; Cindolo, F.; Contin, A.; Corradi, M.; Gialas, I.; Giusti, P.; Iacobucci, G.; Laurenti, G.; Levi, G.; Margotti, A.; Massam, T.; Nania, R.; Nemoz, C.; Palmonari, F.; Polini, A.; Sartorelli, G.; Timellini, R.; Garcia, Y. Zamora; Zichichi, A.; Bargende, A.; Crittenden, J.; Desch, K.; Diekmann, B.; Doeker, T.; Eckert, M.; Feld, L.; Frey, A.; Geerts, M.; Geitz, G.; Grothe, M.; Haas, T.; Hartmann, H.; Haun, D.; Heinloth, K.; Hilger, E.; Jakob, H.-P.; Katz, U. F.; Mari, S. M.; Mass, A.; Mengel, S.; Mollen, J.; Paul, E.; Rembser, Ch.; Schattevoy, R.; Schramm, D.; Stamm, J.; Wedemeyer, R.; Campbell-Robson, S.; Cassidy, A.; Dyce, N.; Foster, B.; George, S.; Gilmore, R.; Heath, G. P.; Heath, H. F.; Llewellyn, T. J.; Morgado, C. J. S.; Norman, D. J. P.; O'Mara, J. A.; Tapper, R. J.; Wilson, S. S.; Yoshida, R.; Rau, R. R.; Arneodo, M.; Iannotti, L.; Schioppa, M.; Susinno, G.; Bernstein, A.; Caldwell, A.; Cartiglia, N.; Parsons, J. A.; Ritz, S.; Sciulli, F.; Straub, P. B.; Wai, L.; Yang, S.; Zhu, Q.; Borzemski, P.; Chwastowski, J.; Eskreys, A.; Piotrzkowski, K.; Zachara, M.; Zawiejski, L.; Adamczyk, L.; Bednarek, B.; Jelén, K.; Kisielewska, D.; Kowalski, T.; Rulikowska-Zarȩbska, E.; Suszycki, L.; Zajaç, J.; Kotański, A.; Przybycień, M.; Bauerdick, L. A. T.; Behrens, U.; Beier, H.; Bienlein, J. K.; Coldewey, C.; Deppe, O.; Desler, K.; Drews, G.; Flasiński, M.; Gilkinson, D. J.; Glasman, C.; Göttlicher, P.; Große-Knetter, J.; Gutjahr, B.; Hain, W.; Hasell, D.; Heßling, H.; Hultschig, H.; Iga, Y.; Joos, P.; Kasemann, M.; Klanner, R.; Koch, W.; Köpke, L.; Kötz, U.; Kowalski, H.; Labs, J.; Ladage, A.; Löhr, B.; Löwe, M.; Lüke, D.; Mańczak, O.; Ng, J. S. T.; Nickel, S.; Notz, D.; Ohrenberg, K.; Roco, M.; Rohde, M.; Roldán, J.; Schneekloth, U.; Schulz, W.; Selonke, F.; Stilliaris, E.; Surrow, B.; Voß, T.; Westphal, D.; Wolf, G.; Youngman, C.; Zhou, J. F.; Grabosch, H. J.; Kharchilava, A.; Leich, A.; Mattingly, M.; Meyer, A.; Schlenstedt, S.; Wulff, N.; Bagbagli, G.; Pelfer, P.; Anzivino, G.; Maccarrone, G.; De Pasquale, S.; Votano, L.; Bamberger, A.; Eisenhardt, S.; Freidhof, A.; Söldner-Rembold, S.; Schroeder, J.; Trefzger, T.; Brook, N. H.; Bussey, P. J.; Doyle, A. T.; Fleck, J. I.; Saxon, D. H.; Utley, M. L.; Wilson, A. S.; Dannemann, A.; Holm, U.; Horstmann, D.; Neumann, T.; Sinkus, R.; Wick, K.; Badura, E.; Burow, B. D.; Hagge, L.; Lohrmann, E.; Mainusch, J.; Milewski, J.; Nakahata, M.; Pavel, N.; Poelz, G.; Schott, W.; Zetsche, F.; Bacon, T. C.; Butterworth, I.; Gallo, E.; Harris, V. L.; Hung, B. Y. H.; Long, K. R.; Miller, D. B.; Morawitz, P. P. O.; Prinias, A.; Sedgbeer, J. K.; Whitfield, A. F.; Mallik, U.; McCliment, E.; Wang, M. Z.; Wang, S. M.; Wu, J. T.; Zhang, Y.; Cloth, P.; Filges, D.; An, S. H.; Hong, S. M.; Nam, S. W.; Park, S. K.; Suh, M. H.; Yon, S. H.; Imlay, R.; Kartik, S.; Kim, H.-J.; McNeil, R. R.; Metcalf, W.; Nadendla, V. K.; Barreiro, F.; Cases, G.; Graciani, R.; Hernández, J. M.; Hervás, L.; Labarga, L.; del Peso, J.; Puga, J.; Terron, J.; de Trocóniz, J. F.; Smith, G. R.; Corriveau, F.; Hanna, D. S.; Hartmann, J.; Hung, L. W.; Lim, J. N.; Matthews, C. G.; Patel, P. M.; Sinclair, L. E.; Stairs, D. G.; St. Laurent, M.; Ullmann, R.; Zacek, G.; Bashkirov, V.; Dolgoshein, B. A.; Stifutkin, A.; Bashindzhagyan, G. L.; Ermolov, P. F.; Gladilin, L. K.; Golubkov, Y. A.; Kobrin, V. D.; Kuzmin, V. A.; Proskuryakov, A. S.; Savin, A. A.; Shcheglova, L. M.; Solomin, A. N.; Zotov, N. P.; Botje, M.; Chlebana, F.; Dake, A.; Engelen, J.; de Kamps, M.; Kooijman, P.; Kruse, A.; Tiecke, H.; Verkerke, W.; Vreeswijk, M.; Wiggers, L.; de Wolf, E.; van Woudenberg, R.; Acosta, D.; Bylsma, B.; Durkin, L. S.; Honscheid, K.; Li, C.; Ling, T. Y.; McLean, K. W.; Murray, W. N.; Park, I. H.; Romanowski, T. A.; Seidlein, R.; Bailey, D. S.; Blair, G. A.; Cashmore, R. J.; Cooper-Sarkar, A. M.; Daniels, D.; Devenish, R. C. E.; Harnew, N.; Lancaster, M.; Luffman, P. E.; Lindemann, L.; McFall, J. D.; Nath, C.; Noyes, V. A.; Quadt, A.; Uijterwaal, H.; Walczak, R.; Wilson, F. F.; Yip, T.; Abbiendi, G.; Bertolin, A.; Brugnera, R.; Carlin, R.; Dal Corso, F.; De Giorgi, M.; Dosselli, U.; Limentani, S.; Morandin, M.; Porocco, M.; Stanco, L.; Stroili, R.; Voci, C.; Bulmahn, J.; Butterworth, J. M.; Feild, R. G.; Oh, B. Y.; Whitmore, J. J.; D'Agostini, G.; Marini, G.; Nigro, A.; Tassi, E.; Hart, J. C.; McCubbin, N. A.; Prytz, K.; Shah, T. P.; Short, T. L.; Barberis, E.; Dubbs, T.; Heusch, C.; Van Hook, M.; Hubbard, B.; Lockman, W.; Rahn, J. T.; Sadrozinski, H. F.-W.; Seiden, A.; Biltzinger, J.; Seifert, R. J.; Walenta, A. H.; Zech, G.; Abramowicz, H.; Briskin, G.; Dagan, S.; Levy, A.; Hasegawa, T.; Hazumi, M.; Ishii, T.; Kuze, M.; Mine, S.; Nagasawa, Y.; Nakao, M.; Suzuki, I.; Tokushuku, K.; Yamada, S.; Yamazaki, Y.; Chiba, M.; Hamatsu, R.; Hirose, T.; Homma, K.; Kitamura, S.; Nakamitsu, Y.; Yamauchi, K.; Cirio, R.; Costa, M.; Ferrero, M. I.; Lamberti, L.; Maselli, S.; Peroni, C.; Sacchi, R.; Solano, A.; Staiano, A.; Dardo, M.; Bailey, D. C.; Bandyopadhyay, D.; Benard, F.; Brkic, M.; Crombie, M. B.; Gingrich, D. M.; Hartner, G. F.; Joo, K. K.; Levman, G. M.; Martin, J. F.; Orr, R. S.; Sampson, C. R.; Teuscher, R. J.; Catterall, C. D.; Jones, T. W.; Kaziewicz, P. B.; Lane, J. B.; Saunders, R. L.; Shulman, J.; Blankenship, K.; Kochocki, J.; Lu, B.; Mo, L. W.; Bogusz, W.; Charchuła, K.; Ciborowski, J.; Gajewski, J.; Grzelak, G.; Kasprzak, M.; Krzyżanowski, M.; Muchorowski, K.; Nowak, R. J.; Pawlak, J. M.; Tymieniecka, T.; Wróblewski, A. K.; Zakrzewski, J. A.; Żarnecki, A. F.; Adamus, M.; Eisenberg, Y.; Karshon, U.; Revel, D.; Zer-Zion, D.; Ali, I.; Badgett, W. F.; Behrens, B.; Dasu, S.; Fordham, C.; Foudas, C.; Goussiou, A.; Loveless, R. J.; Reeder, D. D.; Silverstein, S.; Smith, W. H.; Vaiciulis, A.; Wodarczyk, M.; Tsurugai, T.; Bhadra, S.; Cardy, M. L.; Fagerstroem, C.-P.; Frisken, W. R.; Furutani, K. M.; Khakzad, M.; Schmidke, W. B.; ZEUS Collaboration

    1995-02-01

    Dijet production by almost real photons has been studied at HERA with the ZEUS detector. Jets have been identified using the cone algorithm. A cut on xγOBS, the fraction of the photon energy participating in the production of the two jets of highest transverse energy, is used to define cross sections sensitive to the parton distributions in the proton and in the photon. The dependence of the dijet cross sections on pseudorapidity has been measured for xγOBS ⩾ 0.75 and xγOBS < 0.75. The former is sensitive to the gluon momentum density in the proton. The latter is sensitive to the ginon in the photon. The cross sections are corrected for detector acceptance and compared to leading order QCD calculations.

  17. Infrared (IR) photon-sensitive spectromicroscopy in a cryogenic environment

    DOEpatents

    Pereverzev, Sergey

    2016-06-14

    A system designed to suppress thermal radiation background and to allow IR single-photon sensitive spectromicroscopy of small samples by using both absorption, reflection, and emission/luminescence measurements. The system in one embodiment includes: a light source; a plurality of cold mirrors configured to direct light along a beam path; a cold or warm sample holder in the beam path; windows of sample holder (or whole sample holder) are transparent in a spectral region of interest, so they do not emit thermal radiation in the same spectral region of interest; a cold monochromator or other cold spectral device configured to direct a selected fraction of light onto a cold detector; a system of cold apertures and shields positioned along the beam path to prevent unwanted thermal radiation from arriving at the cold monochromator and/or the detector; a plurality of optical, IR and microwave filters positioned along the beam path and configured to adjust a spectral composition of light incident upon the sample under investigation and/or on the detector; a refrigerator configured to maintain the detector at a temperature below 1.0K; and an enclosure configured to: thermally insulate the light source, the plurality of mirrors, the sample holder, the cold monochromator and the refrigerator.

  18. Uncooled infrared photon detection concepts and devices

    NASA Astrophysics Data System (ADS)

    Piyankarage, Viraj Vishwakantha Jayaweera

    This work describes infrared (IR) photon detector techniques based on novel semiconductor device concepts and detector designs. The aim of the investigation was to examine alternative IR detection concepts with a view to resolve some of the issues of existing IR detectors such as operating temperature and response range. Systems were fabricated to demonstrate the following IR detection concepts and determine detector parameters: (i) Near-infrared (NIR) detection based on dye-sensitization of nanostructured semiconductors, (ii) Displacement currents in semiconductor quantum dots (QDs) embedded dielectric media, (iii) Split-off band transitions in GaAs/AlGaAs heterojunction interfacial workfunction internal photoemission (HEIWIP) detectors. A far-infrared detector based on GaSb homojunction interfacial workfunction internal photoemission (HIWIP) structure is also discussed. Device concepts, detector structures, and experimental results discussed in the text are summarized below. Dye-sensitized (DS) detector structures consisting of n-TiO 2/Dye/p-CuSCN heterostructures with several IR-sensitive dyes showed response peaks at 808, 812, 858, 866, 876, and 1056 nm at room temperature. The peak specific-detectivity (D*) was 9.5x1010 cm Hz-1/2 W-1 at 812 nm at room temperature. Radiation induced carrier generation alters the electronic polarizability of QDs provided the quenching of excitation is suppressed by separation of the QDs. A device constructed to illustrate this concept by embedding PbS QDs in paraffin wax showed a peak D* of 3x108 cm Hz 1/2 W-1 at ˜540 nm at ambient temperature. A typical HEIWIP/HIWIP detector structures consist of single (or multiple) period(s) of doped emitter(s) and undoped barrier(s) which are sandwiched between two highly doped contact layers. A p-GaAs/AlGaAs HEIWIP structure showed enhanced absorption in NIR range due to heavy/light-hole band to split-off band transitions and leading to the development of GaAs based uncooled sensors for IR detection in the 2--5 microm wavelength range with a peak D* of 6.8x105 cm Hz1/2 W-1. A HIWIP detector based on p-GaSb/GaSb showed a free carrier response threshold wavelength at 97 microm (˜3 THz) with a peak D* of 5.7x1011 cm Hz1/2 W-1 at 36 microm and 4.9 K. In this detector, a bolometric type response in the 97--200 microm (3--1.5 THz) range was also observed. INDEX WORDS: Infrared detectors, Photon detection, NIR detectors, THz detectors, Uncooled detectors, Dye-sensitized, IR dye, Quantum dot, Split-off band, GaSb, GaAs, AlGaAs, TiO2, CuSCN, PbS, Homojunction, Heterojunction, Workfunction, Photoemission, Displacement currents, 1/f noise.

  19. Nanoantenna enhancement for telecom-wavelength superconducting single photon detectors.

    PubMed

    Heath, Robert M; Tanner, Michael G; Drysdale, Timothy D; Miki, Shigehito; Giannini, Vincenzo; Maier, Stefan A; Hadfield, Robert H

    2015-02-11

    Superconducting nanowire single photon detectors are rapidly emerging as a key infrared photon-counting technology. Two front-side-coupled silver dipole nanoantennas, simulated to have resonances at 1480 and 1525 nm, were fabricated in a two-step process. An enhancement of 50 to 130% in the system detection efficiency was observed when illuminating the antennas. This offers a pathway to increasing absorption into superconducting nanowires, creating larger active areas, and achieving more efficient detection at longer wavelengths.

  20. Pulse pileup statistics for energy discriminating photon counting x-ray detectors

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wang, Adam S.; Harrison, Daniel; Lobastov, Vladimir

    Purpose: Energy discriminating photon counting x-ray detectors can be subject to a wide range of flux rates if applied in clinical settings. Even when the incident rate is a small fraction of the detector's maximum periodic rate N{sub 0}, pulse pileup leads to count rate losses and spectral distortion. Although the deterministic effects can be corrected, the detrimental effect of pileup on image noise is not well understood and may limit the performance of photon counting systems. Therefore, the authors devise a method to determine the detector count statistics and imaging performance. Methods: The detector count statistics are derived analyticallymore » for an idealized pileup model with delta pulses of a nonparalyzable detector. These statistics are then used to compute the performance (e.g., contrast-to-noise ratio) for both single material and material decomposition contrast detection tasks via the Cramer-Rao lower bound (CRLB) as a function of the detector input count rate. With more realistic unipolar and bipolar pulse pileup models of a nonparalyzable detector, the imaging task performance is determined by Monte Carlo simulations and also approximated by a multinomial method based solely on the mean detected output spectrum. Photon counting performance at different count rates is compared with ideal energy integration, which is unaffected by count rate. Results: The authors found that an ideal photon counting detector with perfect energy resolution outperforms energy integration for our contrast detection tasks, but when the input count rate exceeds 20%N{sub 0}, many of these benefits disappear. The benefit with iodine contrast falls rapidly with increased count rate while water contrast is not as sensitive to count rates. The performance with a delta pulse model is overoptimistic when compared to the more realistic bipolar pulse model. The multinomial approximation predicts imaging performance very close to the prediction from Monte Carlo simulations. The monoenergetic image with maximum contrast-to-noise ratio from dual energy imaging with ideal photon counting is only slightly better than with dual kVp energy integration, and with a bipolar pulse model, energy integration outperforms photon counting for this particular metric because of the count rate losses. However, the material resolving capability of photon counting can be superior to energy integration with dual kVp even in the presence of pileup because of the energy information available to photon counting. Conclusions: A computationally efficient multinomial approximation of the count statistics that is based on the mean output spectrum can accurately predict imaging performance. This enables photon counting system designers to directly relate the effect of pileup to its impact on imaging statistics and how to best take advantage of the benefits of energy discriminating photon counting detectors, such as material separation with spectral imaging.« less

  1. Note: Large active area solid state photon counter with 20 ps timing resolution and 60 fs detection delay stability

    NASA Astrophysics Data System (ADS)

    Prochazka, Ivan; Kodet, Jan; Eckl, Johann; Blazej, Josef

    2017-10-01

    We are reporting on the design, construction, and performance of a photon counting detector system, which is based on single photon avalanche diode detector technology. This photon counting device has been optimized for very high timing resolution and stability of its detection delay. The foreseen application of this detector is laser ranging of space objects, laser time transfer ground to space and fundamental metrology. The single photon avalanche diode structure, manufactured on silicon using K14 technology, is used as a sensor. The active area of the sensor is circular with 200 μm diameter. Its photon detection probability exceeds 40% in the wavelength range spanning from 500 to 800 nm. The sensor is operated in active quenching and gating mode. A new control circuit was optimized to maintain high timing resolution and detection delay stability. In connection to this circuit, timing resolution of the detector is reaching 20 ps FWHM. In addition, the temperature change of the detection delay is as low as 70 fs/K. As a result, the detection delay stability of the device is exceptional: expressed in the form of time deviation, detection delay stability of better than 60 fs has been achieved. Considering the large active area aperture of the detector, this is, to our knowledge, the best timing performance reported for a solid state photon counting detector so far.

  2. Evaluation of a 3D diamond detector for medical radiation dosimetry

    NASA Astrophysics Data System (ADS)

    Kanxheri, K.; Servoli, L.; Oh, A.; Munoz Sanchez, F.; Forcolin, G. T.; Murphy, S. A.; Aitkenhead, A.; Moore, C. J.; Morozzi, A.; Passeri, D.; Bellini, M.; Corsi, C.; Lagomarsino, S.; Sciortino, S.

    2017-01-01

    Synthetic diamond has several properties that are particularly suited to applications in medical radiation dosimetry. It is tissue equivalent, not toxic and shows a high resistance to radiation damage, low leakage current and stability of response. It is an electrical insulator, robust and realizable in small size; due to these features there are several examples of diamond devices, mainly planar single-crystalline chemical vapor depositation (sCVD) diamond, used for relative dose measurement in photon beams. Thanks to a new emerging technology, diamond devices with 3-dimensional structures are produced by using laser pulses to create graphitic paths in the diamond bulk. The necessary bias voltage to operate such detector decreases considerably while the signal response and radiation resistance increase. In order to evaluate the suitability of this new technology for measuring the dose delivered by radiotherapy beams in oncology a 3D polycrystalline (pCVD) diamond detector designed for single charged particle detection has been tested and the photon beam profile has been studied. The good linearity and high sensitivity to the dose observed in the 3D diamond, opens the way to the possibility of realizing a finely segmented device with the potential for dose distribution measurement in a single exposure for small field dosimetry that nowadays is still extremely challenging.

  3. High-resolution single photon planar and spect imaging of brain and neck employing a system of two co-registered opposed gamma imaging heads

    DOEpatents

    Majewski, Stanislaw [Yorktown, VA; Proffitt, James [Newport News, VA

    2011-12-06

    A compact, mobile, dedicated SPECT brain imager that can be easily moved to the patient to provide in-situ imaging, especially when the patient cannot be moved to the Nuclear Medicine imaging center. As a result of the widespread availability of single photon labeled biomarkers, the SPECT brain imager can be used in many locations, including remote locations away from medical centers. The SPECT imager improves the detection of gamma emission from the patient's head and neck area with a large field of view. Two identical lightweight gamma imaging detector heads are mounted to a rotating gantry and precisely mechanically co-registered to each other at 180 degrees. A unique imaging algorithm combines the co-registered images from the detector heads and provides several SPECT tomographic reconstructions of the imaged object thereby improving the diagnostic quality especially in the case of imaging requiring higher spatial resolution and sensitivity at the same time.

  4. Plasmonic Structure Integrated Single-Photon Detector Configurations to Improve Absorptance and Polarization Contrast

    PubMed Central

    Csete, Mária; Szekeres, Gábor; Szenes, András; Szalai, Anikó; Szabó, Gábor

    2015-01-01

    Configurations capable of maximizing both the absorption component of system detection efficiency and the achievable polarization contrast were determined for 1550 nm polarized light illumination of different plasmonic structure integrated superconducting nanowire single-photon detectors (SNSPDs) consisting of p = 264 nm and P = 792 nm periodic niobium nitride (NbN) patterns on silica substrate. Global effective NbN absorptance maxima appear in case of p/s-polarized light illumination in S/P-orientation (γ = 90°/0° azimuthal angle) and the highest polarization contrast is attained in S-orientation of all devices. Common nanophotonical origin of absorptance enhancement is collective resonance on nanocavity gratings with different profiles, which is promoted by coupling between localized modes in quarter-wavelength metal-insulator-metal nanocavities and laterally synchronized Brewster-Zenneck-type surface waves in integrated SNSPDs possessing a three-quarter-wavelength-scaled periodicity. The spectral sensitivity and dispersion characteristics reveal that device design specific optimal configurations exist. PMID:25654724

  5. Enhancing the sensitivity of fluorescence correlation spectroscopy by using time-correlated single photon counting.

    PubMed

    Lamb, D C; Müller, B K; Bräuchle, C

    2005-10-01

    Fluorescence correlation spectroscopy (FCS) and fluorescence cross-correlation spectroscopy (FCCS) are methods that extract information about a sample from the influence of thermodynamic equilibrium fluctuations on the fluorescence intensity. This method allows dynamic information to be obtained from steady state equilibrium measurements and its popularity has dramatically increased in the last 10 years due to the development of high sensitivity detectors and its combination with confocal microscopy. Using time-correlated single-photon counting (TCSPC) detection and pulsed excitation, information over the duration of the excited state can be extracted and incorporated in the analysis. In this short review, we discuss new methodologies that have recently emerged which incorporated fluorescence lifetime information or TCSPC data in the FCS and FCCS analysis. Time-gated FCS discriminates between which photons are to be incorporated in the analysis dependent upon their arrival time after excitation. This allows for accurate FCS measurements in the presence of fluorescent background, determination of sample homogeneity, and the ability to distinguish between static and dynamic heterogeneities. A similar method, time-resolved FCS can be used to resolve the individual correlation functions from multiple fluorophores through the different fluorescence lifetimes. Pulsed interleaved excitation (PIE) encodes the excitation source into the TCSPC data. PIE can be used to perform dual-channel FCCS with a single detector and allows elimination of spectral cross-talk with dual-channel detection. For samples that undergo fluorescence resonance energy transfer (FRET), quantitative FCCS measurements can be performed in spite of the FRET and the static FRET efficiency can be determined.

  6. A study of pile-up in integrated time-correlated single photon counting systems

    NASA Astrophysics Data System (ADS)

    Arlt, Jochen; Tyndall, David; Rae, Bruce R.; Li, David D.-U.; Richardson, Justin A.; Henderson, Robert K.

    2013-10-01

    Recent demonstration of highly integrated, solid-state, time-correlated single photon counting (TCSPC) systems in CMOS technology is set to provide significant increases in performance over existing bulky, expensive hardware. Arrays of single photon single photon avalanche diode (SPAD) detectors, timing channels, and signal processing can be integrated on a single silicon chip with a degree of parallelism and computational speed that is unattainable by discrete photomultiplier tube and photon counting card solutions. New multi-channel, multi-detector TCSPC sensor architectures with greatly enhanced throughput due to minimal detector transit (dead) time or timing channel dead time are now feasible. In this paper, we study the potential for future integrated, solid-state TCSPC sensors to exceed the photon pile-up limit through analytic formula and simulation. The results are validated using a 10% fill factor SPAD array and an 8-channel, 52 ps resolution time-to-digital conversion architecture with embedded lifetime estimation. It is demonstrated that pile-up insensitive acquisition is attainable at greater than 10 times the pulse repetition rate providing over 60 dB of extended dynamic range to the TCSPC technique. Our results predict future CMOS TCSPC sensors capable of live-cell transient observations in confocal scanning microscopy, improved resolution of near-infrared optical tomography systems, and fluorescence lifetime activated cell sorting.

  7. A study of pile-up in integrated time-correlated single photon counting systems.

    PubMed

    Arlt, Jochen; Tyndall, David; Rae, Bruce R; Li, David D-U; Richardson, Justin A; Henderson, Robert K

    2013-10-01

    Recent demonstration of highly integrated, solid-state, time-correlated single photon counting (TCSPC) systems in CMOS technology is set to provide significant increases in performance over existing bulky, expensive hardware. Arrays of single photon single photon avalanche diode (SPAD) detectors, timing channels, and signal processing can be integrated on a single silicon chip with a degree of parallelism and computational speed that is unattainable by discrete photomultiplier tube and photon counting card solutions. New multi-channel, multi-detector TCSPC sensor architectures with greatly enhanced throughput due to minimal detector transit (dead) time or timing channel dead time are now feasible. In this paper, we study the potential for future integrated, solid-state TCSPC sensors to exceed the photon pile-up limit through analytic formula and simulation. The results are validated using a 10% fill factor SPAD array and an 8-channel, 52 ps resolution time-to-digital conversion architecture with embedded lifetime estimation. It is demonstrated that pile-up insensitive acquisition is attainable at greater than 10 times the pulse repetition rate providing over 60 dB of extended dynamic range to the TCSPC technique. Our results predict future CMOS TCSPC sensors capable of live-cell transient observations in confocal scanning microscopy, improved resolution of near-infrared optical tomography systems, and fluorescence lifetime activated cell sorting.

  8. Single photon detection imaging of Cherenkov light emitted during radiation therapy

    NASA Astrophysics Data System (ADS)

    Adamson, Philip M.; Andreozzi, Jacqueline M.; LaRochelle, Ethan; Gladstone, David J.; Pogue, Brian W.

    2018-03-01

    Cherenkov imaging during radiation therapy has been developed as a tool for dosimetry, which could have applications in patient delivery verification or in regular quality audit. The cameras used are intensified imaging sensors, either ICCD or ICMOS cameras, which allow important features of imaging, including: (1) nanosecond time gating, (2) amplification by 103-104, which together allow for imaging which has (1) real time capture at 10-30 frames per second, (2) sensitivity at the level of single photon event level, and (3) ability to suppress background light from the ambient room. However, the capability to achieve single photon imaging has not been fully analyzed to date, and as such was the focus of this study. The ability to quantitatively characterize how a single photon event appears in amplified camera imaging from the Cherenkov images was analyzed with image processing. The signal seen at normal gain levels appears to be a blur of about 90 counts in the CCD detector, after going through the chain of photocathode detection, amplification through a microchannel plate PMT, excitation onto a phosphor screen and then imaged on the CCD. The analysis of single photon events requires careful interpretation of the fixed pattern noise, statistical quantum noise distributions, and the spatial spread of each pulse through the ICCD.

  9. FPGA-based gating and logic for multichannel single photon counting

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Pooser, Raphael C; Earl, Dennis Duncan; Evans, Philip G

    2012-01-01

    We present results characterizing multichannel InGaAs single photon detectors utilizing gated passive quenching circuits (GPQC), self-differencing techniques, and field programmable gate array (FPGA)-based logic for both diode gating and coincidence counting. Utilizing FPGAs for the diode gating frontend and the logic counting backend has the advantage of low cost compared to custom built logic circuits and current off-the-shelf detector technology. Further, FPGA logic counters have been shown to work well in quantum key distribution (QKD) test beds. Our setup combines multiple independent detector channels in a reconfigurable manner via an FPGA backend and post processing in order to perform coincidencemore » measurements between any two or more detector channels simultaneously. Using this method, states from a multi-photon polarization entangled source are detected and characterized via coincidence counting on the FPGA. Photons detection events are also processed by the quantum information toolkit for application testing (QITKAT)« less

  10. UV superconducting nanowire single-photon detectors with high efficiency, low noise, and 4 K operating temperature

    NASA Astrophysics Data System (ADS)

    Wollman, E. E.; Verma, V. B.; Beyer, A. D.; Briggs, R. M.; Korzh, B.; Allmaras, J. P.; Marsili, F.; Lita, A. E.; Mirin, R. P.; Nam, S. W.; Shaw, M. D.

    2017-10-01

    For photon-counting applications at ultraviolet wavelengths, there are currently no detectors that combine high efficiency (> 50%), sub-nanosecond timing resolution, and sub-Hz dark count rates. Superconducting nanowire single-photon detectors (SNSPDs) have seen success over the past decade for photon-counting applications in the near-infrared, but little work has been done to optimize SNSPDs for wavelengths below 400 nm. Here, we describe the design, fabrication, and characterization of UV SNSPDs operating at wavelengths between 250 and 370 nm. The detectors have active areas up to 56 ${\\mu}$m in diameter, 70 - 80% efficiency, timing resolution down to 60 ps FWHM, blindness to visible and infrared photons, and dark count rates of ~ 0.25 counts/hr for a 56 ${\\mu}$m diameter pixel. By using the amorphous superconductor MoSi, these UV SNSPDs are also able to operate at temperatures up to 4.2 K. These performance metrics make UV SNSPDs ideal for applications in trapped-ion quantum information processing, lidar studies of the upper atmosphere, UV fluorescent-lifetime imaging microscopy, and photon-starved UV astronomy.

  11. Polycrystalline lead selenide: the resurgence of an old infrared detector

    NASA Astrophysics Data System (ADS)

    Vergara, G.; Montojo, M. T.; Torquemada, M. C.; Rodrigo, M. T.; Sánchez, F. J.; Gómez, L. J.; Almazán, R. M.; Verdú, M.; Rodríguez, P.; Villamayor, V.; Álvarez, M.; Diezhandino, J.; Plaza, J.; Catalán, I.

    2007-06-01

    The existing technology for uncooled MWIR photon detectors based on polycrystalline lead salts is stigmatized for being a 50-year-old technology. It has been traditionally relegated to single-element detectors and relatively small linear arrays due to the limitations imposed by its standard manufacture process based on a chemical bath deposition technique (CBD) developed more than 40 years ago. Recently, an innovative method for processing detectors, based on a vapour phase deposition (VPD) technique, has allowed manufacturing the first 2D array of polycrystalline PbSe with good electro optical characteristics. The new method of processing PbSe is an all silicon technology and it is compatible with standard CMOS circuitry. In addition to its affordability, VPD PbSe constitutes a perfect candidate to fill the existing gap in the photonic and uncooled IR imaging detectors sensitive to the MWIR photons. The perspectives opened are numerous and very important, converting the old PbSe detector in a serious alternative to others uncooled technologies in the low cost IR detection market. The number of potential applications is huge, some of them with high commercial impact such as personal IR imagers, enhanced vision systems for automotive applications and other not less important in the security/defence domain such as sensors for active protection systems (APS) or low cost seekers. Despite the fact, unanimously accepted, that uncooled will dominate the majority of the future IR detection applications, today, thermal detectors are the unique plausible alternative. There is plenty of room for photonic uncooled and complementary alternatives are needed. This work allocates polycrystalline PbSe in the current panorama of the uncooled IR detectors, underlining its potentiality in two areas of interest, i.e., very low cost imaging IR detectors and MWIR fast uncooled detectors for security and defence applications. The new method of processing again converts PbSe into an emerging technology.

  12. A giant enhancement of multiphoton absorption in single-layer molybdenum disulfide

    NASA Astrophysics Data System (ADS)

    Zhou, Feng; Ji, Wei

    Identifying light absorption mechanisms in nanoscale materials, which are more efficient than those observed in bulk semiconductors, are of paramount importance to next-generation, infrared photo-detection. Here, we report considerable enhancement of degenerate two-photon absorption (2PA) and three-photon absorption (3PA) through two-dimensional (2D) excitonic effects in single-layer molybdenum disulfide (1L-MoS2) . We theoretically predict that both degenerate 2PA and 3PA coefficients of 1L-MoS2 are enhanced by 10-1000 times in the near-infrared (NIR), as compared with those of bulk semiconductors. Our theoretical prediction is validated by measuring photocurrents induced by 2PA or 3PA in a 1L-MoS2 photo-detector at room temperature where excitons in the immediate vicinity of the bandgap are transferred to the conduction band by a very small amount of thermal energy and dissociated under an external electric field. Our finding lays theoretical foundation and provides experimental evidence for developing sensitive infrared multiphoton detectors for nano-photonics. This work was supported by National University of Singapore through a research Grant: R144-000-327-112.

  13. Report on recent results of the PERCIVAL soft X-ray imager

    NASA Astrophysics Data System (ADS)

    Khromova, A.; Cautero, G.; Giuressi, D.; Menk, R.; Pinaroli, G.; Stebel, L.; Correa, J.; Marras, A.; Wunderer, C. B.; Lange, S.; Tennert, M.; Niemann, M.; Hirsemann, H.; Smoljanin, S.; Reza, S.; Graafsma, H.; Göttlicher, P.; Shevyakov, I.; Supra, J.; Xia, Q.; Zimmer, M.; Guerrini, N.; Marsh, B.; Sedgwick, I.; Nicholls, T.; Turchetta, R.; Pedersen, U.; Tartoni, N.; Hyun, H. J.; Kim, K. S.; Rah, S. Y.; Hoenk, M. E.; Jewell, A. D.; Jones, T. J.; Nikzad, S.

    2016-11-01

    The PERCIVAL (Pixelated Energy Resolving CMOS Imager, Versatile And Large) soft X-ray 2D imaging detector is based on stitched, wafer-scale sensors possessing a thick epi-layer, which together with back-thinning and back-side illumination yields elevated quantum efficiency in the photon energy range of 125-1000 eV. Main application fields of PERCIVAL are foreseen in photon science with FELs and synchrotron radiation. This requires high dynamic range up to 105 ph @ 250 eV paired with single photon sensitivity with high confidence at moderate frame rates in the range of 10-120 Hz. These figures imply the availability of dynamic gain switching on a pixel-by-pixel basis and a highly parallel, low noise analog and digital readout, which has been realized in the PERCIVAL sensor layout. Different aspects of the detector performance have been assessed using prototype sensors with different pixel and ADC types. This work will report on the recent test results performed on the newest chip prototypes with the improved pixel and ADC architecture. For the target frame rates in the 10-120 Hz range an average noise floor of 14e- has been determined, indicating the ability of detecting single photons with energies above 250 eV. Owing to the successfully implemented adaptive 3-stage multiple-gain switching, the integrated charge level exceeds 4 · 106 e- or 57000 X-ray photons at 250 eV per frame at 120 Hz. For all gains the noise level remains below the Poisson limit also in high-flux conditions. Additionally, a short overview over the updates on an oncoming 2 Mpixel (P2M) detector system (expected at the end of 2016) will be reported.

  14. Super Photon Counters

    NASA Technical Reports Server (NTRS)

    Mather, John

    1999-01-01

    The perfect photon detector would measure the arrival time, the energy, the polarization, and the position of every arriving quantum, but that is easier said than done. Two groups have now succeeded in doing time-resolved spectroscopy on the Crab Nebula pulsar, measuring everything but the polarization, with reports from Romani et al. at Stanford and from Perryman et al. at ESTEC. Both groups use superconducting detectors to gain the necessary speed and sensitivity. The photon can heat the electrons in a superconductor biased in the middle of its resistive transition, or break bound superconducting electron-hole pairs, which can then be collected. Three years ago, Peacock et al. reported that they had detected single optical photons with a superconducting tunnel junction (STJ), and Paresce wrote a News and Views article. A tunnel junction uses two pieces of conductive material, separated by a tiny gap of insulating material or even vacuum. If the gap is thin enough, electrons can tunnel across anyway, and if the conductors are superconductors, the junction displays very useful quantum mechanical properties and electrical nonlinearities. Amplifiers, detectors, oscillators, and computer circuits can all be made from them. Their special advantage is that they operate at very low temperatures, dissipate very little power, operate very fast, and are very small.

  15. Cryogenic gaseous photomultipliers and liquid hole- multipliers: advances in THGEM-based sensors for future noble-liquid TPCs

    NASA Astrophysics Data System (ADS)

    Arazi, L.; Coimbra, A. E. C.; Erdal, E.; Israelashvili, I.; Rappaport, M. L.; Shchemelinin, S.; Vartsky, D.; dos Santos, J. M. F.; A, Breskin

    2015-11-01

    Dual-phase noble-liquid TPCs are presently the most sensitive instruments for direct dark matter detection. Scaling up existing ton-scale designs to the multi-ton regime may prove to be technologically challenging. This includes both large-area coverage with affordable high-QE UV-photon detectors, and maintaining high precision in measuring the charge and light signals of rare events with keV-scale energy depositions. We present our recent advances in two complementary approaches to these problems: large-area cryogenic gaseous photomultipliers (GPM) for UV-photon detection, and liquid-hole multipliers (LHM) that provide electroluminescence light in response to ionization electrons and primary scintillation photons, using perforated electrodes immersed within the noble liquid. Results from a 10 cm diameter GPM coupled to a dual-phase liquid- xenon TPC demonstrate the feasibility of recording - for the first time - both primary (“S1”) and secondary (“S2”) scintillation signals, over a very broad dynamic range. The detector, comprising a triple-THGEM structure with CsI on the first element, has been operating stably at 180 K with gains larger than 105; it provided high single-photon detection efficiency - in the presence of massive alpha-particle induced S2 signals; S1 scintillation signals were recorded with time resolutions of 1.2 ns (RMS). Results with the LHM operated in liquid xenon yielded large photon gains, with a pulse-height resolution of 11% (RMS) for alpha-particle induced S2 signals. The detector response was stable over several months. The response of the S2 signals to rapid changes in pressure lead to the conclusion that the underlying mechanism for S2 light is electroluminescence in xenon bubbles trapped below the immersed THGEM electrode. Both studies have the potential of paving the way towards new designs of dual- and single-phase noble-liquid TPCs that could simplify the conception of future multi-ton detectors of dark matter and other rare events.

  16. Spectral X-Ray Diffraction using a 6 Megapixel Photon Counting Array Detector.

    PubMed

    Muir, Ryan D; Pogranichniy, Nicholas R; Muir, J Lewis; Sullivan, Shane Z; Battaile, Kevin P; Mulichak, Anne M; Toth, Scott J; Keefe, Lisa J; Simpson, Garth J

    2015-03-12

    Pixel-array array detectors allow single-photon counting to be performed on a massively parallel scale, with several million counting circuits and detectors in the array. Because the number of photoelectrons produced at the detector surface depends on the photon energy, these detectors offer the possibility of spectral imaging. In this work, a statistical model of the instrument response is used to calibrate the detector on a per-pixel basis. In turn, the calibrated sensor was used to perform separation of dual-energy diffraction measurements into two monochromatic images. Targeting applications include multi-wavelength diffraction to aid in protein structure determination and X-ray diffraction imaging.

  17. Spectral x-ray diffraction using a 6 megapixel photon counting array detector

    NASA Astrophysics Data System (ADS)

    Muir, Ryan D.; Pogranichniy, Nicholas R.; Muir, J. Lewis; Sullivan, Shane Z.; Battaile, Kevin P.; Mulichak, Anne M.; Toth, Scott J.; Keefe, Lisa J.; Simpson, Garth J.

    2015-03-01

    Pixel-array array detectors allow single-photon counting to be performed on a massively parallel scale, with several million counting circuits and detectors in the array. Because the number of photoelectrons produced at the detector surface depends on the photon energy, these detectors offer the possibility of spectral imaging. In this work, a statistical model of the instrument response is used to calibrate the detector on a per-pixel basis. In turn, the calibrated sensor was used to perform separation of dual-energy diffraction measurements into two monochromatic images. Targeting applications include multi-wavelength diffraction to aid in protein structure determination and X-ray diffraction imaging.

  18. Full-field fan-beam x-ray fluorescence computed tomography system design with linear-array detectors and pinhole collimation: a rapid Monte Carlo study

    NASA Astrophysics Data System (ADS)

    Zhang, Siyuan; Li, Liang; Li, Ruizhe; Chen, Zhiqiang

    2017-11-01

    We present the design concept and initial simulations for a polychromatic full-field fan-beam x-ray fluorescence computed tomography (XFCT) device with pinhole collimators and linear-array photon counting detectors. The phantom is irradiated by a fan-beam polychromatic x-ray source filtered by copper. Fluorescent photons are stimulated and then collected by two linear-array photon counting detectors with pinhole collimators. The Compton scatter correction and the attenuation correction are applied in the data processing, and the maximum-likelihood expectation maximization algorithm is applied for the image reconstruction of XFCT. The physical modeling of the XFCT imaging system was described, and a set of rapid Monte Carlo simulations was carried out to examine the feasibility and sensitivity of the XFCT system. Different concentrations of gadolinium (Gd) and gold (Au) solutions were used as contrast agents in simulations. Results show that 0.04% of Gd and 0.065% of Au can be well reconstructed with the full scan time set at 6 min. Compared with using the XFCT system with a pencil-beam source or a single-pixel detector, using a full-field fan-beam XFCT device with linear-array detectors results in significant scanning time reduction and may satisfy requirements of rapid imaging, such as in vivo imaging experiments.

  19. Gated IR imaging with 128 × 128 HgCdTe electron avalanche photodiode FPA

    NASA Astrophysics Data System (ADS)

    Beck, Jeff; Woodall, Milton; Scritchfield, Richard; Ohlson, Martha; Wood, Lewis; Mitra, Pradip; Robinson, Jim

    2007-04-01

    The next generation of IR sensor systems will include active imaging capabilities. One example of such a system is a gated-active/passive system. The gated-active/passive system promises long-range target detection and identification. A detector that is capable of both active and passive modes of operation opens up the possibility of a self-aligned system that uses a single focal plane. The detector would need to be sensitive in the 3-5 μm band for passive mode operation. In the active mode, the detector would need to be sensitive in eye-safe range, e.g. 1.55 μm, and have internal gain to achieve the required system sensitivity. The MWIR HgCdTe electron injection avalanche photodiode (e-APD) not only provides state-of-the-art 3-5 μm spectral sensitivity, but also high avalanche photodiode gain without minimal excess noise. Gains of greater than 1000 have been measured in MWIR e-APDs with a gain independent excess noise factor of 1.3. This paper reports the application of the mid-wave HgCdTe e-APD for near-IR gated-active/passive imaging. Specifically a 128x128 FPA composed of 40 μm pitch, 4.2 μm to 5 μm cutoff, APD detectors with a custom readout integrated circuit was designed, fabricated, and tested. Median gains as high as 946 at 11 V bias with noise equivalent inputs as low as 0.4 photon were measured at 80 K. A gated imaging demonstration system was designed and built using commercially available parts. High resolution gated imagery out to 9 km was obtained with this system that demonstrated predicted MTF, precision gating, and sub 10 photon sensitivity.

  20. 3D Silicon Coincidence Avalanche Detector (3D-SiCAD) for charged particle detection

    NASA Astrophysics Data System (ADS)

    Vignetti, M. M.; Calmon, F.; Pittet, P.; Pares, G.; Cellier, R.; Quiquerez, L.; Chaves de Albuquerque, T.; Bechetoille, E.; Testa, E.; Lopez, J.-P.; Dauvergne, D.; Savoy-Navarro, A.

    2018-02-01

    Single-Photon Avalanche Diodes (SPADs) are p-n junctions operated in Geiger Mode by applying a reverse bias above the breakdown voltage. SPADs have the advantage of featuring single photon sensitivity with timing resolution in the picoseconds range. Nevertheless, their relatively high Dark Count Rate (DCR) is a major issue for charged particle detection, especially when it is much higher than the incoming particle rate. To tackle this issue, we have developed a 3D Silicon Coincidence Avalanche Detector (3D-SiCAD). This novel device implements two vertically aligned SPADs featuring on-chip electronics for the detection of coincident avalanche events occurring on both SPADs. Such a coincidence detection mode allows an efficient discrimination of events related to an incoming charged particle (producing a quasi-simultaneous activation of both SPADs) from dark counts occurring independently on each SPAD. A 3D-SiCAD detector prototype has been fabricated in CMOS technology adopting a 3D flip-chip integration technique, and the main results of its characterization are reported in this work. The particle detection efficiency and noise rejection capability for this novel device have been evaluated by means of a β- strontium-90 radioactive source. Moreover the impact of the main operating parameters (i.e. the hold-off time, the coincidence window duration, the SPAD excess bias voltage) over the particle detection efficiency has been studied. Measurements have been performed with different β- particles rates and show that a 3D-SiCAD device outperforms single SPAD detectors: the former is indeed capable to detect particle rates much lower than the individual DCR observed in a single SPAD-based detectors (i.e. 2 to 3 orders of magnitudes lower).

  1. Investigation of the Performance of an Ultralow-Dark-Count Superconducting Nanowire Single-Photon Detector

    NASA Astrophysics Data System (ADS)

    Subashchandran, Shanthi; Okamoto, Ryo; Zhang, Labao; Tanaka, Akira; Okano, Masayuki; Kang, Lin; Chen, Jian; Wu, Peiheng; Takeuchi, Shigeki

    2013-10-01

    The realization of an ultralow-dark-count rate (DCR) along with the conservation of high detection efficiency (DE) is critical for many applications using single photon detectors in quantum information technologies, material sciences, and biological sensing. For this purpose, a fiber-coupled superconducting nanowire single-photon detector (SNSPD) with a meander-type niobium nitride nanowire (width: 50 nm) is studied. Precise measurements of the bias current dependence of DE are carried out for a wide spectral range (from 500 to 1650 nm in steps of 50 nm) using a white light source and a laser line Bragg tunable band-pass filter. An ultralow DCR (0.0015 cps) and high DE (32%) are simultaneously achieved by the SNSPD at a wavelength of 500 nm.

  2. Quantum non-demolition detection of an itinerant microwave photon

    NASA Astrophysics Data System (ADS)

    Kono, S.; Koshino, K.; Tabuchi, Y.; Noguchi, A.; Nakamura, Y.

    2018-06-01

    Photon detectors are an elementary tool to measure electromagnetic waves at the quantum limit1,2 and are heavily demanded in the emerging quantum technologies such as communication3, sensing4 and computing5. Of particular interest is a quantum non-demolition (QND)-type detector, which projects an electromagnetic wave onto the photon-number basis6-10. This is in stark contrast to conventional photon detectors2 that absorb a photon to trigger a `click'. The long-sought QND detection of a flying photon was recently demonstrated in the optical domain using a single atom in a cavity11,12. However, the counterpart for microwaves has been elusive despite the recent progress in microwave quantum optics using superconducting circuits13-19. Here, we implement a deterministic entangling gate between a superconducting qubit and an itinerant microwave photon reflected by a cavity containing the qubit. Using the entanglement and the high-fidelity qubit readout, we demonstrate a QND detection of a single photon with the quantum efficiency of 0.84 and the photon survival probability of 0.87. Our scheme can serve as a building block for quantum networks connecting distant qubit modules as well as a microwave-photon-counting device for multiple-photon signals.

  3. Imaging workflow and calibration for CT-guided time-domain fluorescence tomography

    PubMed Central

    Tichauer, Kenneth M.; Holt, Robert W.; El-Ghussein, Fadi; Zhu, Qun; Dehghani, Hamid; Leblond, Frederic; Pogue, Brian W.

    2011-01-01

    In this study, several key optimization steps are outlined for a non-contact, time-correlated single photon counting small animal optical tomography system, using simultaneous collection of both fluorescence and transmittance data. The system is presented for time-domain image reconstruction in vivo, illustrating the sensitivity from single photon counting and the calibration steps needed to accurately process the data. In particular, laser time- and amplitude-referencing, detector and filter calibrations, and collection of a suitable instrument response function are all presented in the context of time-domain fluorescence tomography and a fully automated workflow is described. Preliminary phantom time-domain reconstructed images demonstrate the fidelity of the workflow for fluorescence tomography based on signal from multiple time gates. PMID:22076264

  4. Sequential x-ray diffraction topography at 1-BM x-ray optics testing beamline at the advanced photon source

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Stoupin, Stanislav, E-mail: sstoupin@aps.anl.gov; Shvyd’ko, Yuri; Trakhtenberg, Emil

    2016-07-27

    We report progress on implementation and commissioning of sequential X-ray diffraction topography at 1-BM Optics Testing Beamline of the Advanced Photon Source to accommodate growing needs of strain characterization in diffractive crystal optics and other semiconductor single crystals. The setup enables evaluation of strain in single crystals in the nearly-nondispersive double-crystal geometry. Si asymmetric collimator crystals of different crystallographic orientations were designed, fabricated and characterized using in-house capabilities. Imaging the exit beam using digital area detectors permits rapid sequential acquisition of X-ray topographs at different angular positions on the rocking curve of a crystal under investigation. Results on sensitivity andmore » spatial resolution are reported based on experiments with high-quality Si and diamond crystals. The new setup complements laboratory-based X-ray topography capabilities of the Optics group at the Advanced Photon Source.« less

  5. Femtosecond Photon-Counting Receiver

    NASA Technical Reports Server (NTRS)

    Krainak, Michael A.; Rambo, Timothy M.; Yang, Guangning; Lu, Wei; Numata, Kenji

    2016-01-01

    An optical correlation receiver is described that provides ultra-precise distance and/or time/pulse-width measurements even for weak (single photons) and short (femtosecond) optical signals. A new type of optical correlation receiver uses a fourth-order (intensity) interferometer to provide micron distance measurements even for weak (single photons) and short (femtosecond) optical signals. The optical correlator uses a low-noise-integrating detector that can resolve photon number. The correlation (range as a function of path delay) is calculated from the variance of the photon number of the difference of the optical signals on the two detectors. Our preliminary proof-of principle data (using a short-pulse diode laser transmitter) demonstrates tens of microns precision.

  6. Femtosecond Photon-Counting Receiver

    NASA Technical Reports Server (NTRS)

    Krainak, Michael A.; Rambo, Timothy M.; Yang, Guangning; Lu, Wei; Numata, Kenji

    2016-01-01

    An optical correlation receiver is described that provides ultra-precise distance and/or time-pulse-width measurements even for weak (single photons) and short (femtosecond) optical signals. A new type of optical correlation receiver uses a fourth-order (intensity) interferometer to provide micron distance measurements even for weak (single photons) and short (femtosecond) optical signals. The optical correlator uses a low-noise-integrating detector that can resolve photon number. The correlation (range as a function of path delay) is calculated from the variance of the photon number of the difference of the optical signals on the two detectors. Our preliminary proof-of principle data (using a short-pulse diode laser transmitter) demonstrates tens of microns precision.

  7. 14C autoradiography with an energy-sensitive silicon pixel detector.

    PubMed

    Esposito, M; Mettivier, G; Russo, P

    2011-04-07

    The first performance tests are presented of a carbon-14 ((14)C) beta-particle digital autoradiography system with an energy-sensitive hybrid silicon pixel detector based on the Timepix readout circuit. Timepix was developed by the Medipix2 Collaboration and it is similar to the photon-counting Medipix2 circuit, except for an added time-based synchronization logic which allows derivation of energy information from the time-over-threshold signal. This feature permits direct energy measurements in each pixel of the detector array. Timepix is bump-bonded to a 300 µm thick silicon detector with 256 × 256 pixels of 55 µm pitch. Since an energetic beta-particle could release its kinetic energy in more than one detector pixel as it slows down in the semiconductor detector, an off-line image analysis procedure was adopted in which the single-particle cluster of hit pixels is recognized; its total energy is calculated and the position of interaction on the detector surface is attributed to the centre of the charge cluster. Measurements reported are detector sensitivity, (4.11 ± 0.03) × 10(-3) cps mm(-2) kBq(-1) g, background level, (3.59 ± 0.01) × 10(-5) cps mm(-2), and minimum detectable activity, 0.0077 Bq. The spatial resolution is 76.9 µm full-width at half-maximum. These figures are compared with several digital imaging detectors for (14)C beta-particle digital autoradiography.

  8. TWO NEW SINGLE-EXPOSURE, MULTI-DETECTOR NEUTRON SPECTROMETERS FOR RADIATION PROTECTION APPLICATIONS IN WORKPLACE MONITORING.

    PubMed

    Gómez-Ros, J M; Bedogni, R; Bortot, D; Domingo, C; Esposito, A; Introini, M V; Lorenzoli, M; Mazzitelli, G; Moraleda, M; Pola, A; Sacco, D

    2017-04-01

    This communication describes two new instruments, based on multiple active thermal neutron detectors arranged within a single moderator, that permit to unfold the neutron spectrum (from thermal to hundreds of MeV) and to determine the corresponding integral quantities with only one exposure. This makes them especially advantageous for neutron field characterisation and workplace monitoring in neutron-producing facilities. One of the devices has spherical geometry and nearly isotropic response, the other one has cylindrical symmetry and it is only sensitive to neutrons incident along the cylinder axis. In both cases, active detectors have been specifically developed looking for the criteria of miniaturisation, high sensitivity, linear response and good photon rejection. The calculated response matrix has been validated by experimental irradiations in neutron reference fields with a global uncertainty of 3%. The measurements performed in realistic neutron fields permitted to determine the neutron spectra and the integral quantities, in particular H*(10). © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  9. Modeling the frequency-dependent detective quantum efficiency of photon-counting x-ray detectors.

    PubMed

    Stierstorfer, Karl

    2018-01-01

    To find a simple model for the frequency-dependent detective quantum efficiency (DQE) of photon-counting detectors in the low flux limit. Formula for the spatial cross-talk, the noise power spectrum and the DQE of a photon-counting detector working at a given threshold are derived. Parameters are probabilities for types of events like single counts in the central pixel, double counts in the central pixel and a neighboring pixel or single count in a neighboring pixel only. These probabilities can be derived in a simple model by extensive use of Monte Carlo techniques: The Monte Carlo x-ray propagation program MOCASSIM is used to simulate the energy deposition from the x-rays in the detector material. A simple charge cloud model using Gaussian clouds of fixed width is used for the propagation of the electric charge generated by the primary interactions. Both stages are combined in a Monte Carlo simulation randomizing the location of impact which finally produces the required probabilities. The parameters of the charge cloud model are fitted to the spectral response to a polychromatic spectrum measured with our prototype detector. Based on the Monte Carlo model, the DQE of photon-counting detectors as a function of spatial frequency is calculated for various pixel sizes, photon energies, and thresholds. The frequency-dependent DQE of a photon-counting detector in the low flux limit can be described with an equation containing only a small set of probabilities as input. Estimates for the probabilities can be derived from a simple model of the detector physics. © 2017 American Association of Physicists in Medicine.

  10. Optomechanical terahertz detection with single meta-atom resonator.

    PubMed

    Belacel, Cherif; Todorov, Yanko; Barbieri, Stefano; Gacemi, Djamal; Favero, Ivan; Sirtori, Carlo

    2017-11-17

    Most of the common technologies for detecting terahertz photons (>1 THz) at room temperature rely on slow thermal devices. The realization of fast and sensitive detectors in this frequency range is indeed a notoriously difficult task. Here we propose a novel device consisting of a subwavelength terahertz meta-atom resonator, which integrates a nanomechanical element and allows energy exchange between the mechanical motion and the electromagnetic degrees of freedom. An incident terahertz wave thus produces a nanomechanical signal that can be read out optically with high precision. We exploit this concept to demonstrate a terahertz detector that operates at room temperature with high sensitivity and a much higher frequency response compared to standard detectors. Beyond the technological issue of terahertz detection, our architecture opens up new perspectives for fundamental science of light-matter interaction at terahertz frequencies, combining optomechanical approaches with semiconductor quantum heterostructures.

  11. Mid-infrared two photon absorption sensitivity of commercial detectors

    NASA Astrophysics Data System (ADS)

    Boiko, D. L.; Antonov, A. V.; Kuritsyn, D. I.; Yablonskiy, A. N.; Sergeev, S. M.; Orlova, E. E.; Vaks, V. V.

    2017-10-01

    We report on broad-band two-photon absorption (TPA) in several commercially available MIR inter-band bulk semiconductor photodetectors with the spectral cutoff in the range of 4.5-6 μm. The highest TPA responsivity of 2 × 10-5 A.mm2/W2 is measured for a nitrogen-cooled InSb photovoltaic detector. Its performance as a two-photon detector is validated by measuring the second-order interferometric autocorrelation function of a multimode quantum cascade laser emitting at the wavelength of 8 μm.

  12. Unconditional violation of the shot-noise limit in photonic quantum metrology

    NASA Astrophysics Data System (ADS)

    Slussarenko, Sergei; Weston, Morgan M.; Chrzanowski, Helen M.; Shalm, Lynden K.; Verma, Varun B.; Nam, Sae Woo; Pryde, Geoff J.

    2017-11-01

    Interferometric phase measurement is widely used to precisely determine quantities such as length, speed and material properties1-3. Without quantum correlations, the best phase sensitivity Δ ϕ achievable using n photons is the shot-noise limit, Δ ϕ =1 /√{n }. Quantum-enhanced metrology promises better sensitivity, but, despite theoretical proposals stretching back decades3,4, no measurement using photonic (that is, definite photon number) quantum states has truly surpassed the shot-noise limit. Instead, all such demonstrations, by discounting photon loss, detector inefficiency or other imperfections, have considered only a subset of the photons used. Here, we use an ultrahigh-efficiency photon source and detectors to perform unconditional entanglement-enhanced photonic interferometry. Sampling a birefringent phase shift, we demonstrate precision beyond the shot-noise limit without artificially correcting our results for loss and imperfections. Our results enable quantum-enhanced phase measurements at low photon flux and open the door to the next generation of optical quantum metrology advances.

  13. An investigation of noise performance in optical lock-in thermography

    NASA Astrophysics Data System (ADS)

    Rajic, Nik; Antolis, Cedric

    2017-12-01

    An investigation into the noise performance of optical lock-in thermography (OLT) is described. The study aims to clarify the influence of infrared detector type and key inspection parameters such as illumination strength and lock-in duration on the quality of OLT amplitude and phase imagery. The study compares the performance of a state-of-the-art cooled photon detector with several lower-cost microbolometers. The results reveal a significant noise performance advantage to the photon detector. Under certain inspection regimes the advantage with respect to phase image quality is disproportionately high relative to detector sensitivities. This is shown to result from an explicit dependence in the phase signal variance on the ratio between the signal amplitude and the detector sensitivity. While this finding supports the preferred use of photon detectors for OLT inspections, it does not exclude microbolometers from a useful role. In cases where the significantly lower capital cost and improved practicality of microbolometers provide an advantage it is shown that performance shortfalls can be overcome with a relatively small factorial increase in optical illumination intensity.

  14. Gigahertz-gated InGaAs/InP single-photon detector with detection efficiency exceeding 55% at 1550 nm

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Comandar, L. C.; Engineering Department, Cambridge University, 9 J J Thomson Ave, Cambridge CB3 0FA; Fröhlich, B.

    We report on a gated single-photon detector based on InGaAs/InP avalanche photodiodes (APDs) with a single-photon detection efficiency exceeding 55% at 1550 nm. Our detector is gated at 1 GHz and employs the self-differencing technique for gate transient suppression. It can operate nearly dead time free, except for the one clock cycle dead time intrinsic to self-differencing, and we demonstrate a count rate of 500 Mcps. We present a careful analysis of the optimal driving conditions of the APD measured with a dead time free detector characterization setup. It is found that a shortened gate width of 360 ps together with anmore » increased driving signal amplitude and operation at higher temperatures leads to improved performance of the detector. We achieve an afterpulse probability of 7% at 50% detection efficiency with dead time free measurement and a record efficiency for InGaAs/InP APDs of 55% at an afterpulse probability of only 10.2% with a moderate dead time of 10 ns.« less

  15. Design and performance of dual-polarization lumped-element kinetic inductance detectors for millimeter-wave polarimetry

    NASA Astrophysics Data System (ADS)

    McCarrick, H.; Jones, G.; Johnson, B. R.; Abitbol, M. H.; Ade, P. A. R.; Bryan, S.; Day, P.; Essinger-Hileman, T.; Flanigan, D.; Leduc, H. G.; Limon, M.; Mauskopf, P.; Miller, A.; Tucker, C.

    2018-02-01

    Aims: Lumped-element kinetic inductance detectors (LEKIDs) are an attractive technology for millimeter-wave observations that require large arrays of extremely low-noise detectors. We designed, fabricated and characterized 64-element (128 LEKID) arrays of horn-coupled, dual-polarization LEKIDs optimized for ground-based CMB polarimetry. Our devices are sensitive to two orthogonal polarizations in a single spectral band centered on 150 GHz with Δν/ν = 0.2. The 65 × 65 mm square arrays are designed to be tiled into the focal plane of an optical system. We demonstrate the viability of these dual-polarization LEKIDs with laboratory measurements. Methods: The LEKID modules are tested with an FPGA-based readout system in a sub-kelvin cryostat that uses a two-stage adiabatic demagnetization refrigerator. The devices are characterized using a blackbody and a millimeter-wave source. The polarization properties are measured with a cryogenic stepped half-wave plate. We measure the resonator parameters and the detector sensitivity, noise spectrum, dynamic range, and polarization response. Results: The resonators have internal quality factors approaching 1 × 106. The detectors have uniform response between orthogonal polarizations and a large dynamic range. The detectors are photon-noise limited above 1 pW of absorbed power. The noise-equivalent temperatures under a 3.4 K blackbody load are <100 μK √s. The polarization fractions of detectors sensitive to orthogonal polarizations are >80%. The entire array is multiplexed on a single readout line, demonstrating a multiplexing factor of 128. The array and readout meet the requirements for 4 arrays to be read out simultaneously for a multiplexing factor of 512. Conclusions: This laboratory study demonstrates the first dual-polarization LEKID array optimized specifically for CMB polarimetry and shows the readiness of the detectors for on-sky observations.

  16. Photon Counting Detectors for the 1.0 - 2.0 Micron Wavelength Range

    NASA Technical Reports Server (NTRS)

    Krainak, Michael A.

    2004-01-01

    We describe results on the development of greater than 200 micron diameter, single-element photon-counting detectors for the 1-2 micron wavelength range. The technical goals include quantum efficiency in the range 10-70%; detector diameter greater than 200 microns; dark count rate below 100 kilo counts-per-second (cps), and maximum count rate above 10 Mcps.

  17. Segmentation and pulse shape discrimination techniques for rejecting background in germanium detectors

    NASA Technical Reports Server (NTRS)

    Roth, J.; Primbsch, J. H.; Lin, R. P.

    1984-01-01

    The possibility of rejecting the internal beta-decay background in coaxial germanium detectors by distinguishing between the multi-site energy losses characteristic of photons and the single-site energy losses of electrons in the range 0.2 - 2 MeV is examined. The photon transport was modeled with a Monte Carlo routine. Background rejection by both multiple segmentation and pulse shape discrimination techniques is investigated. The efficiency of a six 1 cm-thick segment coaxial detector operating in coincidence mode alone is compared to that of a two-segment (1 cm and 5 cm) detector employing both front-rear coincidence and PSD in the rear segment to isolate photon events. Both techniques can provide at least 95 percent rejection of single-site events while accepting at least 80 percent of the multi-site events above 500 keV.

  18. A kilo-pixel imaging system for future space based far-infrared observatories using microwave kinetic inductance detectors

    NASA Astrophysics Data System (ADS)

    Baselmans, J. J. A.; Bueno, J.; Yates, S. J. C.; Yurduseven, O.; Llombart, N.; Karatsu, K.; Baryshev, A. M.; Ferrari, L.; Endo, A.; Thoen, D. J.; de Visser, P. J.; Janssen, R. M. J.; Murugesan, V.; Driessen, E. F. C.; Coiffard, G.; Martin-Pintado, J.; Hargrave, P.; Griffin, M.

    2017-05-01

    Aims: Future astrophysics and cosmic microwave background space missions operating in the far-infrared to millimetre part of the spectrum will require very large arrays of ultra-sensitive detectors in combination with high multiplexing factors and efficient low-noise and low-power readout systems. We have developed a demonstrator system suitable for such applications. Methods: The system combines a 961 pixel imaging array based upon Microwave Kinetic Inductance Detectors (MKIDs) with a readout system capable of reading out all pixels simultaneously with only one readout cable pair and a single cryogenic amplifier. We evaluate, in a representative environment, the system performance in terms of sensitivity, dynamic range, optical efficiency, cosmic ray rejection, pixel-pixel crosstalk and overall yield at an observation centre frequency of 850 GHz and 20% fractional bandwidth. Results: The overall system has an excellent sensitivity, with an average detector sensitivity < NEPdet> =3×10-19 WHz measured using a thermal calibration source. At a loading power per pixel of 50 fW we demonstrate white, photon noise limited detector noise down to 300 mHz. The dynamic range would allow the detection of 1 Jy bright sources within the field of view without tuning the readout of the detectors. The expected dead time due to cosmic ray interactions, when operated in an L2 or a similar far-Earth orbit, is found to be <4%. Additionally, the achieved pixel yield is 83% and the crosstalk between the pixels is <-30 dB. Conclusions: This demonstrates that MKID technology can provide multiplexing ratios on the order of a 1000 with state-of-the-art single pixel performance, and that the technology is now mature enough to be considered for future space based observatories and experiments.

  19. Characterization of silicon carbide and diamond detectors for neutron applications

    NASA Astrophysics Data System (ADS)

    Hodgson, M.; Lohstroh, A.; Sellin, P.; Thomas, D.

    2017-10-01

    The presence of carbon atoms in silicon carbide and diamond makes these materials ideal candidates for direct fast neutron detectors. Furthermore the low atomic number, strong covalent bonds, high displacement energies, wide bandgap and low intrinsic carrier concentrations make these semiconductor detectors potentially suitable for applications where rugged, high-temperature, low-gamma-sensitivity detectors are required, such as active interrogation, electronic personal neutron dosimetry and harsh environment detectors. A thorough direct performance comparison of the detection capabilities of semi-insulating silicon carbide (SiC-SI), single crystal diamond (D-SC), polycrystalline diamond (D-PC) and a self-biased epitaxial silicon carbide (SiC-EP) detector has been conducted and benchmarked against a commercial silicon PIN (Si-PIN) diode, in a wide range of alpha (Am-241), beta (Sr/Y-90), ionizing photon (65 keV to 1332 keV) and neutron radiation fields (including 1.2 MeV to 16.5 MeV mono-energetic neutrons, as well as neutrons from AmBe and Cf-252 sources). All detectors were shown to be able to directly detect and distinguish both the different radiation types and energies by using a simple energy threshold discrimination method. The SiC devices demonstrated the best neutron energy discrimination ratio (E\\max (n=5 MeV)/E\\max (n=1 MeV)  ≈5), whereas a superior neutron/photon cross-sensitivity ratio was observed in the D-PC detector (E\\max (AmBe)/E\\max (Co-60)  ≈16). Further work also demonstrated that the cross-sensitivity ratios can be improved through use of a simple proton-recoil conversion layer. Stability issues were also observed in the D-SC, D-PC and SiC-SI detectors while under irradiation, namely a change of energy peak position and/or count rate with time (often referred to as the polarization effect). This phenomenon within the detectors was non-debilitating over the time period tested (> 5 h) and, as such, stable operation was possible. Furthermore, the D-SC, self-biased SiC-EP and semi-insulating SiC detectors were shown to operate over the temperature range -60 °C to +100 °C.

  20. Electrically driven polarized single-photon emission from an InGaN quantum dot in a GaN nanowire.

    PubMed

    Deshpande, Saniya; Heo, Junseok; Das, Ayan; Bhattacharya, Pallab

    2013-01-01

    In a classical light source, such as a laser, the photon number follows a Poissonian distribution. For quantum information processing and metrology applications, a non-classical emitter of single photons is required. A single quantum dot is an ideal source of single photons and such single-photon sources in the visible spectral range have been demonstrated with III-nitride and II-VI-based single quantum dots. It has been suggested that short-wavelength blue single-photon emitters would be useful for free-space quantum cryptography, with the availability of high-speed single-photon detectors in this spectral region. Here we demonstrate blue single-photon emission with electrical injection from an In0.25Ga0.75N quantum dot in a single nanowire. The emitted single photons are linearly polarized along the c axis of the nanowire with a degree of linear polarization of ~70%.

  1. HgCdTe APDs for time-resolved space applications

    NASA Astrophysics Data System (ADS)

    Rothman, J.; Lasfargues, G.; Delacourt, B.; Dumas, A.; Gibert, F.; Bardoux, A.; Boutillier, M.

    2017-12-01

    The use of HgCdTe avalanche photodiodes (APDs) for resolving the temporal variation of faint light level signals is analyzed. The analysis is based on the performance characteristics such as the gain, the response time, and dark currents in the APDs, measured as a function of operating temperature and Cd composition, and on recently developed detector demonstrator modules. The choice of Cd composition in the APDs is strongly dependent on the application needs in terms of electrical bandwidth and signal-to-noise ratio. A performance model has been developed and used to predict the performance of the future detector modules for different applications such as high bandwidth and/or deep space free space optical telecommunications and lidar, associated with sensitivities down to single photon level at low operating temperature and close to single-photon operation at bandwidth of 10 GHz at room temperature. The predictions are corroborated by the results obtained on detector modules that have been developed and used in lidar and deep space optical communications. In a first lidar prototype, integrating a 200 µm APD, we obtained a maximum sensitivity of 25 fW/√Hz at T = 190 K operating temperature. The detector has been used for differential absorption lidar estimations of the absorption due to presence of CO2 in the atmosphere. A random error of 3-10% was obtained for the estimation of the optical thickness at a distance of 100-3000 m, for a range resolution of 100 m and using and averaging time of 4 s. The pursuit of this development is pending on the space qualification of the technology. Results from first proton and irradiation tests are reported that shows on a close to constant performance during and after the irradiation and endurance tests.

  2. An ultra low noise telecom wavelength free running single photon detector using negative feedback avalanche diode

    NASA Astrophysics Data System (ADS)

    Yan, Zhizhong; Hamel, Deny R.; Heinrichs, Aimee K.; Jiang, Xudong; Itzler, Mark A.; Jennewein, Thomas

    2012-07-01

    It is challenging to implement genuine free running single-photon detectors for the 1550 nm wavelength range with simultaneously high detection efficiency (DE), low dark noise, and good time resolution. We report a novel read out system for the signals from a negative feedback avalanche diode (NFAD) [M. A. Itzler, X. Jiang, B. Nyman, and K. Slomkowski, "Quantum sensing and nanophotonic devices VI," Proc. SPIE 7222, 72221K (2009), 10.1117/12.814669; X. Jiang, M. A. Itzler, K. ODonnell, M. Entwistle, and K. Slomkowski, "Advanced photon counting techniques V," Proc. SPIE 8033, 80330K (2011), 10.1117/12.883543; M. A. Itzler, X. Jiang, B. M. Onat, and K. Slomkowski, "Quantum sensing and nanophotonic devices VII," Proc. SPIE 7608, 760829 (2010), 10.1117/12.843588], which allows useful operation of these devices at a temperature of 193 K and results in very low darkcounts (˜100 counts per second (CPS)), good time jitter (˜30 ps), and good DE (˜10%). We characterized two NFADs with a time-correlation method using photons generated from weak coherent pulses and photon pairs produced by spontaneous parametric down conversion. The inferred detector efficiencies for both types of photon sources agree with each other. The best noise equivalent power of the device is estimated to be 8.1 × 10-18 W Hz-1/2, more than 10 times better than typical InP/InGaAs single photon avalanche diodes (SPADs) show in free running mode. The afterpulsing probability was found to be less than 0.1% per ns at the optimized operating point. In addition, we studied the performance of an entanglement-based quantum key distribution (QKD) using these detectors and develop a model for the quantum bit error rate that incorporates the afterpulsing coefficients. We verified experimentally that using these NFADs it is feasible to implement QKD over 400 km of telecom fiber. Our NFAD photon detector system is very simple, and is well suited for single-photon applications where ultra-low noise and free-running operation is required, and some afterpulsing can be tolerated.

  3. An ultra low noise telecom wavelength free running single photon detector using negative feedback avalanche diode.

    PubMed

    Yan, Zhizhong; Hamel, Deny R; Heinrichs, Aimee K; Jiang, Xudong; Itzler, Mark A; Jennewein, Thomas

    2012-07-01

    It is challenging to implement genuine free running single-photon detectors for the 1550 nm wavelength range with simultaneously high detection efficiency (DE), low dark noise, and good time resolution. We report a novel read out system for the signals from a negative feedback avalanche diode (NFAD) [M. A. Itzler, X. Jiang, B. Nyman, and K. Slomkowski, "Quantum sensing and nanophotonic devices VI," Proc. SPIE 7222, 72221K (2009); X. Jiang, M. A. Itzler, K. ODonnell, M. Entwistle, and K. Slomkowski, "Advanced photon counting techniques V," Proc. SPIE 8033, 80330K (2011); M. A. Itzler, X. Jiang, B. M. Onat, and K. Slomkowski, "Quantum sensing and nanophotonic devices VII," Proc. SPIE 7608, 760829 (2010)], which allows useful operation of these devices at a temperature of 193 K and results in very low darkcounts (∼100 counts per second (CPS)), good time jitter (∼30 ps), and good DE (∼10%). We characterized two NFADs with a time-correlation method using photons generated from weak coherent pulses and photon pairs produced by spontaneous parametric down conversion. The inferred detector efficiencies for both types of photon sources agree with each other. The best noise equivalent power of the device is estimated to be 8.1 × 10(-18) W Hz(-1/2), more than 10 times better than typical InP/InGaAs single photon avalanche diodes (SPADs) show in free running mode. The afterpulsing probability was found to be less than 0.1% per ns at the optimized operating point. In addition, we studied the performance of an entanglement-based quantum key distribution (QKD) using these detectors and develop a model for the quantum bit error rate that incorporates the afterpulsing coefficients. We verified experimentally that using these NFADs it is feasible to implement QKD over 400 km of telecom fiber. Our NFAD photon detector system is very simple, and is well suited for single-photon applications where ultra-low noise and free-running operation is required, and some afterpulsing can be tolerated.

  4. A compact high resolution flat panel PET detector based on the new 4-side buttable MPPC for biomedical applications.

    PubMed

    Wang, Qiang; Wen, Jie; Ravindranath, Bosky; O'Sullivan, Andrew W; Catherall, David; Li, Ke; Wei, Shouyi; Komarov, Sergey; Tai, Yuan-Chuan

    2015-09-11

    Compact high-resolution panel detectors using virtual pinhole (VP) PET geometry can be inserted into existing clinical or pre-clinical PET systems to improve regional spatial resolution and sensitivity. Here we describe a compact panel PET detector built using the new Though Silicon Via (TSV) multi-pixel photon counters (MPPC) detector. This insert provides high spatial resolution and good timing performance for multiple bio-medical applications. Because the TSV MPPC design eliminates wire bonding and has a package dimension which is very close to the MPPC's active area, it is 4-side buttable. The custom designed MPPC array (based on Hamamatsu S12641-PA-50(x)) used in the prototype is composed of 4 × 4 TSV-MPPC cells with a 4.46 mm pitch in both directions. The detector module has 16 × 16 lutetium yttrium oxyorthosilicate (LYSO) crystal array, with each crystal measuring 0.92 × 0.92 × 3 mm 3 with 1.0 mm pitch. The outer diameter of the detector block is 16.8 × 16.8 mm 2 . Thirty-two such blocks will be arranged in a 4 × 8 array with 1 mm gaps to form a panel detector with detection area around 7 cm × 14 cm in the full-size detector. The flood histogram acquired with Ge-68 source showed excellent crystal separation capability with all 256 crystals clearly resolved. The detector module's mean, standard deviation, minimum (best) and maximum (worst) energy resolution were 10.19%, +/-0.68%, 8.36% and 13.45% FWHM, respectively. The measured coincidence time resolution between the block detector and a fast reference detector (around 200 ps single photon timing resolution) was 0.95 ns. When tested with Siemens Cardinal electronics the performance of the detector blocks remain consistent. These results demonstrate that the TSV-MPPC is a promising photon sensor for use in a flat panel PET insert composed of many high resolution compact detector modules.

  5. Accelerated SPECT Monte Carlo Simulation Using Multiple Projection Sampling and Convolution-Based Forced Detection

    NASA Astrophysics Data System (ADS)

    Liu, Shaoying; King, Michael A.; Brill, Aaron B.; Stabin, Michael G.; Farncombe, Troy H.

    2008-02-01

    Monte Carlo (MC) is a well-utilized tool for simulating photon transport in single photon emission computed tomography (SPECT) due to its ability to accurately model physical processes of photon transport. As a consequence of this accuracy, it suffers from a relatively low detection efficiency and long computation time. One technique used to improve the speed of MC modeling is the effective and well-established variance reduction technique (VRT) known as forced detection (FD). With this method, photons are followed as they traverse the object under study but are then forced to travel in the direction of the detector surface, whereby they are detected at a single detector location. Another method, called convolution-based forced detection (CFD), is based on the fundamental idea of FD with the exception that detected photons are detected at multiple detector locations and determined with a distance-dependent blurring kernel. In order to further increase the speed of MC, a method named multiple projection convolution-based forced detection (MP-CFD) is presented. Rather than forcing photons to hit a single detector, the MP-CFD method follows the photon transport through the object but then, at each scatter site, forces the photon to interact with a number of detectors at a variety of angles surrounding the object. This way, it is possible to simulate all the projection images of a SPECT simulation in parallel, rather than as independent projections. The result of this is vastly improved simulation time as much of the computation load of simulating photon transport through the object is done only once for all projection angles. The results of the proposed MP-CFD method agrees well with the experimental data in measurements of point spread function (PSF), producing a correlation coefficient (r2) of 0.99 compared to experimental data. The speed of MP-CFD is shown to be about 60 times faster than a regular forced detection MC program with similar results.

  6. Characterizing multi-photon quantum interference with practical light sources and threshold single-photon detectors

    NASA Astrophysics Data System (ADS)

    Navarrete, Álvaro; Wang, Wenyuan; Xu, Feihu; Curty, Marcos

    2018-04-01

    The experimental characterization of multi-photon quantum interference effects in optical networks is essential in many applications of photonic quantum technologies, which include quantum computing and quantum communication as two prominent examples. However, such characterization often requires technologies which are beyond our current experimental capabilities, and today's methods suffer from errors due to the use of imperfect sources and photodetectors. In this paper, we introduce a simple experimental technique to characterize multi-photon quantum interference by means of practical laser sources and threshold single-photon detectors. Our technique is based on well-known methods in quantum cryptography which use decoy settings to tightly estimate the statistics provided by perfect devices. As an illustration of its practicality, we use this technique to obtain a tight estimation of both the generalized Hong‑Ou‑Mandel dip in a beamsplitter with six input photons and the three-photon coincidence probability at the output of a tritter.

  7. The contribution of bends and constrictions of a superconducting film to the photon detection by a single-photon superconducting detector

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zotova, A. N., E-mail: zotova@imp.sci-nnov.ru

    2016-05-15

    The contribution of bends and constrictions by a superconducting film to the detection by a single photon superconducting detector is investigated. It has been shown that, for currents smaller than the minimal detection current of a straight film, the detection efficiency of a film with a constriction attains saturation upon an increase in the current, which coincides qualitatively with the behavior of this dependence observed in the experiment. It has also been found that the effect of bends in the film and the external magnetic field on the detection efficiency for low-energy photons is essential, while for high-energy photons nomore » such influence is observed.« less

  8. The NSLS 100 element solid state array detector

    PubMed Central

    Furenlid, L.R.; Kraner, H.W.; Rogers, L.C.; Cramer, S.P.; Stephani, D.; Beuttenmuller, R.H.; Beren, J.

    2015-01-01

    X-ray absorption studies of dilute samples require fluorescence detection techniques. Since signal-to-noise ratios are governed by the ratio of fluorescent to scattered photons counted by a detector, solid state detectors which can discriminate between fluorescence and scattered photons have become the instruments of choice for trace element measurements. Commercially available 13 element Ge array detectors permitting total count rates < 500000 counts per second are now in routine use. Since X-ray absorption beamlines at high brightness synchrotron sources can already illuminate most dilute samples with enough flux to saturate the current generation of solid state detectors, the development of next-generation instruments with significantly higher total count rates is essential. We present the design and current status of the 100 element Si array detector being developed in a collaboration between the NSLS and the Instrumentation Division at Brookhaven National Laboratory. The detecting array consists of a 10×10 matrix of 4 mm×4 mm elements laid out on a single piece of ultrahigh purity silicon mounted at the front end of a liquid nitrogen dewar assembly. A matrix of charge sensitive integrating preamplifiers feed signals to an array of shaping amplifiers, single channel analyzers, and scalers. An electronic switch, delay amplifier, linear gate, digital scope, peak sensing A/D converter, and histogramining memory module provide for complete diagnostics and channel calibration. The entire instrument is controlled by a LabView 2 application on a MacII ci; the software also provides full control over beamline hardware and performs the data collection. PMID:26722135

  9. SOI metal-oxide-semiconductor field-effect transistor photon detector based on single-hole counting.

    PubMed

    Du, Wei; Inokawa, Hiroshi; Satoh, Hiroaki; Ono, Atsushi

    2011-08-01

    In this Letter, a scaled-down silicon-on-insulator (SOI) metal-oxide-semiconductor field-effect transistor (MOSFET) is characterized as a photon detector, where photogenerated individual holes are trapped below the negatively biased gate and modulate stepwise the electron current flowing in the bottom channel induced by the positive substrate bias. The output waveforms exhibit clear separation of current levels corresponding to different numbers of trapped holes. Considering this capability of single-hole counting, a small dark count of less than 0.02 s(-1) at room temperature, and low operation voltage of 1 V, SOI MOSFET could be a unique photon-number-resolving detector if the small quantum efficiency were improved. © 2011 Optical Society of America

  10. Itinerant Microwave Photon Detector

    NASA Astrophysics Data System (ADS)

    Royer, Baptiste; Grimsmo, Arne L.; Choquette-Poitevin, Alexandre; Blais, Alexandre

    2018-05-01

    The realization of a high-efficiency microwave single photon detector is a long-standing problem in the field of microwave quantum optics. Here, we propose a quantum nondemolition, high-efficiency photon detector that can readily be implemented in present state-of-the-art circuit quantum electrodynamics. This scheme works in a continuous fashion, gaining information about the photon arrival time as well as about its presence. The key insight that allows us to circumvent the usual limitations imposed by measurement backaction is the use of long-lived dark states in a small ensemble of inhomogeneous artificial atoms to increase the interaction time between the photon and the measurement device. Using realistic system parameters, we show that large detection fidelities are possible.

  11. Practical photon number detection with electric field-modulated silicon avalanche photodiodes.

    PubMed

    Thomas, O; Yuan, Z L; Shields, A J

    2012-01-24

    Low-noise single-photon detection is a prerequisite for quantum information processing using photonic qubits. In particular, detectors that are able to accurately resolve the number of photons in an incident light pulse will find application in functions such as quantum teleportation and linear optics quantum computing. More generally, such a detector will allow the advantages of quantum light detection to be extended to stronger optical signals, permitting optical measurements limited only by fluctuations in the photon number of the source. Here we demonstrate a practical high-speed device, which allows the signals arising from multiple photon-induced avalanches to be precisely discriminated. We use a type of silicon avalanche photodiode in which the lateral electric field profile is strongly modulated in order to realize a spatially multiplexed detector. Clearly discerned multiphoton signals are obtained by applying sub-nanosecond voltage gates in order to restrict the detector current.

  12. X-ray spectrometer with a low-cost SiC photodiode

    NASA Astrophysics Data System (ADS)

    Zhao, S.; Lioliou, G.; Barnett, A. M.

    2018-04-01

    A low-cost Commercial-Off-The-Shelf (COTS) 4H-SiC 0.06 mm2 UV p-n photodiode was coupled to a low-noise charge-sensitive preamplifier and used as photon counting X-ray spectrometer. The photodiode/spectrometer was investigated at X-ray energies from 4.95 keV to 21.17 keV: a Mo cathode X-ray tube was used to fluoresce eight high-purity metal foils to produce characteristic X-ray emission lines which were used to characterise the instrument. The energy resolution (full width at half maximum, FWHM) of the spectrometer was found to be 1.6 keV to 1.8 keV, across the energy range. The energy linearity of the detector/spectrometer (i.e. the detector's charge output per photon as a function of incident photon energy across the 4.95 keV to 21.17 keV energy range), as well as the count rate linearity of the detector/spectrometer (i.e. number of detected photons as a function of photon fluence at a specific energy) were investigated. The energy linearity of the detector/spectrometer was linear with an error < ± 0.7 %; the count rate linearity of the detector/spectrometer was linear with an error < ± 2 %. The use of COTS SiC photodiodes as detectors for X-ray spectrometers is attractive for nanosatellite/CubeSat applications (including solar flare monitoring), and for cost sensitive industrial uses.

  13. Methods for reducing singly reflected rays on the Wolter-I focusing mirrors of the FOXSI rocket experiment

    NASA Astrophysics Data System (ADS)

    Buitrago-Casas, Juan Camilo; Elsner, Ronald; Glesener, Lindsay; Christe, Steven; Ramsey, Brian; Courtade, Sasha; Ishikawa, Shin-nosuke; Narukage, Noriyuki; Turin, Paul; Vievering, Juliana; Athiray, P. S.; Musset, Sophie; Krucker, Säm.

    2017-08-01

    In high energy solar astrophysics, imaging hard X-rays by direct focusing offers higher dynamic range and greater sensitivity compared to past techniques that used indirect imaging. The Focusing Optics X-ray Solar Imager (FOXSI) is a sounding rocket payload that uses seven sets of nested Wolter-I figured mirrors together with seven high-sensitivity semiconductor detectors to observe the Sun in hard X-rays through direct focusing. The FOXSI rocket has successfully flown twice and is funded to fly a third time in summer 2018. The Wolter-I geometry consists of two consecutive mirrors, one paraboloid and one hyperboloid, that reflect photons at grazing angles. Correctly focused X-rays reflect once per mirror segment. For extended sources, like the Sun, off-axis photons at certain incident angles can reflect on only one mirror and still reach the focal plane, generating a background pattern of singly reflected rays (i.e., ghost rays) that can limit the sensitivity of the observation to faint, focused sources. Understanding and mitigating the impact of the singly reflected rays on the FOXSI optical modules will maximize the instruments' sensitivity to background-limited sources. We present an analysis of the FOXSI singly reflected rays based on ray-tracing simulations and laboratory measurements, as well as the effectiveness of different physical strategies to reduce them.

  14. Study of electrode pattern design for a CZT-based PET detector.

    PubMed

    Gu, Y; Levin, C S

    2014-06-07

    We are developing a 1 mm resolution small animal positron emission tomography (PET) system using 3D positioning cadmium zinc telluride photon detectors comprising 40 mm × 40 mm × 5 mm crystals metalized with a cross-strip electrode pattern with a 1 mm anode strip pitch. We optimized the electrode pattern design for intrinsic sensitivity and spatial, energy and time resolution performance using a test detector comprising cathode and steering electrode strips of varying dimensions. The study found 3 and 5 mm width cathode strips locate charge-shared photon interactions near cathode strip boundaries with equal precision. 3 mm width cathode strips exhibited large time resolution variability as a function of photon interaction location between the anode and cathode planes (~26 to ~127.5 ns full width at half maximum (FWHM) for 0.5 mm and 4.2 mm depths, respectively). 5 mm width cathode strips by contrast exhibited more stable time resolution for the same interaction locations (~34 to ~83 ns FWHM), provided more linear spatial positioning in the direction orthogonal to the electrode planes, and as much as 68.4% improvement in photon sensitivity over the 3 mm wide cathode strips. The results were understood by analyzing the cathode strips' weighting functions, which indicated a stronger 'small pixel' effect in the 3 mm wide cathode strips. Photon sensitivity and anode energy resolution were seen to improve with decreasing steering electrode bias from 0 to -80 V w.r.t. the anode potential. A slight improvement in energy resolution was seen for wider steering electrode strips (400 versus 100 µm) for charge-shared photon interactions. Although this study successfully focused on electrode pattern features for PET performance, the results are generally applicable to semiconductor photon detectors employing cross-trip electrode patterns.

  15. Study of electrode pattern design for a CZT-based PET detector

    PubMed Central

    Gu, Y; Levin, C S

    2014-01-01

    We are developing a 1 mm resolution small animal positron emission tomography (PET) system using 3-D positioning Cadmium Zinc Telluride (CZT) photon detectors comprising 40 mm × 40 mm × 5 mm crystals metalized with a cross-strip electrode pattern with a 1 mm anode strip pitch. We optimized the electrode pattern design for intrinsic sensitivity and spatial, energy and time resolution performance using a test detector comprising cathode and steering electrode strips of varying dimensions. The study found 3 mm and 5 mm width cathode strips locate charge-shared photon interactions near cathode strip boundaries with equal precision. 3 mm width cathode strips exhibited large time resolution variability as a function of photon interaction location between the anode and cathode planes (~26 ns to ~127.5 ns FWHM for 0.5 mm and 4.2 mm depths, respectively). 5 mm width cathode strips by contrast exhibited more stable time resolution for the same interaction locations (~34 ns to ~83 ns FWHM), provided more linear spatial positioning in the direction orthogonal to the electrode planes, and as much as 68.4% improvement in photon sensitivity over the 3 mm wide cathode strips. The results were understood by analyzing the cathode strips’ weighting functions, which indicated a stronger “small pixel” effect in the 3 mm wide cathode strips. Photon sensitivity and anode energy resolution were seen to improve with decreasing steering electrode bias from 0 V to −80 V w.r.t the anode potential. A slight improvement in energy resolution was seen for wider steering electrode strips (400 μm vs. 100 μm) for charge-shared photon interactions. Although this study successfully focused on electrode pattern features for PET performance, the results are generally applicable to semiconductor photon detectors employing cross-trip electrode patterns. PMID:24786208

  16. Quantum key distribution over 120 km using ultrahigh purity single-photon source and superconducting single-photon detectors.

    PubMed

    Takemoto, Kazuya; Nambu, Yoshihiro; Miyazawa, Toshiyuki; Sakuma, Yoshiki; Yamamoto, Tsuyoshi; Yorozu, Shinichi; Arakawa, Yasuhiko

    2015-09-25

    Advances in single-photon sources (SPSs) and single-photon detectors (SPDs) promise unique applications in the field of quantum information technology. In this paper, we report long-distance quantum key distribution (QKD) by using state-of-the-art devices: a quantum-dot SPS (QD SPS) emitting a photon in the telecom band of 1.5 μm and a superconducting nanowire SPD (SNSPD). At the distance of 100 km, we obtained the maximal secure key rate of 27.6 bps without using decoy states, which is at least threefold larger than the rate obtained in the previously reported 50-km-long QKD experiment. We also succeeded in transmitting secure keys at the rate of 0.307 bps over 120 km. This is the longest QKD distance yet reported by using known true SPSs. The ultralow multiphoton emissions of our SPS and ultralow dark count of the SNSPD contributed to this result. The experimental results demonstrate the potential applicability of QD SPSs to practical telecom QKD networks.

  17. Photonic sources and detectors for quantum information protocols: A trilogy in eight parts

    NASA Astrophysics Data System (ADS)

    Rangarajan, Radhika

    Quantum information processing (QIP) promises to revolutionize existing methods of manipulating data, via truly unique paradigms based on fundamental nonclassical physical phenomenon. However, the eventual success of optical QIP depends critically on the available technologies. Currently, creating multiple-photon states is extremely inefficient because almost no source thus far has been well optimized. Additionally, high-efficiency single-photon detectors can drastically improve multi-photon QIP (typical efficiencies are ˜70%). In fact, it has been shown that scalable linear optical quantum computing is possible only if the product of the source and detector efficiencies exceeds ˜67%. The research presented here focuses on developing optimized source and detector technologies for enabling scalable QIP. The goal of our source research is to develop an ideal " indistinguishable" source of ultrabright polarization-entangled but spatially- and spectrally-unentangled photon pairs. We engineer such an ideal source by first designing spatio-spectrally unentangled photons using optimized and group-velocity matched spontaneous parametric down conversion (SPDC). Next, we generate polarization-entangled photons using the engineered SPDC. Here we present solutions to the various challenges encountered during the indistinguishable source development. We demonstrate high-fidelity ultrafast pulsed and cw-diode laser-pumped sources of polarization-entangled photons, as well as the first production of polarization-entanglement directly from the highly nonlinear biaxial crystal BiB3O6 (BiBO). We also discuss the first experimental confirmation of the emission-angle dependence of the downconversion polarization (the Migdall effect), and a novel scheme for polarization-dependent focusing. The goal of our single-photon detector research is to develop a very high-efficiency detection system that can also resolve incident photon number, a feature absent from the typical detectors employed for QIP. We discuss the various cryogenic, optical and electronic challenges encountered en route to detector development and present details on detector characterization, ultra-short electronics design and photon-number-resolution studies. The source and detector technologies developed here share a common goal: to enhance the efficiency of existing quantum protocols and pave the way for new ones. Here we discuss some of the possible benefits via a popular quantum protocol---teleportation---as well as a novel quantum communication technique---hyper-fingerprinting. Taken as a whole, this dissertation explores viable technological options for enhancing optical quantum information protocols, offers a perspective on the current status and limitations of existing technologies, and highlights the possibilities enabled by optimized photonic sources and detectors.

  18. Waveguide integrated superconducting single-photon detectors with high internal quantum efficiency at telecom wavelengths

    PubMed Central

    Kahl, Oliver; Ferrari, Simone; Kovalyuk, Vadim; Goltsman, Gregory N.; Korneev, Alexander; Pernice, Wolfram H. P.

    2015-01-01

    Superconducting nanowire single-photon detectors (SNSPDs) provide high efficiency for detecting individual photons while keeping dark counts and timing jitter minimal. Besides superior detection performance over a broad optical bandwidth, compatibility with an integrated optical platform is a crucial requirement for applications in emerging quantum photonic technologies. Here we present SNSPDs embedded in nanophotonic integrated circuits which achieve internal quantum efficiencies close to unity at 1550 nm wavelength. This allows for the SNSPDs to be operated at bias currents far below the critical current where unwanted dark count events reach milli-Hz levels while on-chip detection efficiencies above 70% are maintained. The measured dark count rates correspond to noise-equivalent powers in the 10−19 W/Hz−1/2 range and the timing jitter is as low as 35 ps. Our detectors are fully scalable and interface directly with waveguide-based optical platforms. PMID:26061283

  19. Waveguide integrated superconducting single-photon detectors with high internal quantum efficiency at telecom wavelengths.

    PubMed

    Kahl, Oliver; Ferrari, Simone; Kovalyuk, Vadim; Goltsman, Gregory N; Korneev, Alexander; Pernice, Wolfram H P

    2015-06-10

    Superconducting nanowire single-photon detectors (SNSPDs) provide high efficiency for detecting individual photons while keeping dark counts and timing jitter minimal. Besides superior detection performance over a broad optical bandwidth, compatibility with an integrated optical platform is a crucial requirement for applications in emerging quantum photonic technologies. Here we present SNSPDs embedded in nanophotonic integrated circuits which achieve internal quantum efficiencies close to unity at 1550 nm wavelength. This allows for the SNSPDs to be operated at bias currents far below the critical current where unwanted dark count events reach milli-Hz levels while on-chip detection efficiencies above 70% are maintained. The measured dark count rates correspond to noise-equivalent powers in the 10(-19) W/Hz(-1/2) range and the timing jitter is as low as 35 ps. Our detectors are fully scalable and interface directly with waveguide-based optical platforms.

  20. A compact fiber-optic probe-based singlet oxygen luminescence detection system.

    PubMed

    Gemmell, Nathan R; McCarthy, Aongus; Kim, Michele M; Veilleux, Israel; Zhu, Timothy C; Buller, Gerald S; Wilson, Brian C; Hadfield, Robert H

    2017-02-01

    This paper presents a novel compact fiberoptic based singlet oxygen near-infrared luminescence probe coupled to an InGaAs/InP single photon avalanche diode (SPAD) detector. Patterned time gating of the single-photon detector is used to limit unwanted dark counts and eliminate the strong photosensitizer luminescence background. Singlet oxygen luminescence detection at 1270 nm is confirmed through spectral filtering and lifetime fitting for Rose Bengal in water, and Photofrin in methanol as model photosensitizers. The overall performance, measured by the signal-to-noise ratio, improves by a factor of 50 over a previous system that used a fiberoptic-coupled superconducting nanowire single-photon detector. The effect of adding light scattering to the photosensitizer is also examined as a first step towards applications in tissue in vivo. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. A superconducting focal plane array for ultraviolet, optical, and near-infrared astrophysics.

    PubMed

    Mazin, Benjamin A; Bumble, Bruce; Meeker, Seth R; O'Brien, Kieran; McHugh, Sean; Langman, Eric

    2012-01-16

    Microwave Kinetic Inductance Detectors, or MKIDs, have proven to be a powerful cryogenic detector technology due to their sensitivity and the ease with which they can be multiplexed into large arrays. A MKID is an energy sensor based on a photon-variable superconducting inductance in a lithographed microresonator, and is capable of functioning as a photon detector across the electromagnetic spectrum as well as a particle detector. Here we describe the first successful effort to create a photon-counting, energy-resolving ultraviolet, optical, and near infrared MKID focal plane array. These new Optical Lumped Element (OLE) MKID arrays have significant advantages over semiconductor detectors like charge coupled devices (CCDs). They can count individual photons with essentially no false counts and determine the energy and arrival time of every photon with good quantum efficiency. Their physical pixel size and maximum count rate is well matched with large telescopes. These capabilities enable powerful new astrophysical instruments usable from the ground and space. MKIDs could eventually supplant semiconductor detectors for most astronomical instrumentation, and will be useful for other disciplines such as quantum optics and biological imaging.

  2. High speed superconducting nanowire single-photon detector with nine interleaved nanowires

    NASA Astrophysics Data System (ADS)

    Huang, Jia; Zhang, Weijun; You, Lixing; Zhang, Chengjun; Lv, Chaolin; Wang, Yong; Liu, Xiaoyu; Li, Hao; Wang, Zhen

    2018-07-01

    Count rate (CR) is one of the key parameters of superconducting nanowire single-photon detectors (SNSPDs). The practical SNSPDs usually have a CR of a few MHz to a few tens of MHz owing to the large kinetic inductance originating from the long nanowire, which is necessary for effectively coupling the photons. A feasible approach to decrease the kinetic inductance and consequently increase the detection speed is to replace a long single nanowire with multiple individual nanowires in an array. In this study, we report an SNSPD of nine interleaved nanowires with 70% system detection efficiency (SDE) and 200 Hz dark count rate at the low-photon-flux limit of 1550 nm. Owing to the small dead time (<6 ns) of each nanowire, the SNSPD achieved a maximum CR of 0.93 GHz at a photon flux of 1.26 × 1010 photons s‑1 with an SDE of ∼7.4%, and a CR of 200 MHz with an SDE of over 50%. Furthermore, a photon number resolvability of up to nine photons was also demonstrated.

  3. Sensitivity of photon-counting based K-edge imaging in X-ray computed tomography.

    PubMed

    Roessl, Ewald; Brendel, Bernhard; Engel, Klaus-Jürgen; Schlomka, Jens-Peter; Thran, Axel; Proksa, Roland

    2011-09-01

    The feasibility of K-edge imaging using energy-resolved, photon-counting transmission measurements in X-ray computed tomography (CT) has been demonstrated by simulations and experiments. The method is based on probing the discontinuities of the attenuation coefficient of heavy elements above and below the K-edge energy by using energy-sensitive, photon counting X-ray detectors. In this paper, we investigate the dependence of the sensitivity of K-edge imaging on the atomic number Z of the contrast material, on the object diameter D , on the spectral response of the X-ray detector and on the X-ray tube voltage. We assume a photon-counting detector equipped with six adjustable energy thresholds. Physical effects leading to a degradation of the energy resolution of the detector are taken into account using the concept of a spectral response function R(E,U) for which we assume four different models. As a validation of our analytical considerations and in order to investigate the influence of elliptically shaped phantoms, we provide CT simulations of an anthropomorphic Forbild-Abdomen phantom containing a gold-contrast agent. The dependence on the values of the energy thresholds is taken into account by optimizing the achievable signal-to-noise ratios (SNR) with respect to the threshold values. We find that for a given X-ray spectrum and object size the SNR in the heavy element's basis material image peaks for a certain atomic number Z. The dependence of the SNR in the high- Z basis-material image on the object diameter is the natural, exponential decrease with particularly deteriorating effects in the case where the attenuation from the object itself causes a total signal loss below the K-edge. The influence of the energy-response of the detector is very important. We observed that the optimal SNR values obtained with an ideal detector and with a CdTe pixel detector whose response, showing significant tailing, has been determined at a synchrotron differ by factors of about two to three. The potentially very important impact of scattered X-ray radiation and pulse pile-up occurring at high photon rates on the sensitivity of the technique is qualitatively discussed.

  4. 125 GHz sine wave gating InGaAs/InP single-photon detector with a monolithically integrated readout circuit

    NASA Astrophysics Data System (ADS)

    Jiang, Wen-Hao; Liu, Jian-Hong; Liu, Yin; Jin, Ge; Zhang, Jun; Pan, Jian-Wei

    2017-12-01

    InGaAs/InP single-photon detectors (SPDs) are the key devices for applications requiring near-infrared single-photon detection. Gating mode is an effective approach to synchronous single-photon detection. Increasing gating frequency and reducing module size are important challenges for the design of such detector system. Here we present for the first time an InGaAs/InP SPD with 1.25 GHz sine wave gating using a monolithically integrated readout circuit (MIRC). The MIRC has a size of 15 mm * 15 mm and implements the miniaturization of avalanche extraction for high-frequency sine wave gating. In the MIRC, low-pass filters and a low-noise radio frequency amplifier are integrated based on the technique of low temperature co-fired ceramic, which can effectively reduce the parasitic capacitance and extract weak avalanche signals. We then characterize the InGaAs/InP SPD to verify the functionality and reliability of MIRC, and the SPD exhibits excellent performance with 27.5 % photon detection efficiency, 1.2 kcps dark count rate, and 9.1 % afterpulse probability at 223 K and 100 ns hold-off time. With this MIRC, one can further design miniaturized high-frequency SPD modules that are highly required for practical applications.

  5. Free-space-coupled superconducting nanowire single-photon detectors for infrared optical communications.

    PubMed

    Bellei, Francesco; Cartwright, Alyssa P; McCaughan, Adam N; Dane, Andrew E; Najafi, Faraz; Zhao, Qingyuan; Berggren, Karl K

    2016-02-22

    This paper describes the construction of a cryostat and an optical system with a free-space coupling efficiency of 56.5% ± 3.4% to a superconducting nanowire single-photon detector (SNSPD) for infrared quantum communication and spectrum analysis. A 1K pot decreases the base temperature to T = 1.7 K from the 2.9 K reached by the cold head cooled by a pulse-tube cryocooler. The minimum spot size coupled to the detector chip was 6.6 ± 0.11 µm starting from a fiber source at wavelength, λ = 1.55 µm. We demonstrated photon counting on a detector with an 8 × 7.3 µm2 area. We measured a dark count rate of 95 ± 3.35 kcps and a system detection efficiency of 1.64% ± 0.13%. We explain the key steps that are required to improve further the coupling efficiency.

  6. Detector with internal gain for short-wave infrared ranging applications

    NASA Astrophysics Data System (ADS)

    Fathipour, Vala; Mohseni, Hooman

    2017-09-01

    Abstarct.Highly sensitive photon detectors are regarded as the key enabling elements in many applications. Due to the low photon energy at the short-wave infrared (SWIR), photon detection and imaging at this band are very challenging. As such, many efforts in photon detector research are directed toward improving the performance of the photon detectors operating in this wavelength range. To solve these problems, we have developed an electron-injection (EI) technique. The significance of this detection mechanism is that it can provide both high efficiency and high sensitivity at room temperature, a condition that is very difficult to achieve in conventional SWIR detectors. An EI detector offers an overall system-level sensitivity enhancement due to a feedback stabilized internal avalanche-free gain. Devices exhibit an excess noise of unity, operate in linear mode, require bias voltage of a few volts, and have a cutoff wavelength of 1700 nm. We review the material system, operating principle, and development of EI detectors. The shortcomings of the first-generation devices were addressed in the second-generation detectors. Measurement on second-generation devices showed a high-speed response of ˜6 ns rise time, low jitter of less than 20 ps, high amplification of more than 2000 (at optical power levels larger than a few nW), unity excess noise factor, and low leakage current (amplified dark current ˜10 nA at a bias voltage of -3 V and at room temperature. These characteristics make EI detectors a good candidate for high-resolution flash light detection and ranging (LiDAR) applications with millimeter scale depth resolution at longer ranges compared with conventional p-i-n diodes. Based on our experimentally measured device characteristics, we compare the performance of the EI detector with commercially available linear mode InGaAs avalanche photodiode (APD) as well as a p-i-n diode using a theoretical model. Flash LiDAR images obtained by our model show that the EI detector array achieves better resolution with higher signal-to-noise compared with both the InGaAs APD and the p-i-n array (of 100×100 elements). We have designed a laboratory setup with a receiver optics aperture diameter of 3 mm that allows an EI detector (with 30-μm absorber diameter) to be used for long-range LiDAR imaging with subcentimeter resolution.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/872857','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/872857"><span>Low-resistivity photon-transparent window attached to photo-sensitive silicon detector</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Holland, Stephen Edward</p> <p>2000-02-15</p> <p>The invention comprises a combination of a low resistivity, or electrically conducting, silicon layer that is transparent to long or short wavelength photons and is attached to the backside of a photon-sensitive layer of silicon, such as a silicon wafer or chip. The window is applied to photon sensitive silicon devices such as photodiodes, charge-coupled devices, active pixel sensors, low-energy x-ray sensors and other radiation detectors. The silicon window is applied to the back side of a photosensitive silicon wafer or chip so that photons can illuminate the device from the backside without interference from the circuit printed on the frontside. A voltage sufficient to fully deplete the high-resistivity photosensitive silicon volume of charge carriers is applied between the low-resistivity back window and the front, patterned, side of the device. This allows photon-induced charge created at the backside to reach the front side of the device and to be processed by any circuitry attached to the front side. Using the inventive combination, the photon sensitive silicon layer does not need to be thinned beyond standard fabrication methods in order to achieve full charge-depletion in the silicon volume. In one embodiment, the inventive backside window is applied to high resistivity silicon to allow backside illumination while maintaining charge isolation in CCD pixels.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1263388-radio-hidden-photon-dark-matter-detection','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1263388-radio-hidden-photon-dark-matter-detection"><span>Radio for hidden-photon dark matter detection</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Chaudhuri, Saptarshi; Graham, Peter W.; Irwin, Kent; ...</p> <p>2015-10-08</p> <p>We propose a resonant electromagnetic detector to search for hidden-photon dark matter over an extensive range of masses. Hidden-photon dark matter can be described as a weakly coupled “hidden electric field,” oscillating at a frequency fixed by the mass, and able to penetrate any shielding. At low frequencies (compared to the inverse size of the shielding), we find that the observable effect of the hidden photon inside any shielding is a real, oscillating magnetic field. We outline experimental setups designed to search for hidden-photon dark matter, using a tunable, resonant LC circuit designed to couple to this magnetic field. Ourmore » “straw man” setups take into consideration resonator design, readout architecture and noise estimates. At high frequencies, there is an upper limit to the useful size of a single resonator set by 1/ν. However, many resonators may be multiplexed within a hidden-photon coherence length to increase the sensitivity in this regime. Hidden-photon dark matter has an enormous range of possible frequencies, but current experiments search only over a few narrow pieces of that range. As a result, we find the potential sensitivity of our proposal is many orders of magnitude beyond current limits over an extensive range of frequencies, from 100 Hz up to 700 GHz and potentially higher.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/20853503-development-new-signal-processor-tetralateral-position-sensitive-detector-based-single-chip-microcomputer','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/20853503-development-new-signal-processor-tetralateral-position-sensitive-detector-based-single-chip-microcomputer"><span>Development of a new signal processor for tetralateral position sensitive detector based on single-chip microcomputer</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Huang Meizhen; Shi Longzhao; Wang Yuxing</p> <p>2006-08-15</p> <p>An inherently nonlinear relation between the output current of the tetralateral position sensitive detector (PSD) and the position of the incident light spot has been found theoretically. Based on single-chip microcomputer and the theoretical relation between output current and position, a new signal processor capable of correcting nonlinearity and reducing position measurement deviation of tetralateral PSD was developed. A tetralateral PSD (S1200, 13x13 mm{sup 2}, Hamamatsu Photonics K.K.) was measured with the new signal processor, a linear relation between the output position of the PSD, and the incident position of the light spot was obtained. In the 60% range ofmore » a 13x13 mm{sup 2} active area, the position nonlinearity (rms) was 0.15% and the position measurement deviation (rms) was {+-}20 {mu}m. Compared with traditional analog signal processor, the new signal processor is of better compatibility, lower cost, higher precision, and easier to be interfaced.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006RScI...77h3301H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006RScI...77h3301H"><span>Development of a new signal processor for tetralateral position sensitive detector based on single-chip microcomputer</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Huang, Mei-Zhen; Shi, Long-Zhao; Wang, Yu-Xing; Ni, Yi; Li, Zhen-Qing; Ding, Hai-Feng</p> <p>2006-08-01</p> <p>An inherently nonlinear relation between the output current of the tetralateral position sensitive detector (PSD) and the position of the incident light spot has been found theoretically. Based on single-chip microcomputer and the theoretical relation between output current and position, a new signal processor capable of correcting nonlinearity and reducing position measurement deviation of tetralateral PSD was developed. A tetralateral PSD (S1200, 13×13mm2, Hamamatsu Photonics K.K.) was measured with the new signal processor, a linear relation between the output position of the PSD, and the incident position of the light spot was obtained. In the 60% range of a 13×13mm2 active area, the position nonlinearity (rms) was 0.15% and the position measurement deviation (rms) was ±20μm. Compared with traditional analog signal processor, the new signal processor is of better compatibility, lower cost, higher precision, and easier to be interfaced.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/869742','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/869742"><span>Photon beam position monitor</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Kuzay, Tuncer M.; Shu, Deming</p> <p>1995-01-01</p> <p>A photon beam position monitor for use in the front end of a beamline of a high heat flux and high energy photon source such as a synchrotron radiation storage ring detects and measures the position and, when a pair of such monitors are used in tandem, the slope of a photon beam emanating from an insertion device such as a wiggler or an undulator inserted in the straight sections of the ring. The photon beam position monitor includes a plurality of spaced blades for precisely locating the photon beam, with each blade comprised of chemical vapor deposition (CVD) diamond with an outer metal coating of a photon sensitive metal such as tungsten, molybdenum, etc., which combination emits electrons when a high energy photon beam is incident upon the blade. Two such monitors are contemplated for use in the front end of the beamline, with the two monitors having vertically and horizontally offset detector blades to avoid blade "shadowing". Provision is made for aligning the detector blades with the photon beam and limiting detector blade temperature during operation.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011APS..MARA29003B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011APS..MARA29003B"><span>High-speed single-photon signaling for daytime QKD</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bienfang, Joshua; Restelli, Alessandro; Clark, Charles</p> <p>2011-03-01</p> <p>The distribution of quantum-generated cryptographic key at high throughputs can be critically limited by the performance of the systems' single-photon detectors. While noise and afterpulsing are considerations for all single-photon QKD systems, high-transmission rate systems also have critical detector timing-resolution and recovery time requirements. We present experimental results exploiting the high timing resolution and count-rate stability of modified single-photon avalanche diodes (SPADs) in our GHz QKD system operating over a 1.5 km free-space link that demonstrate the ability to apply extremely short temporal gates, enabling daytime free-space QKD with a 4% QBER. We also discuss recent advances in gating techniques for InGaAs SPADs that are suitable for high-speed fiber-based QKD. We present afterpulse-probability measurements that demonstrate the ability to support single-photon count rates above 100 MHz with low afterpulse probability. These results will benefit the design and characterization of free-space and fiber QKD systems. A. Restelli, J.C. Bienfang A. Mink, and C.W. Clark, IEEE J. Sel. Topics in Quant. Electron 16, 1084 (2010).</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JPhB...51l5501Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JPhB...51l5501Y"><span>Entanglement generation and manipulation in the Hong-Ou-Mandel experiment: a hidden scenario beyond two-photon interference</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yang, Li-Kai; Cai, Han; Peng, Tao; Wang, Da-Wei</p> <p>2018-06-01</p> <p>The Hong‑Ou‑Mandel (HOM) effect was long believed to be a two-photon interference phenomenon. It describes the fact that two indistinguishable photons mixed at a beam splitter will bunch together to one of the two output modes. Considering the two single-photon emitters such as trapped ions, we explore a hidden scenario of the HOM effect, where entanglement can be generated between the two ions when a single photon is detected by one of the detectors. A second photon emitted by the entangled photon sources will be subsequently detected by the same detector. However, we can also control the fate of the second photon by manipulating the entangled state. Instead of two-photon interference, the phase of the entangled state is responsible for the photon’s path in our proposal. Toward a feasible experimental realization, we conduct a quantum jump simulation on the system to show its robustness against experimental errors.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22398882-waveguide-integrated-single-multi-photon-detection-telecom-wavelengths-using-superconducting-nanowires','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22398882-waveguide-integrated-single-multi-photon-detection-telecom-wavelengths-using-superconducting-nanowires"><span>Waveguide-integrated single- and multi-photon detection at telecom wavelengths using superconducting nanowires</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Ferrari, Simone; Kahl, Oliver; Kovalyuk, Vadim</p> <p></p> <p>We investigate single- and multi-photon detection regimes of superconducting nanowire detectors embedded in silicon nitride nanophotonic circuits. At near-infrared wavelengths, simultaneous detection of up to three photons is observed for 120 nm wide nanowires biased far from the critical current, while narrow nanowires below 100 nm provide efficient single photon detection. A theoretical model is proposed to determine the different detection regimes and to calculate the corresponding internal quantum efficiency. The predicted saturation of the internal quantum efficiency in the single photon regime agrees well with plateau behavior observed at high bias currents.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3095970','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3095970"><span>MicroCT with energy-resolved photon-counting detectors</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Wang, X; Meier, D; Mikkelsen, S; Maehlum, G E; Wagenaar, D J; Tsui, BMW; Patt, B E; Frey, E C</p> <p>2011-01-01</p> <p>The goal of this paper was to investigate the benefits that could be realistically achieved on a microCT imaging system with an energy-resolved photon-counting x-ray detector. To this end, we built and evaluated a prototype microCT system based on such a detector. The detector is based on cadmium telluride (CdTe) radiation sensors and application-specific integrated circuit (ASIC) readouts. Each detector pixel can simultaneously count x-ray photons above six energy thresholds, providing the capability for energy-selective x-ray imaging. We tested the spectroscopic performance of the system using polychromatic x-ray radiation and various filtering materials with Kabsorption edges. Tomographic images were then acquired of a cylindrical PMMA phantom containing holes filled with various materials. Results were also compared with those acquired using an intensity-integrating x-ray detector and single-energy (i.e. non-energy-selective) CT. This paper describes the functionality and performance of the system, and presents preliminary spectroscopic and tomographic results. The spectroscopic experiments showed that the energy-resolved photon-counting detector was capable of measuring energy spectra from polychromatic sources like a standard x-ray tube, and resolving absorption edges present in the energy range used for imaging. However, the spectral quality was degraded by spectral distortions resulting from degrading factors, including finite energy resolution and charge sharing. We developed a simple charge-sharing model to reproduce these distortions. The tomographic experiments showed that the availability of multiple energy thresholds in the photon-counting detector allowed us to simultaneously measure target-to-background contrasts in different energy ranges. Compared with single-energy CT with an integrating detector, this feature was especially useful to improve differentiation of materials with different attenuation coefficient energy dependences. PMID:21464527</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21464527','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21464527"><span>MicroCT with energy-resolved photon-counting detectors.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, X; Meier, D; Mikkelsen, S; Maehlum, G E; Wagenaar, D J; Tsui, B M W; Patt, B E; Frey, E C</p> <p>2011-05-07</p> <p>The goal of this paper was to investigate the benefits that could be realistically achieved on a microCT imaging system with an energy-resolved photon-counting x-ray detector. To this end, we built and evaluated a prototype microCT system based on such a detector. The detector is based on cadmium telluride (CdTe) radiation sensors and application-specific integrated circuit (ASIC) readouts. Each detector pixel can simultaneously count x-ray photons above six energy thresholds, providing the capability for energy-selective x-ray imaging. We tested the spectroscopic performance of the system using polychromatic x-ray radiation and various filtering materials with K-absorption edges. Tomographic images were then acquired of a cylindrical PMMA phantom containing holes filled with various materials. Results were also compared with those acquired using an intensity-integrating x-ray detector and single-energy (i.e. non-energy-selective) CT. This paper describes the functionality and performance of the system, and presents preliminary spectroscopic and tomographic results. The spectroscopic experiments showed that the energy-resolved photon-counting detector was capable of measuring energy spectra from polychromatic sources like a standard x-ray tube, and resolving absorption edges present in the energy range used for imaging. However, the spectral quality was degraded by spectral distortions resulting from degrading factors, including finite energy resolution and charge sharing. We developed a simple charge-sharing model to reproduce these distortions. The tomographic experiments showed that the availability of multiple energy thresholds in the photon-counting detector allowed us to simultaneously measure target-to-background contrasts in different energy ranges. Compared with single-energy CT with an integrating detector, this feature was especially useful to improve differentiation of materials with different attenuation coefficient energy dependences.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018LTP....44..213S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018LTP....44..213S"><span>Frequency-tuned microwave photon counter based on a superconductive quantum interferometer</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shnyrkov, V. I.; Yangcao, Wu; Soroka, A. A.; Turutanov, O. G.; Lyakhno, V. Yu.</p> <p>2018-03-01</p> <p>Various types of single-photon counters operating in infrared, ultraviolet, and optical wavelength ranges are successfully used to study electromagnetic fields, analyze radiation sources, and solve problems in quantum informatics. However, their operating principles become ineffective at millimeter band, S-band, and ultra-high frequency bands of wavelengths due to the decrease in quantum energy by 4-5 orders of magnitude. Josephson circuits with discrete Hamiltonians and qubits are a good foundation for the construction of single-photon counters at these frequencies. This paper presents a frequency-tuned microwave photon counter based on a single-junction superconducting quantum interferometer and flux qutrit. The control pulse converts the interferometer into a two-level system for resonance absorption of photons. Decay of the photon-induced excited state changes the magnetic flux in the interferometer, which is measured by a SQUID magnetometer. Schemes for recording the magnetic flux using a DC SQUID or ideal parametric detector, based on a qutrit with high-frequency excitation, are discussed. It is shown that the counter consisting of an interferometer with a Josephson junction and a parametric detector demonstrates high performance and is capable of detecting single photons in a microwave band.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28548532','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28548532"><span>Time-Bin-Encoded Boson Sampling with a Single-Photon Device.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>He, Yu; Ding, X; Su, Z-E; Huang, H-L; Qin, J; Wang, C; Unsleber, S; Chen, C; Wang, H; He, Y-M; Wang, X-L; Zhang, W-J; Chen, S-J; Schneider, C; Kamp, M; You, L-X; Wang, Z; Höfling, S; Lu, Chao-Yang; Pan, Jian-Wei</p> <p>2017-05-12</p> <p>Boson sampling is a problem strongly believed to be intractable for classical computers, but can be naturally solved on a specialized photonic quantum simulator. Here, we implement the first time-bin-encoded boson sampling using a highly indistinguishable (∼94%) single-photon source based on a single quantum-dot-micropillar device. The protocol requires only one single-photon source, two detectors, and a loop-based interferometer for an arbitrary number of photons. The single-photon pulse train is time-bin encoded and deterministically injected into an electrically programmable multimode network. The observed three- and four-photon boson sampling rates are 18.8 and 0.2 Hz, respectively, which are more than 100 times faster than previous experiments based on parametric down-conversion.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22521972-use-shot-noise-photon-counting','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22521972-use-shot-noise-photon-counting"><span>ON THE USE OF SHOT NOISE FOR PHOTON COUNTING</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Zmuidzinas, Jonas, E-mail: jonas@caltech.edu</p> <p></p> <p>Lieu et al. have recently claimed that it is possible to substantially improve the sensitivity of radio-astronomical observations. In essence, their proposal is to make use of the intensity of the photon shot noise as a measure of the photon arrival rate. Lieu et al. provide a detailed quantum-mechanical calculation of a proposed measurement scheme that uses two detectors and conclude that this scheme avoids the sensitivity degradation that is associated with photon bunching. If correct, this result could have a profound impact on radio astronomy. Here I present a detailed analysis of the sensitivity attainable using shot-noise measurement schemesmore » that use either one or two detectors, and demonstrate that neither scheme can avoid the photon bunching penalty. I perform both semiclassical and fully quantum calculations of the sensitivity, obtaining consistent results, and provide a formal proof of the equivalence of these two approaches. These direct calculations are furthermore shown to be consistent with an indirect argument based on a correlation method that establishes an independent limit to the sensitivity of shot-noise measurement schemes. Furthermore, these calculations are directly applicable to the regime of interest identified by Lieu et al. Collectively, these results conclusively demonstrate that the photon-bunching sensitivity penalty applies to shot-noise measurement schemes just as it does to ordinary photon counting, in contradiction to the fundamental claim made by Lieu et al. The source of this contradiction is traced to a logical fallacy in their argument.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23093759','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23093759"><span>X-ray photon correlation spectroscopy using a fast pixel array detector with a grid mask resolution enhancer.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hoshino, Taiki; Kikuchi, Moriya; Murakami, Daiki; Harada, Yoshiko; Mitamura, Koji; Ito, Kiminori; Tanaka, Yoshihito; Sasaki, Sono; Takata, Masaki; Jinnai, Hiroshi; Takahara, Atsushi</p> <p>2012-11-01</p> <p>The performance of a fast pixel array detector with a grid mask resolution enhancer has been demonstrated for X-ray photon correlation spectroscopy (XPCS) measurements to investigate fast dynamics on a microscopic scale. A detecting system, in which each pixel of a single-photon-counting pixel array detector, PILATUS, is covered by grid mask apertures, was constructed for XPCS measurements of silica nanoparticles in polymer melts. The experimental results are confirmed to be consistent by comparison with other independent experiments. By applying this method, XPCS measurements can be carried out by customizing the hole size of the grid mask to suit the experimental conditions, such as beam size, detector size and sample-to-detector distance.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_12 --> <div id="page_13" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="241"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26745406','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26745406"><span>Photon-HDF5: An Open File Format for Timestamp-Based Single-Molecule Fluorescence Experiments.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ingargiola, Antonino; Laurence, Ted; Boutelle, Robert; Weiss, Shimon; Michalet, Xavier</p> <p>2016-01-05</p> <p>We introduce Photon-HDF5, an open and efficient file format to simplify exchange and long-term accessibility of data from single-molecule fluorescence experiments based on photon-counting detectors such as single-photon avalanche diode, photomultiplier tube, or arrays of such detectors. The format is based on HDF5, a widely used platform- and language-independent hierarchical file format for which user-friendly viewers are available. Photon-HDF5 can store raw photon data (timestamp, channel number, etc.) from any acquisition hardware, but also setup and sample description, information on provenance, authorship and other metadata, and is flexible enough to include any kind of custom data. The format specifications are hosted on a public website, which is open to contributions by the biophysics community. As an initial resource, the website provides code examples to read Photon-HDF5 files in several programming languages and a reference Python library (phconvert), to create new Photon-HDF5 files and convert several existing file formats into Photon-HDF5. To encourage adoption by the academic and commercial communities, all software is released under the MIT open source license. Copyright © 2016 Biophysical Society. Published by Elsevier Inc. All rights reserved.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4805879','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4805879"><span>Photon-HDF5: An Open File Format for Timestamp-Based Single-Molecule Fluorescence Experiments</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Ingargiola, Antonino; Laurence, Ted; Boutelle, Robert; Weiss, Shimon; Michalet, Xavier</p> <p>2016-01-01</p> <p>We introduce Photon-HDF5, an open and efficient file format to simplify exchange and long-term accessibility of data from single-molecule fluorescence experiments based on photon-counting detectors such as single-photon avalanche diode, photomultiplier tube, or arrays of such detectors. The format is based on HDF5, a widely used platform- and language-independent hierarchical file format for which user-friendly viewers are available. Photon-HDF5 can store raw photon data (timestamp, channel number, etc.) from any acquisition hardware, but also setup and sample description, information on provenance, authorship and other metadata, and is flexible enough to include any kind of custom data. The format specifications are hosted on a public website, which is open to contributions by the biophysics community. As an initial resource, the website provides code examples to read Photon-HDF5 files in several programming languages and a reference Python library (phconvert), to create new Photon-HDF5 files and convert several existing file formats into Photon-HDF5. To encourage adoption by the academic and commercial communities, all software is released under the MIT open source license. PMID:26745406</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24971965','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24971965"><span>Measuring partial fluorescence yield using filtered detectors.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Boyko, T D; Green, R J; Moewes, A; Regier, T Z</p> <p>2014-07-01</p> <p>Typically, X-ray absorption near-edge structure measurements aim to probe the linear attenuation coefficient. These measurements are often carried out using partial fluorescence yield techniques that rely on detectors having photon energy discrimination improving the sensitivity and the signal-to-background ratio of the measured spectra. However, measuring the partial fluorescence yield in the soft X-ray regime with reasonable efficiency requires solid-state detectors, which have limitations due to the inherent dead-time while measuring. Alternatively, many of the available detectors that are not energy dispersive do not suffer from photon count rate limitations. A filter placed in front of one of these detectors will make the energy-dependent efficiency non-linear, thereby changing the responsivity of the detector. It is shown that using an array of filtered X-ray detectors is a viable method for measuring soft X-ray partial fluorescence yield spectra without dead-time. The feasibility of this technique is further demonstrated using α-Fe2O3 as an example and it is shown that this detector technology could vastly improve the photon collection efficiency at synchrotrons and that these detectors will allow experiments to be completed with a much lower photon flux reducing X-ray-induced damage.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PhDT.......101Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PhDT.......101Z"><span>Pure sources and efficient detectors for optical quantum information processing</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zielnicki, Kevin</p> <p></p> <p>Over the last sixty years, classical information theory has revolutionized the understanding of the nature of information, and how it can be quantified and manipulated. Quantum information processing extends these lessons to quantum systems, where the properties of intrinsic uncertainty and entanglement fundamentally defy classical explanation. This growing field has many potential applications, including computing, cryptography, communication, and metrology. As inherently mobile quantum particles, photons are likely to play an important role in any mature large-scale quantum information processing system. However, the available methods for producing and detecting complex multi-photon states place practical limits on the feasibility of sophisticated optical quantum information processing experiments. In a typical quantum information protocol, a source first produces an interesting or useful quantum state (or set of states), perhaps involving superposition or entanglement. Then, some manipulations are performed on this state, perhaps involving quantum logic gates which further manipulate or entangle the intial state. Finally, the state must be detected, obtaining some desired measurement result, e.g., for secure communication or computationally efficient factoring. The work presented here concerns the first and last stages of this process as they relate to photons: sources and detectors. Our work on sources is based on the need for optimized non-classical states of light delivered at high rates, particularly of single photons in a pure quantum state. We seek to better understand the properties of spontaneous parameteric downconversion (SPDC) sources of photon pairs, and in doing so, produce such an optimized source. We report an SPDC source which produces pure heralded single photons with little or no spectral filtering, allowing a significant rate enhancement. Our work on detectors is based on the need to reliably measure single-photon states. We have focused on optimizing the detection efficiency of visible light photon counters (VLPCs), a single-photon detection technology that is also capable of resolving photon number states. We report a record-breaking quantum efficiency of 91 +/- 3% observed with our detection system. Both sources and detectors are independently interesting physical systems worthy of study, but together they promise to enable entire new classes and applications of information based on quantum mechanics.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012SPIE.8508E..07S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012SPIE.8508E..07S"><span>Dark-count-less photon-counting x-ray computed tomography system using a YAP-MPPC detector</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sato, Eiichi; Sato, Yuich; Abudurexiti, Abulajiang; Hagiwara, Osahiko; Matsukiyo, Hiroshi; Osawa, Akihiro; Enomoto, Toshiyuki; Watanabe, Manabu; Kusachi, Shinya; Sato, Shigehiro; Ogawa, Akira; Onagawa, Jun</p> <p>2012-10-01</p> <p>A high-sensitive X-ray computed tomography (CT) system is useful for decreasing absorbed dose for patients, and a dark-count-less photon-counting CT system was developed. X-ray photons are detected using a YAP(Ce) [cerium-doped yttrium aluminum perovskite] single crystal scintillator and an MPPC (multipixel photon counter). Photocurrents are amplified by a high-speed current-voltage amplifier, and smooth event pulses from an integrator are sent to a high-speed comparator. Then, logical pulses are produced from the comparator and are counted by a counter card. Tomography is accomplished by repeated linear scans and rotations of an object, and projection curves of the object are obtained by the linear scan. The image contrast of gadolinium medium slightly fell with increase in lower-level voltage (Vl) of the comparator. The dark count rate was 0 cps, and the count rate for the CT was approximately 250 kcps.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1439469','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1439469"><span>Photon Detector System Timing Performance in the DUNE 35-ton Prototype Liquid Argon Time Projection Chamber</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Adams, D.L.; et al.</p> <p></p> <p>The 35-ton prototype for the Deep Underground Neutrino Experiment far detector was a single-phase liquid argon time projection chamber with an integrated photon detector system, all situated inside a membrane cryostat. The detector took cosmic-ray data for six weeks during the period of February 1, 2016 to March 12, 2016. The performance of the photon detection system was checked with these data. An installed photon detector was demonstrated to measure the arrival times of cosmic-ray muons with a resolution better than 32 ns, limited by the timing of the trigger system. A measurement of the timing resolution using closely-spaced calibration pulses yielded a resolution of 15 ns for pulses at a level of 6 photo-electrons. Scintillation light from cosmic-ray muons was observed to be attenuated with increasing distance with a characteristic length ofmore » $$155 \\pm 28$$ cm.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22068665-superlinear-threshold-detectors-quantum-cryptography','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22068665-superlinear-threshold-detectors-quantum-cryptography"><span>Superlinear threshold detectors in quantum cryptography</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Lydersen, Lars; Maroey, Oystein; Skaar, Johannes</p> <p>2011-09-15</p> <p>We introduce the concept of a superlinear threshold detector, a detector that has a higher probability to detect multiple photons if it receives them simultaneously rather than at separate times. Highly superlinear threshold detectors in quantum key distribution systems allow eavesdropping the full secret key without being revealed. Here, we generalize the detector control attack, and analyze how it performs against quantum key distribution systems with moderately superlinear detectors. We quantify the superlinearity in superconducting single-photon detectors based on earlier published data, and gated avalanche photodiode detectors based on our own measurements. The analysis shows that quantum key distribution systemsmore » using detector(s) of either type can be vulnerable to eavesdropping. The avalanche photodiode detector becomes superlinear toward the end of the gate. For systems expecting substantial loss, or for systems not monitoring loss, this would allow eavesdropping using trigger pulses containing less than 120 photons per pulse. Such an attack would be virtually impossible to catch with an optical power meter at the receiver entrance.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011SPIE.8143E..0FW','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011SPIE.8143E..0FW"><span>High-performance imaging of stem cells using single-photon emissions</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wagenaar, Douglas J.; Moats, Rex A.; Hartsough, Neal E.; Meier, Dirk; Hugg, James W.; Yang, Tang; Gazit, Dan; Pelled, Gadi; Patt, Bradley E.</p> <p>2011-10-01</p> <p>Radiolabeled cells have been imaged for decades in the field of autoradiography. Recent advances in detector and microelectronics technologies have enabled the new field of "digital autoradiography" which remains limited to ex vivo specimens of thin tissue slices. The 3D field-of-view (FOV) of single cell imaging can be extended to millimeters if the low energy (10-30 keV) photon emissions of radionuclides are used for single-photon nuclear imaging. This new microscope uses a coded aperture foil made of highly attenuating elements such as gold or platinum to form the image as a kind of "lens". The detectors used for single-photon emission microscopy are typically silicon detectors with a pixel pitch less than 60 μm. The goal of this work is to image radiolabeled mesenchymal stem cells in vivo in an animal model of tendon repair processes. Single-photon nuclear imaging is an attractive modality for translational medicine since the labeled cells can be imaged simultaneously with the reparative processes by using the dual-isotope imaging technique. The details our microscope's two-layer gold aperture and the operation of the energy-dispersive, pixellated silicon detector are presented along with the first demonstration of energy discrimination with a 57Co source. Cell labeling techniques have been augmented by genetic engineering with the sodium-iodide symporter, a type of reporter gene imaging method that enables in vivo uptake of free 99mTc or an iodine isotope at a time point days or weeks after the insertion of the genetically modified stem cells into the animal model. This microscopy work in animal research may expand to the imaging of reporter-enabled stem cells simultaneously with the expected biological repair process in human clinical trials of stem cell therapies.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20460400','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20460400"><span>Monte carlo study of MOSFET packaging, optimised for improved energy response: single MOSFET filtration.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Othman, M A R; Cutajar, D L; Hardcastle, N; Guatelli, S; Rosenfeld, A B</p> <p>2010-09-01</p> <p>Monte Carlo simulations of the energy response of a conventionally packaged single metal-oxide field effect transistors (MOSFET) detector were performed with the goal of improving MOSFET energy dependence for personal accident or military dosimetry. The MOSFET detector packaging was optimised. Two different 'drop-in' design packages for a single MOSFET detector were modelled and optimised using the GEANT4 Monte Carlo toolkit. Absorbed photon dose simulations of the MOSFET dosemeter placed in free-air response, corresponding to the absorbed doses at depths of 0.07 mm (D(w)(0.07)) and 10 mm (D(w)(10)) in a water equivalent phantom of size 30 x 30 x 30 cm(3) for photon energies of 0.015-2 MeV were performed. Energy dependence was reduced to within + or - 60 % for photon energies 0.06-2 MeV for both D(w)(0.07) and D(w)(10). Variations in the response for photon energies of 15-60 keV were 200 and 330 % for D(w)(0.07) and D(w)(10), respectively. The obtained energy dependence was reduced compared with that for conventionally packaged MOSFET detectors, which usually exhibit a 500-700 % over-response when used in free-air geometry.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20080004054','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080004054"><span>Delta-doped hybrid advanced detector for low energy particle detection</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cunningham, Thomas J. (Inventor); Fossum, Eric R. (Inventor); Nikzad, Shouleh (Inventor); Pain, Bedabrata (Inventor); Soli, George A. (Inventor)</p> <p>2000-01-01</p> <p>A delta-doped hybrid advanced detector (HAD) is provided which combines at least four types of technologies to create a detector for energetic particles ranging in energy from hundreds of electron volts (eV) to beyond several million eV. The detector is sensitive to photons from visible light to X-rays. The detector is highly energy-sensitive from approximately 10 keV down to hundreds of eV. The detector operates with milliwatt power dissipation, and allows non-sequential readout of the array, enabling various advanced readout schemes.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20080005026','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080005026"><span>Delta-doped hybrid advanced detector for low energy particle detection</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cunningham, Thomas J. (Inventor); Fossum, Eric R. (Inventor); Nikzad, Shouleh (Inventor); Pain, Bedabrata (Inventor); Soli, George A. (Inventor)</p> <p>2002-01-01</p> <p>A delta-doped hybrid advanced detector (HAD) is provided which combines at least four types of technologies to create a detector for energetic particles ranging in energy from hundreds of electron volts (eV) to beyond several million eV. The detector is sensitive to photons from visible light to X-rays. The detector is highly energy-sensitive from approximately 10 keV down to hundreds of eV. The detector operates with milliwatt power dissipation, and allows non-sequential readout of the array, enabling various advanced readout schemes.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1327738','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1327738"><span>Electro-optic modulation for high-speed characterization of entangled photon pairs</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Lukens, Joseph M.; Odele, Ogaga D.; Leaird, Daniel E.</p> <p></p> <p>In this study, we demonstrate a new biphoton manipulation and characterization technique based on electro-optic intensity modulation and time shifting. By applying fast modulation signals with a sharply peaked cross-correlation to each photon from an entangled pair, it is possible to measure temporal correlations with significantly higher precision than that attainable using standard single-photon detection. Low-duty-cycle pulses and maximal-length sequences are considered as modulation functions, reducing the time spread in our correlation measurement by a factor of five compared to our detector jitter. With state-of-the-art electro-optic components, we expect the potential to surpass the speed of any single-photon detectors currentlymore » available.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1327738-electro-optic-modulation-high-speed-characterization-entangled-photon-pairs','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1327738-electro-optic-modulation-high-speed-characterization-entangled-photon-pairs"><span>Electro-optic modulation for high-speed characterization of entangled photon pairs</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Lukens, Joseph M.; Odele, Ogaga D.; Leaird, Daniel E.; ...</p> <p>2015-11-10</p> <p>In this study, we demonstrate a new biphoton manipulation and characterization technique based on electro-optic intensity modulation and time shifting. By applying fast modulation signals with a sharply peaked cross-correlation to each photon from an entangled pair, it is possible to measure temporal correlations with significantly higher precision than that attainable using standard single-photon detection. Low-duty-cycle pulses and maximal-length sequences are considered as modulation functions, reducing the time spread in our correlation measurement by a factor of five compared to our detector jitter. With state-of-the-art electro-optic components, we expect the potential to surpass the speed of any single-photon detectors currentlymore » available.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014SPIE.8952E..18L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014SPIE.8952E..18L"><span>Modeling and experimental validation of angular radiance and distance-dependent radiance in a turbid medium</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, Lingling; Li, Chenxi; Zhao, Huijuan; Yi, Xi; Gao, Feng; Meng, Wei; Lu, Yiming</p> <p>2014-03-01</p> <p>Radiance is sensitive to the variations of tissue optical parameters, such as absorption coefficient μa, scattering coefficient μs, and anisotropy factor g. Therefore, similar to fluence, radiance can be used for tissue characterization. Compared with fluence, radiance has the advantage of offering the direction information of light intensity. Taking such advantage, the optical parameters can be determined by rotating the detector through 360 deg with only a single optode pair. Instead of the translation mode used in the fluence-based technologies, the Rotation mode has less invasiveness in the clinical diagnosis. This paper explores a new method to obtain the optical properties by measuring the distribution of light intensity in liquid phantom with only a single optode pair and the detector rotation through 360 deg. The angular radiance and distance-dependent radiance are verified by comparing experimental measurement data with Monte Carlo (MC) simulation for the short source-detector separations and diffusion approximation for the large source-detector separations. Detecting angular radiance with only a single optode pair under a certain source-detection separation will present a way for prostate diagnose and light dose calculation during the photon dynamic therapy (PDT).</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JInst..12C6002A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JInst..12C6002A"><span>Development of a silicon microstrip detector with single photon sensitivity for fast dynamic diffraction experiments at a synchrotron radiation beam</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Arakcheev, A.; Aulchenko, V.; Kudashkin, D.; Shekhtman, L.; Tolochko, B.; Zhulanov, V.</p> <p>2017-06-01</p> <p>Time-resolved experiments on the diffraction of synchrotron radiation (SR) from crystalline materials provide information on the evolution of a material structure after a heat, electron beam or plasma interaction with a sample under study. Changes in the material structure happen within a microsecond scale and a detector with corresponding parameters is needed. The SR channel 8 of the VEPP-4M storage ring provides radiation from the 7-pole wiggler that allows to reach several tens photons within one μs from a tungsten crystal for the most intensive diffraction peak. In order to perform experiments that allow to measure the evolution of tungsten crystalline structure under the impact of powerful laser beam, a new detector is developed, that can provide information about the distribution of a scattered SR flux in space and its evolution in time at a microsecond scale. The detector is based on the silicon p-in-n microstrip sensor with DC-coupled metal strips. The sensor contains 1024 30 mm long strips with a 50 μm pitch. 64 strips are bonded to the front-end electronics based on APC128 ASICs. The APC128 ASIC contains 128 channels that consist of a low noise integrator with 32 analogue memory cells each. The integrator equivalent noise charge is about 2000 electrons and thus the signal from individual photons with energy above 40 keV can be observed. The signal can be stored at the analogue memory with 10 MHz rate. The first measurements with the beam scattered from a tungsten crystal with energy near 60 keV demonstrated the capability of this prototype to observe the spatial distribution of the photon flux with the intensity from below one photon per channel up to 0~10 photons per channel with a frame rate from 10 kHz up to 1 MHz.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25298932','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25298932"><span>Study of a new design of p-N semiconductor detector array for nuclear medicine imaging by monte carlo simulation codes.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hajizadeh-Safar, M; Ghorbani, M; Khoshkharam, S; Ashrafi, Z</p> <p>2014-07-01</p> <p>Gamma camera is an important apparatus in nuclear medicine imaging. Its detection part is consists of a scintillation detector with a heavy collimator. Substitution of semiconductor detectors instead of scintillator in these cameras has been effectively studied. In this study, it is aimed to introduce a new design of P-N semiconductor detector array for nuclear medicine imaging. A P-N semiconductor detector composed of N-SnO2 :F, and P-NiO:Li, has been introduced through simulating with MCNPX monte carlo codes. Its sensitivity with different factors such as thickness, dimension, and direction of emission photons were investigated. It is then used to configure a new design of an array in one-dimension and study its spatial resolution for nuclear medicine imaging. One-dimension array with 39 detectors was simulated to measure a predefined linear distribution of Tc(99_m) activity and its spatial resolution. The activity distribution was calculated from detector responses through mathematical linear optimization using LINPROG code on MATLAB software. Three different configurations of one-dimension detector array, horizontal, vertical one sided, and vertical double-sided were simulated. In all of these configurations, the energy windows of the photopeak were ± 1%. The results show that the detector response increases with an increase of dimension and thickness of the detector with the highest sensitivity for emission photons 15-30° above the surface. Horizontal configuration array of detectors is not suitable for imaging of line activity sources. The measured activity distribution with vertical configuration array, double-side detectors, has no similarity with emission sources and hence is not suitable for imaging purposes. Measured activity distribution using vertical configuration array, single side detectors has a good similarity with sources. Therefore, it could be introduced as a suitable configuration for nuclear medicine imaging. It has been shown that using semiconductor P-N detectors such as P-NiO:Li, N-SnO2 :F for gamma detection could be possibly applicable for design of a one dimension array configuration with suitable spatial resolution of 2.7 mm for nuclear medicine imaging.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002SPIE.4821..455M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002SPIE.4821..455M"><span>Single photon source with individualized single photon certifications</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Migdall, Alan L.; Branning, David A.; Castelletto, Stefania; Ware, M.</p> <p>2002-12-01</p> <p>As currently implemented, single-photon sources cannot be made to produce single photons with high probability, while simultaneously suppressing the probability of yielding two or more photons. Because of this, single photon sources cannot really produce single photons on demand. We describe a multiplexed system that allows the probabilities of producing one and more photons to be adjusted independently, enabling a much better approximation of a source of single photons on demand. The scheme uses a heralded photon source based on parametric downconversion, but by effectively breaking the trigger detector area into multiple regions, we are able to extract more information about a heralded photon than is possible with a conventional arrangement. This scheme allows photons to be produced along with a quantitative 'certification' that they are single photons. Some of the single-photon certifications can be significantly better than what is possible with conventional downconversion sources, as well as being better than faint laser sources. With such a source of more tightly certified single photons, it should be possible to improve the maximum secure bit rate possible over a quantum cryptographic link. We present an analysis of the relative merits of this method over the conventional arrangement.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22095513-chip-photon-number-resolving-telecommunication-band-detectors-scalable-photonic-information-processing','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22095513-chip-photon-number-resolving-telecommunication-band-detectors-scalable-photonic-information-processing"><span>On-chip, photon-number-resolving, telecommunication-band detectors for scalable photonic information processing</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Gerrits, Thomas; Lita, Adriana E.; Calkins, Brice</p> <p></p> <p>Integration is currently the only feasible route toward scalable photonic quantum processing devices that are sufficiently complex to be genuinely useful in computing, metrology, and simulation. Embedded on-chip detection will be critical to such devices. We demonstrate an integrated photon-number-resolving detector, operating in the telecom band at 1550 nm, employing an evanescently coupled design that allows it to be placed at arbitrary locations within a planar circuit. Up to five photons are resolved in the guided optical mode via absorption from the evanescent field into a tungsten transition-edge sensor. The detection efficiency is 7.2{+-}0.5 %. The polarization sensitivity of themore » detector is also demonstrated. Detailed modeling of device designs shows a clear and feasible route to reaching high detection efficiencies.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27782601','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27782601"><span>Integrated four-channel all-fiber up-conversion single-photon-detector with adjustable efficiency and dark count.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zheng, Ming-Yang; Shentu, Guo-Liang; Ma, Fei; Zhou, Fei; Zhang, Hai-Ting; Dai, Yun-Qi; Xie, Xiuping; Zhang, Qiang; Pan, Jian-Wei</p> <p>2016-09-01</p> <p>Up-conversion single photon detector (UCSPD) has been widely used in many research fields including quantum key distribution, lidar, optical time domain reflectrometry, and deep space communication. For the first time in laboratory, we have developed an integrated four-channel all-fiber UCSPD which can work in both free-running and gate modes. This compact module can satisfy different experimental demands with adjustable detection efficiency and dark count. We have characterized the key parameters of the UCSPD system.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018SuScT..31c5011S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018SuScT..31c5011S"><span>NbN single-photon detectors with saturated dependence of quantum efficiency</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Smirnov, Konstantin; Divochiy, Alexander; Vakhtomin, Yury; Morozov, Pavel; Zolotov, Philipp; Antipov, Andrey; Seleznev, Vitaliy</p> <p>2018-07-01</p> <p>The possibility of creating NbN superconducting single-photon detectors with saturated dependence of quantum efficiency (QE) versus normalized bias current was investigated. It was shown that the saturation increases for the detectors based on finer films with a lower value of R s300/R s20. The decreasing of R s300/R s20 was related to the increasing influence of quantum corrections to conductivity of superconductors and, in turn, to the decrease of the electron diffusion coefficient. The best samples have a constant value of system QE 94% at I b /I c ∼ 0.8 and wavelength 1310 nm.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_13 --> <div id="page_14" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="261"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29240144','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29240144"><span>1.25  GHz sine wave gating InGaAs/InP single-photon detector with a monolithically integrated readout circuit.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jiang, Wen-Hao; Liu, Jian-Hong; Liu, Yin; Jin, Ge; Zhang, Jun; Pan, Jian-Wei</p> <p>2017-12-15</p> <p>InGaAs/InP single-photon detectors (SPDs) are the key devices for applications requiring near-infrared single-photon detection. The gating mode is an effective approach to synchronous single-photon detection. Increasing gating frequency and reducing the module size are important challenges for the design of such a detector system. Here we present for the first time, to the best of our knowledge, an InGaAs/InP SPD with 1.25 GHz sine wave gating (SWG) using a monolithically integrated readout circuit (MIRC). The MIRC has a size of 15  mm×15  mm and implements the miniaturization of avalanche extraction for high-frequency SWG. In the MIRC, low-pass filters and a low-noise radio frequency amplifier are integrated based on the technique of low temperature co-fired ceramic, which can effectively reduce the parasitic capacitance and extract weak avalanche signals. We then characterize the InGaAs/InP SPD to verify the functionality and reliability of the MIRC, and the SPD exhibits excellent performance with 27.5% photon detection efficiency, a 1.2 kcps dark count rate, and 9.1% afterpulse probability at 223 K and 100 ns hold-off time. With this MIRC, one can further design miniaturized high-frequency SPD modules that are highly required for practical applications.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JInst..12.9008J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JInst..12.9008J"><span>Characterization of spectrometric photon-counting X-ray detectors at different pitches</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jurdit, M.; Brambilla, A.; Moulin, V.; Ouvrier-Buffet, P.; Radisson, P.; Verger, L.</p> <p>2017-09-01</p> <p>There is growing interest in energy-sensitive photon-counting detectors based on high flux X-ray imaging. Their potential applications include medical imaging, non-destructive testing and security. Innovative detectors of this type will need to count individual photons and sort them into selected energy bins, at several million counts per second and per mm2. Cd(Zn)Te detector grade materials with a thickness of 1.5 to 3 mm and pitches from 800 μm down to 200 μm were assembled onto interposer boards. These devices were tested using in-house-developed full-digital fast readout electronics. The 16-channel demonstrators, with 256 energy bins, were experimentally characterized by determining spectral resolution, count rate, and charge sharing, which becomes challenging at low pitch. Charge sharing correction was found to efficiently correct X-ray spectra up to 40 × 106 incident photons.s-1.mm-2.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4585911','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4585911"><span>Quantum key distribution over 120 km using ultrahigh purity single-photon source and superconducting single-photon detectors</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Takemoto, Kazuya; Nambu, Yoshihiro; Miyazawa, Toshiyuki; Sakuma, Yoshiki; Yamamoto, Tsuyoshi; Yorozu, Shinichi; Arakawa, Yasuhiko</p> <p>2015-01-01</p> <p>Advances in single-photon sources (SPSs) and single-photon detectors (SPDs) promise unique applications in the field of quantum information technology. In this paper, we report long-distance quantum key distribution (QKD) by using state-of-the-art devices: a quantum-dot SPS (QD SPS) emitting a photon in the telecom band of 1.5 μm and a superconducting nanowire SPD (SNSPD). At the distance of 100 km, we obtained the maximal secure key rate of 27.6 bps without using decoy states, which is at least threefold larger than the rate obtained in the previously reported 50-km-long QKD experiment. We also succeeded in transmitting secure keys at the rate of 0.307 bps over 120 km. This is the longest QKD distance yet reported by using known true SPSs. The ultralow multiphoton emissions of our SPS and ultralow dark count of the SNSPD contributed to this result. The experimental results demonstrate the potential applicability of QD SPSs to practical telecom QKD networks. PMID:26404010</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20000074252&hterms=quasiparticle&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dquasiparticle','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20000074252&hterms=quasiparticle&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dquasiparticle"><span>RF Single Electron Transistor Readout Amplifiers for Superconducting Astronomical Detectors for X-Ray to Sub-mm Wavelengths</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Stevenson, Thomas; Aassime, Abdelhanin; Delsing, Per; Frunzio, Luigi; Li, Li-Qun; Prober, Daniel; Schoelkopf, Robert; Segall, Ken; Wilson, Chris; Stahle, Carl</p> <p>2000-01-01</p> <p>We report progress on using a new type of amplifier, the Radio-Frequency Single-Electron Transistor (RF-SET), to develop multi-channel sensor readout systems for fast and sensitive readout of high impedance cryogenic photodetectors such as Superconducting Tunnel Junctions and Single Quasiparticle Photon Counters. Although cryogenic, these detectors are desirable because of capabilities not other-wise attainable. However, high impedances and low output levels make low-noise, high-speed readouts challenging, and large format arrays would be facilitated by compact, low-power, on-chip integrated amplifiers. Well-suited for this application are RF-SETs, very high performance electrometers which use an rf readout technique to provide 100 MHz bandwidth. Small size, low power, and cryogenic operation allow direct integration with detectors, and using multiple rf carrier frequencies permits simultaneous readout of 20-50 amplifiers with a common electrical connection. We describe both the first 2-channel demonstration of this wavelength division multiplexing technique for RF-SETs, and Charge-Locked-Loop operation with 100 kHz of closed-loop bandwidth.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015ITNS...62..669S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ITNS...62..669S"><span>Data Processing for a High Resolution Preclinical PET Detector Based on Philips DPC Digital SiPMs</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schug, David; Wehner, Jakob; Goldschmidt, Benjamin; Lerche, Christoph; Dueppenbecker, Peter Michael; Hallen, Patrick; Weissler, Bjoern; Gebhardt, Pierre; Kiessling, Fabian; Schulz, Volkmar</p> <p>2015-06-01</p> <p>In positron emission tomography (PET) systems, light sharing techniques are commonly used to readout scintillator arrays consisting of scintillation elements, which are smaller than the optical sensors. The scintillating element is then identified evaluating the signal heights in the readout channels using statistical algorithms, the center of gravity (COG) algorithm being the simplest and mostly used one. We propose a COG algorithm with a fixed number of input channels in order to guarantee a stable calculation of the position. The algorithm is implemented and tested with the raw detector data obtained with the Hyperion-II D preclinical PET insert which uses Philips Digital Photon Counting's (PDPC) digitial SiPMs. The gamma detectors use LYSO scintillator arrays with 30 ×30 crystals of 1 ×1 ×12 mm3 in size coupled to 4 ×4 PDPC DPC 3200-22 sensors (DPC) via a 2-mm-thick light guide. These self-triggering sensors are made up of 2 ×2 pixels resulting in a total of 64 readout channels. We restrict the COG calculation to a main pixel, which captures most of the scintillation light from a crystal, and its (direct and diagonal) neighboring pixels and reject single events in which this data is not fully available. This results in stable COG positions for a crystal element and enables high spatial image resolution. Due to the sensor layout, for some crystals it is very likely that a single diagonal neighbor pixel is missing as a result of the low light level on the corresponding DPC. This leads to a loss of sensitivity, if these events are rejected. An enhancement of the COG algorithm is proposed which handles the potentially missing pixel separately both for the crystal identification and the energy calculation. Using this advancement, we show that the sensitivity of the Hyperion-II D insert using the described scintillator configuration can be improved by 20-100% for practical useful readout thresholds of a single DPC pixel ranging from 17-52 photons. Furthermore, we show that the energy resolution of the scanner is superior for all readout thresholds if singles with a single missing pixel are accepted and correctly handled compared to the COG method only accepting singles with all neighbors present by 0-1.6% (relative difference). The presented methods can not only be applied to gamma detectors employing DPC sensors, but can be generalized to other similarly structured and self-triggering detectors, using light sharing techniques, as well.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JInst..12P2032S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JInst..12P2032S"><span>Applications of a pnCCD detector coupled to columnar structure CsI(Tl) scintillator system in ultra high energy X-ray Laue diffraction</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shokr, M.; Schlosser, D.; Abboud, A.; Algashi, A.; Tosson, A.; Conka, T.; Hartmann, R.; Klaus, M.; Genzel, C.; Strüder, L.; Pietsch, U.</p> <p>2017-12-01</p> <p>Most charge coupled devices (CCDs) are made of silicon (Si) with typical active layer thicknesses of several microns. In case of a pnCCD detector the sensitive Si thickness is 450 μm. However, for silicon based detectors the quantum efficiency for hard X-rays drops significantly for photon energies above 10 keV . This drawback can be overcome by combining a pixelated silicon-based detector system with a columnar scintillator. Here we report on the characterization of a low noise, fully depleted 128×128 pixels pnCCD detector with 75×75 μm2 pixel size coupled to a 700 μm thick columnar CsI(Tl) scintillator in the photon range between 1 keV to 130 keV . The excellent performance of the detection system in the hard X-ray range is demonstrated in a Laue type X-ray diffraction experiment performed at EDDI beamline of the BESSY II synchrotron taken at a set of several GaAs single crystals irradiated by white synchrotron radiation. With the columnar structure of the scintillator, the position resolution of the whole system reaches a value of less than one pixel. Using the presented detector system and considering the functional relation between indirect and direct photon events Laue diffraction peaks with X-ray energies up to 120 keV were efficiently detected. As one of possible applications of the combined CsI-pnCCD system we demonstrate that the accuracy of X-ray structure factors extracted from Laue diffraction peaks can be significantly improved in hard X-ray range using the combined CsI(Tl)-pnCCD system compared to a bare pnCCD.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22825199','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22825199"><span>Crosstalk-free operation of multielement superconducting nanowire single-photon detector array integrated with single-flux-quantum circuit in a 0.1 W Gifford-McMahon cryocooler.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yamashita, Taro; Miki, Shigehito; Terai, Hirotaka; Makise, Kazumasa; Wang, Zhen</p> <p>2012-07-15</p> <p>We demonstrate the successful operation of a multielement superconducting nanowire single-photon detector (SSPD) array integrated with a single-flux-quantum (SFQ) readout circuit in a compact 0.1 W Gifford-McMahon cryocooler. A time-resolved readout technique, where output signals from each element enter the SFQ readout circuit with finite time intervals, revealed crosstalk-free operation of the four-element SSPD array connected with the SFQ readout circuit. The timing jitter and the system detection efficiency were measured to be 50 ps and 11.4%, respectively, which were comparable to the performance of practical single-pixel SSPD systems.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28032369','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28032369"><span>Spectral distribution of particle fluence in small field detectors and its implication on small field dosimetry.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Benmakhlouf, Hamza; Andreo, Pedro</p> <p>2017-02-01</p> <p>Correction factors for the relative dosimetry of narrow megavoltage photon beams have recently been determined in several publications. These corrections are required because of the several small-field effects generally thought to be caused by the lack of lateral charged particle equilibrium (LCPE) in narrow beams. Correction factors for relative dosimetry are ultimately necessary to account for the fluence perturbation caused by the detector. For most small field detectors the perturbation depends on field size, resulting in large correction factors when the field size is decreased. In this work, electron and photon fluence differential in energy will be calculated within the radiation sensitive volume of a number of small field detectors for 6 MV linear accelerator beams. The calculated electron spectra will be used to determine electron fluence perturbation as a function of field size and its implication on small field dosimetry analyzed. Fluence spectra were calculated with the user code PenEasy, based on the PENELOPE Monte Carlo system. The detectors simulated were one liquid ionization chamber, two air ionization chambers, one diamond detector, and six silicon diodes, all manufactured either by PTW or IBA. The spectra were calculated for broad (10 cm × 10 cm) and narrow (0.5 cm × 0.5 cm) photon beams in order to investigate the field size influence on the fluence spectra and its resulting perturbation. The photon fluence spectra were used to analyze the impact of absorption and generation of photons. These will have a direct influence on the electrons generated in the detector radiation sensitive volume. The electron fluence spectra were used to quantify the perturbation effects and their relation to output correction factors. The photon fluence spectra obtained for all detectors were similar to the spectrum in water except for the shielded silicon diodes. The photon fluence in the latter group was strongly influenced, mostly in the low-energy region, by photoabsorption in the high-Z shielding material. For the ionization chambers and the diamond detector, the electron fluence spectra were found to be similar to that in water, for both field sizes. In contrast, electron spectra in the silicon diodes were much higher than that in water for both field sizes. The estimated perturbations of the fluence spectra for the silicon diodes were 11-21% for the large fields and 14-27% for the small fields. These perturbations are related to the atomic number, density and mean excitation energy (I-value) of silicon, as well as to the influence of the "extracameral"' components surrounding the detector sensitive volume. For most detectors the fluence perturbation was also found to increase when the field size was decreased, in consistency with the increased small-field effects observed for the smallest field sizes. The present work improves the understanding of small-field effects by relating output correction factors to spectral fluence perturbations in small field detectors. It is shown that the main reasons for the well-known small-field effects in silicon diodes are the high-Z and density of the "extracameral" detector components and the high I-value of silicon relative to that of water and diamond. Compared to these parameters, the density and atomic number of the radiation sensitive volume material play a less significant role. © 2016 American Association of Physicists in Medicine.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013SPIE.8905E..0IW','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013SPIE.8905E..0IW"><span>Intensity information extraction in Geiger mode detector array based three-dimensional imaging applications</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Fei</p> <p>2013-09-01</p> <p>Geiger-mode detectors have single photon sensitivity and picoseconds timing resolution, which make it a good candidate for low light level ranging applications, especially in the case of flash three dimensional imaging applications where the received laser power is extremely limited. Another advantage of Geiger-mode APD is their capability of large output current which can drive CMOS timing circuit directly, which means that larger format focal plane arrays can be easily fabricated using the mature CMOS technology. However Geiger-mode detector based FPAs can only measure the range information of a scene but not the reflectivity. Reflectivity is a major characteristic which can help target classification and identification. According to Poisson statistic nature, detection probability is tightly connected to the incident number of photon. Employing this relation, a signal intensity estimation method based on probability inversion is proposed. Instead of measuring intensity directly, several detections are conducted, then the detection probability is obtained and the intensity is estimated using this method. The relation between the estimator's accuracy, measuring range and number of detections are discussed based on statistical theory. Finally Monte-Carlo simulation is conducted to verify the correctness of this theory. Using 100 times of detection, signal intensity equal to 4.6 photons per detection can be measured using this method. With slight modification of measuring strategy, intensity information can be obtained using current Geiger-mode detector based FPAs, which can enrich the information acquired and broaden the application field of current technology.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017NIMPA.845..528O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017NIMPA.845..528O"><span>Liquid xenon calorimeter for MEG II experiment with VUV-sensitive MPPCs</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ogawa, Shinji; MEG II Collaboration</p> <p>2017-02-01</p> <p>The MEG II experiment is an upgrade of the MEG experiment to search for the charged lepton flavor violating decay of muon, μ+ →e+ γ . The MEG II experiment is expected to reach a branching ratio sensitivity of 4 ×10-14 , which is one order of magnitude better than the sensitivity of the current MEG experiment. The performance of the liquid xenon (LXe) γ-ray detector will be greatly improved with a highly granular scintillation readout realized by replacing 216 photomultiplier tubes (PMTs) on the γ-ray entrance face with 4092 Multi-Pixel Photon Counters (MPPCs). For this purpose, we have developed a new type of MPPC which is sensitive to the LXe scintillation light in vacuum ultraviolet (VUV) range, in collaboration with Hamamatsu Photonics K.K. We have measured the performance of the MPPC in LXe, and an excellent performance has been confirmed including high photon detection efficiency (> 15 %) for LXe scintillation light. An excellent performance of the LXe detector has been confirmed by Monte Carlo simulations based on the measured properties of the MPPC. The construction of the detector is in progress, aiming to start physics data taking in 2017.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24401331','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24401331"><span>Detecting single-electron events in TEM using low-cost electronics and a silicon strip sensor.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gontard, Lionel C; Moldovan, Grigore; Carmona-Galán, Ricardo; Lin, Chao; Kirkland, Angus I</p> <p>2014-04-01</p> <p>There is great interest in developing novel position-sensitive direct detectors for transmission electron microscopy (TEM) that do not rely in the conversion of electrons into photons. Direct imaging improves contrast and efficiency and allows the operation of the microscope at lower energies and at lower doses without loss in resolution, which is especially important for studying soft materials and biological samples. We investigate the feasibility of employing a silicon strip detector as an imaging detector for TEM. This device, routinely used in high-energy particle physics, can detect small variations in electric current associated with the impact of a single charged particle. The main advantages of using this type of sensor for direct imaging in TEM are its intrinsic radiation hardness and large detection area. Here, we detail design, simulation, fabrication and tests in a TEM of the front-end electronics developed using low-cost discrete components and discuss the limitations and applications of this technology for TEM.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/11871381','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/11871381"><span>An investigation of the operating characteristics of two PTW diamond detectors in photon and electron beams.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>De Angelis, C; Onori, S; Pacilio, M; Cirrone, G A P; Cuttone, G; Raffaele, L; Bucciolini, M; Mazzocchi, S</p> <p>2002-02-01</p> <p>The dosimetric properties of two PTW Riga diamond detectors type 60003 were studied in high-energy photon and electron therapy beam. Properties under study were current-voltage characteristic, polarization effect, time stability of response, dose response, dose-rate dependence, temperature stability, and beam quality dependence of the sensitivity factor. Differences were shown between the two detectors for most of the previous properties. Also, the observed behavior was, to some extent, different from what was reported in the PTW technical specifications. The necessity to characterize each diamond detector individually was addressed.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/AD1043103','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/AD1043103"><span>Setting Single Photon Detectors for Use with an Entangled Photon Distribution System</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2017-12-01</p> <p>NOTICES Disclaimers The findings in this report are not to be construed as an official Department of the Army position unless so designated by...diode (as small as that provided by one photon incident on the detector) triggers an avalanche pulse. This output avalanche pulse is then compared with...with raw concurrence and fidelity ( compared with the Bell state given by Eq. 1) values of 0.871 and 0.934. Furthermore, the accidental-subtracted</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22095532-entangled-photon-compressive-ghost-imaging','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22095532-entangled-photon-compressive-ghost-imaging"><span>Entangled-photon compressive ghost imaging</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Zerom, Petros; Chan, Kam Wai Clifford; Howell, John C.</p> <p>2011-12-15</p> <p>We have experimentally demonstrated high-resolution compressive ghost imaging at the single-photon level using entangled photons produced by a spontaneous parametric down-conversion source and using single-pixel detectors. For a given mean-squared error, the number of photons needed to reconstruct a two-dimensional image is found to be much smaller than that in quantum ghost imaging experiments employing a raster scan. This procedure not only shortens the data acquisition time, but also suggests a more economical use of photons for low-light-level and quantum image formation.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4437302','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4437302"><span>Three Temperature Regimes in Superconducting Photon Detectors: Quantum, Thermal and Multiple Phase-Slips as Generators of Dark Counts</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Murphy, Andrew; Semenov, Alexander; Korneev, Alexander; Korneeva, Yulia; Gol’tsman, Gregory; Bezryadin, Alexey</p> <p>2015-01-01</p> <p>We perform measurements of the switching current distributions of three w ≈ 120 nm wide, 4 nm thick NbN superconducting strips which are used for single-photon detectors. These strips are much wider than the diameter of the vortex cores, so they are classified as quasi-two-dimensional (quasi-2D). We discover evidence of macroscopic quantum tunneling by observing the saturation of the standard deviation of the switching distributions at temperatures around 2 K. We analyze our results using the Kurkijärvi-Garg model and find that the escape temperature also saturates at low temperatures, confirming that at sufficiently low temperatures, macroscopic quantum tunneling is possible in quasi-2D strips and can contribute to dark counts observed in single photon detectors. At the highest temperatures the system enters a multiple phase-slip regime. In this range single phase-slips are unable to produce dark counts and the fluctuations in the switching current are reduced. PMID:25988591</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25988591','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25988591"><span>Three temperature regimes in superconducting photon detectors: quantum, thermal and multiple phase-slips as generators of dark counts.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Murphy, Andrew; Semenov, Alexander; Korneev, Alexander; Korneeva, Yulia; Gol'tsman, Gregory; Bezryadin, Alexey</p> <p>2015-05-19</p> <p>We perform measurements of the switching current distributions of three w ≈ 120 nm wide, 4 nm thick NbN superconducting strips which are used for single-photon detectors. These strips are much wider than the diameter of the vortex cores, so they are classified as quasi-two-dimensional (quasi-2D). We discover evidence of macroscopic quantum tunneling by observing the saturation of the standard deviation of the switching distributions at temperatures around 2 K. We analyze our results using the Kurkijärvi-Garg model and find that the escape temperature also saturates at low temperatures, confirming that at sufficiently low temperatures, macroscopic quantum tunneling is possible in quasi-2D strips and can contribute to dark counts observed in single photon detectors. At the highest temperatures the system enters a multiple phase-slip regime. In this range single phase-slips are unable to produce dark counts and the fluctuations in the switching current are reduced.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SPIE10353E..09F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SPIE10353E..09F"><span>Timing resolution and time walk in SLiK SPAD: measurement and optimization</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fong, Bernicy S.; Davies, Murray; Deschamps, Pierre</p> <p>2017-08-01</p> <p>Timing resolution (or timing jitter) and time walk are separate parameters associated with a detector's response time. Studies have been done mostly on the time resolution of various single photon detectors [1]. As the designer and manufacturer of the ultra-low noise (ƙ-factor) silicon avalanche photodiode the SLiK SPAD, which is used in many single photon counting applications, we often get inquiries from customers to better understand how this detector behaves under different operating conditions. Hence, here we will be focusing on the study of these time related parameters specifically for the SLiK SPAD, as a way to provide the most direct information for users of this detector to help with its use more efficiently and effectively. We will be providing the study data on how these parameters can be affected by temperature (both intrinsic to the detector chip and environmental input based on operating conditions), operating voltage, photon wavelength, as well as light spot size. How these parameters can be optimized and the trade-offs from optimization from the desired performance will be presented.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22492779-how-noise-affects-quantum-detector-tomography','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22492779-how-noise-affects-quantum-detector-tomography"><span>How noise affects quantum detector tomography</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Wang, Q., E-mail: wang@physics.leidenuniv.nl; Renema, J. J.; Exter, M. P.van</p> <p>2015-10-07</p> <p>We determine the full photon number response of a NbN superconducting nanowire single photon detector via quantum detector tomography, and the results show the separation of linear, effective absorption efficiency from the internal detection efficiencies. In addition, we demonstrate an error budget for the complete quantum characterization of the detector. We find that for short times, the dominant noise source is shot noise, while laser power fluctuations limit the accuracy for longer timescales. The combined standard uncertainty of the internal detection efficiency derived from our measurements is about 2%.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SPIE10075E..0TP','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SPIE10075E..0TP"><span>Detecting infrared luminescence and non-chemical signaling of living cells: single cell mid-IR spectroscopy in cryogenic environments</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pereverzev, Sergey</p> <p>2017-02-01</p> <p>Many life-relevant interaction energies are in IR range, and it is reasonable to believe that some biochemical reactions inside cells can results in emission of IR photons. Cells can use this emission for non-chemical and non-electrical signaling. Detecting weak infrared radiation from live cells is complicated because of strong thermal radiation background and absorption of radiation by tissues. A microfluidic device with live cells inside a vacuum cryogenic environment should suppress this background, and thereby permit observation of live cell auto-luminescence or signaling in the IR regime. One can make IR-transparent windows not emitting in this range, so only the cell and a small amount of liquid around it will emit infrared radiation. Currently mid-IR spectroscopy of single cells requires the use of a synchrotron source to measure absorption or reflection spectra. Decreasing of thermal radiation background will allow absorption and reflection spectroscopy of cells without using synchrotron light. Moreover, cell auto-luminescence can be directly measured. The complete absence of thermal background radiation for cryogenically cooled samples allows the use IR photon-sensitive detectors and obtaining single molecule sensitivity in IR photo-luminescence measurements. Due to low photon energies, photo-luminescence measurements will be non-distractive for pressures samples. The technique described here is based upon US patent 9366574.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20160002949','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20160002949"><span>Novel Photon-Counting Detectors for Free-Space Communication</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Krainak, M. A.; Yang, G.; Sun, X.; Lu, W.; Merritt, S.; Beck, J.</p> <p>2016-01-01</p> <p>We present performance data for novel photon-counting detectors for free space optical communication. NASA GSFC is testing the performance of two types of novel photon-counting detectors 1) a 2x8 mercury cadmium telluride (HgCdTe) avalanche array made by DRS Inc., and a 2) a commercial 2880-element silicon avalanche photodiode (APD) array. We present and compare dark count, photon-detection efficiency, wavelength response and communication performance data for these detectors. We successfully measured real-time communication performance using both the 2 detected-photon threshold and AND-gate coincidence methods. Use of these methods allows mitigation of dark count, after-pulsing and background noise effects. The HgCdTe APD array routinely demonstrated photon detection efficiencies of greater than 50% across 5 arrays, with one array reaching a maximum PDE of 70%. We performed high-resolution pixel-surface spot scans and measured the junction diameters of its diodes. We found that decreasing the junction diameter from 31 micrometers to 25 micrometers doubled the e- APD gain from 470 for an array produced in the year 2010 to a gain of 1100 on an array delivered to NASA GSFC recently. The mean single-photon SNR was over 12 and the excess noise factors measurements were 1.2-1.3. The commercial silicon APD array exhibited a fast output with rise times of 300 ps and pulse widths of 600 ps. On-chip individually filtered signals from the entire array were multiplexed onto a single fast output.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_14 --> <div id="page_15" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="281"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/6580022','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/biblio/6580022"><span>Photon beam position monitor</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Kuzay, T.M.; Shu, D.</p> <p>1995-02-07</p> <p>A photon beam position monitor is disclosed for use in the front end of a beamline of a high heat flux and high energy photon source such as a synchrotron radiation storage ring detects and measures the position and, when a pair of such monitors are used in tandem, the slope of a photon beam emanating from an insertion device such as a wiggler or an undulator inserted in the straight sections of the ring. The photon beam position monitor includes a plurality of spaced blades for precisely locating the photon beam, with each blade comprised of chemical vapor deposition (CVD) diamond with an outer metal coating of a photon sensitive metal such as tungsten, molybdenum, etc., which combination emits electrons when a high energy photon beam is incident upon the blade. Two such monitors are contemplated for use in the front end of the beamline, with the two monitors having vertically and horizontally offset detector blades to avoid blade ''shadowing''. Provision is made for aligning the detector blades with the photon beam and limiting detector blade temperature during operation. 18 figs.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017APS..APR.E2003B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017APS..APR.E2003B"><span>Development of compact particle detectors for space based instruments</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Barner, Lindsey; Grove, Andrew; Mohler, Jacob; Sisson, Caleb; Roth, Alex; Kryemadhi, Abaz</p> <p>2017-01-01</p> <p>The Silicon Photomultipliers (SiPMs) are new photon-detectors which have been increasingly used in particle physics. Their small size, good single photon resolution, simple readout, and immunity to magnetic fields offers benefits compared to traditional photomultipliers. LYSO and CeBr3 crystals are relatively new scintillators with high stopping power, very good light yield and fast decay time. The response of these detectors to low energy gamma rays will be presented. NASA Pennsylvania Space Grant Consortium.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28862618','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28862618"><span>The EIGER detector for low-energy electron microscopy and photoemission electron microscopy.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tinti, G; Marchetto, H; Vaz, C A F; Kleibert, A; Andrä, M; Barten, R; Bergamaschi, A; Brückner, M; Cartier, S; Dinapoli, R; Franz, T; Fröjdh, E; Greiffenberg, D; Lopez-Cuenca, C; Mezza, D; Mozzanica, A; Nolting, F; Ramilli, M; Redford, S; Ruat, M; Ruder, Ch; Schädler, L; Schmidt, Th; Schmitt, B; Schütz, F; Shi, X; Thattil, D; Vetter, S; Zhang, J</p> <p>2017-09-01</p> <p>EIGER is a single-photon-counting hybrid pixel detector developed at the Paul Scherrer Institut, Switzerland. It is designed for applications at synchrotron light sources with photon energies above 5 keV. Features of EIGER include a small pixel size (75 µm × 75 µm), a high frame rate (up to 23 kHz), a small dead-time between frames (down to 3 µs) and a dynamic range up to 32-bit. In this article, the use of EIGER as a detector for electrons in low-energy electron microscopy (LEEM) and photoemission electron microscopy (PEEM) is reported. It is demonstrated that, with only a minimal modification to the sensitive part of the detector, EIGER is able to detect electrons emitted or reflected by the sample and accelerated to 8-20 keV. The imaging capabilities are shown to be superior to the standard microchannel plate detector for these types of applications. This is due to the much higher signal-to-noise ratio, better homogeneity and improved dynamic range. In addition, the operation of the EIGER detector is not affected by radiation damage from electrons in the present energy range and guarantees more stable performance over time. To benchmark the detector capabilities, LEEM experiments are performed on selected surfaces and the magnetic and electronic properties of individual iron nanoparticles with sizes ranging from 8 to 22 nm are detected using the PEEM endstation at the Surface/Interface Microscopy (SIM) beamline of the Swiss Light Source.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29140321','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29140321"><span>Single-silicon CCD-CMOS platform for multi-spectral detection from terahertz to x-rays.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Shalaby, Mostafa; Vicario, Carlo; Hauri, Christoph P</p> <p>2017-11-15</p> <p>Charge-coupled devices (CCDs) are a well-established imaging technology in the visible and x-ray frequency ranges. However, the small quantum photon energies of terahertz radiation have hindered the use of this mature semiconductor technological platform in this frequency range, leaving terahertz imaging totally dependent on low-resolution bolometer technologies. Recently, it has been shown that silicon CCDs can detect terahertz photons at a high field, but the detection sensitivity is limited. Here we show that silicon, complementary metal-oxide-semiconductor (CMOS) technology offers enhanced detection sensitivity of almost two orders of magnitude, compared to CCDs. Our findings allow us to extend the low-frequency terahertz cutoff to less than 2 THz, nearly closing the technological gap with electronic imagers operating up to 1 THz. Furthermore, with the silicon CCD/CMOS technology being sensitive to mid-infrared (mid-IR) and the x-ray ranges, we introduce silicon as a single detector platform from 1 EHz to 2 THz. This overcomes the present challenge in spatially overlapping a terahertz/mid-IR pump and x-ray probe radiation at facilities such as free electron lasers, synchrotron, and laser-based x-ray sources.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018NIMPA.895...84T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018NIMPA.895...84T"><span>Application of Timepix3 based CdTe spectral sensitive photon counting detector for PET imaging</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Turecek, Daniel; Jakubek, Jan; Trojanova, Eliska; Sefc, Ludek; Kolarova, Vera</p> <p>2018-07-01</p> <p>Positron emission tomography (PET) is a nuclear medicine functional imaging technique. It is used in clinical oncology (medical imaging of tumors and the search for metastases), and pre-clinical studies using animals. PET uses small amounts of radioactive materials (radiotracers) and a special photon sensitive camera. Most of these cameras use scintillators with photomultipliers as detectors. However, these detectors have limited energy sensitivity and large pixels. Therefore, the false signal caused by a scattering poses a significant problem. In this work we study properties of position, energy and time sensitive semiconductor detector of Timepix3 type and its applicability for PET measurements. This work presents an initial study and evaluation of two Timepix3 detectors with 2 mm thick CdTe sensors used in simplified geometry for PET imaging. The study is performed on 2 samples - a capillary tube and a cylindrical plexiglass phantom with cavities. Both samples are filled with fluodeoxyglucose (FDG) solution that is used as a radiotracer. The Timepix3 offers better properties compared to conventional detectors - high granularity (55 μm pixel pitch), good energy resolution (1 keV at 60 keV) and sufficient time resolution (1.6 ns). The spectral sensitivity of Timepix3 together with coincidence/anticoincidence technique allows for significant reduction of background signal caused by Compton scattering and internal X-ray fluorescence of Cd and Te.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012SPIE.8504E..0DA','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012SPIE.8504E..0DA"><span>Bunch by bunch beam monitoring in 3rd and 4th generation light sources by means of single crystal diamond detectors and quantum well devices</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Antonelli, M.; Di Fraia, M.; Tallaire, A.; Achard, J.; Carrato, S.; Menk, R. H.; Cautero, G.; Giuressi, D.; Jark, W. H.; Biasiol, G.; Ganbold, T.; Oliver, K.; Callegari, C.; Coreno, M.; De Sio, A.; Pace, E.</p> <p>2012-10-01</p> <p>New generation Synchrotron Radiation (SR) sources and Free Electron Lasers (FEL) require novel concepts of beam diagnostics to keep photon beams under surveillance, asking for simultaneous position and intensity monitoring. To deal with high power load and short time pulses provided by these sources, novel materials and methods are needed for the next generation BPMs. Diamond is a promising material for the production of semitransparent in situ X-ray BPMs withstanding the high dose rates of SR rings and high energy FELs. We report on the development of freestanding, single crystal CVD diamond detectors. Performances in both low and radio frequency SR beam monitoring are presented. For the former, sensitivity deviation was found to be approximately 2%; a 0.05% relative precision in the intensity measurements and a 0.1-μm precision in the position encoding have been estimated. For the latter, single-shot characterizations revealed sub-nanosecond rise-times and spatial precisions below 6 μm, which allowed bunch-by-bunch monitoring in multi-bunch operation. Preliminary measurements at the Fermi FEL have been performed with this detector, extracting quantitative intensity and position information for FEL pulses (~ 100 fs, energy 12 ÷ 60 eV), with a long-term spatial precision of about 85 μm results on FEL radiation damages are also reported. Due to their direct, low-energy band gap, InGaAs quantum well devices too may be used as fast detectors for photons ranging from visible to X-ray. Results are reported which show the capability of a novel InGaAs/InAlAs device to detect intensity and position of 100-fs-wide laser pulses.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JInst..13C3043S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JInst..13C3043S"><span>SiPM photosensors and fast timing readout for the Barrel Time-of-Flight detector in bar PANDA</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Suzuki, K.</p> <p>2018-03-01</p> <p>The Barrel Time-of-Flight detector system will be installed in the upcoming bar PANDA experiment at FAIR in Germany. The detector has a barrel shape of phi=0.5 m and 1.8 m long, covering about 5 m2, which corresponds to the laboratory polar angle coverage of 22o<θ<140o. The detector is a scintillation tile hodoscope. A single scintillation tile segment has a dimension of 90× 30 mm2 and 5 mm thickness, and photons are detected by Silicon Photomultipliers at both ends. 4 Silicon Photomultipliers are combined to work as a single sensor in order to increase the sensitive area and to improve the timing performance. In total, the system consists of 1920 scintillator tiles, 3840 readout channels, and makes use of 15360 Silicon Photomultiplier sensors. In this paper, the requirement, design and the result of an actual performance test of the bar PANDA Barrel Time-of-Flight detector are presented. The test shows that the current design fulfils satisfactorily the required timing performance (σt~ 56 ps) and the timing performance depends little on the hit position on the surface.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4465487','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4465487"><span>A compact high resolution flat panel PET detector based on the new 4-side buttable MPPC for biomedical applications</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Wang, Qiang; Wen, Jie; Ravindranath, Bosky; O’Sullivan, Andrew W.; Catherall, David; Li, Ke; Wei, Shouyi; Komarov, Sergey; Tai, Yuan-Chuan</p> <p>2015-01-01</p> <p>Compact high-resolution panel detectors using virtual pinhole (VP) PET geometry can be inserted into existing clinical or pre-clinical PET systems to improve regional spatial resolution and sensitivity. Here we describe a compact panel PET detector built using the new Though Silicon Via (TSV) multi-pixel photon counters (MPPC) detector. This insert provides high spatial resolution and good timing performance for multiple bio-medical applications. Because the TSV MPPC design eliminates wire bonding and has a package dimension which is very close to the MPPC’s active area, it is 4-side buttable. The custom designed MPPC array (based on Hamamatsu S12641-PA-50(x)) used in the prototype is composed of 4 × 4 TSV-MPPC cells with a 4.46 mm pitch in both directions. The detector module has 16 × 16 lutetium yttrium oxyorthosilicate (LYSO) crystal array, with each crystal measuring 0.92 × 0.92 × 3 mm3 with 1.0 mm pitch. The outer diameter of the detector block is 16.8 × 16.8 mm2. Thirty-two such blocks will be arranged in a 4 × 8 array with 1 mm gaps to form a panel detector with detection area around 7 cm × 14 cm in the full-size detector. The flood histogram acquired with Ge-68 source showed excellent crystal separation capability with all 256 crystals clearly resolved. The detector module’s mean, standard deviation, minimum (best) and maximum (worst) energy resolution were 10.19%, +/−0.68%, 8.36% and 13.45% FWHM, respectively. The measured coincidence time resolution between the block detector and a fast reference detector (around 200 ps single photon timing resolution) was 0.95 ns. When tested with Siemens Cardinal electronics the performance of the detector blocks remain consistent. These results demonstrate that the TSV-MPPC is a promising photon sensor for use in a flat panel PET insert composed of many high resolution compact detector modules. PMID:26085702</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018LaPhy..28e5401R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018LaPhy..28e5401R"><span>Excited-state lifetime measurement of silicon vacancy centers in diamond by single-photon frequency upconversion</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rong, Youying; Ma, Jianhui; Chen, Lingxiao; Liu, Yan; Siyushev, Petr; Wu, Botao; Pan, Haifeng; Jelezko, Fedor; Wu, E.; Zeng, Heping</p> <p>2018-05-01</p> <p>We report a method with high time resolution to measure the excited-state lifetime of silicon vacancy centers in bulk diamond avoiding timing jitter from the single-photon detectors. Frequency upconversion of the fluorescence emitted from silicon vacancy centers was achieved from 738 nm to 436 nm via sum frequency generation with a short pump pulse. The excited-state lifetime can be obtained by measuring the intensity of upconverted light while the pump delay changes. As a probe, a pump laser with pulse duration of 11 ps provided a high temporal resolution of the measurement. The lifetime extracted from the pump–probe curve was 0.755 ns, which was comparable to the timing jitter of the single-photon detectors.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70000749','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70000749"><span>Application of epithermal neutron activation in multielement analysis of silicate rocks employing both coaxial Ge(Li) and low energy photon detector systems</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Baedecker, P.A.; Rowe, J.J.; Steinnes, E.</p> <p>1977-01-01</p> <p>The instrumental activation analysis of silicate rocks using epithermal neutrons has been studied using both high resolution coaxial Ge(Li) detectors and low energy photon detectors, and applied to the determination of 23 elements in eight new U.S.G.S. standard rocks. The analytical use X-ray peaks associated with electron capture or internal conversion processes has been evaluated. Of 28 elements which can be considered to be determinable by instrumental means, the epithermal activation approach is capable of giving improved sensitivity and precision in 16 cases, over the normal INAA procedure. In eleven cases the use of the low energy photon detector is thought to show advantages over convertional coaxial Ge(Li) spectroscopy. ?? 1977 Akade??miai Kiado??.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4420547','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4420547"><span>X-ray imaging detectors for synchrotron and XFEL sources</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Hatsui, Takaki; Graafsma, Heinz</p> <p>2015-01-01</p> <p>Current trends for X-ray imaging detectors based on hybrid and monolithic detector technologies are reviewed. Hybrid detectors with photon-counting pixels have proven to be very powerful tools at synchrotrons. Recent developments continue to improve their performance, especially for higher spatial resolution at higher count rates with higher frame rates. Recent developments for X-ray free-electron laser (XFEL) experiments provide high-frame-rate integrating detectors with both high sensitivity and high peak signal. Similar performance improvements are sought in monolithic detectors. The monolithic approach also offers a lower noise floor, which is required for the detection of soft X-ray photons. The link between technology development and detector performance is described briefly in the context of potential future capabilities for X-ray imaging detectors. PMID:25995846</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017NIMPA.875...87B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017NIMPA.875...87B"><span>A method for characterizing after-pulsing and dark noise of PMTs and SiPMs</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Butcher, A.; Doria, L.; Monroe, J.; Retière, F.; Smith, B.; Walding, J.</p> <p>2017-12-01</p> <p>Photo-multiplier tubes (PMTs) and silicon photo-multipliers (SiPMs) are detectors sensitive to single photons that are widely used for the detection of scintillation and Cerenkov light in subatomic physics and medical imaging. This paper presents a method for characterizing two of the main noise sources that PMTs and SiPMs share: dark noise and correlated noise (after-pulsing). The proposed method allows for a model-independent measurement of the after-pulsing timing distribution and dark noise rate.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28796522','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28796522"><span>On-Chip Waveguide Coupling of a Layered Semiconductor Single-Photon Source.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tonndorf, Philipp; Del Pozo-Zamudio, Osvaldo; Gruhler, Nico; Kern, Johannes; Schmidt, Robert; Dmitriev, Alexander I; Bakhtinov, Anatoly P; Tartakovskii, Alexander I; Pernice, Wolfram; Michaelis de Vasconcellos, Steffen; Bratschitsch, Rudolf</p> <p>2017-09-13</p> <p>Fully integrated quantum technology based on photons is in the focus of current research, because of its immense potential concerning performance and scalability. Ideally, the single-photon sources, the processing units, and the photon detectors are all combined on a single chip. Impressive progress has been made for on-chip quantum circuits and on-chip single-photon detection. In contrast, nonclassical light is commonly coupled onto the photonic chip from the outside, because presently only few integrated single-photon sources exist. Here, we present waveguide-coupled single-photon emitters in the layered semiconductor gallium selenide as promising on-chip sources. GaSe crystals with a thickness below 100 nm are placed on Si 3 N 4 rib or slot waveguides, resulting in a modified mode structure efficient for light coupling. Using optical excitation from within the Si 3 N 4 waveguide, we find nonclassicality of generated photons routed on the photonic chip. Thus, our work provides an easy-to-implement and robust light source for integrated quantum technology.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA596425','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA596425"><span>Low Noise Mid-Wavelength IR Photodetectors</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2014-02-19</p> <p>Theoretical Framework and Calculated Results We will first review the theoretical limit for single-stage photovoltaic (PV) detectors and then proceed...efficient the device utilizes the incident photons. We see that Eq. 12 reduces to the standard expression for a single-absorber photovoltaic detector...mid-IR spectrum, one can expect growing demands and applications for high-speed detectors that operate at thermoelectric cooler temperatures with</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SPIE10229E..0DP','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SPIE10229E..0DP"><span>Development of a high-performance multichannel system for time-correlated single photon counting</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Peronio, P.; Cominelli, A.; Acconcia, G.; Rech, I.; Ghioni, M.</p> <p>2017-05-01</p> <p>Time-Correlated Single Photon Counting (TCSPC) is one of the most effective techniques for measuring weak and fast optical signals. It outperforms traditional "analog" techniques due to its high sensitivity along with high temporal resolution. Despite those significant advantages, a main drawback still exists, which is related to the long acquisition time needed to perform a measurement. In past years many TCSPC systems have been developed with higher and higher number of channels, aimed to dealing with that limitation. Nevertheless, modern systems suffer from a strong trade-off between parallelism level and performance: the higher the number of channels the poorer the performance. In this work we present the design of a 32x32 TCSPC system meant for overtaking the existing trade-off. To this aim different technologies has been employed, to get the best performance both from detectors and sensing circuits. The exploitation of different technologies will be enabled by Through Silicon Vias (TSVs) which will be investigated as a possible solution for connecting the detectors to the sensing circuits. When dealing with a high number of channels, the count rate is inevitably set by the affordable throughput to the external PC. We targeted a throughput of 10Gb/s, which is beyond the state of the art, and designed the number of TCSPC channels accordingly. A dynamic-routing logic will connect the detectors to the lower number of acquisition chains.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3982391','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3982391"><span>New photon-counting detectors for single-molecule fluorescence spectroscopy and imaging</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Michalet, X.; Colyer, R. A.; Scalia, G.; Weiss, S.; Siegmund, Oswald H. W.; Tremsin, Anton S.; Vallerga, John V.; Villa, F.; Guerrieri, F.; Rech, I.; Gulinatti, A.; Tisa, S.; Zappa, F.; Ghioni, M.; Cova, S.</p> <p>2013-01-01</p> <p>Solution-based single-molecule fluorescence spectroscopy is a powerful new experimental approach with applications in all fields of natural sciences. Two typical geometries can be used for these experiments: point-like and widefield excitation and detection. In point-like geometries, the basic concept is to excite and collect light from a very small volume (typically femtoliter) and work in a concentration regime resulting in rare burst-like events corresponding to the transit of a single-molecule. Those events are accumulated over time to achieve proper statistical accuracy. Therefore the advantage of extreme sensitivity is somewhat counterbalanced by a very long acquisition time. One way to speed up data acquisition is parallelization. Here we will discuss a general approach to address this issue, using a multispot excitation and detection geometry that can accommodate different types of novel highly-parallel detector arrays. We will illustrate the potential of this approach with fluorescence correlation spectroscopy (FCS) and single-molecule fluorescence measurements. In widefield geometries, the same issues of background reduction and single-molecule concentration apply, but the duration of the experiment is fixed by the time scale of the process studied and the survival time of the fluorescent probe. Temporal resolution on the other hand, is limited by signal-to-noise and/or detector resolution, which calls for new detector concepts. We will briefly present our recent results in this domain. PMID:24729836</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24729836','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24729836"><span>New photon-counting detectors for single-molecule fluorescence spectroscopy and imaging.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Michalet, X; Colyer, R A; Scalia, G; Weiss, S; Siegmund, Oswald H W; Tremsin, Anton S; Vallerga, John V; Villa, F; Guerrieri, F; Rech, I; Gulinatti, A; Tisa, S; Zappa, F; Ghioni, M; Cova, S</p> <p>2011-05-13</p> <p>Solution-based single-molecule fluorescence spectroscopy is a powerful new experimental approach with applications in all fields of natural sciences. Two typical geometries can be used for these experiments: point-like and widefield excitation and detection. In point-like geometries, the basic concept is to excite and collect light from a very small volume (typically femtoliter) and work in a concentration regime resulting in rare burst-like events corresponding to the transit of a single-molecule. Those events are accumulated over time to achieve proper statistical accuracy. Therefore the advantage of extreme sensitivity is somewhat counterbalanced by a very long acquisition time. One way to speed up data acquisition is parallelization. Here we will discuss a general approach to address this issue, using a multispot excitation and detection geometry that can accommodate different types of novel highly-parallel detector arrays. We will illustrate the potential of this approach with fluorescence correlation spectroscopy (FCS) and single-molecule fluorescence measurements. In widefield geometries, the same issues of background reduction and single-molecule concentration apply, but the duration of the experiment is fixed by the time scale of the process studied and the survival time of the fluorescent probe. Temporal resolution on the other hand, is limited by signal-to-noise and/or detector resolution, which calls for new detector concepts. We will briefly present our recent results in this domain.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013PhDT.........8H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013PhDT.........8H"><span>Brownian Thermal Noise in Interferometric Gravitational Wave Detectors and Single Photon Optomechanics</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hong, Ting</p> <p></p> <p>The Laser Interferometric Gravitational-Wave Observatory (LIGO) is designed to detect the Gravitational Waves (GW) predicted by Albert Einstein's general theory of relativity. The advanced LIGO project is ongoing an upgrade to increase the detection sensitivity by more than a factor of 10, which will make the events detection a routine occurrence. In addition to using higher power lasers, heavier test mass, and better isolation systems, several new designs and techniques are proposed in the long-term upgrade, such as modifying the optics configuration to reduce the quantum noise, active noise cancellation of the Newtonian noise, optimizing the coating structure, and employing non-Guassian laser beams etc. In the first part of my thesis (Chapters 2 and 3), I apply statistical mechanics and elastostatics to the LIGO coated mirrors, and study the thermal fluctuations that dominate advanced LIGO's most sensitive frequency band from 40 Hz to 200 Hz. In particular, in Chapter 2, I study the so-called coating Brownian noise, fluctuations of mirrors coated with multiple layers of dielectrics due to internal friction. Assuming coating materials to be isotropic and homogeneous, I calculate the cross spectra of Brownian fluctuations in the bulk and shear strains of the coating layers, as well as fluctuations in the height of the coating-substrate interface. The additional phase shifting and back-scattering caused by photo elastic effects are also considered for the first time. In Chapter 3, I study whether it is realistic to adopt higher-order Laguerre-Gauss modes in LIGO, in order to mitigate the effect of mirror thermal noise. We investigate the effect on the detector's contrast defect caused by the mode degeneracy. With both analytical calculation and numerical simulation, we show that with this approach, the detector's susceptibility to mirror figure errors is reduced greatly compared to using the nondegenerate modes, therefore making it unacceptable for LIGO requirements. For the future GW detectors, with much lower noises and higher sensitivity, this might be used to investigate the quantum behaviors of macroscopic mechanical objects. In recent years the linear optomechanical systems with cavity modes coupling to a mechanical oscillator have been studied extensively. In the second part of my thesis (Chapter 4), I study the interaction between a single photon and a high-finesse cavity with a movable mirror, in the so-called strong coupling regime, where the recoil of the photon can cause significant change in the momentum of the mirror. The results are applied to analyze the case with a Fabry-Perot cavity. We also present that with engineering the photon wave function, it is possible to prepare the oscillator into an arbitrary quantum state.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4570314','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4570314"><span>Twenty Years of Rad-Hard K14 SPAD in Space Projects</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Michálek, Vojtěch; Procházka, Ivan; Blažej, Josef</p> <p>2015-01-01</p> <p>During last two decades, several photon counting detectors have been developed in our laboratory. One of the most promising detector coming from our group silicon K14 Single Photon Avalanche Diode (SPAD) is presented with its valuable features and space applications. Based on the control electronics, it can be operated in both gated and non-gated mode. Although it was designed for photon counting detection, it can be employed for multiphoton detection as well. With respect to control electronics employed, the timing jitter can be as low as 20 ps RMS. Detection efficiency is about 40 % in range of 500 nm to 800 nm. The detector including gating and quenching circuitry has outstanding timing stability. Due to its radiation resistivity, the diode withstands 100 krad gamma ray dose without parameters degradation. Single photon detectors based on K14 SPAD were used for planetary altimeter and atmospheric lidar in MARS92/96 and Mars Surveyor ’98 space projects, respectively. Recent space applications of K14 SPAD comprises LIDAR and mainly time transfer between ground stations and artificial satellites. These include Laser Time Transfer, Time Transfer by Laser Link, and European Laser Timing projects. PMID:26213945</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JInst..12C1060D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JInst..12C1060D"><span>Microtomography with photon counting detectors: improving the quality of tomographic reconstruction by voxel-space oversampling</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dudak, J.; Zemlicka, J.; Karch, J.; Hermanova, Z.; Kvacek, J.; Krejci, F.</p> <p>2017-01-01</p> <p>Photon counting detectors Timepix are known for their unique properties enabling X-ray imaging with extremely high contrast-to-noise ratio. Their applicability has been recently further improved since a dedicated technique for assembling large area Timepix detector arrays was introduced. Despite the fact that the sensitive area of Timepix detectors has been significantly increased, the pixel pitch is kept unchanged (55 microns). This value is much larger compared to widely used and popular X-ray imaging cameras utilizing scintillation crystals and CCD-based read-out. On the other hand, photon counting detectors provide steeper point-spread function. Therefore, with given effective pixel size of an acquired radiography, Timepix detectors provide higher spatial resolution than X-ray cameras with scintillation-based devices unless the image is affected by penumbral blur. In this paper we take an advance of steep PSF of photon counting detectors and test the possibility to improve the quality of computed tomography reconstruction using finer sampling of reconstructed voxel space. The achieved results are presented in comparison with data acquired under the same conditions using a commercially available state-of-the-art CCD X-ray camera.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_15 --> <div id="page_16" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="301"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016NatSR...631135S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016NatSR...631135S"><span>Wiring up pre-characterized single-photon emitters by laser lithography</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shi, Q.; Sontheimer, B.; Nikolay, N.; Schell, A. W.; Fischer, J.; Naber, A.; Benson, O.; Wegener, M.</p> <p>2016-08-01</p> <p>Future quantum optical chips will likely be hybrid in nature and include many single-photon emitters, waveguides, filters, as well as single-photon detectors. Here, we introduce a scalable optical localization-selection-lithography procedure for wiring up a large number of single-photon emitters via polymeric photonic wire bonds in three dimensions. First, we localize and characterize nitrogen vacancies in nanodiamonds inside a solid photoresist exhibiting low background fluorescence. Next, without intermediate steps and using the same optical instrument, we perform aligned three-dimensional laser lithography. As a proof of concept, we design, fabricate, and characterize three-dimensional functional waveguide elements on an optical chip. Each element consists of one single-photon emitter centered in a crossed-arc waveguide configuration, allowing for integrated optical excitation and efficient background suppression at the same time.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA502752','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA502752"><span>Quantum Key Distribution Using Polarized Single Photons</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2009-04-01</p> <p>liquid helium the SSPD with a low - noise , cryogenic high-electron-mobility transistor (HEMT) with high-input impedance. This arrangement allowed us...Sobolewski, IEEE Trans. Appl. Supercon., accepted (2009). 19. " Measurements of amplitude distributions of dark counts and photon counts in NbN ...75, 174507 (2007). 6. "Fiber-Coupled NbN Superconducting Single-Photon Detectors for Quantum Correlation Measurements ," W. Slysz, M. Wegrzecki, J</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010ITNS...57.1570M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010ITNS...57.1570M"><span>Optimization of a LSO-Based Detector Module for Time-of-Flight PET</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Moses, W. W.; Janecek, M.; Spurrier, M. A.; Szupryczynski, P.; Choong, W.-S.; Melcher, C. L.; Andreaco, M.</p> <p>2010-06-01</p> <p>We have explored methods for optimizing the timing resolution of an LSO-based detector module for a single-ring, “demonstration” time-of-flight PET camera. By maximizing the area that couples the scintillator to the PMT and minimizing the average path length that the scintillation photons travel, a single detector timing resolution of 218 ps fwhm is measured, which is considerably better than the 385 ps fwhm obtained by commercial LSO or LYSO TOF detector modules. We explored different surface treatments (saw-cut, mechanically polished, and chemically etched) and reflector materials (Teflon tape, ESR, Lumirror, Melinex, white epoxy, and white paint), and found that for our geometry, a chemically etched surface had 5% better timing resolution than the saw-cut or mechanically polished surfaces, and while there was little dependence on the timing resolution between the various reflectors, white paint and white epoxy were a few percent better. Adding co-dopants to LSO shortened the decay time from 40 ns to 30 ns but maintained the same or higher total light output. This increased the initial photoelectron rate and so improved the timing resolution by 15%. Using photomultiplier tubes with higher quantum efficiency (blue sensitivity index of 13.5 rather than 12) improved the timing resolution by an additional 5%. By choosing the optimum surface treatment (chemically etched), reflector (white paint), LSO composition (co-doped), and PMT (13.5 blue sensitivity index), the coincidence timing resolution of our detector module was reduced from 309 ps to 220 ps fwhm.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29488920','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29488920"><span>Evaluation of the UFXC32k photon-counting detector for pump-probe experiments using synchrotron radiation.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Koziol, Anna; Bordessoule, Michel; Ciavardini, Alessandra; Dawiec, Arkadiusz; Da Silva, Paulo; Desjardins, Kewin; Grybos, Pawel; Kanoute, Brahim; Laulhe, Claire; Maj, Piotr; Menneglier, Claude; Mercere, Pascal; Orsini, Fabienne; Szczygiel, Robert</p> <p>2018-03-01</p> <p>This paper presents the performance of a single-photon-counting hybrid pixel X-ray detector with synchrotron radiation. The camera was evaluated with respect to time-resolved experiments, namely pump-probe-probe experiments held at SOLEIL. The UFXC camera shows very good energy resolution of around 1.5 keV and allows the minimum threshold setting to be as low as 3 keV keeping the high-count-rate capabilities. Measurements of a synchrotron characteristic filling mode prove the proper separation of an isolated bunch of photons and the usability of the detector in time-resolved experiments.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010SPIE.7780E..1MI','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010SPIE.7780E..1MI"><span>Design and performance of single photon APD focal plane arrays for 3-D LADAR imaging</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Itzler, Mark A.; Entwistle, Mark; Owens, Mark; Patel, Ketan; Jiang, Xudong; Slomkowski, Krystyna; Rangwala, Sabbir; Zalud, Peter F.; Senko, Tom; Tower, John; Ferraro, Joseph</p> <p>2010-08-01</p> <p>×We describe the design, fabrication, and performance of focal plane arrays (FPAs) for use in 3-D LADAR imaging applications requiring single photon sensitivity. These 32 × 32 FPAs provide high-efficiency single photon sensitivity for three-dimensional LADAR imaging applications at 1064 nm. Our GmAPD arrays are designed using a planarpassivated avalanche photodiode device platform with buried p-n junctions that has demonstrated excellent performance uniformity, operational stability, and long-term reliability. The core of the FPA is a chip stack formed by hybridizing the GmAPD photodiode array to a custom CMOS read-out integrated circuit (ROIC) and attaching a precision-aligned GaP microlens array (MLA) to the back-illuminated detector array. Each ROIC pixel includes an active quenching circuit governing Geiger-mode operation of the corresponding avalanche photodiode pixel as well as a pseudo-random counter to capture per-pixel time-of-flight timestamps in each frame. The FPA has been designed to operate at frame rates as high as 186 kHz for 2 μs range gates. Effective single photon detection efficiencies as high as 40% (including all optical transmission and MLA losses) are achieved for dark count rates below 20 kHz. For these planar-geometry diffused-junction GmAPDs, isolation trenches are used to reduce crosstalk due to hot carrier luminescence effects during avalanche events, and we present details of the crosstalk performance for different operating conditions. Direct measurement of temporal probability distribution functions due to cumulative timing uncertainties of the GmAPDs and ROIC circuitry has demonstrated a FWHM timing jitter as low as 265 ps (standard deviation is ~100 ps).</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JInst..13C1001T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JInst..13C1001T"><span>Evaluation of Timepix3 based CdTe photon counting detector for fully spectroscopic small animal SPECT imaging</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Trojanova, E.; Jakubek, J.; Turecek, D.; Sykora, V.; Francova, P.; Kolarova, V.; Sefc, L.</p> <p>2018-01-01</p> <p>The imaging method of SPECT (Single Photon Emission Computed Tomography) is used in nuclear medicine for diagnostics of various diseases or organs malfunctions. The distribution of medically injected, inhaled, or ingested radionuclides (radiotracers) in the patient body is imaged using gamma-ray sensitive camera with suitable imaging collimator. The 3D image is then calculated by combining many images taken from different observation angles. Most of SPECT systems use scintillator based cameras. These cameras do not provide good energy resolution and do not allow efficient suppression of unwanted signals such as those caused by Compton scattering. The main goal of this work is evaluation of Timepix3 detector properties for SPECT method for functional imaging of small animals during preclinical studies. Advantageous Timepix3 properties such as energy and spatial resolution are exploited for significant image quality improvement. Preliminary measurements were performed on specially prepared plastic phantom with cavities filled by radioisotopes and then repeated with in vivo mouse sample.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28295068','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28295068"><span>Two-photon Shack-Hartmann wavefront sensor.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Xia, Fei; Sinefeld, David; Li, Bo; Xu, Chris</p> <p>2017-03-15</p> <p>We introduce a simple wavefront sensing scheme for aberration measurement of pulsed laser beams in near-infrared wavelengths (<2200  nm), where detectors are not always available or are very expensive. The method is based on two-photon absorption in a silicon detector array for longer wavelengths detection. We demonstrate the simplicity of such implementations with a commercially available Shack-Hartmann wavefront sensor and discuss the detection sensitivity of this method.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3831293','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3831293"><span>An on-chip coupled resonator optical waveguide single-photon buffer</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Takesue, Hiroki; Matsuda, Nobuyuki; Kuramochi, Eiichi; Munro, William J.; Notomi, Masaya</p> <p>2013-01-01</p> <p>Integrated quantum optical circuits are now seen as one of the most promising approaches with which to realize single-photon quantum information processing. Many of the core elements for such circuits have been realized, including sources, gates and detectors. However, a significant missing function necessary for photonic quantum information processing on-chip is a buffer, where single photons are stored for a short period of time to facilitate circuit synchronization. Here we report an on-chip single-photon buffer based on coupled resonator optical waveguides (CROW) consisting of 400 high-Q photonic crystal line-defect nanocavities. By using the CROW, a pulsed single photon is successfully buffered for 150 ps with 50-ps tunability while maintaining its non-classical properties. Furthermore, we show that our buffer preserves entanglement by storing and retrieving one photon from a time-bin entangled state. This is a significant step towards an all-optical integrated quantum information processor. PMID:24217422</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23736605','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23736605"><span>On-chip low loss heralded source of pure single photons.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Spring, Justin B; Salter, Patrick S; Metcalf, Benjamin J; Humphreys, Peter C; Moore, Merritt; Thomas-Peter, Nicholas; Barbieri, Marco; Jin, Xian-Min; Langford, Nathan K; Kolthammer, W Steven; Booth, Martin J; Walmsley, Ian A</p> <p>2013-06-03</p> <p>A key obstacle to the experimental realization of many photonic quantum-enhanced technologies is the lack of low-loss sources of single photons in pure quantum states. We demonstrate a promising solution: generation of heralded single photons in a silica photonic chip by spontaneous four-wave mixing. A heralding efficiency of 40%, corresponding to a preparation efficiency of 80% accounting for detector performance, is achieved due to efficient coupling of the low-loss source to optical fibers. A single photon purity of 0.86 is measured from the source number statistics without narrow spectral filtering, and confirmed by direct measurement of the joint spectral intensity. We calculate that similar high-heralded-purity output can be obtained from visible to telecom spectral regions using this approach. On-chip silica sources can have immediate application in a wide range of single-photon quantum optics applications which employ silica photonics.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19870000462&hterms=metal+detector&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dmetal%2Bdetector','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19870000462&hterms=metal+detector&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dmetal%2Bdetector"><span>High-Rydberg Xenon Submillimeter-Wave Detector</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chutjian, Ara</p> <p>1987-01-01</p> <p>Proposed detector for infrared and submillimeter-wavelength radiation uses excited xenon atoms as Rydberg sensors instead of customary beams of sodium, potassium, or cesium. Chemically inert xenon easily stored in pressurized containers, whereas beams of dangerously reactive alkali metals must be generated in cumbersome, unreliable ovens. Xenon-based detector potential for infrared astronomy and for Earth-orbiter detection of terrestrial radiation sources. Xenon atoms excited to high energy states in two stages. Doubly excited atoms sensitive to photons in submillimeter wavelength range, further excited by these photons, then ionized and counted.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006SPIE.6142..523B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006SPIE.6142..523B"><span>Dual-energy imaging using a photon counting detector with electronic spectrum-splitting</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bornefalk, Hans; Lundqvist, Mats</p> <p>2006-03-01</p> <p>This paper presents a dual-energy imaging technique optimized for contrast-enhanced mammography using a photon counting detector. Each photon pulse is processed separately in the detector and the addition of an electronic threshold near the middle of the energy range of the x-ray spectrum allows discrimination of high and low energy photons. This effectively makes the detector energy sensitive, and allows the acquisition of high- and low-energy images simultaneously. These high- and low-energy images can be combined to dual-energy images where the anatomical clutter has been suppressed. By setting the electronic threshold close to 33.2 keV (the k-edge of iodine) the system is optimized for dual-energy contrast-enhanced imaging of breast tumors. Compared to other approaches, this method not only eliminates the need for separate exposures that might lead to motion artifacts, it also eliminates the otherwise deteriorating overlap between high- and low-energy spectra. We present phantom dual-energy images acquired on a prototype system to illustrate that the technique is already operational, albeit in its infancy. We also present a theoretical estimation of the potential gain in tumor signal-difference-to-noise ratio when using this electronic spectrum-splitting method as opposed to acquiring the high- and low-energy images separately with double exposures with separate x-ray spectra. Assuming ideal energy sensitive photon counting detectors, we arrive at the conclusion that the signal-difference-to-noise ratio could be increased by 145% at constant dose. We also illustrate our results on synthetic images.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003SPIE.5030..547L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003SPIE.5030..547L"><span>Measurements on a full-field digital mammography system with a photon counting crystalline silicon detector</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lundqvist, Mats; Danielsson, Mats; Cederstroem, Bjoern; Chmill, Valery; Chuntonov, Alexander; Aslund, Magnus</p> <p>2003-06-01</p> <p>Sectra Microdose is the first single photon counting mammography detector. An edge-on crystalline silicon detector is connected to application specific integrated circuits that individually process each photon. The detector is scanned across the breast and the rejection of scattered radiation exceeds 97% without the use of a Bucky. Processing of each x-rays individually enables an optimization of the information transfer from the x-rays to the image in a way previously not possible. Combined with an almost absence of noise from scattered radiation and from electronics we foresee a possibility to reduce the radiation dose and/or increase the image quality. We will discuss fundamental features of the new direct photon counting technique in terms of dose efficiency and present preliminary measurements for a prototype on physical parameters such as Noise Power Spectra (NPS), MTF and DQE.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21133457','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21133457"><span>Imaging visible light with Medipix2.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mac Raighne, Aaron; Brownlee, Colin; Gebert, Ulrike; Maneuski, Dzmitry; Milnes, James; O'Shea, Val; Rügheimer, Tilman K</p> <p>2010-11-01</p> <p>A need exists for high-speed single-photon counting optical imaging detectors. Single-photon counting high-speed detection of x rays is possible by using Medipix2 with pixelated silicon photodiodes. In this article, we report on a device that exploits the Medipix2 chip for optical imaging. The fabricated device is capable of imaging at >3000 frames/s over a 256×256 pixel matrix. The imaging performance of the detector device via the modulation transfer function is measured, and the presence of ion feedback and its degradation of the imaging properties are discussed.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017NIMPA.876..217C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017NIMPA.876..217C"><span>Photodetectors and front-end electronics for the LHCb RICH upgrade</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cassina, L.; LHCb RICH</p> <p>2017-12-01</p> <p>The RICH detectors of the LHCb experiment provide identification of hadrons produced in high energy proton-proton collisions in the LHC at CERN over a wide momentum range (2-100 GeV/c). Cherenkov light is collected on photon detector planes sensitive to single photons. The RICH will be upgraded (in 2019) to read out every bunch crossing, at a rate of 40 MHz. The current hybrid photon detectors (HPD) will be replaced with multi-anode photomultiplier tubes (customisations of the Hamamatsu R11265 and the H12699 MaPMTs). These 8×8 pixel devices meet the experimental requirements thanks to their small pixel size, high gain, negligible dark count rate (∼50 Hz/cm2) and moderate cross-talk. The measured performance of several tubes is reported, together with their long-term stability. A new 8-channel front-end chip, named CLARO, has been designed in 0.35 μm CMOS AMS technology for the MaPMT readout. The CLARO chip operates in binary mode and combines low power consumption (∼1 mW/Ch), wide bandwidth (baseline restored in ⩽ 25 ns) and radiation hardness. A 12-bit digital register permits the optimisation of the dynamic range and the threshold level for each channel and provides tools for the on-site calibration. The design choices and the characterization of the electronics are presented.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25832073','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25832073"><span>CHERENCUBE: concept definition and implementation challenges of a Cherenkov-based detector block for PET.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Somlai-Schweiger, I; Ziegler, S I</p> <p>2015-04-01</p> <p>A new concept for a depth-of-interaction (DOI) capable time-of-flight (TOF) PET detector is defined, based only on the detection of Cherenkov photons. The proposed "CHERENCUBE" consists of a cubic Cherenkov radiator with position-sensitive photodetectors covering each crystal face. By means of the spatial distribution of the detected photons and their time of arrival, the point of interaction of the gamma-ray in the crystal can be determined. This study analyzes through theoretical calculations and Monte Carlo simulations the potential advantages of the concept toward reaching a Cherenkov-only detector for TOF-PET with DOI capability. Furthermore, an algorithm for the DOI estimation is presented and the requirements for a practical implementation of the proposed concept are defined. The Monte Carlo simulations consisted of a cubic crystal with one photodetector coupled to each one of the faces of the cube. The sensitive area of the detector matched exactly the crystal size, which was varied in 1 mm steps between 1 × 1 × 1 mm(3) and 10 × 10 × 10 mm(3). For each size, five independent simulations of ten thousand 511 keV gamma-rays were triggered at a fixed distance of 10 mm. The crystal chosen was PbWO4. Its scintillation properties were simulated, but only Cherenkov photons were analyzed. Photodetectors were simulated having perfect photodetection efficiency and infinite time resolution. For every generated particle, the analysis considered its creation process, parent and daughter particles, energy, origin coordinates, trajectory, and time and position of detection. The DOI determination is based on the distribution of the emission time of all photons per event. These values are calculated as a function of the coordinates of detection and origin for every photon. The common origin is estimated by finding the distribution with the most similar emission time-points. Detection efficiency increases with crystal size from 8.2% (1 × 1 × 1 mm(3)) to 58.6% (10 × 10 × 10 mm(3)) and decreases applying a photon detection threshold of 5/10/20 photons to 6.3%/4.3%/0.7% and 49.3%/30.4%/2.8%, respectively. The detection rate in the six photodetectors is uniform due to the nearly isotropic cone emission. Most cones originated after a photoelectric effect interaction, with two dominating peaks for the kinetic energy of the electron at 422.99 and 441.47 keV. The detection distance between same-event photons defines the spatial resolution of the detector required for individual photon recognition, with 20% of the detected photons having their closest neighbor within a distance of 5% of the length of the cube. Same-event photons are detected within a time window whose width is determined by the crystal size, with values of 30 and 150 ps for a 1 × 1 × 1 mm(3) and a 10 × 10 × 10 mm(3) cube, respectively. The DOI reconstruction has an accuracy of approximately 23% of the length of the cube, with an average value of 2.2 mm for a 10 × 10 × 10 mm(3) CHERENCUBE. The proposed concept requires a detector with high photodetection efficiency. The structure of the sensitive surface of the detector should be a two dimensional array of microcells, able to provide individual detection coordinates and time stamps. The microcell size determines the ability to recognize individual photons, influencing detection efficiency. The 3D DOI recognition relies on the accuracy of the time stamps and detection coordinates, without the need for a recognition of the projected patterns of photons. The refractive index of the material defines a detector intrinsic energy-based rejection of scattered PET events at the cost of reduced sensitivity.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22413512-cherencube-concept-definition-implementation-challenges-cherenkov-based-detector-block-pet','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22413512-cherencube-concept-definition-implementation-challenges-cherenkov-based-detector-block-pet"><span>CHERENCUBE: Concept definition and implementation challenges of a Cherenkov-based detector block for PET</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Somlai-Schweiger, I., E-mail: ian.somlai@tum.de; Ziegler, S. I.</p> <p></p> <p>Purpose: A new concept for a depth-of-interaction (DOI) capable time-of-flight (TOF) PET detector is defined, based only on the detection of Cherenkov photons. The proposed “CHERENCUBE” consists of a cubic Cherenkov radiator with position-sensitive photodetectors covering each crystal face. By means of the spatial distribution of the detected photons and their time of arrival, the point of interaction of the gamma-ray in the crystal can be determined. This study analyzes through theoretical calculations and Monte Carlo simulations the potential advantages of the concept toward reaching a Cherenkov-only detector for TOF-PET with DOI capability. Furthermore, an algorithm for the DOI estimationmore » is presented and the requirements for a practical implementation of the proposed concept are defined. Methods: The Monte Carlo simulations consisted of a cubic crystal with one photodetector coupled to each one of the faces of the cube. The sensitive area of the detector matched exactly the crystal size, which was varied in 1 mm steps between 1 × 1 × 1 mm{sup 3} and 10 × 10 × 10 mm{sup 3}. For each size, five independent simulations of ten thousand 511 keV gamma-rays were triggered at a fixed distance of 10 mm. The crystal chosen was PbWO{sub 4}. Its scintillation properties were simulated, but only Cherenkov photons were analyzed. Photodetectors were simulated having perfect photodetection efficiency and infinite time resolution. For every generated particle, the analysis considered its creation process, parent and daughter particles, energy, origin coordinates, trajectory, and time and position of detection. The DOI determination is based on the distribution of the emission time of all photons per event. These values are calculated as a function of the coordinates of detection and origin for every photon. The common origin is estimated by finding the distribution with the most similar emission time-points. Results: Detection efficiency increases with crystal size from 8.2% (1 × 1 × 1 mm{sup 3}) to 58.6% (10 × 10 × 10 mm{sup 3}) and decreases applying a photon detection threshold of 5/10/20 photons to 6.3%/4.3%/0.7% and 49.3%/30.4%/2.8%, respectively. The detection rate in the six photodetectors is uniform due to the nearly isotropic cone emission. Most cones originated after a photoelectric effect interaction, with two dominating peaks for the kinetic energy of the electron at 422.99 and 441.47 keV. The detection distance between same-event photons defines the spatial resolution of the detector required for individual photon recognition, with 20% of the detected photons having their closest neighbor within a distance of 5% of the length of the cube. Same-event photons are detected within a time window whose width is determined by the crystal size, with values of 30 and 150 ps for a 1 × 1 × 1 mm{sup 3} and a 10 × 10 × 10 mm{sup 3} cube, respectively. The DOI reconstruction has an accuracy of approximately 23% of the length of the cube, with an average value of 2.2 mm for a 10 × 10 × 10 mm{sup 3} CHERENCUBE. Conclusions: The proposed concept requires a detector with high photodetection efficiency. The structure of the sensitive surface of the detector should be a two dimensional array of microcells, able to provide individual detection coordinates and time stamps. The microcell size determines the ability to recognize individual photons, influencing detection efficiency. The 3D DOI recognition relies on the accuracy of the time stamps and detection coordinates, without the need for a recognition of the projected patterns of photons. The refractive index of the material defines a detector intrinsic energy-based rejection of scattered PET events at the cost of reduced sensitivity.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1399723','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1399723"><span></span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Ingargiola, A.; Laurence, T. A.; Boutelle, R.</p> <p></p> <p>We introduce Photon-HDF5, an open and efficient file format to simplify exchange and long term accessibility of data from single-molecule fluorescence experiments based on photon-counting detectors such as single-photon avalanche diode (SPAD), photomultiplier tube (PMT) or arrays of such detectors. The format is based on HDF5, a widely used platform- and language-independent hierarchical file format for which user-friendly viewers are available. Photon-HDF5 can store raw photon data (timestamp, channel number, etc) from any acquisition hardware, but also setup and sample description, information on provenance, authorship and other metadata, and is flexible enough to include any kind of custom data. Themore » format specifications are hosted on a public website, which is open to contributions by the biophysics community. As an initial resource, the website provides code examples to read Photon-HDF5 files in several programming languages and a reference python library (phconvert), to create new Photon-HDF5 files and convert several existing file formats into Photon-HDF5. As a result, to encourage adoption by the academic and commercial communities, all software is released under the MIT open source license.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19940011099','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19940011099"><span>The solid state detector technology for picosecond laser ranging</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Prochazka, Ivan</p> <p>1993-01-01</p> <p>We developed an all solid state laser ranging detector technology, which makes the goal of millimeter accuracy achievable. Our design and construction philosophy is to combine the techniques of single photon ranging, ultrashort laser pulses, and fast fixed threshold discrimination while avoiding any analog signal processing within the laser ranging chain. The all solid state laser ranging detector package consists of the START detector and the STOP solid state photon counting module. Both the detectors are working in an optically triggered avalanche switching regime. The optical signal is triggering an avalanche current buildup which results in the generation of a uniform, fast risetime output pulse.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3017366','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3017366"><span>System Integration of FastSPECT III, a Dedicated SPECT Rodent-Brain Imager Based on BazookaSPECT Detector Technology</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Miller, Brian W.; Furenlid, Lars R.; Moore, Stephen K.; Barber, H. Bradford; Nagarkar, Vivek V.; Barrett, Harrison H.</p> <p>2010-01-01</p> <p>FastSPECT III is a stationary, single-photon emission computed tomography (SPECT) imager designed specifically for imaging and studying neurological pathologies in rodent brain, including Alzheimer’s and Parkinsons’s disease. Twenty independent BazookaSPECT [1] gamma-ray detectors acquire projections of a spherical field of view with pinholes selected for desired resolution and sensitivity. Each BazookaSPECT detector comprises a columnar CsI(Tl) scintillator, image-intensifier, optical lens, and fast-frame-rate CCD camera. Data stream back to processing computers via firewire interfaces, and heavy use of graphics processing units (GPUs) ensures that each frame of data is processed in real time to extract the images of individual gamma-ray events. Details of the system design, imaging aperture fabrication methods, and preliminary projection images are presented. PMID:21218137</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017hsa9.conf..707V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017hsa9.conf..707V"><span>EMCCD calibration for astronomical imaging: Wide FastCam at the Telescopio Carlos Sánchez</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Velasco, S.; Oscoz, A.; López, R. L.; Puga, M.; Pérez-Garrido, A.; Pallé, E.; Ricci, D.; Ayuso, I.; Hernández-Sánchez, M.; Vázquez-Martín, S.; Protasio, C.; Béjar, V.; Truant, N.</p> <p>2017-03-01</p> <p>The evident benefits of Electron Multiplying CCDs (EMCCDs) -speed, high sensitivity, low noise and their capability of detecting single photon events whilst maintaining high quantum efficiency- are bringing these kinds of detectors to many state-of-the-art astronomical instruments (Velasco et al. 2016; Oscoz et al. 2008). The EMCCDs are the perfect answer to the need for great sensitivity levels as they are not limited by the readout noise of the output amplifier, while conventional CCDs are, even when operated at high readout frame rates. Here we present a quantitative on-sky method to calibrate EMCCD detectors dedicated to astronomical imaging, developed during the commissioning process (Velasco et al. 2016) and first observations (Ricci et al. 2016, in prep.) with Wide FastCam (Marga et al. 2014) at Telescopio Carlos Sánchez (TCS) in the Observatorio del Teide.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_16 --> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SPD....4830504B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SPD....4830504B"><span>Methods for reducing ghost rays on the Wolter-I focusing figures of the FOXSI rocket payload</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Buitrago-Casas, Juan Camilo; Glesener, Lindsay; Christe, Steven; Ramsey, Brian; Elsner, Ronald; Courtade, Sasha; Vievering, Juliana; Subramania, Athiray; Krucker, Sam; Bale, Stuart</p> <p>2017-08-01</p> <p>In high energy solar astrophysics, imaging hard X-rays by direct focusing offers higher dynamic range and greater sensitivity compared to past techniques that used indirect imaging. The Focusing Optics X-ray Solar Imager (FOXSI) is a sounding rocket payload which uses seven sets of nested Wolter-I figured mirrors that, together with seven high-sensitive semiconductor detectors, observes the Sun in hard X-rays by direct focusing. The FOXSI rocket has successfully flown twice and is funded to fly a third time in summer 2018.The Wolter-I geometry consists of two consecutive mirrors, one paraboloid, and one hyperboloid, that reflect photons at grazing angles. Correctly focused X-rays reflect twice, once per mirror segment. For extended sources, like the Sun, off-axis photons at certain incident angles can reflect on only one mirror and still reach the focal plane, generating a pattern of single-bounce photons, or ‘ghost rays’ that can limit the sensitivity of the observation of focused X-rays. Understanding and cutting down the ghost rays on the FOXSI optics will maximize the instrument’s sensitivity of the solar faintest sources for future flights. We present an analysis of the FOXSI ghost rays based on ray-tracing simulations, as well as the effectiveness of different physical strategies to reduce them.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29401859','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29401859"><span>Tuning single-photon sources for telecom multi-photon experiments.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Greganti, Chiara; Schiansky, Peter; Calafell, Irati Alonso; Procopio, Lorenzo M; Rozema, Lee A; Walther, Philip</p> <p>2018-02-05</p> <p>Multi-photon state generation is of great interest for near-future quantum simulation and quantum computation experiments. To-date spontaneous parametric down-conversion is still the most promising process, even though two major impediments still exist: accidental photon noise (caused by the probabilistic non-linear process) and imperfect single-photon purity (arising from spectral entanglement between the photon pairs). In this work, we overcome both of these difficulties by (1) exploiting a passive temporal multiplexing scheme and (2) carefully optimizing the spectral properties of the down-converted photons using periodically-poled KTP crystals. We construct two down-conversion sources in the telecom wavelength regime, finding spectral purities of > 91%, while maintaining high four-photon count rates. We use single-photon grating spectrometers together with superconducting nanowire single-photon detectors to perform a detailed characterization of our multi-photon source. Our methods provide practical solutions to produce high-quality multi-photon states, which are in demand for many quantum photonics applications.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20100024439','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20100024439"><span>Photon Counting Using Edge-Detection Algorithm</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gin, Jonathan W.; Nguyen, Danh H.; Farr, William H.</p> <p>2010-01-01</p> <p>New applications such as high-datarate, photon-starved, free-space optical communications require photon counting at flux rates into gigaphoton-per-second regimes coupled with subnanosecond timing accuracy. Current single-photon detectors that are capable of handling such operating conditions are designed in an array format and produce output pulses that span multiple sample times. In order to discern one pulse from another and not to overcount the number of incoming photons, a detection algorithm must be applied to the sampled detector output pulses. As flux rates increase, the ability to implement such a detection algorithm becomes difficult within a digital processor that may reside within a field-programmable gate array (FPGA). Systems have been developed and implemented to both characterize gigahertz bandwidth single-photon detectors, as well as process photon count signals at rates into gigaphotons per second in order to implement communications links at SCPPM (serial concatenated pulse position modulation) encoded data rates exceeding 100 megabits per second with efficiencies greater than two bits per detected photon. A hardware edge-detection algorithm and corresponding signal combining and deserialization hardware were developed to meet these requirements at sample rates up to 10 GHz. The photon discriminator deserializer hardware board accepts four inputs, which allows for the ability to take inputs from a quadphoton counting detector, to support requirements for optical tracking with a reduced number of hardware components. The four inputs are hardware leading-edge detected independently. After leading-edge detection, the resultant samples are ORed together prior to deserialization. The deserialization is performed to reduce the rate at which data is passed to a digital signal processor, perhaps residing within an FPGA. The hardware implements four separate analog inputs that are connected through RF connectors. Each analog input is fed to a high-speed 1-bit comparator, which digitizes the input referenced to an adjustable threshold value. This results in four independent serial sample streams of binary 1s and 0s, which are ORed together at rates up to 10 GHz. This single serial stream is then deserialized by a factor of 16 to create 16 signal lines at a rate of 622.5 MHz or lower for input to a high-speed digital processor assembly. The new design and corresponding hardware can be employed with a quad-photon counting detector capable of handling photon rates on the order of multi-gigaphotons per second, whereas prior art was only capable of handling a single input at 1/4 the flux rate. Additionally, the hardware edge-detection algorithm has provided the ability to process 3-10 higher photon flux rates than previously possible by removing the limitation that photoncounting detector output pulses on multiple channels being ORed not overlap. Now, only the leading edges of the pulses are required to not overlap. This new photon counting digitizer hardware architecture supports a universal front end for an optical communications receiver operating at data rates from kilobits to over one gigabit per second to meet increased mission data volume requirements.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2819128','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2819128"><span>Photon-Counting H33D Detector for Biological Fluorescence Imaging</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Michalet, X.; Siegmund, O.H.W.; Vallerga, J.V.; Jelinsky, P.; Millaud, J.E.; Weiss, S.</p> <p>2010-01-01</p> <p>We have developed a photon-counting High-temporal and High-spatial resolution, High-throughput 3-Dimensional detector (H33D) for biological imaging of fluorescent samples. The design is based on a 25 mm diameter S20 photocathode followed by a 3-microchannel plate stack, and a cross delay line anode. We describe the bench performance of the H33D detector, as well as preliminary imaging results obtained with fluorescent beads, quantum dots and live cells and discuss applications of future generation detectors for single-molecule imaging and high-throughput study of biomolecular interactions. PMID:20151021</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014SPIE.9289E..0HB','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014SPIE.9289E..0HB"><span>Single-photon interference experiment for high schools</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bondani, Maria</p> <p>2014-07-01</p> <p>We follow the reductio ad absurdum reasoning described in the book "Sneaking a Look at God's Cards" by Giancarlo Ghirardi to demonstrate the wave-particle duality of light in a Mach-Zehnder interferometric setup analog to the conventional Young double-slit experiment. We aim at showing the double nature of light by measuring the existence of interference fringes down to the single-photon level. The setup includes a strongly attenuated laser, polarizing beam splitters, half-waveplates, polarizers and single-photon detectors.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009PhDT.........1L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009PhDT.........1L"><span>Characterization of the polarization and frequency selective bolometric detector architecture</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Leong, Jonathan Ryan Kyoung Ho</p> <p>2009-01-01</p> <p>The Cosmic Microwave Background (CMB) has been a wonderful probe of fundamental physics and cosmology. In the future, we look towards using the polarization information encoded in the CMB for investigating the gravity waves generated by inflation. This is a daunting task as it requires orders of magnitude increases in sensitivity as well as close attention to systematic rejection and astrophysical foreground removal. We have characterized a novel detector architecture which is aimed at making these leaps towards gravity wave detection in the CMB. These detectors are called the Polarization and Frequency Selective Bolometers (PFSBs). They attempt to use all the available photon information incident on a single pixel by selecting out the two orthogonal polarizations and multiple frequency bands into separately stacked detectors in a smooth-walled waveguide. This approach is inherently multimoded and thus solves problems with downlink and readout throughput by catching more photons per detector at the higher frequencies where the number of detectors required is prohibitively large. We have found that the PFSB architecture requires the use of a square cross-section waveguide. A simulation we developed has illuminated the fact that the curved field lines of the higher order modes can be eliminated by degeneracies which exist only for a square guide and not a circular one. In the square guide configuration, the PFSBs show good band selection and polarization efficiency to a level of about 90% over the beam out to at least 20° from on-axis.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010NIMPA.619..262S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010NIMPA.619..262S"><span>Energy-discriminating X-ray computed tomography system utilizing a cadmium telluride detector</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sato, Eiichi; Abderyim, Purkhet; Enomoto, Toshiyuki; Watanabe, Manabu; Hitomi, Keitaro; Takahasi, Kiyomi; Sato, Shigehiro; Ogawae, Akira; Onagawa, Jun</p> <p>2010-07-01</p> <p>An energy-discriminating K-edge X-ray computed tomography (CT) system is useful for increasing contrast resolution of a target region utilizing contrast media and for reducing the absorbed dose for patients. The CT system is of the first-generation type with a cadmium telluride (CdTe) detector, and a projection curve is obtained by translation scanning using the CdTe detector in conjunction with an x-stage. An object is rotated by the rotation step angle using a turntable between the translation scans. Thus, CT is carried out by repeating the translation scanning and the rotation of an object. Penetrating X-ray photons from the object are detected by the CdTe detector, and event signals of X-ray photons are produced using charge-sensitive and shaping amplifiers. Both the photon energy and the energy width are selected by use of a multi-channel analyzer, and the number of photons is counted by a counter card. Demonstration of enhanced iodine K-edge X-ray CT was carried out by selecting photons with energies just beyond the iodine K-edge energy of 33.2 keV.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28789045','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28789045"><span>Fully integrated free-running InGaAs/InP single-photon detector for accurate lidar applications.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yu, Chao; Shangguan, Mingjia; Xia, Haiyun; Zhang, Jun; Dou, Xiankang; Pan, Jian-Wei</p> <p>2017-06-26</p> <p>We present a fully integrated InGaAs/InP negative feedback avalanche diode (NFAD) based free-running single-photon detector (SPD) designed for accurate lidar applications. A free-piston Stirling cooler is used to cool down the NFAD with a large temperature range, and an active hold-off circuit implemented in a field programmable gate array is applied to further suppress the afterpulsing contribution. The key parameters of the free-running SPD including photon detection efficiency (PDE), dark count rate (DCR), afterpulse probability, and maximum count rate (MCR) are dedicatedly optimized for lidar application in practice. We then perform a field experiment using a Mie lidar system with 20 kHz pulse repetition frequency to compare the performance between the free-running InGaAs/InP SPD and a commercial superconducting nanowire single-photon detector (SNSPD). Our detector exhibits good performance with 1.6 Mcps MCR (0.6 μs hold-off time), 10% PDE, 950 cps DCR, and 18% afterpulse probability over 50 μs period. Such performance is worse than the SNSPD with 60% PDE and 300 cps DCR. However, after performing a specific algorithm that we have developed for afterpulse and count rate corrections, the lidar system performance in terms of range-corrected signal (Pr 2 ) distribution using our SPD agrees very well with the result using the SNSPD, with only a relative error of ∼2%. Due to the advantages of low-cost and small size of InGaAs/InP NFADs, such detector provides a practical solution for accurate lidar applications.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AIPC.1085..866O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AIPC.1085..866O"><span>Focal Plane Detectors for the Advanced Gamma-Ray Imaging System (AGIS)</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Otte, A. N.; Byrum, K.; Drake, G.; Falcone, A.; Funk, S.; Horan, D.; Mukherjee, R.; Smith, A.; Tajima, H.; Wagner, R. G.; Williams, D. A.</p> <p>2008-12-01</p> <p>The Advanced Gamma-Ray Imaging System (AGIS) is a concept for the next generation observatory in ground-based very high energy gamma-ray astronomy. Design goals are ten times better sensitivity, higher angular resolution, and a lower energy threshold than existing Cherenkov telescopes. Simulations show that a substantial improvement in angular resolution may be achieved if the pixel diameter is reduced to the order of 0.05 deg, i.e. two to three times smaller than the pixel diameter of current Cherenkov telescope cameras. At these dimensions, photon detectors with smaller physical dimensions can be attractive alternatives to the classical photomultiplier tube (PMT). Furthermore, the operation of an experiment with the size of AGIS requires photon detectors that are among other things more reliable, more durable, and possibly higher efficiency photon detectors. Alternative photon detectors we are considering for AGIS include both silicon photomultipliers (SiPMs) and multi-anode photomultipliers (MAPMTs). Here we present results from laboratory testing of MAPMTs and SiPMs along with results from the first incorporation of these devices into cameras on test bed Cherenkov telescopes.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018EPJWC.17402008K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018EPJWC.17402008K"><span>Operation of an InGrid based X-ray detector at the CAST experiment</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Krieger, Christoph; Desch, Klaus; Kaminski, Jochen; Lupberger, Michael</p> <p>2018-02-01</p> <p>The CERN Axion Solar Telescope (CAST) is searching for axions and other particles which could be candidates for DarkMatter and even Dark Energy. These particles could be produced in the Sun and detected by a conversion into soft X-ray photons inside a strong magnetic field. In order to increase the sensitivity for physics beyond the Standard Model, detectors with a threshold below 1 keV as well as efficient background rejection methods are required to compensate for low energies and weak couplings resulting in very low detection rates. Those criteria are fulfilled by a detector utilizing the combination of a pixelized readout chip with an integrated Micromegas stage. These InGrid (Integrated Grid) devices can be build by photolithographic postprocessing techniques, resulting in a close to perfect match of grid and pixels facilitating the detection of single electrons on the chip surface. The high spatial resolution allows for energy determination by simple electron counting as well as for an event-shape based analysis as background rejection method. Tests at an X-ray generator revealed the energy threshold of an InGrid based X-ray detector to be well below the carbon Kα line at 277 eV. After the successful demonstration of the detectors key features, the detector was mounted at one of CAST's four detector stations behind an X-ray telescope in 2014. After several months of successful operation without any detector related interruptions, the InGrid based X-ray detector continues data taking at CAST in 2015. During operation at the experiment, background rates in the order of 10-5 keV-1 cm-2 s-1 have been achieved by application of a likelihood based method discriminating the non-photon background originating mostly from cosmic rays. For continued operation in 2016, an upgraded InGrid based detector is to be installed among other improvements including decoupling and sampling of the signal induced on the grid as well as a veto scintillator to further lower the observed background rates and improving sensitivity.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24140804','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24140804"><span>High-sensitivity brain SPECT system using cadmium telluride (CdTe) semiconductor detector and 4-pixel matched collimator.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Suzuki, Atsuro; Takeuchi, Wataru; Ishitsu, Takafumi; Tsuchiya, Katsutoshi; Morimoto, Yuichi; Ueno, Yuichiro; Kobashi, Keiji; Kubo, Naoki; Shiga, Tohru; Tamaki, Nagara</p> <p>2013-11-07</p> <p>For high-sensitivity brain imaging, we have developed a two-head single-photon emission computed tomography (SPECT) system using a CdTe semiconductor detector and 4-pixel matched collimator (4-PMC). The term, '4-PMC' indicates that the collimator hole size is matched to a 2 × 2 array of detector pixels. By contrast, a 1-pixel matched collimator (1-PMC) is defined as a collimator whose hole size is matched to one detector pixel. The performance of the higher-sensitivity 4-PMC was experimentally compared with that of the 1-PMC. The sensitivities of the 1-PMC and 4-PMC were 70 cps/MBq/head and 220 cps/MBq/head, respectively. The SPECT system using the 4-PMC provides superior image resolution in cold and hot rods phantom with the same activity and scan time to that of the 1-PMC. In addition, with half the usual scan time the 4-PMC provides comparable image quality to that of the 1-PMC. Furthermore, (99m)Tc-ECD brain perfusion images of healthy volunteers obtained using the 4-PMC demonstrated acceptable image quality for clinical diagnosis. In conclusion, our CdTe SPECT system equipped with the higher-sensitivity 4-PMC can provide better spatial resolution than the 1-PMC either in half the imaging time with the same administered activity, or alternatively, in the same imaging time with half the activity.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013NIMPA.730..164A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013NIMPA.730..164A"><span>Fast synchrotron and FEL beam monitors based on single-crystal diamond detectors and InGaAs/InAlAs quantum well devices</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Antonelli, M.; Di Fraia, M.; Carrato, S.; Cautero, G.; Menk, R. H.; Jark, W. H.; Ganbold, T.; Biasiol, G.; Callegari, C.; Coreno, M.; De Sio, A.; Pace, E.</p> <p>2013-12-01</p> <p>Simultaneous photon-beam position and intensity monitoring is becoming of increasing importance for new-generation synchrotron radiation sources and free-electron lasers (FEL). Thus, novel concepts of beam diagnostics are required in order to keep such beams under control. From this perspective diamond is a promising material for the production of semitransparent in situ photon beam monitors, which can withstand the high dose rates occurring in such radiation facilities. Here, we report on the development of freestanding, single-crystal chemical-vapor-deposited diamond detectors with segmented electrodes. Due to their direct, low-energy band gap, InGaAs quantum well devices operated at room temperature may also be used as fast detectors for photons ranging from visible to X-ray. These features are valuable in low-energy and time-resolved FEL applications. In particular, a novel segmented InGaAs/InAlAs device has been developed and will be discussed. Dedicated measurements carried out on both these devices at the Elettra Synchrotron show their capability to monitor the position and the intensity of the photon beam with bunch-by-bunch temporal performances. Furthermore, preliminary tests have been performed on diamond detectors at the Fermi FEL, extracting quantitative intensity and position information for 100-fs-wide FEL pulses with a photon energy of 28.8 eV.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20721069','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20721069"><span>Long-distance entanglement-based quantum key distribution experiment using practical detectors.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Takesue, Hiroki; Harada, Ken-Ichi; Tamaki, Kiyoshi; Fukuda, Hiroshi; Tsuchizawa, Tai; Watanabe, Toshifumi; Yamada, Koji; Itabashi, Sei-Ichi</p> <p>2010-08-02</p> <p>We report an entanglement-based quantum key distribution experiment that we performed over 100 km of optical fiber using a practical source and detectors. We used a silicon-based photon-pair source that generated high-purity time-bin entangled photons, and high-speed single photon detectors based on InGaAs/InP avalanche photodiodes with the sinusoidal gating technique. To calculate the secure key rate, we employed a security proof that validated the use of practical detectors. As a result, we confirmed the successful generation of sifted keys over 100 km of optical fiber with a key rate of 4.8 bit/s and an error rate of 9.1%, with which we can distill secure keys with a key rate of 0.15 bit/s.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27383791','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27383791"><span>A photon-photon quantum gate based on a single atom in an optical resonator.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hacker, Bastian; Welte, Stephan; Rempe, Gerhard; Ritter, Stephan</p> <p>2016-08-11</p> <p>That two photons pass each other undisturbed in free space is ideal for the faithful transmission of information, but prohibits an interaction between the photons. Such an interaction is, however, required for a plethora of applications in optical quantum information processing. The long-standing challenge here is to realize a deterministic photon-photon gate, that is, a mutually controlled logic operation on the quantum states of the photons. This requires an interaction so strong that each of the two photons can shift the other's phase by π radians. For polarization qubits, this amounts to the conditional flipping of one photon's polarization to an orthogonal state. So far, only probabilistic gates based on linear optics and photon detectors have been realized, because "no known or foreseen material has an optical nonlinearity strong enough to implement this conditional phase shift''. Meanwhile, tremendous progress in the development of quantum-nonlinear systems has opened up new possibilities for single-photon experiments. Platforms range from Rydberg blockade in atomic ensembles to single-atom cavity quantum electrodynamics. Applications such as single-photon switches and transistors, two-photon gateways, nondestructive photon detectors, photon routers and nonlinear phase shifters have been demonstrated, but none of them with the ideal information carriers: optical qubits in discriminable modes. Here we use the strong light-matter coupling provided by a single atom in a high-finesse optical resonator to realize the Duan-Kimble protocol of a universal controlled phase flip (π phase shift) photon-photon quantum gate. We achieve an average gate fidelity of (76.2 ± 3.6) per cent and specifically demonstrate the capability of conditional polarization flipping as well as entanglement generation between independent input photons. This photon-photon quantum gate is a universal quantum logic element, and therefore could perform most existing two-photon operations. The demonstrated feasibility of deterministic protocols for the optical processing of quantum information could lead to new applications in which photons are essential, especially long-distance quantum communication and scalable quantum computing.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvA..96d3807M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvA..96d3807M"><span>Temporal and spectral manipulations of correlated photons using a time lens</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mittal, Sunil; Orre, Venkata Vikram; Restelli, Alessandro; Salem, Reza; Goldschmidt, Elizabeth A.; Hafezi, Mohammad</p> <p>2017-10-01</p> <p>A common challenge in quantum information processing with photons is the limited ability to manipulate and measure correlated states. An example is the inability to measure picosecond-scale temporal correlations of a multiphoton state, given state-of-the-art detectors have a temporal resolution of about 100 ps. Here, we demonstrate temporal magnification of time-bin-entangled two-photon states using a time lens and measure their temporal correlation function, which is otherwise not accessible because of the limited temporal resolution of single-photon detectors. Furthermore, we show that the time lens maps temporal correlations of photons to frequency correlations and could be used to manipulate frequency-bin-entangled photons. This demonstration opens a new avenue to manipulate and analyze spectral and temporal wave functions of many-photon states.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19997192','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19997192"><span>Three-photon N00N states generated by photon subtraction from double photon pairs.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kim, Heonoh; Park, Hee Su; Choi, Sang-Kyung</p> <p>2009-10-26</p> <p>We describe an experimental demonstration of a novel three-photon N00N state generation scheme using a single source of photons based on spontaneous parametric down-conversion (SPDC). The three-photon entangled state is generated when a photon is subtracted from a double pair of photons and detected by a heralding counter. Interference fringes measured with an emulated three-photon detector reveal the three-photon de Broglie wavelength and exhibit visibility > 70% without background subtraction.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PMB....63a5001K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PMB....63a5001K"><span>The ‘cutting away’ of potential secondary electron tracks explains the effects of beam size and detector wall density in small-field photon dosimetry</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Khee Looe, Hui; Delfs, Björn; Poppinga, Daniela; Jiang, Ping; Harder, Dietrich; Poppe, Björn</p> <p>2018-01-01</p> <p>The well-known field-size dependent overresponse in small-field photon-beam dosimetry of solid-state detectors equipped with very thin sensitive volumes, such as the PTW microDiamond, cannot be caused by the photon and electron interactions within these sensitive layers because they are only a few micrometers thick. The alternative explanation is that their overresponse is caused by the combination of two effects, the modification of the secondary electron fluence profile (i) by a field size too small to warrant lateral secondary electron equilibrium and (ii) by the density-dependent electron ranges in the structural detector materials placed in front of or backing the sensitive layer. The present study aims at the numerical demonstration and visualization of this combined mechanism. The lateral fluence profiles of the secondary electrons hitting a 1 µm thick scoring layer were Monte-Carlo simulated by modelling their generation and transport in the upstream or downstream adjacent layers of thickness 0.6 mm and densities from 0.0012 to 3 g cm-3, whose atomic composition was constantly kept water-like. The scoring layer/adjacent layer sandwich was placed in an infinite water phantom irradiated by circular 60Co, 6 MV and 15 MV photon beams with diameters from 3 to 40 mm. The interpretation starts from the ideal case of lateral secondary electron equilibrium, where the Fano theorem excludes any density effect. If the field size is then reduced, electron tracks potentially originating from source points outside the field border will then be numerically ‘cut away’. This geometrical effect reduces the secondary electron fluence at the field center, but the magnitude of this reduction also varies with the density-dependent electron ranges in the adjacent layers. This combined mechanism, which strongly depends on the photon spectrum, explains the field size and material density effect on the response of detectors with very thin sensitive layers used in small-field photon-beam dosimetry.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JPhB...51h5502I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JPhB...51h5502I"><span>Tomography of a displacement photon counter for discrimination of single-rail optical qubits</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Izumi, Shuro; Neergaard-Nielsen, Jonas S.; Andersen, Ulrik L.</p> <p>2018-04-01</p> <p>We investigate the performance of a detection strategy composed of a displacement operation and a photon counter, which is known as a beneficial tool in optical coherent communications, to the quantum state discrimination of the two superpositions of vacuum and single photon states corresponding to the {\\hat{σ }}x eigenstates in the single-rail encoding of photonic qubits. We experimentally characterize the detection strategy in vacuum-single photon two-dimensional space using quantum detector tomography and evaluate the achievable discrimination error probability from the reconstructed measurement operators. We furthermore derive the minimum error rate obtainable with Gaussian transformations and homodyne detection. Our proof-of-principle experiment shows that the proposed scheme can achieve a discrimination error surpassing homodyne detection.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25408390','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25408390"><span>Detector response function of an energy-resolved CdTe single photon counting detector.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Liu, Xin; Lee, Hyoung Koo</p> <p>2014-01-01</p> <p>While spectral CT using single photon counting detector has shown a number of advantages in diagnostic imaging, knowledge of the detector response function of an energy-resolved detector is needed to correct the signal bias and reconstruct the image more accurately. The objective of this paper is to study the photo counting detector response function using laboratory sources, and investigate the signal bias correction method. Our approach is to model the detector response function over the entire diagnostic energy range (20 keV <E< 140 keV) using a semi-analytical method with 12 parameters. The model includes a primary photo peak, an exponential tail, and four escape peaks. Four radioactive isotopes including Cdmium-109, Barium-133, Americium-241 and Cobalt-57 are used to generate the detector response function at six photon energies. The 12 parameters are obtained by non-linear least-square fitting with the measured detector response functions at the six energies. The correlations of the 12 parameters with energy are also investigated with the measured data. The analytical model generally describes the detector response function and is in good agreement with the measured data. The trend lines of the 12 parameters indicate higher energies tend to cause grater spectrum distortion. The spectrum distortion caused by the detector response function on spectral CT reconstruction is analyzed theoretically, and a solution to correct this spectrum distortion is also proposed. In spectral and fluorescence CT, the spectrum distortion caused by detector response function poses a problem and cannot be ignored in any quantitative analysis. The detector response function of a CdTe detector can be obtained by a semi-analytical method.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPIE10224E..2UK','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPIE10224E..2UK"><span>Effect of crosstalk on QBER in QKD in urban telecommunication fiber lines</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kurochkin, Vladimir L.; Kurochkin, Yuriy V.; Miller, Alexander V.; Sokolov, Alexander S.; Kanapin, Alan A.</p> <p>2016-12-01</p> <p>Quantum key distribution (QKD) as a technology is being actively implemented into existing urban telecommunication networks. QKD devices are commercially available products. While sending single photons through optical fiber, adjacent fibers, which are used to transfer classical information, might influence the amount of registrations of single photon detectors. This influence is registered, since it directly introduces a higher quantum bit error rate (QBER) into the final key [1-3]. Our report presents the results of the first tests of the QKD device, developed in the Russian Quantum Center. These tests were conducted in Moscow, and are the first of such a device in Russia in urban optical fiber telecommunication networks. The device in question is based on a two-pass auto-compensating optical scheme, which provides stable single photon transfer through urban optical fiber telecommunication networks [4,5]. The single photon detectors ID230 by ID Quantique were used. They operate in free-running mode, and with a quantum effectiveness of 10 % have a dark count 10 Hz. The background signal level in the dedicated fiber was no less than 5.6•10-14 W, which corresponds to 4.4•104 detector clicks per second. The single mode fiber length in Moscow was 30.6 km, the total attenuation equal to 11.7 dB. The sifted quantum key bit rate reached values of 1.9 kbit/s with the QBER level equal to 5.1 %. Methods of lowering the influence of crosstalk on the QBER are considered.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_17 --> <div id="page_18" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="341"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014ApPhL.104h1108K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014ApPhL.104h1108K"><span>Free-running InGaAs single photon detector with 1 dark count per second at 10% efficiency</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Korzh, B.; Walenta, N.; Lunghi, T.; Gisin, N.; Zbinden, H.</p> <p>2014-02-01</p> <p>We present a free-running single photon detector for telecom wavelengths based on a negative feedback avalanche photodiode (NFAD). A dark count rate as low as 1 cps was obtained at a detection efficiency of 10%, with an afterpulse probability of 2.2% for 20 μs of deadtime. This was achieved by using an active hold-off circuit and cooling the NFAD with a free-piston stirling cooler down to temperatures of -110 °C. We integrated two detectors into a practical, 625 MHz clocked quantum key distribution system. Stable, real-time key distribution in the presence of 30 dB channel loss was possible, yielding a secret key rate of 350 bps.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JInst..13C3026D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JInst..13C3026D"><span>Cryogenic readout for multiple VUV4 Multi-Pixel Photon Counters in liquid xenon</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Di Giovanni, A.</p> <p>2018-03-01</p> <p>This work concerned the preliminary tests and characterization of a cryogenic preamplifier board for an array made of 16 S13370-3050CN (VUV4 family) Multi-Pixel Photon Counters manufactured by Hamamatsu and operated at liquid xenon temperature. The proposed prototype is based on the use of the Analog Devices AD8011 current feedback operational amplifier. The detector allows for single photon detection, making this device a promising choice for the future generation of neutrino and dark matter detectors based on liquid xenon targets.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JInst..12C2055S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JInst..12C2055S"><span>Double Photon Emission Coincidence Imaging using GAGG-SiPM pixel detectors</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shimazoe, K.; Uenomachi, M.; Mizumachi, Y.; Takahashi, H.; Masao, Y.; Shoji, Y.; Kamada, K.; Yoshikawa, A.</p> <p>2017-12-01</p> <p>Single photon emission computed tomography(SPECT) is a useful medical imaging modality using single photon detection from radioactive tracers, such as 99Tc and 111In, however further development of increasing the contrast in the image is still under investigation. A novel method (Double Photon Emission CT / DPECT) using a coincidence detection of two cascade gamma-rays from 111In is proposed and characterized in this study. 111In, which is well-known and commonly used as a SPECT tracer, emits two cascade photons of 171 keV and 245 keV with a short delay of approximately 85 ns. The coincidence detection of two gamma-rays theoretically determines the position in a single point compared with a line in single photon detection and increases the signal to noise ratio drastically. A fabricated pixel detector for this purpose consists of 8 × 8 array of high-resolution type 1.5 mm thickness Ce:GAGG (3.9% @ 662 keV, 6.63g/cm3, C&A Co. Ce:Gd3Ga2.7Al2.3O12 2.5 × 2.5 × 1.5 mm3) crystals coupled a 3 mm pixel SiPM array (Hamamatsu MPPC S13361-2050NS-08). The signal from each pixel is processed and readout using time over threshold (TOT) based parallel processing circuit to extract the energy and timing information. The coincidence was detected by FPGA with the frequency of 400 MHz. Two pixel detectors coupled to parallel-hole collimators are located at the degree of 90 to determine the position and coincidence events (time window =1 μs) are detected and used for making back-projection image. The basic principle of DPECT is characterized including the detection efficiency and timing resolution.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JLTP..tmp..115F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JLTP..tmp..115F"><span>Confocal Microscopy Imaging with an Optical Transition Edge Sensor</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fukuda, D.; Niwa, K.; Hattori, K.; Inoue, S.; Kobayashi, R.; Numata, T.</p> <p>2018-05-01</p> <p>Fluorescence color imaging at an extremely low excitation intensity was performed using an optical transition edge sensor (TES) embedded in a confocal microscope for the first time. Optical TES has the ability to resolve incident single photon energy; therefore, the wavelength of each photon can be measured without spectroscopic elements such as diffraction gratings. As target objects, animal cells labeled with two fluorescent dyes were irradiated with an excitation laser at an intensity below 1 μW. In our confocal system, an optical fiber-coupled TES device is used to detect photons instead of the pinhole and photomultiplier tube used in typical confocal microscopes. Photons emitted from the dyes were collected by the objective lens, and sent to the optical TES via the fiber. The TES measures the wavelength of each photon arriving in an exposure time of 70 ms, and a fluorescent photon spectrum is constructed. This measurement is repeated by scanning the target sample, and finally a two-dimensional RGB-color image is obtained. The obtained image showed that the photons emitted from the dyes of mitochondria and cytoskeletons were clearly resolved at a detection intensity level of tens of photons. TES exhibits ideal performance as a photon detector with a low dark count rate (< 1 Hz) and wavelength resolving power. In the single-mode fiber-coupled system, the confocal microscope can be operated in the super-resolution mode. These features are very promising to realize high-sensitivity and high-resolution photon spectral imaging, and would help avoid cell damage and photobleaching of fluorescence dyes.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JInst..10C4015Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JInst..10C4015Z"><span>The Dosepix detector—an energy-resolving photon-counting pixel detector for spectrometric measurements</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zang, A.; Anton, G.; Ballabriga, R.; Bisello, F.; Campbell, M.; Celi, J. C.; Fauler, A.; Fiederle, M.; Jensch, M.; Kochanski, N.; Llopart, X.; Michel, N.; Mollenhauer, U.; Ritter, I.; Tennert, F.; Wölfel, S.; Wong, W.; Michel, T.</p> <p>2015-04-01</p> <p>The Dosepix detector is a hybrid photon-counting pixel detector based on ideas of the Medipix and Timepix detector family. 1 mm thick cadmium telluride and 300 μm thick silicon were used as sensor material. The pixel matrix of the Dosepix consists of 16 x 16 square pixels with 12 rows of (200 μm)2 and 4 rows of (55 μm)2 sensitive area for the silicon sensor layer and 16 rows of pixels with 220 μm pixel pitch for CdTe. Besides digital energy integration and photon-counting mode, a novel concept of energy binning is included in the pixel electronics, allowing energy-resolved measurements in 16 energy bins within one acquisition. The possibilities of this detector concept range from applications in personal dosimetry and energy-resolved imaging to quality assurance of medical X-ray sources by analysis of the emitted photon spectrum. In this contribution the Dosepix detector, its response to X-rays as well as spectrum measurements with Si and CdTe sensor layer are presented. Furthermore, a first evaluation was carried out to use the Dosepix detector as a kVp-meter, that means to determine the applied acceleration voltage from measured X-ray tubes spectra.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22300068-characterization-superconducting-nanowire-single-photon-detector-artificial-constrictions','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22300068-characterization-superconducting-nanowire-single-photon-detector-artificial-constrictions"><span>Characterization of superconducting nanowire single-photon detector with artificial constrictions</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Zhang, Ling; Liu, Dengkuan; Wu, Junjie</p> <p>2014-06-15</p> <p>Statistical studies on the performance of different superconducting nanowire single-photon detectors (SNSPDs) on one chip suggested that random constrictions existed in the nanowire that were barely registered by scanning electron microscopy. With the aid of advanced e-beam lithography, artificial geometric constrictions were fabricated on SNSPDs as well as single nanowires. In this way, we studied the influence of artificial constrictions on SNSPDs in a straight forward manner. By introducing artificial constrictions with different wire widths in single nanowires, we concluded that the dark counts of SNSPDs originate from a single constriction. Further introducing artificial constrictions in SNSPDs, we studied themore » relationship between detection efficiency and kinetic inductance and the bias current, confirming the hypothesis that constrictions exist in SNSPDs.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4416674','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4416674"><span>Correction of complex nonlinear signal response from a pixel array detector</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>van Driel, Tim Brandt; Herrmann, Sven; Carini, Gabriella; Nielsen, Martin Meedom; Lemke, Henrik Till</p> <p>2015-01-01</p> <p>The pulsed free-electron laser light sources represent a new challenge to photon area detectors due to the intrinsic spontaneous X-ray photon generation process that makes single-pulse detection necessary. Intensity fluctuations up to 100% between individual pulses lead to high linearity requirements in order to distinguish small signal changes. In real detectors, signal distortions as a function of the intensity distribution on the entire detector can occur. Here a robust method to correct this nonlinear response in an area detector is presented for the case of exposures to similar signals. The method is tested for the case of diffuse scattering from liquids where relevant sub-1% signal changes appear on the same order as artifacts induced by the detector electronics. PMID:25931072</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25931072','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25931072"><span>Correction of complex nonlinear signal response from a pixel array detector.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>van Driel, Tim Brandt; Herrmann, Sven; Carini, Gabriella; Nielsen, Martin Meedom; Lemke, Henrik Till</p> <p>2015-05-01</p> <p>The pulsed free-electron laser light sources represent a new challenge to photon area detectors due to the intrinsic spontaneous X-ray photon generation process that makes single-pulse detection necessary. Intensity fluctuations up to 100% between individual pulses lead to high linearity requirements in order to distinguish small signal changes. In real detectors, signal distortions as a function of the intensity distribution on the entire detector can occur. Here a robust method to correct this nonlinear response in an area detector is presented for the case of exposures to similar signals. The method is tested for the case of diffuse scattering from liquids where relevant sub-1% signal changes appear on the same order as artifacts induced by the detector electronics.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1188672','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1188672"><span></span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>van Driel, Tim Brandt; Herrmann, Sven; Carini, Gabriella</p> <p></p> <p>The pulsed free-electron laser light sources represent a new challenge to photon area detectors due to the intrinsic spontaneous X-ray photon generation process that makes single-pulse detection necessary. Intensity fluctuations up to 100% between individual pulses lead to high linearity requirements in order to distinguish small signal changes. In real detectors, signal distortions as a function of the intensity distribution on the entire detector can occur. Here a robust method to correct this nonlinear response in an area detector is presented for the case of exposures to similar signals. The method is tested for the case of diffuse scattering frommore » liquids where relevant sub-1% signal changes appear on the same order as artifacts induced by the detector electronics.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20030095965','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20030095965"><span>Applications of Gas Imaging Micro-Well Detectors to an Advanced Compton Telescope</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bloser, P. F.; Hunter, S. D.; Ryan, J. M.; McConnell, M. L.; Miller, R. S.; Jackson, T. N.; Bai, B.; Jung, S.</p> <p>2003-01-01</p> <p>We present a concept for an Advanced Compton Telescope (ACT) based on the use of pixelized gas micro-well detectors to form a three-dimensional electron track imager. A micro-well detector consists of an array of individual micro-patterned proportional counters opposite a planar drift electrode. When combined with thin film transistor array readouts, large gas volumes may be imaged with very good spatial and energy resolution at reasonable cost. The third dimension is determined by timing the drift of the ionization electrons. The primary advantage of this approach is the excellent tracking of the Compton recoil electron that is possible in a gas volume. Such good electron tracking allows us to reduce the point spread function of a single incident photon dramatically, greatly improving the imaging capability and sensitivity. The polarization sensitivity, which relies on events with large Compton scattering angles, is particularly enhanced. We describe a possible ACT implementation of this technique, in which the gas tracking volume is surrounded by a CsI calorimeter, and present our plans to build and test a small prototype over the next three years.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28789122','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28789122"><span>Single photon detection in a waveguide-coupled Ge-on-Si lateral avalanche photodiode.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Martinez, Nicholas J D; Gehl, Michael; Derose, Christopher T; Starbuck, Andrew L; Pomerene, Andrew T; Lentine, Anthony L; Trotter, Douglas C; Davids, Paul S</p> <p>2017-07-10</p> <p>We examine gated-Geiger mode operation of an integrated waveguide-coupled Ge-on-Si lateral avalanche photodiode (APD) and demonstrate single photon detection at low dark count for this mode of operation. Our integrated waveguide-coupled APD is fabricated using a selective epitaxial Ge-on-Si growth process resulting in a separate absorption and charge multiplication (SACM) design compatible with our silicon photonics platform. Single photon detection efficiency and dark count rate is measured as a function of temperature in order to understand and optimize performance characteristics in this device. We report single photon detection of 5.27% at 1310 nm and a dark count rate of 534 kHz at 80 K for a Ge-on-Si single photon avalanche diode. Dark count rate is the lowest for a Ge-on-Si single photon detector in this range of temperatures while maintaining competitive detection efficiency. A jitter of 105 ps was measured for this device.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016IJTP...55.1128Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016IJTP...55.1128Z"><span>Entanglement Concentration for Arbitrary Four-Photon Cluster State Assisted with Single Photons</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhao, Sheng-Yang; Cai, Chun; Liu, Jiong; Zhou, Lan; Sheng, Yu-Bo</p> <p>2016-02-01</p> <p>We present an entanglement concentration protocol (ECP) to concentrate arbitrary four-photon less-entangled cluster state into maximally entangled cluster state. Different from other ECPs for cluster state, we only exploit the single photon as auxiliary, which makes this protocol feasible and economic. In our ECP, the concentrated maximally entangled state can be retained for further application and the discarded state can be reused for a higher success probability. This ECP works with the help of cross-Kerr nonlinearity and conventional photon detectors. This ECP may be useful in future one-way quantum computation.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29088186','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29088186"><span>Micro-pulse polarization lidar at 1.5  μm using a single superconducting nanowire single-photon detector.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Qiu, Jiawei; Xia, Haiyun; Shangguan, Mingjia; Dou, Xiankang; Li, Manyi; Wang, Chong; Shang, Xiang; Lin, Shengfu; Liu, Jianjiang</p> <p>2017-11-01</p> <p>An all-fiber, eye-safe and micro-pulse polarization lidar is demonstrated with a polarization-maintaining structure, incorporating a single superconducting nanowire single-photon detector (SNSPD) at 1.5 μm. The time-division multiplexing technique is used to achieve a calibration-free optical layout. A single piece of detector is used to detect the backscatter signals at two orthogonal states in an alternative sequence. Thus, regular calibration of the two detectors in traditional polarization lidars is avoided. The signal-to-noise ratio of the lidar is guaranteed by using an SNSPD, providing high detection efficiency and low dark count noise. The linear depolarization ratio (LDR) of the urban aerosol is observed horizontally over 48 h in Hefei [N31°50'37'', E117°15'54''], when a heavy air pollution is spreading from the north to the central east of China. Phenomena of LDR bursts are detected at a location where a building is under construction. The lidar results show good agreement with the data detected from a sun photometer, a 532 nm visibility lidar, and the weather forecast information.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015A%26A...574A...9L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015A%26A...574A...9L"><span>Simulated low-intensity optical pulsar observation with single-photon detector</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Leeb, W. R.; Alves, J.; Meingast, S.; Brunner, M.</p> <p>2015-02-01</p> <p>Context. Optical radiation of pulsars offers valuable clues to the physics of neutron stars, which are our only probes of the most extreme states of matter in the present-day universe. Still, only about 1% of all cataloged pulsars have known optical counterparts. Aims: The goal of this work is to develop an observational method optimized for discovering faint optical pulsars. Methods: A single-photon detector transforms the signal received by the telescope into a pulse sequence. The events obtained are time tagged and transformed into a histogram of event time differences. The histogram envelope presents the autocorrelation of the recorded optical signal and thus displays any periodicity of the input signal. Results: Simulations show that faint pulsars radiating in the optical regime can be detected in a straightforward way. As an example, a fictitious pulsar with a V-magnitude of 24.6 mag and a signature like the Crab pulsar can be discovered within one minute using an 8-m class telescope. At the detector's peak sensitivity the average optical flux density would then amount to Fν = 0.63 μJy. With a 40-m class telescope, such as the forthcoming European ELT, the detection of optical pulsars with magnitudes V< 30 mag is within reach for a measurement time of one minute. A two-hour "blind search" with the ELT could reach V ~ 31.3 mag. Conclusions: This method allows detecting faint periodic optical radiation with simple equipment and easy signal processing.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AIPC..958..136D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AIPC..958..136D"><span>In-Vivo Real-Time X-ray μ-Imaging</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dammer, Jiri; Holy, Tomas; Jakubek, Jan; Jakubek, Martin; Pospisil, Stanislav; Vavrík, Daniel</p> <p>2007-11-01</p> <p>The technique of X-ray transmission imaging is available for more than 100 years and it is still one of the fastest and easiest ways how to study the internal structure of living biological samples. The advances in semiconductor technology in last years make possible to fabricate new types of X-ray detectors with direct conversion of interacting X-ray photon to an electric signal. Especially semiconductor pixel detectors seem to be very promising. Compared to the film technique they bring single-quantum and real-time digital information about the studied object with high resolution, high sensitivity and broad dynamic range. These pixel detector-based imaging stand promising as a new tool in the field of small animal imaging, for cancer research and for observation of dynamic processes inside organisms. These detectors open up for instance new possibilities for researchers to perform non-invasive studies of tissue for mutations or pathologies and to monitor disease progression or response to therapy.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JLTP..tmp..112S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JLTP..tmp..112S"><span>Photon-Number-Resolving Transition-Edge Sensors for the Metrology of Quantum Light Sources</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schmidt, M.; von Helversen, M.; López, M.; Gericke, F.; Schlottmann, E.; Heindel, T.; Kück, S.; Reitzenstein, S.; Beyer, J.</p> <p>2018-05-01</p> <p>Low-temperature photon-number-resolving detectors allow for direct access to the photon number distribution of quantum light sources and can thus be exploited to explore the photon statistics, e.g., solid-state-based non-classical light sources. In this work, we report on the setup and calibration of a detection system based on fiber-coupled tungsten transition-edge sensors (W-TESs). Our stand-alone system comprises two W-TESs, read out by two 2-stage-SQUID current sensors, operated in a compact detector unit that is integrated in an adiabatic demagnetization refrigerator. Fast low-noise analog amplifiers and digitizers are used for signal acquisition. The detection efficiency of the single-mode fiber-coupled detector system in the spectral region of interest (850-950 nm) is determined to be larger than 87 %. The presented detector system opens up new routes in the characterization of quantum light sources for quantum information, quantum-enhanced sensing and quantum metrology.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2764549','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2764549"><span>Six orders of magnitude dynamic range in capillary electrophoresis with ultrasensitive laser-induced fluorescence detection</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Whitmore, Colin D.; Essaka, David; Dovichi, Norman J.</p> <p>2009-01-01</p> <p>An ultrasensitive laser-induced fluorescence detector was used with capillary electrophoresis for the study of 5-carboxy-tetramethylrhodamine. The raw signal from the detector provided roughly three orders of magnitude dynamic range. The signal saturated at high analyte concentrations due to the dead time associated with the single-photon counting avalanche photodiode employed in the detector. The signal can be corrected for the detector dead time, providing an additional order of magnitude dynamic range. To further increase dynamic range, two fiber-optic beam-splitters were cascaded to generate a primary signal and two attenuated signals, each monitored by a single-photon counting avalanche photodiode. The combined signals from the three photodiodes are reasonably linear from the concentration detection limit of 3 pM to 10 μM, the maximum concentration investigated, a range of 3,000,000. Mass detection limits were 150 yoctomoles injected onto the capillary. PMID:19836546</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3925999','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3925999"><span>Fluctuations in the electron system of a superconductor exposed to a photon flux</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>de Visser, P. J.; Baselmans, J. J. A.; Bueno, J.; Llombart, N.; Klapwijk, T. M.</p> <p>2014-01-01</p> <p>In a superconductor, in which electrons are paired, the density of unpaired electrons should become zero when approaching zero temperature. Therefore, radiation detectors based on breaking of pairs promise supreme sensitivity, which we demonstrate using an aluminium superconducting microwave resonator. Here we show that the resonator also enables the study of the response of the electron system of the superconductor to pair-breaking photons, microwave photons and varying temperatures. A large range in radiation power (at 1.54 THz) can be chosen by carefully filtering the radiation from a blackbody source. We identify two regimes. At high radiation power, fluctuations in the electron system caused by the random arrival rate of the photons are resolved, giving a straightforward measure of the optical efficiency (48±8%) and showing an unprecedented detector sensitivity. At low radiation power, fluctuations are dominated by excess quasiparticles, the number of which is measured through their recombination lifetime. PMID:24496036</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5069691','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5069691"><span>Realizing the measure-device-independent quantum-key-distribution with passive heralded-single photon sources</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Wang, Qin; Zhou, Xing-Yu; Guo, Guang-Can</p> <p>2016-01-01</p> <p>In this paper, we put forward a new approach towards realizing measurement-device-independent quantum key distribution with passive heralded single-photon sources. In this approach, both Alice and Bob prepare the parametric down-conversion source, where the heralding photons are labeled according to different types of clicks from the local detectors, and the heralded ones can correspondingly be marked with different tags at the receiver’s side. Then one can obtain four sets of data through using only one-intensity of pump light by observing different kinds of clicks of local detectors. By employing the newest formulae to do parameter estimation, we could achieve very precise prediction for the two-single-photon pulse contribution. Furthermore, by carrying out corresponding numerical simulations, we compare the new method with other practical schemes of measurement-device-independent quantum key distribution. We demonstrate that our new proposed passive scheme can exhibit remarkable improvement over the conventional three-intensity decoy-state measurement-device-independent quantum key distribution with either heralded single-photon sources or weak coherent sources. Besides, it does not need intensity modulation and can thus diminish source-error defects existing in several other active decoy-state methods. Therefore, if taking intensity modulating errors into account, our new method will show even more brilliant performance. PMID:27759085</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011NIMPA.632..142M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011NIMPA.632..142M"><span>Application of an oscillation-type linear cadmium telluride detector to enhanced gadolinium K-edge computed tomography</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Matsukiyo, Hiroshi; Sato, Eiichi; Hagiwara, Osahiko; Abudurexiti, Abulajiang; Osawa, Akihiro; Enomoto, Toshiyuki; Watanabe, Manabu; Nagao, Jiro; Sato, Shigehiro; Ogawa, Akira; Onagawa, Jun</p> <p>2011-03-01</p> <p>A linear cadmium telluride (CdTe) detector is useful for carrying out energy-discrimination X-ray imaging, including computed tomography (CT). To perform enhanced gadolinium K-edge CT, we used an oscillation-type linear CdTe detector with an energy resolution of 1.2 keV. CT is performed by repeating the linear scan and the rotation of an object. Penetrating X-ray photons from the object are detected by the CdTe detector, and event signals of X-ray photons are produced using charge-sensitive and shaping amplifiers. Both the photon energy and the energy width are selected using a multichannel analyzer, and the number of photons is counted by a counter card. In energy-discrimination CT, tube voltage and current were 80 kV and 20 μA, respectively, and X-ray intensity was 1.55 μGy/s at 1.0 m from the source at a tube voltage of 80 kV. Demonstration of enhanced gadolinium K-edge X-ray CT was carried out by selecting photons with energies just beyond gadolinium K-edge energy of 50.3 keV.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_18 --> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22253543-micron-resolution-optical-scanner-characterization-silicon-detectors','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22253543-micron-resolution-optical-scanner-characterization-silicon-detectors"><span>A micron resolution optical scanner for characterization of silicon detectors</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Shukla, R. A.; Dugad, S. R., E-mail: dugad@cern.ch; Gopal, A. V.</p> <p>2014-02-15</p> <p>The emergence of high position resolution (∼10 μm) silicon detectors in recent times have highlighted the urgent need for the development of new automated optical scanners of micron level resolution suited for characterizing microscopic features of these detectors. More specifically, for the newly developed silicon photo-multipliers (SiPM) that are compact, possessing excellent photon detection efficiency with gain comparable to photo-multiplier tube. In a short time, since their invention the SiPMs are already being widely used in several high-energy physics and astrophysics experiments as the photon readout element. The SiPM is a high quantum efficiency, multi-pixel photon counting detector with fastmore » timing and high gain. The presence of a wide variety of photo sensitive silicon detectors with high spatial resolution requires their performance evaluation to be carried out by photon beams of very compact spot size. We have designed a high resolution optical scanner that provides a monochromatic focused beam on a target plane. The transverse size of the beam was measured by the knife-edge method to be 1.7 μm at 1 − σ level. Since the beam size was an order of magnitude smaller than the typical feature size of silicon detectors, this optical scanner can be used for selective excitation of these detectors. The design and operational details of the optical scanner, high precision programmed movement of target plane (0.1 μm) integrated with general purpose data acquisition system developed for recording static and transient response photo sensitive silicon detector are reported in this paper. Entire functionality of scanner is validated by using it for selective excitation of individual pixels in a SiPM and identifying response of active and dead regions within SiPM. Results from these studies are presented in this paper.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014SPIE.9033E..3MZ','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014SPIE.9033E..3MZ"><span>Characterization of a hybrid energy-resolving photon-counting detector</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zang, A.; Pelzer, G.; Anton, G.; Ballabriga Sune, R.; Bisello, F.; Campbell, M.; Fauler, A.; Fiederle, M.; Llopart Cudie, X.; Ritter, I.; Tennert, F.; Wölfel, S.; Wong, W. S.; Michel, T.</p> <p>2014-03-01</p> <p>Photon-counting detectors in medical x-ray imaging provide a higher dose efficiency than integrating detectors. Even further possibilities for imaging applications arise, if the energy of each photon counted is measured, as for example K-edge-imaging or optimizing image quality by applying energy weighting factors. In this contribution, we show results of the characterization of the Dosepix detector. This hybrid photon- counting pixel detector allows energy resolved measurements with a novel concept of energy binning included in the pixel electronics. Based on ideas of the Medipix detector family, it provides three different modes of operation: An integration mode, a photon-counting mode, and an energy-binning mode. In energy-binning mode, it is possible to set 16 energy thresholds in each pixel individually to derive a binned energy spectrum in every pixel in one acquisition. The hybrid setup allows using different sensor materials. For the measurements 300 μm Si and 1 mm CdTe were used. The detector matrix consists of 16 x 16 square pixels for CdTe (16 x 12 for Si) with a pixel pitch of 220 μm. The Dosepix was originally intended for applications in the field of radiation measurement. Therefore it is not optimized towards medical imaging. The detector concept itself still promises potential as an imaging detector. We present spectra measured in one single pixel as well as in the whole pixel matrix in energy-binning mode with a conventional x-ray tube. In addition, results concerning the count rate linearity for the different sensor materials are shown as well as measurements regarding energy resolution.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SuScT..30h4008Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SuScT..30h4008Y"><span>Superconducting nanowire single-photon detector on dielectric optical films for visible and near infrared wavelengths</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>You, Lixing; Li, Hao; Zhang, Weijun; Yang, Xiaoyan; Zhang, Lu; Chen, Sijing; Zhou, Hui; Wang, Zhen; Xie, Xiaoming</p> <p>2017-08-01</p> <p>The detection efficiency (DE) of superconducting nanowire single-photon detectors (SNSPDs) at 1550 nm has been significantly improved in the past decades as a result of evolution of the optical structure, the materials, and the fabrication process. We discuss the general optical design for a high-efficiency SNSPD based on dielectric optical films that can detect wavelengths from visible to near infrared regions. This structure shows close-to-unity absorption and good insensitivity to the fine wavelength and the incident angle. We demonstrate an SNSPD specifically fabricated for the detection of 1064 nm wavelength with a maximal system DE of 87.4% ± 3.7%. The DEs of the SNSPDs for visible and near infrared wavelengths are also summarized and compared with those of semiconducting detectors.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014SPIE.9290E..2FK','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014SPIE.9290E..2FK"><span>Fast modular data acquisition system for GEM-2D detector</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kasprowicz, G.; Byszuk, Adrian; Wojeński, A.; Zienkiewicz, P.; Czarski, T.; Chernyshova, M.; Poźniak, K.; Rzadkiewicz, J.; Zabolotny, W.; Juszczyk, B.</p> <p>2014-11-01</p> <p>A novel approach to two dimensional Gas Electron Multiplier (GEM) detector readout is presented. Unlike commonly used methods, based on discriminators and analogue FIFOs, the method developed uses simulta- neously sampling high speed ADCs with fast hybrid integrator and advanced FPGA-based processing logic to estimate the energy of every single photon. Such a method is applied to every GEM strip / pixel signal. It is especially useful in case of crystal-based spectrometers for soft X-rays, 2D imaging for plasma tomography and all these applications where energy resolution of every single photon is required. For the purpose of the detector readout, a novel, highly modular and extendable conception of the measurement platform was developed. It is evolution of already deployed measurement system for JET Spectrometer.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4722905','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4722905"><span>Time-resolved singlet-oxygen luminescence detection with an efficient and practical semiconductor single-photon detector</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Boso, Gianluca; Ke, Damei; Korzh, Boris; Bouilloux, Jordan; Lange, Norbert; Zbinden, Hugo</p> <p>2015-01-01</p> <p>In clinical applications, such as PhotoDynamic Therapy, direct singlet-oxygen detection through its luminescence in the near-infrared range (1270 nm) has been a challenging task due to its low emission probability and the lack of suitable single-photon detectors. Here, we propose a practical setup based on a negative-feedback avalanche diode detector that is a viable alternative to the current state-of-the art for different clinical scenarios, especially where geometric collection efficiency is limited (e.g. fiber-based systems, confocal microscopy, scanning systems etc.). The proposed setup is characterized with Rose Bengal as a standard photosensitizer and it is used to measure the singlet-oxygen quantum yield of a new set of photosensitizers for site-selective photodynamic therapy. PMID:26819830</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22293064-free-running-ingaas-single-photon-detector-dark-count-per-second-efficiency','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22293064-free-running-ingaas-single-photon-detector-dark-count-per-second-efficiency"><span>Free-running InGaAs single photon detector with 1 dark count per second at 10% efficiency</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Korzh, B., E-mail: Boris.Korzh@unige.ch; Walenta, N.; Lunghi, T.</p> <p></p> <p>We present a free-running single photon detector for telecom wavelengths based on a negative feedback avalanche photodiode (NFAD). A dark count rate as low as 1 cps was obtained at a detection efficiency of 10%, with an afterpulse probability of 2.2% for 20 μs of deadtime. This was achieved by using an active hold-off circuit and cooling the NFAD with a free-piston stirling cooler down to temperatures of −110 °C. We integrated two detectors into a practical, 625 MHz clocked quantum key distribution system. Stable, real-time key distribution in the presence of 30 dB channel loss was possible, yielding a secret key rate of 350 bps.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1188672-correction-complex-nonlinear-signal-response-from-pixel-array-detector','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1188672-correction-complex-nonlinear-signal-response-from-pixel-array-detector"><span>Correction of complex nonlinear signal response from a pixel array detector</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>van Driel, Tim Brandt; Herrmann, Sven; Carini, Gabriella; ...</p> <p>2015-04-22</p> <p>The pulsed free-electron laser light sources represent a new challenge to photon area detectors due to the intrinsic spontaneous X-ray photon generation process that makes single-pulse detection necessary. Intensity fluctuations up to 100% between individual pulses lead to high linearity requirements in order to distinguish small signal changes. In real detectors, signal distortions as a function of the intensity distribution on the entire detector can occur. Here a robust method to correct this nonlinear response in an area detector is presented for the case of exposures to similar signals. The method is tested for the case of diffuse scattering frommore » liquids where relevant sub-1% signal changes appear on the same order as artifacts induced by the detector electronics.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015APS..DMP.J7005C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015APS..DMP.J7005C"><span>Hong-Ou-Mandel Interference Between Triggered And Heralded Single Photons From Separate Atomic Systems</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cere, Alessandro; Leong, Victor; Kaur Gulati, Gurpreet; Srivathsan, Bharath; Kosen, Sandoko; Kurtsiefer, Christian</p> <p>2015-05-01</p> <p>The realization of quantum networks and long distance quantum communication rely on the capability of generating entanglement between separated nodes. We demonstrate the compatibility of two different sources of single photons: a single atom and four-wave mixing in a cold cloud of atoms. The four-wave mixing process in a cloud of cold 87Rb generates photon pairs. The cascade level scheme used ensures the generation of heralded single photons with exponentially decaying temporal envelope. The temporal shape of the heralding photons matches the shape of photons emitted by spontaneous decay but for the shorter coherence time A single 87Rb atom is trapped in an far-off-resonance optical dipole trap and can be excited with high probability using a short (~3 ns) intense pulse of resonant light, emitting a single photon by spontaneous decay. A large numerical aperture lens collects ~4% of the total fluorescence. The heralded and the triggered photons are launched into a Houng-Ou-Mandel interferometer: a symmetrical beam-splitter with outputs connected to single photon detectors. Scanning the relative delay between the two sources we observe the HOM dip with a maximum visibility of 70 +/-4%.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25369288','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25369288"><span>Energy response calibration of photon-counting detectors using x-ray fluorescence: a feasibility study.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cho, H-M; Ding, H; Ziemer, B P; Molloi, S</p> <p>2014-12-07</p> <p>Accurate energy calibration is critical for the application of energy-resolved photon-counting detectors in spectral imaging. The aim of this study is to investigate the feasibility of energy response calibration and characterization of a photon-counting detector using x-ray fluorescence. A comprehensive Monte Carlo simulation study was performed using Geant4 Application for Tomographic Emission (GATE) to investigate the optimal technique for x-ray fluorescence calibration. Simulations were conducted using a 100 kVp tungsten-anode spectra with 2.7 mm Al filter for a single pixel cadmium telluride (CdTe) detector with 3 × 3 mm(2) in detection area. The angular dependence of x-ray fluorescence and scatter background was investigated by varying the detection angle from 20° to 170° with respect to the beam direction. The effects of the detector material, shape, and size on the recorded x-ray fluorescence were investigated. The fluorescent material size effect was considered with and without the container for the fluorescent material. In order to provide validation for the simulation result, the angular dependence of x-ray fluorescence from five fluorescent materials was experimentally measured using a spectrometer. Finally, eleven of the fluorescent materials were used for energy calibration of a CZT-based photon-counting detector. The optimal detection angle was determined to be approximately at 120° with respect to the beam direction, which showed the highest fluorescence to scatter ratio (FSR) with a weak dependence on the fluorescent material size. The feasibility of x-ray fluorescence for energy calibration of photon-counting detectors in the diagnostic x-ray energy range was verified by successfully calibrating the energy response of a CZT-based photon-counting detector. The results of this study can be used as a guideline to implement the x-ray fluorescence calibration method for photon-counting detectors in a typical imaging laboratory.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PMB....59.7211C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PMB....59.7211C"><span>Energy response calibration of photon-counting detectors using x-ray fluorescence: a feasibility study</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cho, H.-M.; Ding, H.; Ziemer, BP; Molloi, S.</p> <p>2014-12-01</p> <p>Accurate energy calibration is critical for the application of energy-resolved photon-counting detectors in spectral imaging. The aim of this study is to investigate the feasibility of energy response calibration and characterization of a photon-counting detector using x-ray fluorescence. A comprehensive Monte Carlo simulation study was performed using Geant4 Application for Tomographic Emission (GATE) to investigate the optimal technique for x-ray fluorescence calibration. Simulations were conducted using a 100 kVp tungsten-anode spectra with 2.7 mm Al filter for a single pixel cadmium telluride (CdTe) detector with 3  ×  3 mm2 in detection area. The angular dependence of x-ray fluorescence and scatter background was investigated by varying the detection angle from 20° to 170° with respect to the beam direction. The effects of the detector material, shape, and size on the recorded x-ray fluorescence were investigated. The fluorescent material size effect was considered with and without the container for the fluorescent material. In order to provide validation for the simulation result, the angular dependence of x-ray fluorescence from five fluorescent materials was experimentally measured using a spectrometer. Finally, eleven of the fluorescent materials were used for energy calibration of a CZT-based photon-counting detector. The optimal detection angle was determined to be approximately at 120° with respect to the beam direction, which showed the highest fluorescence to scatter ratio (FSR) with a weak dependence on the fluorescent material size. The feasibility of x-ray fluorescence for energy calibration of photon-counting detectors in the diagnostic x-ray energy range was verified by successfully calibrating the energy response of a CZT-based photon-counting detector. The results of this study can be used as a guideline to implement the x-ray fluorescence calibration method for photon-counting detectors in a typical imaging laboratory.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4241961','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4241961"><span>Energy response calibration of photon-counting detectors using X-ray fluorescence: a feasibility study</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Cho, H-M; Ding, H; Ziemer, BP; Molloi, S</p> <p>2014-01-01</p> <p>Accurate energy calibration is critical for the application of energy-resolved photon-counting detectors in spectral imaging. The aim of this study is to investigate the feasibility of energy response calibration and characterization of a photon-counting detector using X-ray fluorescence. A comprehensive Monte Carlo simulation study was performed using Geant4 Application for Tomographic Emission (GATE) to investigate the optimal technique for X-ray fluorescence calibration. Simulations were conducted using a 100 kVp tungsten-anode spectra with 2.7 mm Al filter for a single pixel cadmium telluride (CdTe) detector with 3 × 3 mm2 in detection area. The angular dependence of X-ray fluorescence and scatter background was investigated by varying the detection angle from 20° to 170° with respect to the beam direction. The effects of the detector material, shape, and size on the recorded X-ray fluorescence were investigated. The fluorescent material size effect was considered with and without the container for the fluorescent material. In order to provide validation for the simulation result, the angular dependence of X-ray fluorescence from five fluorescent materials was experimentally measured using a spectrometer. Finally, eleven of the fluorescent materials were used for energy calibration of a CZT-based photon-counting detector. The optimal detection angle was determined to be approximately at 120° with respect to the beam direction, which showed the highest fluorescence to scatter ratio (FSR) with a weak dependence on the fluorescent material size. The feasibility of X-ray fluorescence for energy calibration of photon-counting detectors in the diagnostic X-ray energy range was verified by successfully calibrating the energy response of a CZT-based photon-counting detector. The results of this study can be used as a guideline to implement the X-ray fluorescence calibration method for photon-counting detectors in a typical imaging laboratory. PMID:25369288</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhLB..761....1K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhLB..761....1K"><span>Searching for photon-sector Lorentz violation using gravitational-wave detectors</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kostelecký, V. Alan; Melissinos, Adrian C.; Mewes, Matthew</p> <p>2016-10-01</p> <p>We study the prospects for using interferometers in gravitational-wave detectors as tools to search for photon-sector violations of Lorentz symmetry. Existing interferometers are shown to be exquisitely sensitive to tiny changes in the effective refractive index of light occurring at frequencies around and below the microhertz range, including at the harmonics of the frequencies of the Earth's sidereal rotation and annual revolution relevant for tests of Lorentz symmetry. We use preliminary data obtained by the Laser Interferometer Gravitational-Wave Observatory (LIGO) in 2006-2007 to place constraints on coefficients for Lorentz violation in the photon sector exceeding current limits by about four orders of magnitude.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016RScI...87g3101M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016RScI...87g3101M"><span>Time-resolved single-photon detection module based on silicon photomultiplier: A novel building block for time-correlated measurement systems</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Martinenghi, E.; Di Sieno, L.; Contini, D.; Sanzaro, M.; Pifferi, A.; Dalla Mora, A.</p> <p>2016-07-01</p> <p>We present the design and preliminary characterization of the first detection module based on Silicon Photomultiplier (SiPM) tailored for single-photon timing applications. The aim of this work is to demonstrate, thanks to the design of a suitable module, the possibility to easily exploit SiPM in many applications as an interesting detector featuring large active area, similarly to photomultipliers tubes, but keeping the advantages of solid state detectors (high quantum efficiency, low cost, compactness, robustness, low bias voltage, and insensitiveness to magnetic field). The module integrates a cooled SiPM with a total photosensitive area of 1 mm2 together with the suitable avalanche signal read-out circuit, the signal conditioning, the biasing electronics, and a Peltier cooler driver for thermal stabilization. It is able to extract the single-photon timing information with resolution better than 100 ps full-width at half maximum. We verified the effective stabilization in response to external thermal perturbations, thus proving the complete insensitivity of the module to environment temperature variations, which represents a fundamental parameter to profitably use the instrument for real-field applications. We also characterized the single-photon timing resolution, the background noise due to both primary dark count generation and afterpulsing, the single-photon detection efficiency, and the instrument response function shape. The proposed module can become a reliable and cost-effective building block for time-correlated single-photon counting instruments in applications requiring high collection capability of isotropic light and detection efficiency (e.g., fluorescence decay measurements or time-domain diffuse optics systems).</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20090014216&hterms=pixel+array+detector&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dpixel%2Barray%2Bdetector','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20090014216&hterms=pixel+array+detector&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dpixel%2Barray%2Bdetector"><span>Recent Developments in Transition-Edge Strip Detectors for Solar X-Rays</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rausch, Adam J.; Deiker, Steven W.; Hilton, Gene; Irwin, Kent D.; Martinez-Galarce, Dennis S.; Shing, Lawrence; Stern, Robert A.; Ullom, Joel N.; Vale, Leila R.</p> <p>2008-01-01</p> <p>LMSAL and NIST are developing position-sensitive x-ray strip detectors based on Transition Edge Sensor (TES) microcalorimeters optimized for solar physics. By combining high spectral (E/ delta E approximately equals 1600) and temporal (single photon delta t approximately equals 10 micro s) resolutions with imaging capabilities, these devices will be able to study high-temperature (>l0 MK) x-ray lines as never before. Diagnostics from these lines should provide significant new insight into the physics of both microflares and the early stages of flares. Previously, the large size of traditional TESs, along with the heat loads associated with wiring large arrays, presented obstacles to using these cryogenic detectors for solar missions. Implementing strip detector technology at small scales, however, addresses both issues: here, a line of substantially smaller effective pixels requires only two TESs, decreasing both the total array size and the wiring requirements for the same spatial resolution. Early results show energy resolutions of delta E(sub fwhm) approximately equals 30 eV and spatial resolutions of approximately 10-15 micron, suggesting the strip-detector concept is viable.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1336982-dual-crystal-ray-spectrometer-kev-high-repetition-rate-single-photon-counting-spectroscopy-experiments','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1336982-dual-crystal-ray-spectrometer-kev-high-repetition-rate-single-photon-counting-spectroscopy-experiments"><span>Dual crystal x-ray spectrometer at 1.8 keV for high repetition-rate single-photon counting spectroscopy experiments</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Gamboa, E. J.; Bachmann, B.; Kraus, D.; ...</p> <p>2016-08-01</p> <p>The recent development of high-repetition rate x-ray free electron lasers (FEL), makes it possible to perform x-ray scattering and emission spectroscopy measurements from thin foils or gasses heated to high-energy density conditions by integrating over many experimental shots. Since the expected signal may be weaker than the typical CCD readout noise over the region-of-interest, it is critical to the success of this approach to use a detector with high-energy resolution so that single x-ray photons may be isolated. We describe a dual channel x-ray spectrometer developed for the Atomic and Molecular Optics endstation at the Linac Coherent Light Source (LCLS)more » for x-ray spectroscopy near the K-edge of aluminum. The spectrometer is based on a pair of curved PET (002) crystals coupled to a single pnCCD detector which simultaneously measures x-ray scattering and emission in the forward and backward directions. Furthermore, the signals from single x-ray photons are accumulated permitting continuous single-shot acquisition at 120 Hz.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014OExpr..22.6734T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014OExpr..22.6734T"><span>Optimised quantum hacking of superconducting nanowire single-photon detectors</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tanner, Michael G.; Makarov, Vadim; Hadfield, Robert H.</p> <p>2014-03-01</p> <p>We explore bright-light control of superconducting nanowire single-photon detectors (SNSPDs) in the shunted configuration (a practical measure to avoid latching). In an experiment, we simulate an illumination pattern the SNSPD would receive in a typical quantum key distribution system under hacking attack. We show that it effectively blinds and controls the SNSPD. The transient blinding illumination lasts for a fraction of a microsecond and produces several deterministic fake clicks during this time. This attack does not lead to elevated timing jitter in the spoofed output pulse, and hence does not introduce significant errors. Five different SNSPD chip designs were tested. We consider possible countermeasures to this attack.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24664022','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24664022"><span>Optimised quantum hacking of superconducting nanowire single-photon detectors.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tanner, Michael G; Makarov, Vadim; Hadfield, Robert H</p> <p>2014-03-24</p> <p>We explore bright-light control of superconducting nanowire single-photon detectors (SNSPDs) in the shunted configuration (a practical measure to avoid latching). In an experiment, we simulate an illumination pattern the SNSPD would receive in a typical quantum key distribution system under hacking attack. We show that it effectively blinds and controls the SNSPD. The transient blinding illumination lasts for a fraction of a microsecond and produces several deterministic fake clicks during this time. This attack does not lead to elevated timing jitter in the spoofed output pulse, and hence does not introduce significant errors. Five different SNSPD chip designs were tested. We consider possible countermeasures to this attack.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28249471','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28249471"><span>Note: Fully integrated active quenching circuit achieving 100 MHz count rate with custom technology single photon avalanche diodes.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Acconcia, G; Labanca, I; Rech, I; Gulinatti, A; Ghioni, M</p> <p>2017-02-01</p> <p>The minimization of Single Photon Avalanche Diodes (SPADs) dead time is a key factor to speed up photon counting and timing measurements. We present a fully integrated Active Quenching Circuit (AQC) able to provide a count rate as high as 100 MHz with custom technology SPAD detectors. The AQC can also operate the new red enhanced SPAD and provide the timing information with a timing jitter Full Width at Half Maximum (FWHM) as low as 160 ps.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008PhDT.......222G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008PhDT.......222G"><span>The Physics of Superconducting Microwave Resonators</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gao, Jiansong</p> <p></p> <p>Over the past decade, low temperature detectors have brought astronomers revolutionary new observational capabilities and led to many great discoveries. Although a single low temperature detector has very impressive sensitivity, a large detector array would be much more powerful and are highly demanded for the study of more difficult and fundamental problems in astronomy. However, current detector technologies, such as transition edge sensors and superconducting tunnel junction detectors, are difficult to integrate into a large array. The microwave kinetic inductance detector (MKID) is a promising new detector technology invented at Caltech and JPL which provides both high sensitivity and an easy solution to the detector integration. It senses the change in the surface impedance of a superconductor as incoming photons break Cooper pairs, by using high-Q superconducting microwave resonators capacitively coupled to a common feedline. This architecture allows thousands of detectors to be easily integrated through passive frequency domain multiplexing. In this thesis, we explore the rich and interesting physics behind these superconducting microwave resonators. The first part of the thesis discusses the surface impedance of a superconductor, the kinetic inductance of a superconducting coplanar waveguide, and the circuit response of a resonator. These topics are related with the responsivity of MKIDs. The second part presents the study of the excess frequency noise that is universally observed in these resonators. The properties of the excess noise, including power, temperature, material, and geometry dependence, have been quantified. The noise source has been identified to be the two-level systems in the dielectric material on the surface of the resonator. A semi-empirical noise model has been developed to explain the power and geometry dependence of the noise, which is useful to predict the noise for a specified resonator geometry. The detailed physical noise mechanism, however, is still not clear. With the theoretical results of the responsivity and the semi-empirical noise model established in this thesis, a prediction of the detector sensitivity (noise equivalent power) and an optimization of the detector design are now possible.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PhDT.........5F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PhDT.........5F"><span>Kinetic Inductance Detectors for Measuring the Polarization of the Cosmic Microwave Background</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Flanigan, Daniel</p> <p></p> <p>Kinetic inductance detectors (KIDs) are superconducting thin-film microresonators that are sensitive photon detectors. These detectors are a candidate for the next generation of experiments designed to measure the polarization of the cosmic microwave background (CMB). I discuss the basic theory needed to understand the response of a KID to light, focusing on the dynamics of the quasiparticle system. I derive an equation that describes the dynamics of the quasiparticle number, solve it in a simplified form not previously published, and show that it can describe the dynamic response of a detector. Magnetic flux vortices in a superconducting thin film can be a significant source of dissipation, and I demonstrate some techniques to prevent their formation. Based on the presented theory, I derive a corrected version of a widely-used equation for the quasiparticle recombination noise in a KID. I show that a KID consisting of a lumped-element resonator can be sensitive enough to be limited by photon noise, which is the fundamental limit for photometry, at a level of optical loading below levels in ground-based CMB experiments. Finally, I describe an ongoing project to develop multichroic KID pixels that are each sensitive to two linear polarization states in two spectral bands, intended for the next generation of CMB experiments. I show that a prototype 23-pixel array can detect millimeter-wave light, and present characterization measurements of the detectors.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19760007903','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19760007903"><span>Preliminary design report, Large Space Telescope OTA/SI Phase B study: High speed area photometer. [systems analysis</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1975-01-01</p> <p>A photometer is examined which combines several features from separate instruments into a single package. The design presented has both point and area photometry capability with provision for inserting filters to provide spectral discrimination. The electronics provide for photon counting mode for the point detectors and both photon counting and analog modes for the area detector. The area detector also serves as a target locating device for the point detectors. Topics discussed include: (1) electronic equipment requirements, (2) optical properties, (3) structural housing for the instrument, (4) motors and other mechanical components, (5) ground support equipment, and (6) environment control for the instrument. Engineering drawings and block diagrams are shown.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA486091','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA486091"><span>Implementing a Multiplexed System of Detectors for Higher Photon Counting Rates</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2007-01-01</p> <p>D1 D2 Fig. 3. (a) Setup for testing different arrangements of InGaAs SPAD assemblies; (b) three different InGaAs SPAD assemblies; ( c ) schematic of...presently available, either commercial or prototype, the deadtimes range from ≈50 ns for actively quenched single photon avalanche detectors ( SPADs ...to ≈10 µs for passively quenched SPADs , although even actively quenched SPADs sometimes employ µs deadtimes to avoid excessive afterpulsing rates. In</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA548830','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA548830"><span>Feasibility of Dual Optical/Ultrasound Imaging and Contrast Media for the Detection and Characterization of Prostate Cancer</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2011-04-01</p> <p>NUMBER OF PAGES 19a. NAME OF RESPONSIBLE PERSON USAMRMC a. REPORT U b. ABSTRACT U c . THIS PAGE U UU 19b. TELEPHONE NUMBER (include...a) (b) ( c ) Figure 2a) Experimental set-up for detection of ultrasound-modulated coherent light with a silicon photodetector 2b...also explored using their novel photon detector technology, known as a single photon avalanche diode ( SPAD ) detector [13], to detect ultrasound</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28590750','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28590750"><span>On-Chip Single-Plasmon Nanocircuit Driven by a Self-Assembled Quantum Dot.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wu, Xiaofei; Jiang, Ping; Razinskas, Gary; Huo, Yongheng; Zhang, Hongyi; Kamp, Martin; Rastelli, Armando; Schmidt, Oliver G; Hecht, Bert; Lindfors, Klas; Lippitz, Markus</p> <p>2017-07-12</p> <p>Quantum photonics holds great promise for future technologies such as secure communication, quantum computation, quantum simulation, and quantum metrology. An outstanding challenge for quantum photonics is to develop scalable miniature circuits that integrate single-photon sources, linear optical components, and detectors on a chip. Plasmonic nanocircuits will play essential roles in such developments. However, for quantum plasmonic circuits, integration of stable, bright, and narrow-band single photon sources in the structure has so far not been reported. Here we present a plasmonic nanocircuit driven by a self-assembled GaAs quantum dot. Through a planar dielectric-plasmonic hybrid waveguide, the quantum dot efficiently excites narrow-band single plasmons that are guided in a two-wire transmission line until they are converted into single photons by an optical antenna. Our work demonstrates the feasibility of fully on-chip plasmonic nanocircuits for quantum optical applications.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28094849','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28094849"><span>The "collimator monitoring fill factor" of a two-dimensional detector array, a measure of its ability to detect collimation errors.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Stelljes, Tenzin Sonam; Looe, Hui Khee; Harder, Dietrich; Poppe, Björn</p> <p>2017-03-01</p> <p>Two-dimensional detector arrays are routinely used for constancy checks and treatment plan verification in photon-beam radiotherapy. In addition to the spatial resolution of the dose profiles, the "coverage" of the radiation field with respect to the detection of any beam collimation deficiency appears as the second characteristic feature of a detector array. The here proposed "collimator monitoring fill factor" (CM fill factor) has been conceived to serve as a quantitative characteristic of this "coverage". The CM fill factor is defined as the probability of a 2D array to detect any collimator position error. Therefore, it is represented by the ratio of the "sensitive area" of a single detector, in which collimator position errors are detectable, and the geometrical "cell area" associated with this detector within the array. Numerical values of the CM fill factor have been Monte Carlo simulated for 2D detector arrays equipped with air-vented ionization chambers, liquid-filled ionization chambers and diode detectors and were compared with the "FWHM fill factor" defined by Gago-Arias et al. (2012). For arrays with vented ionization chambers, the differences between the CM fill factor and the FWHM fill factor are moderate, but occasionally the latter exceeds unity. For narrower detectors such as liquid-filled ionization chambers and Si diodes and for small sampling distances, large differences between the FWHM fill factor and the CM fill factor have been observed. These differences can be explained by the shapes of the fluence response functions of these narrow detectors. A new parameter "collimator monitoring fill factor" (CM fill factor), applicable to quantitate the collimator position error detection probability of a 2D detector array, has been proposed. It is designed as a help in classifying the clinical performance of two-dimensional detector arrays in photon-beam radiotherapy. © 2017 American Association of Physicists in Medicine.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4826388','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4826388"><span>Photon-counting hexagonal pixel array CdTe detector: Spatial resolution characteristics for image-guided interventional applications</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Shrestha, Suman; Karellas, Andrew; Shi, Linxi; Gounis, Matthew J.; Bellazzini, Ronaldo; Spandre, Gloria; Brez, Alessandro; Minuti, Massimo</p> <p>2016-01-01</p> <p>Purpose: High-resolution, photon-counting, energy-resolved detector with fast-framing capability can facilitate simultaneous acquisition of precontrast and postcontrast images for subtraction angiography without pixel registration artifacts and can facilitate high-resolution real-time imaging during image-guided interventions. Hence, this study was conducted to determine the spatial resolution characteristics of a hexagonal pixel array photon-counting cadmium telluride (CdTe) detector. Methods: A 650 μm thick CdTe Schottky photon-counting detector capable of concurrently acquiring up to two energy-windowed images was operated in a single energy-window mode to include photons of 10 keV or higher. The detector had hexagonal pixels with apothem of 30 μm resulting in pixel pitch of 60 and 51.96 μm along the two orthogonal directions. The detector was characterized at IEC-RQA5 spectral conditions. Linear response of the detector was determined over the air kerma rate relevant to image-guided interventional procedures ranging from 1.3 nGy/frame to 91.4 μGy/frame. Presampled modulation transfer was determined using a tungsten edge test device. The edge-spread function and the finely sampled line spread function accounted for hexagonal sampling, from which the presampled modulation transfer function (MTF) was determined. Since detectors with hexagonal pixels require resampling to square pixels for distortion-free display, the optimal square pixel size was determined by minimizing the root-mean-squared-error of the aperture functions for the square and hexagonal pixels up to the Nyquist limit. Results: At Nyquist frequencies of 8.33 and 9.62 cycles/mm along the apothem and orthogonal to the apothem directions, the modulation factors were 0.397 and 0.228, respectively. For the corresponding axis, the limiting resolution defined as 10% MTF occurred at 13.3 and 12 cycles/mm, respectively. Evaluation of the aperture functions yielded an optimal square pixel size of 54 μm. After resampling to 54 μm square pixels using trilinear interpolation, the presampled MTF at Nyquist frequency of 9.26 cycles/mm was 0.29 and 0.24 along the orthogonal directions and the limiting resolution (10% MTF) occurred at approximately 12 cycles/mm. Visual analysis of a bar pattern image showed the ability to resolve close to 12 line-pairs/mm and qualitative evaluation of a neurovascular nitinol-stent showed the ability to visualize its struts at clinically relevant conditions. Conclusions: Hexagonal pixel array photon-counting CdTe detector provides high spatial resolution in single-photon counting mode. After resampling to optimal square pixel size for distortion-free display, the spatial resolution is preserved. The dual-energy capabilities of the detector could allow for artifact-free subtraction angiography and basis material decomposition. The proposed high-resolution photon-counting detector with energy-resolving capability can be of importance for several image-guided interventional procedures as well as for pediatric applications. PMID:27147324</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27147324','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27147324"><span>Photon-counting hexagonal pixel array CdTe detector: Spatial resolution characteristics for image-guided interventional applications.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Vedantham, Srinivasan; Shrestha, Suman; Karellas, Andrew; Shi, Linxi; Gounis, Matthew J; Bellazzini, Ronaldo; Spandre, Gloria; Brez, Alessandro; Minuti, Massimo</p> <p>2016-05-01</p> <p>High-resolution, photon-counting, energy-resolved detector with fast-framing capability can facilitate simultaneous acquisition of precontrast and postcontrast images for subtraction angiography without pixel registration artifacts and can facilitate high-resolution real-time imaging during image-guided interventions. Hence, this study was conducted to determine the spatial resolution characteristics of a hexagonal pixel array photon-counting cadmium telluride (CdTe) detector. A 650 μm thick CdTe Schottky photon-counting detector capable of concurrently acquiring up to two energy-windowed images was operated in a single energy-window mode to include photons of 10 keV or higher. The detector had hexagonal pixels with apothem of 30 μm resulting in pixel pitch of 60 and 51.96 μm along the two orthogonal directions. The detector was characterized at IEC-RQA5 spectral conditions. Linear response of the detector was determined over the air kerma rate relevant to image-guided interventional procedures ranging from 1.3 nGy/frame to 91.4 μGy/frame. Presampled modulation transfer was determined using a tungsten edge test device. The edge-spread function and the finely sampled line spread function accounted for hexagonal sampling, from which the presampled modulation transfer function (MTF) was determined. Since detectors with hexagonal pixels require resampling to square pixels for distortion-free display, the optimal square pixel size was determined by minimizing the root-mean-squared-error of the aperture functions for the square and hexagonal pixels up to the Nyquist limit. At Nyquist frequencies of 8.33 and 9.62 cycles/mm along the apothem and orthogonal to the apothem directions, the modulation factors were 0.397 and 0.228, respectively. For the corresponding axis, the limiting resolution defined as 10% MTF occurred at 13.3 and 12 cycles/mm, respectively. Evaluation of the aperture functions yielded an optimal square pixel size of 54 μm. After resampling to 54 μm square pixels using trilinear interpolation, the presampled MTF at Nyquist frequency of 9.26 cycles/mm was 0.29 and 0.24 along the orthogonal directions and the limiting resolution (10% MTF) occurred at approximately 12 cycles/mm. Visual analysis of a bar pattern image showed the ability to resolve close to 12 line-pairs/mm and qualitative evaluation of a neurovascular nitinol-stent showed the ability to visualize its struts at clinically relevant conditions. Hexagonal pixel array photon-counting CdTe detector provides high spatial resolution in single-photon counting mode. After resampling to optimal square pixel size for distortion-free display, the spatial resolution is preserved. The dual-energy capabilities of the detector could allow for artifact-free subtraction angiography and basis material decomposition. The proposed high-resolution photon-counting detector with energy-resolving capability can be of importance for several image-guided interventional procedures as well as for pediatric applications.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/1424113-improved-modeling-photon-observables-event-event-fission-model-freya','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1424113-improved-modeling-photon-observables-event-event-fission-model-freya"><span></span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Vogt, R.; Randrup, J.</p> <p></p> <p>The event-by-event fission model FREYA has been improved, in particular to address deficiencies in the calculation of photon observables. In this paper, we discuss the improvements that have been made and introduce several new variables, some detector dependent, that affect the photon observables. We show the sensitivity of FREYA to these variables. Finally, we then compare the results to the available photon data from spontaneous and thermal neutron-induced fission.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/12870591','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/12870591"><span>First images of a digital autoradiography system based on a Medipix2 hybrid silicon pixel detector.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mettivier, Giovanni; Montesi, Maria Cristina; Russo, Paolo</p> <p>2003-06-21</p> <p>We present the first images of beta autoradiography obtained with the high-resolution hybrid pixel detector consisting of the Medipix2 single photon counting read-out chip bump-bonded to a 300 microm thick silicon pixel detector. This room temperature system has 256 x 256 square pixels of 55 microm pitch (total sensitive area of 14 x 14 mm2), with a double threshold discriminator and a 13-bit counter in each pixel. It is read out via a dedicated electronic interface and control software, also developed in the framework of the European Medipix2 Collaboration. Digital beta autoradiograms of 14C microscale standard strips (containing separate bands of increasing specific activity in the range 0.0038-32.9 kBq g(-1)) indicate system linearity down to a total background noise of 1.8 x 10(-3) counts mm(-2) s(-1). The minimum detectable activity is estimated to be 0.012 Bq for 36,000 s exposure and 0.023 Bq for 10,800 s exposure. The measured minimum detection threshold is less than 1600 electrons (equivalent to about 6 keV Si). This real-time system for beta autoradiography offers lower pixel pitch and higher sensitive area than the previous Medipix1-based system. It has a 14C sensitivity better than that of micro channel plate based systems, which, however, shows higher spatial resolution and sensitive area.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1012683','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1012683"><span>High-speed digitization readout of silicon photomultipliers for time of flight positron emission tomography</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Ronzhin, A.; Los, S.; Martens, M.</p> <p>2011-02-01</p> <p>We report on work to develop a system with about 100 picoseconds (ps) time resolution for time of flight positron emission tomography [TOF-PET]. The chosen photo detectors for the study were Silicon Photomultipliers (SiPM's). This study was based on extensive experience in studying timing properties of SiPM's. The readout of these devices used the commercial high speed digitizer DRS4. We applied different algorithms to get the best time resolution of 155 ps Guassian (sigma) for a LYSO crystal coupled to a SiPM. We consider the work as a first step in building a prototype TOF-PET module. The field of positron-emission-tomographymore » (PET) has been rapidly developing. But there are significant limitations in how well current PET scanners can reconstruct images, related to how fast data can be acquired, how much volume they can image, and the spatial and temporal resolution of the generated photons. Typical modern scanners now include multiple rings of detectors, which can image a large volume of the patient. In this type of scanner, one can treat each ring as a separate detector and require coincidences only within the ring, or treat the entire region viewed by the scanner as a single 3 dimensional volume. This 3d technique has significantly better sensitivity since more photon pair trajectories are accepted. However, the scattering of photons within the volume of the patient, and the effect of random coincidences limits the technique. The advent of sub-nanosecond timing resolution detectors means that there is potentially much better rejection of scattered photon events and random coincidence events in the 3D technique. In addition, if the timing is good enough, then the origin of photons pairs can be determined better, resulting in improved spatial resolution - so called 'Time-of-Flight' PET, or TOF-PET. Currently a lot of activity has occurred in applications of SiPMs for TOF-PET. This is due to the devices very good time resolution, low profile, lack of high voltage needed, and their non-sensitivity to magnetic fields. While investigations into this technique have begun elsewhere, we feel that the extensive SiPM characterization and data acquisition expertise of Fermilab, and the historical in-depth research of PET imaging at University of Chicago will combine to make significant strides in this field. We also benefit by a working relationship with the SiPM producer STMicroelectronics (STM).« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010PhDT........55J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010PhDT........55J"><span>Design, construction, and evaluation of new high resolution medical imaging detector/systems</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jain, Amit</p> <p></p> <p>Increasing need of minimally invasive endovascular image guided interventional procedures (EIGI) for accurate and successful treatment of vascular disease has set a quest for better image quality. Current state of the art detectors are not up to the mark for these complex procedures due to their inherent limitations. Our group has been actively working on the design and construction of a high resolution, region of interest CCD-based X-ray imager for some time. As a part of that endeavor, a Micro-angiographic fluoroscope (MAF) was developed to serve as a high resolution, ROI X-ray imaging detector in conjunction with large lower resolution full field of view (FOV) state-of-the-art x-ray detectors. The newly developed MAF is an indirect x-ray imaging detector capable of providing real-time images with high resolution, high sensitivity, no lag and low instrumentation noise. It consists of a CCD camera coupled to a light image intensifier (LII) through a fiber optic taper. The CsI(Tl) phosphor serving as the front end is coupled to the LII. For this work, the MAF was designed and constructed. The linear system cascade theory was used to evaluate the performance theoretically. Linear system metrics such as MTF and DQE were used to gauge the detector performance experimentally. The capabilities of the MAF as a complete system were tested using generalized linear system metrics. With generalized linear system metrics the effects of finite size focal spot, geometric magnification and the presence of scatter are included in the analysis and study. To minimize the effect of scatter, an anti-scatter grid specially designed for the MAF was also studied. The MAF was compared with the flat panel detector using signal-to-noise ratio and the two dimensional linear system metrics. The signal-to-noise comparison was carried out to point out the effect of pixel size and Point Spread Function of the detector. The two dimensional linear system metrics were used to investigate the comparative performance of both the detectors in similar simulated clinical neuro-vascular conditions. The last part of this work presents a unique quality of the MAF: operation in single photon mode. The successful operation of the MAF was demonstrated with considerable improvement in spatial and contrast resolution over conventional energy integrating mode. The work presented shows the evolution of a high resolution, high sensitivity, and region of interest x-ray imaging detector as an attractive and capable x-ray imager for the betterment of complex EIGI procedures. The capability of single photon counting mode imaging provides the potential for additional uses of the MAF including the possibility of use in dual modality imaging with radionuclide sources as well as x-rays.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013SPIE.8804E..02D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013SPIE.8804E..02D"><span>Functional near-infrared spectroscopy at small source-detector distance by means of high dynamic-range fast-gated SPAD acquisitions: first in-vivo measurements</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Di Sieno, L.; Contini, D.; Dalla Mora, A.; Torricelli, A.; Spinelli, L.; Cubeddu, R.; Tosi, A.; Boso, G.; Pifferi, A.</p> <p>2013-06-01</p> <p>In this article, we show experimental results of time-resolved optical spectroscopy performed with small distance between launching and detecting fibers. It was already demonstrated that depth discrimination is independent of source-detector separation and that measurements at small source detector distance provide better contrast and spatial resolution. The main disadvantage is represent by the huge increase in early photons (scarcely diffused by tissue) peak that can saturate the dynamic range of most detectors, hiding information carried by late photons. Thanks to a fast-gated Single- Photon Avalanche Diode (SPAD) module, we are able to reject the peak of early photons and to obtain high-dynamic range acquisitions. We exploit fast-gated SPAD module to perform for the first time functional near-infrared spectroscopy (fNIRS) at small source-detector distance for in vivo measurements and we demonstrate the possibility to detect non-invasively the dynamics of oxygenated and deoxygenated haemoglobin occurring in the motor cortex during a motor task. We also show the improvement in terms of signal amplitude and Signal-to-Noise Ratio (SNR) obtained exploiting fast-gated SPAD performances with respect to "non-gated" measurements.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1424113-improved-modeling-photon-observables-event-event-fission-model-freya','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1424113-improved-modeling-photon-observables-event-event-fission-model-freya"><span>Improved modeling of photon observables with the event-by-event fission model FREYA</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Vogt, R.; Randrup, J.</p> <p>2017-12-28</p> <p>The event-by-event fission model FREYA has been improved, in particular to address deficiencies in the calculation of photon observables. In this paper, we discuss the improvements that have been made and introduce several new variables, some detector dependent, that affect the photon observables. We show the sensitivity of FREYA to these variables. Finally, we then compare the results to the available photon data from spontaneous and thermal neutron-induced fission.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhDT........55K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhDT........55K"><span>Single Photon Counting Detectors for Low Light Level Imaging Applications</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kolb, Kimberly</p> <p>2015-10-01</p> <p>This dissertation presents the current state-of-the-art of semiconductor-based photon counting detector technologies. HgCdTe linear-mode avalanche photodiodes (LM-APDs), silicon Geiger-mode avalanche photodiodes (GM-APDs), and electron-multiplying CCDs (EMCCDs) are compared via their present and future performance in various astronomy applications. LM-APDs are studied in theory, based on work done at the University of Hawaii. EMCCDs are studied in theory and experimentally, with a device at NASA's Jet Propulsion Lab. The emphasis of the research is on GM-APD imaging arrays, developed at MIT Lincoln Laboratory and tested at the RIT Center for Detectors. The GM-APD research includes a theoretical analysis of SNR and various performance metrics, including dark count rate, afterpulsing, photon detection efficiency, and intrapixel sensitivity. The effects of radiation damage on the GM-APD were also characterized by introducing a cumulative dose of 50 krad(Si) via 60 MeV protons. Extensive development of Monte Carlo simulations and practical observation simulations was completed, including simulated astronomical imaging and adaptive optics wavefront sensing. Based on theoretical models and experimental testing, both the current state-of-the-art performance and projected future performance of each detector are compared for various applications. LM-APD performance is currently not competitive with other photon counting technologies, and are left out of the application-based comparisons. In the current state-of-the-art, EMCCDs in photon counting mode out-perform GM-APDs for long exposure scenarios, though GM-APDs are better for short exposure scenarios (fast readout) due to clock-induced-charge (CIC) in EMCCDs. In the long term, small improvements in GM-APD dark current will make them superior in both long and short exposure scenarios for extremely low flux. The efficiency of GM-APDs will likely always be less than EMCCDs, however, which is particularly disadvantageous for moderate to high flux rates where dark noise and CIC are insignificant noise sources. Research into decreasing the dark count rate of GM-APDs will lead to development of imaging arrays that are competitive for low light level imaging and spectroscopy applications in the near future.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23038530','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23038530"><span>Real-time monitoring of single-photon detectors against eavesdropping in quantum key distribution systems.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>da Silva, Thiago Ferreira; Xavier, Guilherme B; Temporão, Guilherme P; von der Weid, Jean Pierre</p> <p>2012-08-13</p> <p>By employing real-time monitoring of single-photon avalanche photodiodes we demonstrate how two types of practical eavesdropping strategies, the after-gate and time-shift attacks, may be detected. Both attacks are identified with the detectors operating without any special modifications, making this proposal well suited for real-world applications. The monitoring system is based on accumulating statistics of the times between consecutive detection events, and extracting the afterpulse and overall efficiency of the detectors in real-time using mathematical models fit to the measured data. We are able to directly observe changes in the afterpulse probabilities generated from the after-gate and faint after-gate attacks, as well as different timing signatures in the time-shift attack. We also discuss the applicability of our scheme to other general blinding attacks.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22581385-performance-todays-dual-energy-ct-future-multi-energy-ct-virtual-non-contrast-imaging-iodine-quantification-simulation-study','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22581385-performance-todays-dual-energy-ct-future-multi-energy-ct-virtual-non-contrast-imaging-iodine-quantification-simulation-study"><span>Performance of today’s dual energy CT and future multi energy CT in virtual non-contrast imaging and in iodine quantification: A simulation study</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Faby, Sebastian, E-mail: sebastian.faby@dkfz.de; Kuchenbecker, Stefan; Sawall, Stefan</p> <p>2015-07-15</p> <p>Purpose: To study the performance of different dual energy computed tomography (DECT) techniques, which are available today, and future multi energy CT (MECT) employing novel photon counting detectors in an image-based material decomposition task. Methods: The material decomposition performance of different energy-resolved CT acquisition techniques is assessed and compared in a simulation study of virtual non-contrast imaging and iodine quantification. The material-specific images are obtained via a statistically optimal image-based material decomposition. A projection-based maximum likelihood approach was used for comparison with the authors’ image-based method. The different dedicated dual energy CT techniques are simulated employing realistic noise models andmore » x-ray spectra. The authors compare dual source DECT with fast kV switching DECT and the dual layer sandwich detector DECT approach. Subsequent scanning and a subtraction method are studied as well. Further, the authors benchmark future MECT with novel photon counting detectors in a dedicated DECT application against the performance of today’s DECT using a realistic model. Additionally, possible dual source concepts employing photon counting detectors are studied. Results: The DECT comparison study shows that dual source DECT has the best performance, followed by the fast kV switching technique and the sandwich detector approach. Comparing DECT with future MECT, the authors found noticeable material image quality improvements for an ideal photon counting detector; however, a realistic detector model with multiple energy bins predicts a performance on the level of dual source DECT at 100 kV/Sn 140 kV. Employing photon counting detectors in dual source concepts can improve the performance again above the level of a single realistic photon counting detector and also above the level of dual source DECT. Conclusions: Substantial differences in the performance of today’s DECT approaches were found for the application of virtual non-contrast and iodine imaging. Future MECT with realistic photon counting detectors currently can only perform comparably to dual source DECT at 100 kV/Sn 140 kV. Dual source concepts with photon counting detectors could be a solution to this problem, promising a better performance.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017NaPho..11..247Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017NaPho..11..247Z"><span>Single-photon imager based on a superconducting nanowire delay line</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhao, Qing-Yuan; Zhu, Di; Calandri, Niccolò; Dane, Andrew E.; McCaughan, Adam N.; Bellei, Francesco; Wang, Hao-Zhu; Santavicca, Daniel F.; Berggren, Karl K.</p> <p>2017-03-01</p> <p>Detecting spatial and temporal information of individual photons is critical to applications in spectroscopy, communication, biological imaging, astronomical observation and quantum-information processing. Here we demonstrate a scalable single-photon imager using a single continuous superconducting nanowire that is not only a single-photon detector but also functions as an efficient microwave delay line. In this context, photon-detection pulses are guided in the nanowire and enable the readout of the position and time of photon-absorption events from the arrival times of the detection pulses at the nanowire's two ends. Experimentally, we slowed down the velocity of pulse propagation to ∼2% of the speed of light in free space. In a 19.7 mm long nanowire that meandered across an area of 286 × 193 μm2, we were able to resolve ∼590 effective pixels with a temporal resolution of 50 ps (full width at half maximum). The nanowire imager presents a scalable approach for high-resolution photon imaging in space and time.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110015903','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110015903"><span>Single photon detection with self-quenching multiplication</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Zheng, Xinyu (Inventor); Cunningham, Thomas J. (Inventor); Pain, Bedabrata (Inventor)</p> <p>2011-01-01</p> <p>A photoelectronic device and an avalanche self-quenching process for a photoelectronic device are described. The photoelectronic device comprises a nanoscale semiconductor multiplication region and a nanoscale doped semiconductor quenching structure including a depletion region and an undepletion region. The photoelectronic device can act as a single photon detector or a single carrier multiplier. The avalanche self-quenching process allows electrical field reduction in the multiplication region by movement of the multiplication carriers, thus quenching the avalanche.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/871238','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/871238"><span>Apparatus and method for heterodyne-generated two-dimensional detector array using a single element detector</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Strauss, Charlie E.</p> <p>1997-01-01</p> <p>Apparatus and method for heterodyne-generated, two-dimensional detector array using a single detector. Synthetic-array heterodyne detection, permits a single-element optical detector to behave as though it were divided into an array of separate heterodyne detector elements. A fifteen-element synthetic array has successfully been experimentally realized on a single-element detector, permitting all of the array elements to be read out continuously and in parallel from one electrical connection. A CO.sub.2 laser and a single-element HgCdTe photodiode are employed. A different heterodyne local oscillator frequency is incident upon the spatially resolvable regions of the detector surface. Thus, different regions are mapped to different heterodyne beat frequencies. One can determine where the photons were incident on the detector surface even though a single electrical connection to the detector is used. This also prevents the destructive interference that occurs when multiple speckles are imaged (similar to spatial diversity), In coherent LIDAR this permits a larger field of view. An acoustooptic modulator generates the local oscillator frequencies and can achieve adequate spatial separation of optical frequencies of the order of a megahertz apart.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/563711','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/biblio/563711"><span>Apparatus and method for heterodyne-generated two-dimensional detector array using a single element detector</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Strauss, C.E.</p> <p>1997-11-18</p> <p>Apparatus and method are disclosed for heterodyne-generated, two-dimensional detector array using a single detector. Synthetic-array heterodyne detection, permits a single-element optical detector to behave as though it were divided into an array of separate heterodyne detector elements. A fifteen-element synthetic array has successfully been experimentally realized on a single-element detector, permitting all of the array elements to be read out continuously and in parallel from one electrical connection. A CO{sub 2} laser and a single-element HgCdTe photodiode are employed. A different heterodyne local oscillator frequency is incident upon the spatially resolvable regions of the detector surface. Thus, different regions are mapped to different heterodyne beat frequencies. One can determine where the photons were incident on the detector surface even though a single electrical connection to the detector is used. This also prevents the destructive interference that occurs when multiple speckles are imaged (similar to spatial diversity), In coherent LIDAR this permits a larger field of view. An acoustooptic modulator generates the local oscillator frequencies and can achieve adequate spatial separation of optical frequencies of the order of a megahertz apart. 4 figs.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PhRvP...9e4027V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PhRvP...9e4027V"><span>Josephson Photodetectors via Temperature-to-Phase Conversion</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Virtanen, P.; Ronzani, A.; Giazotto, F.</p> <p>2018-05-01</p> <p>We theoretically investigate the temperature-to-phase conversion (TPC) process occurring in dc superconducting quantum interferometers based on superconductor-normal-metal-superconductor (S -N -S ) mesoscopic Josephson junctions. In particular, we predict the temperature-driven rearrangement of the phase gradients in the interferometer under the fixed constraints of fluxoid quantization and supercurrent conservation. This mechanism allows sizeable phase variations across the junctions for suitable structure parameters and temperatures. We show that the TPC can be a basis for sensitive single-photon sensors or bolometers. We propose a radiation detector realizable with conventional materials and state-of-the-art nanofabrication techniques. Integrated with a superconducting quantum-interference proximity transistor as a readout setup, an aluminum-based TPC calorimeter can provide a large signal-to-noise ratio >100 in the 10-GHz-10-THz frequency range and a resolving power larger than 1 02 below 50 mK for terahertz photons. In the bolometric operation, electrical noise equivalent power of approximately 10-22 W /√{Hz } is predicted at 50 mK. This device can be attractive as a cryogenic single-photon sensor operating in the giga- and terahertz regime with applications in dark-matter searches.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..APRH17002K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..APRH17002K"><span>Study the performance of LYSO and CeBr3 crystals using Silicon Photomultipliers</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kryemadhi, Abaz</p> <p>2016-03-01</p> <p>The Silicon Photomultipliers (SiPMs) are novel photon-detectors which have been progressively found their use in particle physics. Their small size, good single photon resolution, simple readout, and immunity to magnetic fields offers advantages compared to traditional photomultipliers. LYSO and CeBr3 crystals are relatively new scintillators with high light yield and fast decay time. The response of these detectors to low energy gamma rays and cosmic ray muons will be presented. Messiah College Workload Reallocation Program.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015NIMPA.785..129Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015NIMPA.785..129Y"><span>Development of a three-layer phoswich alpha-beta-gamma imaging detector</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yamamoto, Seiichi; Ishibashi, Hiroyuki</p> <p>2015-06-01</p> <p>For radiation monitoring at the sites of such nuclear power plant accidents as Fukushima Daiichi, radiation detectors are needed not only for gamma photons but also for alpha and beta particles because some nuclear fission products emit beta particles and gamma photons and some nuclear fuels contain plutonium that emits alpha particles. In some applications, imaging detectors are required to detect the distribution of plutonium particles that emit alpha particles and radiocesium in foods that emits beta particles and gamma photons. To solve these requirements, we developed an imaging detector that can measure the distribution of alpha and beta particles as well as gamma photons. The imaging detector consists of three-layer scintillators optically coupled to each other and to a position sensitive photomultiplier tube (PSPMT). The first layer, which is made of a thin plastic scintillator (decay time: 5 ns), detects alpha particles. The second layer, which is made of a thin Gd2SiO5 (GSO) scintillator with 1.5 mol% Ce (decay time: 35 ns), detects beta particles. The third layer made of a thin GSO scintillator with 0.4 mol% Ce (decay time: 70 ns) detects gamma photons. Using pulse shape discrimination, the images of these layers can be separated. The position information is calculated by the Anger principle from 8×8 anode signals from the PSPMT. The images for the alpha and beta particles and the gamma photons are individually formed by the pulse shape discriminations for each layer. We detected alpha particle images in the first layer and beta particle images in the second layer. Gamma photon images were detected in the second and third layers. The spatial resolution for the alpha and beta particles was 1.25 mm FWHM and less than 2 mm FWHM for the gamma photons. We conclude that our developed alpha-beta-gamma imaging detector is promising for imaging applications not only for the environmental monitoring of radionuclides but also for medical and molecular imaging.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011JAP...109j3302M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011JAP...109j3302M"><span>Full characterization of laser-accelerated ion beams using Faraday cup, silicon carbide, and single-crystal diamond detectors</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Margarone, D.; Krása, J.; Giuffrida, L.; Picciotto, A.; Torrisi, L.; Nowak, T.; Musumeci, P.; Velyhan, A.; Prokůpek, J.; Láska, L.; Mocek, T.; Ullschmied, J.; Rus, B.</p> <p>2011-05-01</p> <p>Multi-MeV beams of light ions have been produced using the 300 picosecond, kJ-class iodine laser, operating at the Prague Asterix Laser System facility in Prague. Real-time ion diagnostics have been performed by the use of various time-of-flight (TOF) detectors: ion collectors (ICs) with and without absorber thin films, new prototypes of single-crystal diamond and silicon carbide detectors, and an electrostatic ion mass spectrometer (IEA). In order to suppress the long photopeak induced by soft X-rays and to avoid the overlap with the signal from ultrafast particles, the ICs have been shielded with Al foil filters. The application of large-bandgap semiconductor detectors (>3 eV) ensured cutting of the plasma-emitted visible and soft-UV radiation and enhancing the sensitivity to the very fast proton/ion beams. Employing the IEA spectrometer, various ion species and charge states in the expanding laser-plasma have been determined. Processing of the experimental data based on the TOF technique, including estimation of the plasma fast proton maximum and peak energy, ion beam currents and total charge, total number of fast protons, as well as deconvolution processes, ion stopping power, and ion/photon transmission calculations for the different metallic filters used, are reported.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20040015244&hterms=infrared+temperature+sensor&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dinfrared%2Btemperature%2Bsensor','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20040015244&hterms=infrared+temperature+sensor&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dinfrared%2Btemperature%2Bsensor"><span>The Single Aperture Far-Infrared (SAFIR) Observatory and its Cryogenic Detector Needs</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Benford, Dominic J.; Moseley, S. H.</p> <p>2003-01-01</p> <p>The development of a large, far-infrared telescope in space has taken on a new urgency with breakthroughs in detector technology and recognition of the fundamental importance of the far-infrared spectral region to questions ranging from cosmology to our own Solar System. The Single Aperture Far-InfraRed (SAFIR) Observatory is l0m-class far-infrared observatory that would begin development later in this decade to meet these needs. SAFIR's science goals are driven by the fact that youngest stages of almost all phenomena in the universe are shrouded in absorption by and emission from cool dust that emits strongly in the far-infrared, 20 microns - 1mm. Its operating temperature (4 K) and instrument complement would be optimized to reach the natural sky confusion limit in the far-infrared with diffraction-limited performance down to at least the atmospheric cutoff at 40 microns. This would provide a point source sensitivity improvement of several orders of magnitude over that of SIRTF. In order to achieve this, large arrays of detectors with NEPs ranging from a few to a hundred zeptowatts/sqrt(Hz) are needed. Very low temperature superconducting transition edge sensors and far-infrared "photon counting" detectors are critical technologies requiring development for the SAFIR mission.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29159881','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29159881"><span>Characterization of photon-counting multislit breast tomosynthesis.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Berggren, Karl; Cederström, Björn; Lundqvist, Mats; Fredenberg, Erik</p> <p>2018-02-01</p> <p>It has been shown that breast tomosynthesis may improve sensitivity and specificity compared to two-dimensional mammography, resulting in increased detection-rate of cancers or lowered call-back rates. The purpose of this study is to characterize a spectral photon-counting multislit breast tomosynthesis system that is able to do single-scan spectral imaging with multiple collimated x-ray beams. The system differs in many aspects compared to conventional tomosynthesis using energy-integrating flat-panel detectors. The investigated system was a prototype consisting of a dual-threshold photon-counting detector with 21 collimated line detectors scanning across the compressed breast. A review of the system is done in terms of detector, acquisition geometry, and reconstruction methods. Three reconstruction methods were used, simple back-projection, filtered back-projection and an iterative algebraic reconstruction technique. The image quality was evaluated by measuring the modulation transfer-function (MTF), normalized noise-power spectrum, detective quantum-efficiency (DQE), and artifact spread-function (ASF) on reconstructed spectral tomosynthesis images for a total-energy bin (defined by a low-energy threshold calibrated to remove electronic noise) and for a high-energy bin (with a threshold calibrated to split the spectrum in roughly equal parts). Acquisition was performed using a 29 kVp W/Al x-ray spectrum at a 0.24 mGy exposure. The difference in MTF between the two energy bins was negligible, that is, there was no energy dependence on resolution. The MTF dropped to 50% at 1.5 lp/mm to 2.3 lp/mm in the scan direction and 2.4 lp/mm to 3.3 lp/mm in the slit direction, depending on the reconstruction method. The full width at half maximum of the ASF was found to range from 13.8 mm to 18.0 mm for the different reconstruction methods. The zero-frequency DQE of the system was found to be 0.72. The fraction of counts in the high-energy bin was measured to be 59% of the total detected spectrum. Scantimes ranged from 4 s to 16.5 s depending on voltage and current settings. The characterized system generates spectral tomosynthesis images with a dual-energy photon-counting detector. Measurements show a high DQE, enabling high image quality at a low dose, which is beneficial for low-dose applications such as screening. The single-scan spectral images open up for applications such as quantitative material decomposition and contrast-enhanced tomosynthesis. © 2017 American Association of Physicists in Medicine.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JInst..12C1006S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JInst..12C1006S"><span>A sub-millimeter resolution detector module for small-animal PET applications</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sacco, I.; Dohle, R.; Fischer, P.; Gola, A.; Piemonte, C.; Ritzert, M.</p> <p>2017-01-01</p> <p>We present a gamma detection module optimized for very high resolution PET applications, able to resolve arrays of scintillating crystals with sub-millimeter pitch. The detector is composed of a single ceramic substrate (LTCC): it hosts four flip-chip mounted PETA5 ASICs on the bottom side and an array of SiPM sensors on the top surface, fabricated in HD-RGB technology by FBK. Each chip has 36 channels, for a maximum of 144 readout channels on a sensitive area of about 32 mm × 32 mm. The module is MR-compatible. The thermal decoupling of the readout electronics from the photon sensors is obtained with an efficient internal liquid channel, integrated within the ceramic substrate. Two modules have been designed, based on different SiPM topologies: • Light spreader-based: an array of 12 × 12 SiPMs, with an overall pitch of 2.5 mm, is coupled with a scintillators array using a 1 mm thick glass plate. The light from one crystal is spread over a group of SiPMs, which are read out in parallel using PETA5 internal neighbor logic. • Interpolating SiPM-based: ISiPMs are intrinsic position-sensitive sensors. The photon diodes in the array are connected to one of the four available outputs so that the center of gravity of any bunch of detected photons can be reconstructed using a proper weight function of the read out amplitudes. An array of ISiPMs, each 7.5 mm× 5 mm sized, is directly coupled with the scintillating crystals. Both modules can clearly resolve LYSO arrays with a pitch of only 0.833 mm. The detector can be adjusted for clinical PET, where it has already shown ToF resolution of about 230 ps CRT at FWHM. The module designs, their features and results are described.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19770025926','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19770025926"><span>Development and test of photon-counting microchannel plate detector arrays for use on space telescopes</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Timothy, J. G.</p> <p>1976-01-01</p> <p>The full sensitivity, dynamic range, and photometric stability of microchannel array plates(MCP) are incorporated into a photon-counting detection system for space operations. Components of the system include feedback-free MCP's for high gain and saturated output pulse-height distribution with a stable response; multi-anode readout arrays mounted in proximity focus with the output face of the MCP; and multi-layer ceramic headers to provide electrical interface between the anode array in a sealed detector tube and the associated electronics.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1399638-searching-photon-sector-lorentz-violation-using-gravitational-wave-detectors','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1399638-searching-photon-sector-lorentz-violation-using-gravitational-wave-detectors"><span>Searching for photon-sector Lorentz violation using gravitational-wave detectors</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Kostelecký, V. Alan; Melissinos, Adrian C.; Mewes, Matthew</p> <p>2016-08-04</p> <p>Here, we study the prospects for using interferometers in gravitational-wave detectors as tools to search for photon-sector violations of Lorentz symmetry. Existing interferometers are shown to be exquisitely sensitive to tiny changes in the effective refractive index of light occurring at frequencies around and below the microhertz range, including at the harmonics of the frequencies of the Earth's sidereal rotation and annual revolution relevant for tests of Lorentz symmetry. We use preliminary data obtained by the Laser Interferometer Gravitational-Wave Observatory (LIGO) in 2006-2007 to place constraints on coefficients for Lorentz violation in the photon sector exceeding current limits by aboutmore » four orders of magnitude.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1992ApJ...395..637S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1992ApJ...395..637S"><span>SN 1987A - The impact of greater than 50 MeV gamma-ray luminosity limits on theories of particle acceleration</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sood, R. K.; Waldron, L.; Rochester, G. K.; Sumner, T. J.; Frye, G.; Jenkins, T.; Staubert, R.; Kendziorra, E.; Ubertini, P.; Bazzano, A.</p> <p>1992-08-01</p> <p>Analysis of the data obtained from two flights of a balloonborne gamma-ray detector to observe SN 1987A was completed. The detector, which included a spark chamber to determine the arrival directions of the photons, was sensitive in the energy range 50-500 MeV. The 95 percent confidence upper limit to the flux on day 55 after the explosion has been established to be 1.1 x 10 exp -5 photons/sq cm/s and on day 407 to be 3.4 x 10 exp -5 photons/sq cm/s. These limits are compared with various theoretical predictions.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PhRvL.120t3604D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PhRvL.120t3604D"><span>General Model of Photon-Pair Detection with an Image Sensor</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Defienne, Hugo; Reichert, Matthew; Fleischer, Jason W.</p> <p>2018-05-01</p> <p>We develop an analytic model that relates intensity correlation measurements performed by an image sensor to the properties of photon pairs illuminating it. Experiments using an effective single-photon counting camera, a linear electron-multiplying charge-coupled device camera, and a standard CCD camera confirm the model. The results open the field of quantum optical sensing using conventional detectors.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20173815','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20173815"><span>Analysis of photogenerated random telegraph signal in single electron detector (photo-SET).</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Troudi, M; Sghaier, Na; Kalboussi, A; Souifi, A</p> <p>2010-01-04</p> <p>In this paper, we analyzed slow single traps, situated inside the tunnel oxide of small area single electron photo-detector (photo-SET or nanopixel). The relationship between excitation signal (photons) and random-telegraph-signal (RTS) was evidenced. We demonstrated that photoinduced RTS observed on a photo-detector is due to the interaction between single photogenerated charges that tunnel from dot to dot and current path. Based on RTS analysis for various temperatures, gate bias and optical power we determined the characteristics of these single photogenerated traps: the energy position within the silicon bandgap, capture cross section and the position within the Si/SiO(x = 1.5) interfaces.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22597902-time-resolved-single-photon-detection-module-based-silicon-photomultiplier-novel-building-block-time-correlated-measurement-systems','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22597902-time-resolved-single-photon-detection-module-based-silicon-photomultiplier-novel-building-block-time-correlated-measurement-systems"><span>Time-resolved single-photon detection module based on silicon photomultiplier: A novel building block for time-correlated measurement systems</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Martinenghi, E., E-mail: edoardo.martinenghi@polimi.it; Di Sieno, L.; Contini, D.</p> <p>2016-07-15</p> <p>We present the design and preliminary characterization of the first detection module based on Silicon Photomultiplier (SiPM) tailored for single-photon timing applications. The aim of this work is to demonstrate, thanks to the design of a suitable module, the possibility to easily exploit SiPM in many applications as an interesting detector featuring large active area, similarly to photomultipliers tubes, but keeping the advantages of solid state detectors (high quantum efficiency, low cost, compactness, robustness, low bias voltage, and insensitiveness to magnetic field). The module integrates a cooled SiPM with a total photosensitive area of 1 mm{sup 2} together with themore » suitable avalanche signal read-out circuit, the signal conditioning, the biasing electronics, and a Peltier cooler driver for thermal stabilization. It is able to extract the single-photon timing information with resolution better than 100 ps full-width at half maximum. We verified the effective stabilization in response to external thermal perturbations, thus proving the complete insensitivity of the module to environment temperature variations, which represents a fundamental parameter to profitably use the instrument for real-field applications. We also characterized the single-photon timing resolution, the background noise due to both primary dark count generation and afterpulsing, the single-photon detection efficiency, and the instrument response function shape. The proposed module can become a reliable and cost-effective building block for time-correlated single-photon counting instruments in applications requiring high collection capability of isotropic light and detection efficiency (e.g., fluorescence decay measurements or time-domain diffuse optics systems).« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4667636','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4667636"><span>Planar-integrated single-crystalline perovskite photodetectors</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Saidaminov, Makhsud I.; Adinolfi, Valerio; Comin, Riccardo; Abdelhady, Ahmed L.; Peng, Wei; Dursun, Ibrahim; Yuan, Mingjian; Hoogland, Sjoerd; Sargent, Edward H.; Bakr, Osman M.</p> <p>2015-01-01</p> <p>Hybrid perovskites are promising semiconductors for optoelectronic applications. However, they suffer from morphological disorder that limits their optoelectronic properties and, ultimately, device performance. Recently, perovskite single crystals have been shown to overcome this problem and exhibit impressive improvements: low trap density, low intrinsic carrier concentration, high mobility, and long diffusion length that outperform perovskite-based thin films. These characteristics make the material ideal for realizing photodetection that is simultaneously fast and sensitive; unfortunately, these macroscopic single crystals cannot be grown on a planar substrate, curtailing their potential for optoelectronic integration. Here we produce large-area planar-integrated films made up of large perovskite single crystals. These crystalline films exhibit mobility and diffusion length comparable with those of single crystals. Using this technique, we produced a high-performance light detector showing high gain (above 104 electrons per photon) and high gain-bandwidth product (above 108 Hz) relative to other perovskite-based optical sensors. PMID:26548941</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/21308652-large-aperture-grb-observatory','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/21308652-large-aperture-grb-observatory"><span>the Large Aperture GRB Observatory</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Bertou, Xavier</p> <p>2009-04-30</p> <p>The Large Aperture GRB Observatory (LAGO) aims at the detection of high energy photons from Gamma Ray Bursts (GRB) using the single particle technique (SPT) in ground based water Cherenkov detectors (WCD). To reach a reasonable sensitivity, high altitude mountain sites have been selected in Mexico (Sierra Negra, 4550 m a.s.l.), Bolivia (Chacaltaya, 5300 m a.s.l.) and Venezuela (Merida, 4765 m a.s.l.). We report on the project progresses and the first operation at high altitude, search for bursts in 6 months of preliminary data, as well as search for signal at ground level when satellites report a burst.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27131653','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27131653"><span>CdTe Timepix detectors for single-photon spectroscopy and linear polarimetry of high-flux hard x-ray radiation.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hahn, C; Weber, G; Märtin, R; Höfer, S; Kämpfer, T; Stöhlker, Th</p> <p>2016-04-01</p> <p>Single-photon spectroscopy of pulsed, high-intensity sources of hard X-rays - such as laser-generated plasmas - is often hampered by the pileup of several photons absorbed by the unsegmented, large-volume sensors routinely used for the detection of high-energy radiation. Detectors based on the Timepix chip, with a segmentation pitch of 55 μm and the possibility to be equipped with high-Z sensor chips, constitute an attractive alternative to commonly used passive solutions such as image plates. In this report, we present energy calibration and characterization measurements of such devices. The achievable energy resolution is comparable to that of scintillators for γ spectroscopy. Moreover, we also introduce a simple two-detector Compton polarimeter setup with a polarimeter quality of (98 ± 1)%. Finally, a proof-of-principle polarimetry experiment is discussed, where we studied the linear polarization of bremsstrahlung emitted by a laser-driven plasma and found an indication of the X-ray polarization direction depending on the polarization state of the incident laser pulse.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016RScI...87d3106H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016RScI...87d3106H"><span>CdTe Timepix detectors for single-photon spectroscopy and linear polarimetry of high-flux hard x-ray radiation</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hahn, C.; Weber, G.; Märtin, R.; Höfer, S.; Kämpfer, T.; Stöhlker, Th.</p> <p>2016-04-01</p> <p>Single-photon spectroscopy of pulsed, high-intensity sources of hard X-rays — such as laser-generated plasmas — is often hampered by the pileup of several photons absorbed by the unsegmented, large-volume sensors routinely used for the detection of high-energy radiation. Detectors based on the Timepix chip, with a segmentation pitch of 55 μm and the possibility to be equipped with high-Z sensor chips, constitute an attractive alternative to commonly used passive solutions such as image plates. In this report, we present energy calibration and characterization measurements of such devices. The achievable energy resolution is comparable to that of scintillators for γ spectroscopy. Moreover, we also introduce a simple two-detector Compton polarimeter setup with a polarimeter quality of (98 ± 1)%. Finally, a proof-of-principle polarimetry experiment is discussed, where we studied the linear polarization of bremsstrahlung emitted by a laser-driven plasma and found an indication of the X-ray polarization direction depending on the polarization state of the incident laser pulse.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22597115-cdte-timepix-detectors-single-photon-spectroscopy-linear-polarimetry-high-flux-hard-ray-radiation','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22597115-cdte-timepix-detectors-single-photon-spectroscopy-linear-polarimetry-high-flux-hard-ray-radiation"><span>CdTe Timepix detectors for single-photon spectroscopy and linear polarimetry of high-flux hard x-ray radiation</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Hahn, C., E-mail: christoph.hahn@uni-jena.de; Höfer, S.; Kämpfer, T.</p> <p></p> <p>Single-photon spectroscopy of pulsed, high-intensity sources of hard X-rays — such as laser-generated plasmas — is often hampered by the pileup of several photons absorbed by the unsegmented, large-volume sensors routinely used for the detection of high-energy radiation. Detectors based on the Timepix chip, with a segmentation pitch of 55 μm and the possibility to be equipped with high-Z sensor chips, constitute an attractive alternative to commonly used passive solutions such as image plates. In this report, we present energy calibration and characterization measurements of such devices. The achievable energy resolution is comparable to that of scintillators for γ spectroscopy.more » Moreover, we also introduce a simple two-detector Compton polarimeter setup with a polarimeter quality of (98 ± 1)%. Finally, a proof-of-principle polarimetry experiment is discussed, where we studied the linear polarization of bremsstrahlung emitted by a laser-driven plasma and found an indication of the X-ray polarization direction depending on the polarization state of the incident laser pulse.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1416345-small-fdirc-designs','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1416345-small-fdirc-designs"><span>Small FDIRC designs</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Dey, B.; Ratcliff, B.; Va’vra, J.</p> <p>2017-02-16</p> <p>In this article, we explore the angular resolution limits attainable in small FDIRC designs taking advantage of the new highly pixelated detectors that are now available. Since the basic FDIRC design concept attains its particle separation performance mostly in the angular domain as measured by two-dimensional pixels, this paper relies primarily on a pixel-based analysis, with additional chromatic corrections using the time domain, requiring single photon timing resolution at a level of 100–200 ps only. This approach differs from other modern DIRC design concepts such as TOP or TORCH detectors, whose separation performances rely more strongly on time-dependent analyses. Inmore » conclusion, we find excellent single photon resolution with a geometry where individual bars are coupled to a single plate, which is coupled in turn to a cylindrical lens focusing camera.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1416345','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1416345"><span>Small FDIRC designs</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Dey, B.; Ratcliff, B.; Va’vra, J.</p> <p></p> <p>In this article, we explore the angular resolution limits attainable in small FDIRC designs taking advantage of the new highly pixelated detectors that are now available. Since the basic FDIRC design concept attains its particle separation performance mostly in the angular domain as measured by two-dimensional pixels, this paper relies primarily on a pixel-based analysis, with additional chromatic corrections using the time domain, requiring single photon timing resolution at a level of 100–200 ps only. This approach differs from other modern DIRC design concepts such as TOP or TORCH detectors, whose separation performances rely more strongly on time-dependent analyses. Inmore » conclusion, we find excellent single photon resolution with a geometry where individual bars are coupled to a single plate, which is coupled in turn to a cylindrical lens focusing camera.« less</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APh....79...31Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APh....79...31Z"><span>Cryogenic phonon-scintillation detectors with PMT readout for rare event search experiments</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, X.; Lin, J.; Mikhailik, V. B.; Kraus, H.</p> <p>2016-06-01</p> <p>Cryogenic phonon-scintillation detectors (CPSD) for rare event search experiments require reliable, efficient and robust photon detectors that can resolve individual photons in a scintillation event. We report on a cryogenic detector containing a scintillating crystal, equipped with an NTD-Ge phonon sensor and a photon detector based on a low-temperature photomultiplier tube (PMT) that is powered by a Cockcroft-Walton generator. Here we present results from the characterisation of two detector modules, one with CaWO4, the other with CaMoO4 as scintillator. The energy resolutions (FWHM) at 122.1 keV for the scintillation/PMT channel are 19.9% and 29.7% respectively for CaWO4 and CaMoO4 while the energy resolutions (FWHM) for the phonon channels are 2.17 keV (1.8%) and 0.97 keV (0.79%). These characteristics compare favourably with other CPSDs currently used in cryogenic rare-event search experiments. The detection module with PMT readout benefits from the implementation of a well-understood, reliable, and commercially available component and improved time resolution, while retaining the major advantages of conventional CPSD, such as high sensitivity, resolving power and discrimination ability.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014SPIE.8948E..04K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014SPIE.8948E..04K"><span>Quantitative multiphoton imaging</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>König, Karsten; Weinigel, Martin; Breunig, Hans Georg; Uchugonova, Aisada</p> <p>2014-02-01</p> <p>Certified clinical multiphoton tomographs for label-free multidimensional high-resolution in vivo imaging have been introduced to the market several years ago. Novel tomographs include a flexible 360° scan head attached to a mechanooptical arm for autofluorescence and SHG imaging as well as a CARS module. Non-fluorescent lipids and water, mitochondrial fluorescent NAD(P)H, fluorescent elastin, keratin, and melanin as well as SHG-active collagen can be imaged in vivo with submicron resolution in human skin. Sensitive and rapid detectors allow single photon counting and the construction of 3D maps where the number of detected photons per voxel is depicted. Intratissue concentration profiles from endogenous as well exogenous substances can be generated when the number of detected photons can be correlated with the number of molecules with respect to binding and scattering behavior. Furthermore, the skin ageing index SAAID based on the ratio elastin/collagen as well as the epidermis depth based on the onset of SHG generation can be determined.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PhRvA..97c3836Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PhRvA..97c3836Y"><span>Fundamental limits to single-photon detection determined by quantum coherence and backaction</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Young, Steve M.; Sarovar, Mohan; Léonard, François</p> <p>2018-03-01</p> <p>Single-photon detectors have achieved impressive performance and have led to a number of new scientific discoveries and technological applications. Existing models of photodetectors are semiclassical in that the field-matter interaction is treated perturbatively and time-separated from physical processes in the absorbing matter. An open question is whether a fully quantum detector, whereby the optical field, the optical absorption, and the amplification are considered as one quantum system, could have improved performance. Here we develop a theoretical model of such photodetectors and employ simulations to reveal the critical role played by quantum coherence and amplification backaction in dictating the performance. We show that coherence and backaction lead to trade-offs between detector metrics and also determine optimal system designs through control of the quantum-classical interface. Importantly, we establish the design parameters that result in a ideal photodetector with 100% efficiency, no dark counts, and minimal jitter, thus paving the route for next-generation detectors.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009NIMPA.604..218M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009NIMPA.604..218M"><span>Image charge multi-role and function detectors</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Milnes, James; Lapington, Jon S.; Jagutzki, Ottmar; Howorth, Jon</p> <p>2009-06-01</p> <p>The image charge technique used with microchannel plate imaging tubes provides several operational and practical benefits by serving to isolate the electronic image readout from the detector. The simple dielectric interface between detector and readout provides vacuum isolation and no vacuum electrical feed-throughs are required. Since the readout is mechanically separate from the detector, an image tube of generic design can be simply optimised for various applications by attaching it to different readout devices and electronics. We present imaging performance results using a single image tube with a variety of readout devices suited to differing applications: (a) A four electrode charge division tetra wedge anode, optimised for best spatial resolution in photon counting mode. (b) A cross delay line anode, enabling higher count rate, and the possibility of discriminating near co-incident events, and an event timing resolution of better than 1 ns. (c) A multi-anode readout connected, either to a multi-channel oscilloscope for analogue measurements of fast optical pulses, or alternately, to a multi-channel time correlated single photon counting (TCSPC) card.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013NuPhS.239..258S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013NuPhS.239..258S"><span>UVSiPM: A light detector instrument based on a SiPM sensor working in single photon counting</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sottile, G.; Russo, F.; Agnetta, G.; Belluso, M.; Billotta, S.; Biondo, B.; Bonanno, G.; Catalano, O.; Giarrusso, S.; Grillo, A.; Impiombato, D.; La Rosa, G.; Maccarone, M. C.; Mangano, A.; Marano, D.; Mineo, T.; Segreto, A.; Strazzeri, E.; Timpanaro, M. C.</p> <p>2013-06-01</p> <p>UVSiPM is a light detector designed to measure the intensity of electromagnetic radiation in the 320-900 nm wavelength range. It has been developed in the framework of the ASTRI project whose main goal is the design and construction of an end-to-end Small Size class Telescope prototype for the Cherenkov Telescope Array. The UVSiPM instrument is composed by a multipixel Silicon Photo-Multiplier detector unit coupled to an electronic chain working in single photon counting mode with 10 nanosecond double pulse resolution, and by a disk emulator interface card for computer connection. The detector unit of UVSiPM is of the same kind as the ones forming the camera at the focal plane of the ASTRI prototype. Eventually, the UVSiPM instrument can be equipped with a collimator to regulate its angular aperture. UVSiPM, with its peculiar characteristics, will permit to perform several measurements both in lab and on field, allowing the absolute calibration of the ASTRI prototype.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JInst..12P3001M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JInst..12P3001M"><span>Characterisation of a CZT detector for dosimetry of molecular radiotherapy</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>McAreavey, L. H.; Harkness-Brennan, L. J.; Colosimo, S. J.; Judson, D. S.; Boston, A. J.; Boston, H. C.; Nolan, P. J.; Flux, G. D.; Denis-Bacelar, A. M.; Harris, B.; Radley, I.; Carroll, M.</p> <p>2017-03-01</p> <p>A pixelated cadmium zinc telluride (CZT) detector has been characterised for the purpose of developing a quantitative single photon emission computed tomography (SPECT) system for dosimetry of molecular radiotherapy (MRT). This is the aim of the Dosimetric Imaging with CZT (DEPICT) project, which is a collaboration between the University of Liverpool, The Royal Marsden Hospital, The Royal Liverpool and Broadgreen University Hospital, and the commercial partner Kromek. CZT is a direct band gap semiconductor with superior energy resolution and stopping power compared to scintillator detectors used in current SPECT systems. The inherent detector properties have been investigated and operational parameters such as bias voltage and peaking time have been selected to optimise the performance of the system. Good energy resolution is required to discriminate γ-rays that are scattered as they are emitted from the body and within the collimator, and high photon throughput is essential due to the high activities of isotopes administered in MRT. The system has an average measured electronic noise of 3.31 keV full width at half maximum (FWHM), determined through the use of an internal pulser. The energy response of the system was measured across the energy region of interest 59.5 keV to 364.5 keV and found to be linear. The reverse bias voltage and peaking time producing the optimum FWHM and maximum photon throughput were 600 V and 0.5 μs respectively. The average dead time of the system was measured as 4.84 μs and charge sharing was quantified to be 0.71 % at 59.5 keV . A pixel sensitivity calibration map was created and planar images of the medical imaging isotopes 99mTc and 123I were acquired by coupling the device to a prototype collimator, thereby demonstrating the suitability of the detector for the DEPICT project.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20180000540&hterms=astronomy&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dastronomy','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20180000540&hterms=astronomy&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dastronomy"><span>High-Energy 3D Calorimeter for Use in Gamma-Ray Astronomy Based on Position-Sensitive Virtual Frisch-Grid CdZnTe Detectors</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Moiseev, A.; Bolotnikov, A.; DeGeronimo, G.; Hays, E.; James, R.; Thompson, D.; Vernon, E.</p> <p>2017-01-01</p> <p>We will present a concept for a calorimeter based on a novel approach of 3D position-sensitive virtual Frisch-grid CdZnTe (hereafter CZT) detectors. This calorimeter aims to measure photons with energies from approximately 100 keV to 20 - 50 MeV . The expected energy resolution at 662 keV is better than 1% FWHM, and the photon interaction position-measurement accuracy is better than 1 mm in all 3 dimensions. Each CZT bar is a rectangular prism with typical cross-section from 5 x 5 to 7 x 7 mm2 and length of 2 - 4 cm. The bars are arranged in modules of 4 x 4 bars, and the modules themselves can be assembled into a larger array. The 3D virtual voxel approach solves a long-standing problem with CZT detectors associated with material imperfections that limit the performance and usefulness of relatively thick detectors (i.e., greater than 1 cm). Also, it allows us to use the standard (unselected) grade crystals, while achieving the energy resolution of the premium detectors and thus substantially reducing the cost of the instrument. Such a calorimeter can be successfully used in space telescopes that use Compton scattering of gamma rays, such as AMEGO, serving as part of its calorimeter and providing the position and energy measurement for Compton-scattered photons (like a focal plane detector in a Compton camera). Also, it could provide suitable energy resolution to allow for spectroscopic measurements of gamma ray lines from nuclear decays.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/1439432-high-energy-calorimeter-use-gamma-ray-astronomy-based-position-sensitive-virtual-frisch-grid-cdznte-detectors','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1439432-high-energy-calorimeter-use-gamma-ray-astronomy-based-position-sensitive-virtual-frisch-grid-cdznte-detectors"><span>High-energy 3D calorimeter for use in gamma-ray astronomy based on position-sensitive virtual Frisch-grid CdZnTe detectors</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Moiseev, Alexander; Bolotnikov, A.; DeGeronimo, G.</p> <p></p> <p>Here, we will present a concept for a calorimeter based on a novel approach of 3D position-sensitive virtual Frisch-grid CdZnTe (hereafter CZT) detectors. This calorimeter aims to measure photons with energies from ~100 keV to 20–50 MeV . The expected energy resolution at 662 keV is better than 1% FWHM, and the photon interaction position-measurement accuracy is better than 1 mm in all 3 dimensions. Each CZT bar is a rectangular prism with typical cross-section from 5×5 to 7×7 mm 2 and length of 2–4 cm. The bars are arranged in modules of 4×4 bars, and the modules themselves canmore » be assembled into a larger array. The 3D virtual voxel approach solves a long-standing problem with CZT detectors associated with material imperfections that limit the performance and usefulness of relatively thick detectors (i.e., >1 cm). Also, it allows us to use the standard (unselected) grade crystals, while achieving the energy resolution of the premium detectors and thus substantially reducing the cost of the instrument. Such a calorimeter can be successfully used in space telescopes that use Compton scattering of γ-rays, such as AMEGO, serving as part of its calorimeter and providing the position and energy measurement for Compton-scattered photons (like a focal plane detector in a Compton camera). Also, it could provide suitable energy resolution to allow for spectroscopic measurements of γ-ray lines from nuclear decays.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1439432-high-energy-calorimeter-use-gamma-ray-astronomy-based-position-sensitive-virtual-frisch-grid-cdznte-detectors','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1439432-high-energy-calorimeter-use-gamma-ray-astronomy-based-position-sensitive-virtual-frisch-grid-cdznte-detectors"><span>High-energy 3D calorimeter for use in gamma-ray astronomy based on position-sensitive virtual Frisch-grid CdZnTe detectors</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Moiseev, Alexander; Bolotnikov, A.; DeGeronimo, G.; ...</p> <p>2017-12-19</p> <p>Here, we will present a concept for a calorimeter based on a novel approach of 3D position-sensitive virtual Frisch-grid CdZnTe (hereafter CZT) detectors. This calorimeter aims to measure photons with energies from ~100 keV to 20–50 MeV . The expected energy resolution at 662 keV is better than 1% FWHM, and the photon interaction position-measurement accuracy is better than 1 mm in all 3 dimensions. Each CZT bar is a rectangular prism with typical cross-section from 5×5 to 7×7 mm 2 and length of 2–4 cm. The bars are arranged in modules of 4×4 bars, and the modules themselves canmore » be assembled into a larger array. The 3D virtual voxel approach solves a long-standing problem with CZT detectors associated with material imperfections that limit the performance and usefulness of relatively thick detectors (i.e., >1 cm). Also, it allows us to use the standard (unselected) grade crystals, while achieving the energy resolution of the premium detectors and thus substantially reducing the cost of the instrument. Such a calorimeter can be successfully used in space telescopes that use Compton scattering of γ-rays, such as AMEGO, serving as part of its calorimeter and providing the position and energy measurement for Compton-scattered photons (like a focal plane detector in a Compton camera). Also, it could provide suitable energy resolution to allow for spectroscopic measurements of γ-ray lines from nuclear decays.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3931223','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3931223"><span>ScintSim1: A new Monte Carlo simulation code for transport of optical photons in 2D arrays of scintillation detectors</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Mosleh-Shirazi, Mohammad Amin; Zarrini-Monfared, Zinat; Karbasi, Sareh; Zamani, Ali</p> <p>2014-01-01</p> <p>Two-dimensional (2D) arrays of thick segmented scintillators are of interest as X-ray detectors for both 2D and 3D image-guided radiotherapy (IGRT). Their detection process involves ionizing radiation energy deposition followed by production and transport of optical photons. Only a very limited number of optical Monte Carlo simulation models exist, which has limited the number of modeling studies that have considered both stages of the detection process. We present ScintSim1, an in-house optical Monte Carlo simulation code for 2D arrays of scintillation crystals, developed in the MATLAB programming environment. The code was rewritten and revised based on an existing program for single-element detectors, with the additional capability to model 2D arrays of elements with configurable dimensions, material, etc., The code generates and follows each optical photon history through the detector element (and, in case of cross-talk, the surrounding ones) until it reaches a configurable receptor, or is attenuated. The new model was verified by testing against relevant theoretically known behaviors or quantities and the results of a validated single-element model. For both sets of comparisons, the discrepancies in the calculated quantities were all <1%. The results validate the accuracy of the new code, which is a useful tool in scintillation detector optimization. PMID:24600168</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24600168','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24600168"><span>ScintSim1: A new Monte Carlo simulation code for transport of optical photons in 2D arrays of scintillation detectors.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mosleh-Shirazi, Mohammad Amin; Zarrini-Monfared, Zinat; Karbasi, Sareh; Zamani, Ali</p> <p>2014-01-01</p> <p>Two-dimensional (2D) arrays of thick segmented scintillators are of interest as X-ray detectors for both 2D and 3D image-guided radiotherapy (IGRT). Their detection process involves ionizing radiation energy deposition followed by production and transport of optical photons. Only a very limited number of optical Monte Carlo simulation models exist, which has limited the number of modeling studies that have considered both stages of the detection process. We present ScintSim1, an in-house optical Monte Carlo simulation code for 2D arrays of scintillation crystals, developed in the MATLAB programming environment. The code was rewritten and revised based on an existing program for single-element detectors, with the additional capability to model 2D arrays of elements with configurable dimensions, material, etc., The code generates and follows each optical photon history through the detector element (and, in case of cross-talk, the surrounding ones) until it reaches a configurable receptor, or is attenuated. The new model was verified by testing against relevant theoretically known behaviors or quantities and the results of a validated single-element model. For both sets of comparisons, the discrepancies in the calculated quantities were all <1%. The results validate the accuracy of the new code, which is a useful tool in scintillation detector optimization.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25166078','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25166078"><span>Quantum key distribution over a 72 dB channel loss using ultralow dark count superconducting single-photon detectors.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Shibata, Hiroyuki; Honjo, Toshimori; Shimizu, Kaoru</p> <p>2014-09-01</p> <p>We report the first quantum key distribution (QKD) experiment over a 72 dB channel loss using superconducting nanowire single-photon detectors (SSPD, SNSPD) with the dark count rate (DCR) of 0.01 cps. The DCR of the SSPD, which is dominated by the blackbody radiation at room temperature, is blocked by introducing cold optical bandpass filter. We employ the differential phase shift QKD (DPS-QKD) scheme with a 1 GHz system clock rate. The quantum bit error rate (QBER) below 3% is achieved when the length of the dispersion shifted fiber (DSF) is 336 km (72 dB loss), which is low enough to generate secure keys.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20160014546','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20160014546"><span>Photonic Integrated Circuits</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Krainak, Michael; Merritt, Scott</p> <p>2016-01-01</p> <p>Integrated photonics generally is the integration of multiple lithographically defined photonic and electronic components and devices (e.g. lasers, detectors, waveguides passive structures, modulators, electronic control and optical interconnects) on a single platform with nanometer-scale feature sizes. The development of photonic integrated circuits permits size, weight, power and cost reductions for spacecraft microprocessors, optical communication, processor buses, advanced data processing, and integrated optic science instrument optical systems, subsystems and components. This is particularly critical for small spacecraft platforms. We will give an overview of some NASA applications for integrated photonics.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013APS..APRB14005V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013APS..APRB14005V"><span>Investigation of Avalanche Photodiodes and Multipixel Photon Counters as Light Detectors for Cosmic Rays</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vasquez, Jaime; Saavedra, Arthur; Ramos, Roxana; Tavares, Pablo; Wade, Marcus; Fan, Sewan; Haag, Brooke</p> <p>2013-04-01</p> <p>Through the Research Scholars Institute, students of Hartnell Community College experimented with the application of avalanche photodiodes (APDs) as cosmic ray detectors during the summer of 2012. An APD detector was coupled with a 10 meter long wavelength shifting fiber (WSF) wrapped around a cylindrical plastic scintillator to maximize signal detection. A photomultiplier tube (PMT) was used in conjunction to detect the same scintillation light caused by incoming cosmic rays. Two APD detectors were evaluated to confirm the viability of the setup. In addition, a similar setup was recently utilized to implement multi-pixel photon counters (MPPCs) as readout detectors. Under this configuration, a high gain preamplifier was used to amplify the signals for both the MPPC and APD detectors. We report on our results characterizing the MPPC and discuss its overall performance. Compared to the APD, our findings suggest that the MPPC detector has greater sensitivity in detecting weak light signals, and can be used in place of the PMT for certain counting applications.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007SPIE.6585E..1CJ','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007SPIE.6585E..1CJ"><span>A position- and time-sensitive photon-counting detector with delay- line read-out</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jagutzki, Ottmar; Dangendorf, Volker; Lauck, Ronald; Czasch, Achim; Milnes, James</p> <p>2007-05-01</p> <p>We have developed image intensifier tubes with delay-anode read-out for time- and position-sensitive photon counting. The timing precision is better than 1 ns with 1000x1000 pixels position resolution and up to one megacounts/s processing rate. Large format detectors of 40 and 75 mm active diameter with internal helical-wire delay-line anodes have been produced and specified. A different type of 40 and 25 mm tubes with semi-conducting screen for image charge read-out allow for an economic and robust tube design and for placing the read-out anodes outside the sealed housing. Two types of external delay-line anodes, i.e. pick-up electrodes for the image charge, have been tested. We present tests of the detector and anode performance. Due to the low background this technique is well suited for applications with very low light intensity and especially if a precise time tagging for each photon is required. As an example we present the application of scintillator read-out in time-of-flight (TOF) neutron radiography. Further applications so far are Fluorescence Life-time Microscopy (FLIM) and Astronomy.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PhRvL.120k1301K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PhRvL.120k1301K"><span>Directional Sensitivity in Light-Mass Dark Matter Searches with Single-Electron-Resolution Ionization Detectors</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kadribasic, Fedja; Mirabolfathi, Nader; Nordlund, Kai; Sand, Andrea E.; Holmström, Eero; Djurabekova, Flyura</p> <p>2018-03-01</p> <p>We propose a method using solid state detectors with directional sensitivity to dark matter interactions to detect low-mass weakly interacting massive particles (WIMPs) originating from galactic sources. In spite of a large body of literature for high-mass WIMP detectors with directional sensitivity, no available technique exists to cover WIMPs in the mass range <1 GeV /c2 . We argue that single-electron-resolution semiconductor detectors allow for directional sensitivity once properly calibrated. We examine the commonly used semiconductor material response to these low-mass WIMP interactions.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1072144-toward-real-time-quantum-imaging-single-pixel-camera','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1072144-toward-real-time-quantum-imaging-single-pixel-camera"><span>Toward real-time quantum imaging with a single pixel camera</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Lawrie, B. J.; Pooser, R. C.</p> <p>2013-03-19</p> <p>In this paper, we present a workbench for the study of real-time quantum imaging by measuring the frame-by-frame quantum noise reduction of multi-spatial-mode twin beams generated by four wave mixing in Rb vapor. Exploiting the multiple spatial modes of this squeezed light source, we utilize spatial light modulators to selectively pass macropixels of quantum correlated modes from each of the twin beams to a high quantum efficiency balanced detector. Finally, in low-light-level imaging applications, the ability to measure the quantum correlations between individual spatial modes and macropixels of spatial modes with a single pixel camera will facilitate compressive quantum imagingmore » with sensitivity below the photon shot noise limit.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5711122','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5711122"><span>Clinical radiation therapy measurements with a new commercial synthetic single crystal diamond detector</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Crilly, Richard</p> <p>2014-01-01</p> <p>A commercial version of a synthetic single crystal diamond detector (SCDD) in a Schottky diode configuration was recently released as the new type 60019 microDiamond detector (PTW‐Freiburg, Germany). In this study we investigate the dosimetric properties of this detector to independently confirm that findings from the developing group of the SCDDs still hold true for the commercial version of the SCDDs. We further explore if the use of the microDiamond detector can be expanded to high‐energy photon beams of up to 15 MV and to large field measurements. Measurements were performed with an Elekta Synergy linear accelerator delivering 6, 10, and 15 MV X‐rays, as well as 6, 9, 12, 15, and 20 MeV electron beams. The dependence of the microdiamond detector response on absorbed dose after connecting the detector was investigated. Furthermore, the dark current of the diamond detector was observed after irradiation. Results are compared to similar results from measurements with a diamond detector type 60003. Energy dependency was investigated, as well. Photon depth‐dose curves were measured for field sizes 3×3,10×10, and 30×30cm2. PDDs were measured with the Semiflex type 31010 detector, microLion type 31018 detector, P Diode type 60016, SRS Diode type 60018, and the microDiamond type 60019 detector (all PTW‐Freiburg). Photon profiles were measured at a depth of 10 cm. Electron depth‐dose curves normalized to the dose maximum were measured with the 14×14cm2 electron cone. PDDs were measured with a Markus chamber type 23343, an E Diode type 60017 and the microDiamond type 60019 detector (all PTW‐Freiburg). Profiles were measured with the E Diode and microDiamond at half of D90,D90,D70, and D50 depths and for electron cone sizes of 6×6cm2, 14×14cm2, and 20×20cm2. Within a tolerance of 0.5% detector response of the investigated detector was stable without any preirradiation. After preirradition with approximately 250 cGy the detector response was stable within 0.1%. A dark current after irradiation was not observed. The microDiamond detector shows no energy dependence in high energy photon or electron dosimetry. Electron PDD measurements with the E Diode and microDiamond are in good agreement. However, compared to E Diode measurements, dose values in the bremsstrahlungs region are about 0.5% lower when measured with the microDiamond detector. Markus detector measurements agree with E Diode measurements in the bremsstrahlungs region. For depths larger than dmax, depth‐dose curves of photon beams measured with the microDiamond detector are in close agreement to those measured with the microLion detector for small fields and with those measured with a Semiflex 0.125 cc ionization chamber for large fields. Differences are in the range of 0.25% and less. For profile measurements, microDiamond detector measurements agree well with microLion and P Diode measurements in the high‐dose region of the profile and the penumbra region. For areas outside the open field, P Diode measurements are about 0.5%–1.0% higher than microDiamond and microLion measurements. Thus it becomes evident that the investigated diamond detector (type 60019) is suitable for a wide range of applications in high‐energy photon and electron dosimetry and is interesting for relative, as well as absolute, dosimetry. PACS numbers: 00.06, 80.87 PMID:25493512</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018OptEL..14..129P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018OptEL..14..129P"><span>Dynamic time-correlated single-photon counting laser ranging</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Peng, Huan; Wang, Yu-rong; Meng, Wen-dong; Yan, Pei-qin; Li, Zhao-hui; Li, Chen; Pan, Hai-feng; Wu, Guang</p> <p>2018-03-01</p> <p>We demonstrate a photon counting laser ranging experiment with a four-channel single-photon detector (SPD). The multi-channel SPD improve the counting rate more than 4×107 cps, which makes possible for the distance measurement performed even in daylight. However, the time-correlated single-photon counting (TCSPC) technique cannot distill the signal easily while the fast moving targets are submersed in the strong background. We propose a dynamic TCSPC method for fast moving targets measurement by varying coincidence window in real time. In the experiment, we prove that targets with velocity of 5 km/s can be detected according to the method, while the echo rate is 20% with the background counts of more than 1.2×107 cps.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19790027970&hterms=bybee&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dbybee','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19790027970&hterms=bybee&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dbybee"><span>Multi-anode microchannel arrays</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Timothy, J. G.; Bybee, R. L.</p> <p>1977-01-01</p> <p>A development program is currently being undertaken to produce photon-counting detector arrays which are suitable for use in both ground-based and space-borne instruments and which utilize the full sensitivity, dynamic range and photometric stability of the microchannel array plate (MCP). The construction of the detector arrays and the status of the development program are described.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012NIMPA.695..420G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012NIMPA.695..420G"><span>An acquisition system for CMOS imagers with a genuine 10 Gbit/s bandwidth</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Guérin, C.; Mahroug, J.; Tromeur, W.; Houles, J.; Calabria, P.; Barbier, R.</p> <p>2012-12-01</p> <p>This paper presents a high data throughput acquisition system for pixel detector readout such as CMOS imagers. This CMOS acquisition board offers a genuine 10 Gbit/s bandwidth to the workstation and can provide an on-line and continuous high frame rate imaging capability. On-line processing can be implemented either on the Data Acquisition Board or on the multi-cores workstation depending on the complexity of the algorithms. The different parts composing the acquisition board have been designed to be used first with a single-photon detector called LUSIPHER (800×800 pixels), developed in our laboratory for scientific applications ranging from nano-photonics to adaptive optics. The architecture of the acquisition board is presented and the performances achieved by the produced boards are described. The future developments (hardware and software) concerning the on-line implementation of algorithms dedicated to single-photon imaging are tackled.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1402844','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1402844"><span>Picosecond UV single photon detectors with lateral drift field: Concept and technologies</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Yakimov, M.; Oktyabrsky, S.; Murat, P.</p> <p>2015-09-01</p> <p>Group III–V semiconductor materials are being considered as a Si replacement for advanced logic devices for quite some time. Advances in III–V processing technologies, such as interface and surface passivation, large area deep submicron lithography with high-aspect ratio etching primarily driven by the metal-oxide-semiconductor field-effect transistor development can also be used for other applications. In this paper we will focus on photodetectors with the drift field parallel to the surface. We compare the proposed concept to the state-of-the-art Si-based technology and discuss requirements which need to be satisfied for such detectors to be used in a single photon counting modemore » in blue and ultraviolet spectral region with about 10 ps photon timing resolution essential for numerous applications ranging from high-energy physics to medical imaging.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018NIMPA.893..117A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018NIMPA.893..117A"><span>Cryogenic readout for multiple VUV4 Multi-Pixel Photon Counters in liquid xenon</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Arneodo, F.; Benabderrahmane, M. L.; Bruno, G.; Conicella, V.; Di Giovanni, A.; Fawwaz, O.; Messina, M.; Candela, A.; Franchi, G.</p> <p>2018-06-01</p> <p>We present the performances and characterization of an array made of S13370-3050CN (VUV4 generation) Multi-Pixel Photon Counters manufactured by Hamamatsu and equipped with a low power consumption preamplifier operating at liquid xenon temperature (∼ 175 K). The electronics is designed for the readout of a matrix of maximum dimension of 8 × 8 individual photosensors and it is based on a single operational amplifier. The detector prototype presented in this paper utilizes the Analog Devices AD8011 current feedback operational amplifier, but other models can be used depending on the application. A biasing correction circuit has been implemented for the gain equalization of photosensors operating at different voltages. The results show single photon detection capability making this device a promising choice for future generation of large scale dark matter detectors based on liquid xenon, such as DARWIN.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ApPhA.123..701S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ApPhA.123..701S"><span>Performance of InGaAs short wave infrared avalanche photodetector for low flux imaging</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Singh, Anand; Pal, Ravinder</p> <p>2017-11-01</p> <p>Opto-electronic performance of the InGaAs/i-InGaAs/InP short wavelength infrared focal plane array suitable for high resolution imaging under low flux conditions and ranging is presented. More than 85% quantum efficiency is achieved in the optimized detector structure. Isotropic nature of the wet etching process poses a challenge in maintaining the required control in the small pitch high density detector array. Etching process is developed to achieve low dark current density of 1 nA/cm2 in the detector array with 25 µm pitch at 298 K. Noise equivalent photon performance less than one is achievable showing single photon detection capability. The reported photodiode with low photon flux is suitable for active cum passive imaging, optical information processing and quantum computing applications.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20040074289','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20040074289"><span>The Case for Space-Borne Far-Infrared Line Surveys</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bock, J. J.; Bradford, C. M.; Dragovan, M.; Earle, L.; Glenn, J.; Naylor, B.; Nguyen, H. T.; Zmuidzinas, J.</p> <p>2004-01-01</p> <p>The combination of sensitive direct detectors and a cooled aperture promises orders of magnitude improvement in the sensitivity and survey time for far-infrared and submillimeter spectroscopy compared to existing or planned capabilities. Continuing advances in direct detector technology enable spectroscopy that approaches the background limit available only from space at these wavelengths. Because the spectral confusion limit is significantly lower than the more familiar spatial confusion limit encountered in imaging applications, spectroscopy can be carried out to comparable depth with a significantly smaller aperture. We are developing a novel waveguide-coupled grating spectrometer that disperses radiation into a wide instantaneous bandwidth with moderate resolution (R 1000) in a compact 2-dimensional format. A line survey instrument coupled to a modest cooled single aperture provides an attractive scientific application for spectroscopy with direct detectors. Using a suite of waveguide spectrometers, we can obtain complete coverage over the entire far-infrared and sub-millimeter. This concept requires no moving parts to modulate the optical signal. Such an instrument would be able to conduct a far-infrared line survey 10 6 times faster than planned capabilities, assuming existing detector technology. However, if historical improvements in bolometer sensitivity continue, so that photon-limited sensitivity is obtained, the integration time can be further reduced by 2 to 4 orders of magnitude, depending on wavelength. The line flux sensitivity would be comparable to ALMA, but at shorter wavelengths and with the continuous coverage needed to extract line fluxes for sources at unknown redshifts. For example, this capability would break the current spectroscopic bottleneck in the study of far-infrared galaxies, the recently discovered, rapidly evolving objects abundant at cosmological distances.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007PMB....52..303P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007PMB....52..303P"><span>Monte Carlo simulation of MOSFET detectors for high-energy photon beams using the PENELOPE code</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Panettieri, Vanessa; Amor Duch, Maria; Jornet, Núria; Ginjaume, Mercè; Carrasco, Pablo; Badal, Andreu; Ortega, Xavier; Ribas, Montserrat</p> <p>2007-01-01</p> <p>The aim of this work was the Monte Carlo (MC) simulation of the response of commercially available dosimeters based on metal oxide semiconductor field effect transistors (MOSFETs) for radiotherapeutic photon beams using the PENELOPE code. The studied Thomson&Nielsen TN-502-RD MOSFETs have a very small sensitive area of 0.04 mm2 and a thickness of 0.5 µm which is placed on a flat kapton base and covered by a rounded layer of black epoxy resin. The influence of different metallic and Plastic water™ build-up caps, together with the orientation of the detector have been investigated for the specific application of MOSFET detectors for entrance in vivo dosimetry. Additionally, the energy dependence of MOSFET detectors for different high-energy photon beams (with energy >1.25 MeV) has been calculated. Calculations were carried out for simulated 6 MV and 18 MV x-ray beams generated by a Varian Clinac 1800 linear accelerator, a Co-60 photon beam from a Theratron 780 unit, and monoenergetic photon beams ranging from 2 MeV to 10 MeV. The results of the validation of the simulated photon beams show that the average difference between MC results and reference data is negligible, within 0.3%. MC simulated results of the effect of the build-up caps on the MOSFET response are in good agreement with experimental measurements, within the uncertainties. In particular, for the 18 MV photon beam the response of the detectors under a tungsten cap is 48% higher than for a 2 cm Plastic water™ cap and approximately 26% higher when a brass cap is used. This effect is demonstrated to be caused by positron production in the build-up caps of higher atomic number. This work also shows that the MOSFET detectors produce a higher signal when their rounded side is facing the beam (up to 6%) and that there is a significant variation (up to 50%) in the response of the MOSFET for photon energies in the studied energy range. All the results have shown that the PENELOPE code system can successfully reproduce the response of a detector with such a small active area.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17183143','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17183143"><span>Monte Carlo simulation of MOSFET detectors for high-energy photon beams using the PENELOPE code.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Panettieri, Vanessa; Duch, Maria Amor; Jornet, Núria; Ginjaume, Mercè; Carrasco, Pablo; Badal, Andreu; Ortega, Xavier; Ribas, Montserrat</p> <p>2007-01-07</p> <p>The aim of this work was the Monte Carlo (MC) simulation of the response of commercially available dosimeters based on metal oxide semiconductor field effect transistors (MOSFETs) for radiotherapeutic photon beams using the PENELOPE code. The studied Thomson&Nielsen TN-502-RD MOSFETs have a very small sensitive area of 0.04 mm(2) and a thickness of 0.5 microm which is placed on a flat kapton base and covered by a rounded layer of black epoxy resin. The influence of different metallic and Plastic water build-up caps, together with the orientation of the detector have been investigated for the specific application of MOSFET detectors for entrance in vivo dosimetry. Additionally, the energy dependence of MOSFET detectors for different high-energy photon beams (with energy >1.25 MeV) has been calculated. Calculations were carried out for simulated 6 MV and 18 MV x-ray beams generated by a Varian Clinac 1800 linear accelerator, a Co-60 photon beam from a Theratron 780 unit, and monoenergetic photon beams ranging from 2 MeV to 10 MeV. The results of the validation of the simulated photon beams show that the average difference between MC results and reference data is negligible, within 0.3%. MC simulated results of the effect of the build-up caps on the MOSFET response are in good agreement with experimental measurements, within the uncertainties. In particular, for the 18 MV photon beam the response of the detectors under a tungsten cap is 48% higher than for a 2 cm Plastic water cap and approximately 26% higher when a brass cap is used. This effect is demonstrated to be caused by positron production in the build-up caps of higher atomic number. This work also shows that the MOSFET detectors produce a higher signal when their rounded side is facing the beam (up to 6%) and that there is a significant variation (up to 50%) in the response of the MOSFET for photon energies in the studied energy range. All the results have shown that the PENELOPE code system can successfully reproduce the response of a detector with such a small active area.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AIPC.1126...82C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AIPC.1126...82C"><span>The Simbol-X Anticoincidence</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chabaud, J.; Laurent, P.; Colonges, S.; Barbay, J.; Baronick, J. P.; Benallou, M.; Ferrando, P.; Gilliot, M.; Jaeger, J. J.; Nicolas, M.; Ollivier, E.; Waisbard, J.; Yoffo, B.</p> <p>2009-05-01</p> <p>The Simbol-X telescope will be constitued by two satellites in formation flight. One will host the mirror module and the other the detector payload. This payload will be built with two main detectors able to measure the position, energy and arrival time of each focused photon, between 0.5 and 80 keV. The high sensitivity required by Simbol-X will necessitate low noise background detectors. To achieve this goal, those detectors will be surrounded by a passive graded shield, aimed to stop the out of field of view photons, and an active anticoïncidence system to tag the passing particles. This anticoïncidence detector, whose conception, optimisation and realization are under responsibility of the APC Laboratory, Paris, is based on plastic scintillator plates associated to multi-anodes photo-multipliers via optical fibers. In this paper, we will present the present status of the anticoïncidence system and its expected performances.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22036420-long-range-time-flight-scanning-sensor-based-high-speed-time-correlated-single-photon-counting','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22036420-long-range-time-flight-scanning-sensor-based-high-speed-time-correlated-single-photon-counting"><span>Long-range time-of-flight scanning sensor based on high-speed time-correlated single-photon counting</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>McCarthy, Aongus; Collins, Robert J.; Krichel, Nils J.</p> <p>2009-11-10</p> <p>We describe a scanning time-of-flight system which uses the time-correlated single-photon counting technique to produce three-dimensional depth images of distant, noncooperative surfaces when these targets are illuminated by a kHz to MHz repetition rate pulsed laser source. The data for the scene are acquired using a scanning optical system and an individual single-photon detector. Depth images have been successfully acquired with centimeter xyz resolution, in daylight conditions, for low-signature targets in field trials at distances of up to 325 m using an output illumination with an average optical power of less than 50 {mu}W.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPIE.9896E..0YI','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPIE.9896E..0YI"><span>A current-assisted CMOS photonic sampler with two taps for fluorescence lifetime sensing</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ingelberts, H.; Kuijk, M.</p> <p>2016-04-01</p> <p>Imaging based on fluorescence lifetime is becoming increasingly important in medical and biological applications. State-of- the-art fluorescence lifetime microscopes either use bulky and expensive gated image intensifiers coupled to a CCD or single-photon detectors in a slow scanning setup. Numerous attempts are being made to create compact, cost-effective all- CMOS imagers for fluorescence lifetime sensing. Single-photon avalanche diode (SPAD) imagers can have very good timing resolution and noise characteristics but have low detection efficiency. Another approach is to use CMOS imagers based on demodulation detectors. These imagers can be either very fast or very efficient but it remains a challenge to combine both characteristics. Recently we developed the current-assisted photonic sampler (CAPS) to tackle these problems and in this work, we present a new CAPS with two detection taps that can sample a fluorescence decay in two time windows. In the case of mono-exponential decays, two windows provide enough information to resolve the lifetime. We built an electro-optical setup to characterize the detector and use it for fluorescence lifetime measurements. It consists of a supercontinuum pulsed laser source, an optical system to focus light into the detector and picosecond timing electronics. We describe the structure and operation of the two-tap CAPS and provide basic characterization of the speed performance at multiple wavelengths in the visible and near-infrared spectrum. We also record fluorescence decays of different visible and NIR fluorescent dyes and provide different methods to resolve the fluorescence lifetime.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013SPIE.8993E..2HA','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013SPIE.8993E..2HA"><span>Integrated electronics for time-resolved array of single-photon avalanche diodes</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Acconcia, G.; Crotti, M.; Rech, I.; Ghioni, M.</p> <p>2013-12-01</p> <p>The Time Correlated Single Photon Counting (TCSPC) technique has reached a prominent position among analytical methods employed in a great variety of fields, from medicine and biology (fluorescence spectroscopy) to telemetry (laser ranging) and communication (quantum cryptography). Nevertheless the development of TCSPC acquisition systems featuring both a high number of parallel channels and very high performance is still an open challenge: to satisfy the tight requirements set by the applications, a fully parallel acquisition system requires not only high efficiency single photon detectors but also a read-out electronics specifically designed to obtain the highest performance in conjunction with these sensors. To this aim three main blocks have been designed: a gigahertz bandwidth front-end stage to directly read the custom technology SPAD array avalanche current, a reconfigurable logic to route the detectors output signals to the acquisition chain and an array of time measurement circuits capable of recording the photon arrival times with picoseconds time resolution and a very high linearity. An innovative architecture based on these three circuits will feature a very high number of detectors to perform a truly parallel spatial or spectral analysis and a smaller number of high performance time-to-amplitude converter offering very high performance and a very high conversion frequency while limiting the area occupation and power dissipation. The routing logic will make the dynamic connection between the two arrays possible in order to guarantee that no information gets lost.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21795055','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21795055"><span>15Mcps photon-counting X-ray computed tomography system using a ZnO-MPPC detector and its application to gadolinium imaging.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sato, Eiichi; Sugimura, Shigeaki; Endo, Haruyuki; Oda, Yasuyuki; Abudurexiti, Abulajiang; Hagiwara, Osahiko; Osawa, Akihiro; Matsukiyo, Hiroshi; Enomoto, Toshiyuki; Watanabe, Manabu; Kusachi, Shinya; Sato, Shigehiro; Ogawa, Akira; Onagawa, Jun</p> <p>2012-01-01</p> <p>15Mcps photon-counting X-ray computed tomography (CT) system is a first-generation type and consists of an X-ray generator, a turntable, a translation stage, a two-stage controller, a detector consisting of a 2mm-thick zinc-oxide (ZnO) single-crystal scintillator and an MPPC (multipixel photon counter) module, a counter card (CC), and a personal computer (PC). High-speed photon counting was carried out using the detector in the X-ray CT system. The maximum count rate was 15Mcps (mega counts per second) at a tube voltage of 100kV and a tube current of 1.95mA. Tomography is accomplished by repeated translations and rotations of an object, and projection curves of the object are obtained by the translation. The pulses of the event signal from the module are counted by the CC in conjunction with the PC. The minimum exposure time for obtaining a tomogram was 15min, and photon-counting CT was accomplished using gadolinium-based contrast media. Copyright © 2011 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19960025015','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19960025015"><span>Two-Photon Ghost Image and Interference-Diffraction</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Shih, Y. H.; Sergienko, A. V.; Pittman, T. B.; Strekalov, D. V.; Klyshko, D. N.</p> <p>1996-01-01</p> <p>One of the most surprising consequences of quantum mechanics is entanglement of two or more distance particles. The two-particle entangled state was mathematically formulated by Schrodinger. Based on this unusual quantum behavior, EPR defined their 'physical reality' and then asked the question: 'Can Quantum-Mechanical Description of Physical Reality Be Considered Complete?' One may not appreciate EPR's criterion of physical reality and insist that 'no elementary quantum phenomenon is a phenomenon until it is a recorded phenomenon'. Optical spontaneous parametric down conversion (SPDC) is the most effective mechanism to generate an EPR type entangled two-photon state. In SPDC, an optical beam, called the pump, is incident on a birefringent crystal. The pump is intense enough so that nonlinear effects lead to the conversion of pump photons into pairs of photons, historically called signal and idler. Technically, the SPDC is said to be type-1 or type-2, depending on whether the signal and idler beams have parallel or orthogonal polarization. The SPDC conversion efficiency is typically on the order of 10(exp -9) to 10(exp -11), depending on the SPDC nonlinear material. The signal and idler intensities are extremely low, only single photon detection devices can register them. The quantum entanglement nature of SPDC has been demonstrated in EPR-Bohm experiments and Bell's inequality measurements. The following two experiments were recently performed in our laboratory, which are more closely related to the original 1935 EPR gedankenezperiment. The first experiment is a two-photon optical imaging type experiment, which has been named 'ghost image' by the physics community. The signal and idler beams of SPDC are sent in different directions, so that the detection of the signal and idler photons can be performed by two distant photon counting detectors. An aperture object (mask) is placed in front of the signal photon detector and illuminated by the signal beam through a convex lens. Surprisingly, an image of this aperture is observed in the idler beam, by scanning the idler photon detector in the transverse plane of the idler beam, if we are sure that the idler photon detector 'catches' the 'twin brother' of the signal, which can be easily performed by a coincidence measurement. This effect is even more striking when we found that the object-lens-image relationship satisfies the Gaussian thin lens equation. The second experiment demonstrates two-photon 'ghost' interference-diffraction. The experimental set up is similar to the image experiment, except that rather than a lens and an aperture it is a Young's double-slit (or a single-slit) inserted into the path of the signal beam. We could not find any interference (or diffraction) pattern behind the slit. Surprisingly, an interference (or diffraction) pattern is observed when scanning the detector in the idler beam, if we are sure that the idler photon detector 'catches' the 'twin brother' of the signal.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SPIE10229E..0AA','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SPIE10229E..0AA"><span>High-performance integrated pick-up circuit for SPAD arrays in time-correlated single photon counting</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Acconcia, Giulia; Cominelli, Alessandro; Peronio, Pietro; Rech, Ivan; Ghioni, Massimo</p> <p>2017-05-01</p> <p>The analysis of optical signals by means of Single Photon Avalanche Diodes (SPADs) has been subject to a widespread interest in recent years. The development of multichannel high-performance Time Correlated Single Photon Counting (TCSPC) acquisition systems has undergone a fast trend. Concerning the detector performance, best in class results have been obtained resorting to custom technologies leading also to a strong dependence of the detector timing jitter from the threshold used to determine the onset of the photogenerated current flow. In this scenario, the avalanche current pick-up circuit plays a key role in determining the timing performance of the TCSPC acquisition system, especially with a large array of SPAD detectors because of electrical crosstalk issues. We developed a new current pick-up circuit based on a transimpedance amplifier structure able to extract the timing information from a 50-μm-diameter custom technology SPAD with a state-of-art timing jitter as low as 32ps and suitable to be exploited with SPAD arrays. In this paper we discuss the key features of this structure and we present a new version of the pick-up circuit that also provides quenching capabilities in order to minimize the number of interconnections required, an aspect that becomes more and more crucial in densely integrated systems.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018NIMPA.883...75S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018NIMPA.883...75S"><span>ZnO:Zn/6LiF scintillator-A low afterglow alternative to ZnS:Ag/6LiF for thermal neutron detection</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sykora, G. Jeff; Schooneveld, Erik M.; Rhodes, Nigel J.</p> <p>2018-03-01</p> <p>Current ZnS:Ag/6LiF based scintillation detectors are often count rate limited by the long lifetime afterglow in the scintillator. Despite this drawback, new instruments at neutron scattering facilities, like ISIS in the UK, would still like to use ZnS:Ag/6LiF detectors due to their low gamma sensitivity, high light output, simplicity of detector design and relatively inexpensive production. One particular advantage of ZnS:Ag/6LiF detectors is their ability to provide strong pulse shape discrimination between neutrons and gammas. Despite the advantages of these detectors, it is becoming clear that new and upgraded instruments will be limited by the count rate capability of ZnS:Ag/6LiF, so an alternative scintillator technology with equivalent simplicity is being sought. ZnO:Zn/6LiF is investigated here as a low afterglow alternative to ZnS:Ag/6LiF. Basic scintillation properties of ZnO:Zn are studied and are discussed. Pulse shape discrimination between neutrons and gammas is explored and taken advantage of through simple single photon counting methods. A further step toward a realistic detector for neutron scattering is also taken by fiber coupling the ZnO:Zn/6LiF to a PMT. In an initial study of this fiber coupled configuration, 60Co gamma sensitivity of ∼ 7 × 10-6 is shown and improvements in count rate capability of at least a factor of 6 over ZnS:Ag/6LiF based neutron detectors are demonstrated.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/866621','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/866621"><span>Radiation dose-rate meter using an energy-sensitive counter</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Kopp, Manfred K.</p> <p>1988-01-01</p> <p>A radiation dose-rate meter is provided which uses an energy-sensitive detector and combines charge quantization and pulse-rate measurement to monitor radiation dose rates. The charge from each detected photon is quantized by level-sensitive comparators so that the resulting total output pulse rate is proportional to the dose-rate.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1212317-gamma-ray-momentum-reconstruction-from-compton-electron-trajectories-filtered-back-projection','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1212317-gamma-ray-momentum-reconstruction-from-compton-electron-trajectories-filtered-back-projection"><span>Gamma-ray momentum reconstruction from Compton electron trajectories by filtered back-projection</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Haefner, A.; Gunter, D.; Plimley, B.; ...</p> <p>2014-11-03</p> <p>Gamma-ray imaging utilizing Compton scattering has traditionally relied on measuring coincident gamma-ray interactions to map directional information of the source distribution. This coincidence requirement makes it an inherently inefficient process. We present an approach to gamma-ray reconstruction from Compton scattering that requires only a single electron tracking detector, thus removing the coincidence requirement. From the Compton scattered electron momentum distribution, our algorithm analytically computes the incident photon's correlated direction and energy distributions. Because this method maps the source energy and location, it is useful in applications, where prior information about the source distribution is unknown. We demonstrate this method withmore » electron tracks measured in a scientific Si charge coupled device. While this method was demonstrated with electron tracks in a Si-based detector, it is applicable to any detector that can measure electron direction and energy, or equivalently the electron momentum. For example, it can increase the sensitivity to obtain energy and direction in gas-based systems that suffer from limited efficiency.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007NIMPA.582..175L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007NIMPA.582..175L"><span>CCD detector development projects by the Beamline Technical Support Group at the Advanced Photon Source</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lee, John H.; Fernandez, Patricia; Madden, Tim; Molitsky, Michael; Weizeorick, John</p> <p>2007-11-01</p> <p>This paper will describe two ongoing detector projects being developed by the Beamline Technical Support Group at the Advanced Photon Source (APS) at Argonne National Laboratory (ANL). The first project is the design and construction of two detectors: a single-CCD system and a two-by-two Mosaic CCD camera for Small-Angle X-ray Scattering (SAXS). Both of these systems utilize the Kodak KAF-4320E CCD coupled to fiber optic tapers, custom mechanical hardware, electronics, and software developed at ANL. The second project is a Fast-CCD (FCCD) detector being developed in a collaboration between ANL and Lawrence Berkeley National Laboratory (LBNL). This detector will use ANL-designed readout electronics and a custom LBNL-designed CCD, with 480×480 pixels and 96 outputs, giving very fast readout.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20090002674','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20090002674"><span>Implementation of Complex Signal Processing Algorithms for Position-Sensitive Microcalorimeters</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Smith, Stephen J.</p> <p>2008-01-01</p> <p>We have recently reported on a theoretical digital signal-processing algorithm for improved energy and position resolution in position-sensitive, transition-edge sensor (POST) X-ray detectors [Smith et al., Nucl, lnstr and Meth. A 556 (2006) 2371. PoST's consists of one or more transition-edge sensors (TES's) on a large continuous or pixellated X-ray absorber and are under development as an alternative to arrays of single pixel TES's. PoST's provide a means to increase the field-of-view for the fewest number of read-out channels. In this contribution we extend the theoretical correlated energy position optimal filter (CEPOF) algorithm (originally developed for 2-TES continuous absorber PoST's) to investigate the practical implementation on multi-pixel single TES PoST's or Hydras. We use numerically simulated data for a nine absorber device, which includes realistic detector noise, to demonstrate an iterative scheme that enables convergence on the correct photon absorption position and energy without any a priori assumptions. The position sensitivity of the CEPOF implemented on simulated data agrees very well with the theoretically predicted resolution. We discuss practical issues such as the impact of random arrival phase of the measured data on the performance of the CEPOF. The CEPOF algorithm demonstrates that full-width-at- half-maximum energy resolution of < 8 eV coupled with position-sensitivity down to a few 100 eV should be achievable for a fully optimized device.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4934352','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4934352"><span>Single Photon Counting UV Solar-Blind Detectors Using Silicon and III-Nitride Materials</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Nikzad, Shouleh; Hoenk, Michael; Jewell, April D.; Hennessy, John J.; Carver, Alexander G.; Jones, Todd J.; Goodsall, Timothy M.; Hamden, Erika T.; Suvarna, Puneet; Bulmer, J.; Shahedipour-Sandvik, F.; Charbon, Edoardo; Padmanabhan, Preethi; Hancock, Bruce; Bell, L. Douglas</p> <p>2016-01-01</p> <p>Ultraviolet (UV) studies in astronomy, cosmology, planetary studies, biological and medical applications often require precision detection of faint objects and in many cases require photon-counting detection. We present an overview of two approaches for achieving photon counting in the UV. The first approach involves UV enhancement of photon-counting silicon detectors, including electron multiplying charge-coupled devices and avalanche photodiodes. The approach used here employs molecular beam epitaxy for delta doping and superlattice doping for surface passivation and high UV quantum efficiency. Additional UV enhancements include antireflection (AR) and solar-blind UV bandpass coatings prepared by atomic layer deposition. Quantum efficiency (QE) measurements show QE > 50% in the 100–300 nm range for detectors with simple AR coatings, and QE ≅ 80% at ~206 nm has been shown when more complex AR coatings are used. The second approach is based on avalanche photodiodes in III-nitride materials with high QE and intrinsic solar blindness. PMID:27338399</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_23 --> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27478293','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27478293"><span>RADIANCE AND PHOTON NOISE: Imaging in geometrical optics, physical optics, quantum optics and radiology.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Barrett, Harrison H; Myers, Kyle J; Caucci, Luca</p> <p>2014-08-17</p> <p>A fundamental way of describing a photon-limited imaging system is in terms of a Poisson random process in spatial, angular and wavelength variables. The mean of this random process is the spectral radiance. The principle of conservation of radiance then allows a full characterization of the noise in the image (conditional on viewing a specified object). To elucidate these connections, we first review the definitions and basic properties of radiance as defined in terms of geometrical optics, radiology, physical optics and quantum optics. The propagation and conservation laws for radiance in each of these domains are reviewed. Then we distinguish four categories of imaging detectors that all respond in some way to the incident radiance, including the new category of photon-processing detectors. The relation between the radiance and the statistical properties of the detector output is discussed and related to task-based measures of image quality and the information content of a single detected photon.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4962917','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4962917"><span>RADIANCE AND PHOTON NOISE: Imaging in geometrical optics, physical optics, quantum optics and radiology</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Barrett, Harrison H.; Myers, Kyle J.; Caucci, Luca</p> <p>2016-01-01</p> <p>A fundamental way of describing a photon-limited imaging system is in terms of a Poisson random process in spatial, angular and wavelength variables. The mean of this random process is the spectral radiance. The principle of conservation of radiance then allows a full characterization of the noise in the image (conditional on viewing a specified object). To elucidate these connections, we first review the definitions and basic properties of radiance as defined in terms of geometrical optics, radiology, physical optics and quantum optics. The propagation and conservation laws for radiance in each of these domains are reviewed. Then we distinguish four categories of imaging detectors that all respond in some way to the incident radiance, including the new category of photon-processing detectors. The relation between the radiance and the statistical properties of the detector output is discussed and related to task-based measures of image quality and the information content of a single detected photon. PMID:27478293</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27338399','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27338399"><span>Single Photon Counting UV Solar-Blind Detectors Using Silicon and III-Nitride Materials.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nikzad, Shouleh; Hoenk, Michael; Jewell, April D; Hennessy, John J; Carver, Alexander G; Jones, Todd J; Goodsall, Timothy M; Hamden, Erika T; Suvarna, Puneet; Bulmer, J; Shahedipour-Sandvik, F; Charbon, Edoardo; Padmanabhan, Preethi; Hancock, Bruce; Bell, L Douglas</p> <p>2016-06-21</p> <p>Ultraviolet (UV) studies in astronomy, cosmology, planetary studies, biological and medical applications often require precision detection of faint objects and in many cases require photon-counting detection. We present an overview of two approaches for achieving photon counting in the UV. The first approach involves UV enhancement of photon-counting silicon detectors, including electron multiplying charge-coupled devices and avalanche photodiodes. The approach used here employs molecular beam epitaxy for delta doping and superlattice doping for surface passivation and high UV quantum efficiency. Additional UV enhancements include antireflection (AR) and solar-blind UV bandpass coatings prepared by atomic layer deposition. Quantum efficiency (QE) measurements show QE > 50% in the 100-300 nm range for detectors with simple AR coatings, and QE ≅ 80% at ~206 nm has been shown when more complex AR coatings are used. The second approach is based on avalanche photodiodes in III-nitride materials with high QE and intrinsic solar blindness.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3380817','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3380817"><span>Phasor imaging with a widefield photon-counting detector</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Siegmund, Oswald H. W.; Tremsin, Anton S.; Vallerga, John V.; Weiss, Shimon</p> <p>2012-01-01</p> <p>Abstract. Fluorescence lifetime can be used as a contrast mechanism to distinguish fluorophores for localization or tracking, for studying molecular interactions, binding, assembly, and aggregation, or for observing conformational changes via Förster resonance energy transfer (FRET) between donor and acceptor molecules. Fluorescence lifetime imaging microscopy (FLIM) is thus a powerful technique but its widespread use has been hampered by demanding hardware and software requirements. FLIM data is often analyzed in terms of multicomponent fluorescence lifetime decays, which requires large signals for a good signal-to-noise ratio. This confines the approach to very low frame rates and limits the number of frames which can be acquired before bleaching the sample. Recently, a computationally efficient and intuitive graphical representation, the phasor approach, has been proposed as an alternative method for FLIM data analysis at the ensemble and single-molecule level. In this article, we illustrate the advantages of combining phasor analysis with a widefield time-resolved single photon-counting detector (the H33D detector) for FLIM applications. In particular we show that phasor analysis allows real-time subsecond identification of species by their lifetimes and rapid representation of their spatial distribution, thanks to the parallel acquisition of FLIM information over a wide field of view by the H33D detector. We also discuss possible improvements of the H33D detector’s performance made possible by the simplicity of phasor analysis and its relaxed timing accuracy requirements compared to standard time-correlated single-photon counting (TCSPC) methods. PMID:22352658</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25524646','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25524646"><span>Efficient generation of twin photons at telecom wavelengths with 2.5 GHz repetition-rate-tunable comb laser.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jin, Rui-Bo; Shimizu, Ryosuke; Morohashi, Isao; Wakui, Kentaro; Takeoka, Masahiro; Izumi, Shuro; Sakamoto, Takahide; Fujiwara, Mikio; Yamashita, Taro; Miki, Shigehito; Terai, Hirotaka; Wang, Zhen; Sasaki, Masahide</p> <p>2014-12-19</p> <p>Efficient generation and detection of indistinguishable twin photons are at the core of quantum information and communications technology (Q-ICT). These photons are conventionally generated by spontaneous parametric down conversion (SPDC), which is a probabilistic process, and hence occurs at a limited rate, which restricts wider applications of Q-ICT. To increase the rate, one had to excite SPDC by higher pump power, while it inevitably produced more unwanted multi-photon components, harmfully degrading quantum interference visibility. Here we solve this problem by using recently developed 10 GHz repetition-rate-tunable comb laser, combined with a group-velocity-matched nonlinear crystal, and superconducting nanowire single photon detectors. They operate at telecom wavelengths more efficiently with less noises than conventional schemes, those typically operate at visible and near infrared wavelengths generated by a 76 MHz Ti Sapphire laser and detected by Si detectors. We could show high interference visibilities, which are free from the pump-power induced degradation. Our laser, nonlinear crystal, and detectors constitute a powerful tool box, which will pave a way to implementing quantum photonics circuits with variety of good and low-cost telecom components, and will eventually realize scalable Q-ICT in optical infra-structures.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006amos.confE..10S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006amos.confE..10S"><span>Advanced Photon Counting Imaging Detectors with 100ps Timing for Astronomical and Space Sensing Applications</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Siegmund, O.; Vallerga, J.; Welsh, B.; Rabin, M.; Bloch, J.</p> <p></p> <p>In recent years EAG has implemented a variety of high-resolution, large format, photon-counting MCP detectors in space instrumentation for satellite FUSE, GALEX, IMAGE, SOHO, HST-COS, rocket, and shuttle payloads. Our scheme of choice has been delay line readouts encoding photon event position centroids, by determination of the difference in arrival time of the event charge at the two ends of a distributed resistive-capacitive (RC) delay line. Our most commonly used delay line configuration is the cross delay line (XDL). In its simplest form the delay-line encoding electronics consists of a fast amplifier for each end of the delay line, followed by time-to-digital converters (TDC's). We have achieved resolutions of < 25 μm in tests over 65 mm x 65 mm (3k x3k resolution elements) with excellent linearity. Using high speed TDC's, we have been able to encode event positions for random photon rates of ~1 MHz, while time tagging events using the MCP output signal to better than 100 ps. The unique ability to record photon X,Y,T high fidelity information has advantages over "frame driven" recording devices for some important applications. For example we have built open face and sealed tube cross delay line detectors used for biological fluorescence lifetime imaging, observation of flare stars, orbital satellites and space debris with the GALEX satellite, and time resolved imaging of the Crab Pulsar with a telescope as small as 1m. Although microchannel plate delay line detectors meet many of the imaging and timing demands of various applications, they have limitations. The relatively high gain (107) reduces lifetime and local counting rate, and the fixed delay (10's of ns) makes multiple simultaneous event recording problematic. To overcome these limitations we have begun development of cross strip readout anodes for microchannel plate detectors. The cross strip (XS) anode is a coarse (~0.5 mm) multi-layer metal and ceramic pattern of crossed fingers on an alumina substrate. The charge cloud is matched to the anode period so that it is collected on several neighboring fingers to ensure an accurate event charge centroid can be determined. Each finger of the anode is connected to a low noise charge sensitive amplifier and followed by subsequent A/D conversion of individual strip charge values and a hardware centroid determination of better than 1/100 of a strip are possible. Recently we have commissioned a full 32 x 32 mm XS open face laboratory detector and demonstrated excellent resolution (<6 μm FWHM, ~5k x 5k resolution) using low MCP gain (<5 x 105) thus increasing the MCP local counting rate capacity and overall lifetime of the detector system. In collaboration with Los Alamos National Laboratory, NASA and NSF we are developing high rate (>107 Hz) XS encoding electronics that will encode temporally simultaneous events (non spatially overlapping). Sealed tube XS detectors with GaAs and other photocathodes are also under development to increase detection efficiency and extend the sensitivity range. This type of sensor could be a significant enabling technology for several important applications, including airborne and space situational awareness, high-speed adaptive optics (by increasing the SNR and speed in the control loop), astronomy of transient and time-variable sources, optical metrology, and secure quantum communication (as a receiver of cryptographic keys for three-dimensional imaging), single-molecule fluorescence lifetime microscopy (simultaneously tracking and measuring ~1000 molecules), optical/NIR LIDAR, hybrid mass spectrometry and optical night-time/reconnaissance (LANL-ASPIRE).</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26907952','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26907952"><span>Sub-millimetre DOI detector based on monolithic LYSO and digital SiPM for a dedicated small-animal PET system.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Marcinkowski, Radosław; Mollet, Pieter; Van Holen, Roel; Vandenberghe, Stefaan</p> <p>2016-03-07</p> <p>The mouse model is widely used in a vast range of biomedical and preclinical studies. Thanks to the ability to detect and quantify biological processes at the molecular level in vivo, PET has become a well-established tool in these investigations. However, the need to visualize and quantify radiopharmaceuticals in anatomic structures of millimetre or less requires good spatial resolution and sensitivity from small-animal PET imaging systems.In previous work we have presented a proof-of-concept of a dedicated high-resolution small-animal PET scanner based on thin monolithic scintillator crystals and Digital Photon Counter photosensor. The combination of thin monolithic crystals and MLE positioning algorithm resulted in an excellent spatial resolution of 0.7 mm uniform in the entire field of view (FOV). However, the limitation of the scanner was its low sensitivity due to small thickness of the lutetium-yttrium oxyorthosilicate (LYSO) crystals (2 mm).Here we present an improved detector design for a small-animal PET system that simultaneously achieves higher sensitivity and sustains a sub-millimetre spatial resolution. The proposed detector consists of a 5 mm thick monolithic LYSO crystal optically coupled to a Digital Photon Counter. Mean nearest neighbour (MNN) positioning combined with depth of interaction (DOI) decoding was employed to achieve sub-millimetre spatial resolution. To evaluate detector performance the intrinsic spatial resolution, energy resolution and coincidence resolving time (CRT) were measured. The average intrinsic spatial resolution of the detector was 0.60 mm full-width-at-half-maximum (FWHM). A DOI resolution of 1.66 mm was achieved. The energy resolution was 23% FWHM at 511 keV and CRT of 529 ps were measured. The improved detector design overcomes the sensitivity limitation of the previous design by increasing the nominal sensitivity of the detector block and retains an excellent intrinsic spatial resolution.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007SPIE.6771E..0PT','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007SPIE.6771E..0PT"><span>Germanium and InGaAs/InP SPADs for single-photon detection in the near-infrared</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tosi, Alberto; Dalla Mora, Alberto; Zappa, Franco; Cova, Sergio</p> <p>2007-09-01</p> <p>Single-Photon Avalanche Diodes (SPADs) for near-infrared (800-1700 nm) wavelengths can be manufactured both in InGaAs/InP and in germanium. Recently, new InGaAs/InP SPADs became commercially available with good overall performances, but with the intrinsic bottleneck of strong afterpulsing effect, originated in the InP multiplication layer. At present, germanium technology is not exploited for single-photon detectors, but previous devices demonstrate lower afterpulsing even at very low temperatures and promising dark count rate when employing pure manufacturing process. In this work, we compare germanium and InGaAs/InP SPADs in terms of dark counts, afterpulsing, timing jitter, and quantum efficiency. Eventually, we highlight the motivations for considering germanium as a key material for single-photon counting in the NIR.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002AGUSM.G32A..06D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002AGUSM.G32A..06D"><span>Photon-Counting Laser Altimeters: Aircraft Demonstration and Future Application to Globally Contiguous Spaceborne Topographic Mapping</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Degnan, J. J.</p> <p>2002-05-01</p> <p>We have recently demonstrated a scanning, photon-counting, laser altimeter, which is capable of daylight operations from aircraft cruise altitudes. The instrument measures the times-of-flight of individual photons to deduce the distances between the instrument reference and points on the underlying terrain from which the arriving photons were reflected. By imaging the terrain onto a highly pixellated detector followed by a multi-channel timing receiver, one can make multiple spatially-resolved measurements to the surface within a single laser pulse. The horizontal spatial resolution is limited by the optical projection of a single pixel onto the surface. In short, a 3D image of the terrain within the laser ground spot is obtained on each laser fire, assuming at least one signal photon is recorded by each pixel.. In test flights, a prototype airborne system has successfully recorded few kHz rate, single photon returns from clouds, soils, man-made objects, vegetation, and water surfaces at mid-day under conditions of maximum solar illumination. The system has also demonstrated a capability to resolve volumetrically distributed targets, such as tree canopies, and has performed wave height measurements and shallow water bathymetry over the Chesapeake Bay and Atlantic Ocean. The signal photons were reliably extracted from the solar noise background using an optimized Post-Detection Poisson Filter. The passively Q-switched microchip Nd:YAG laser transmitter measures only 2.25 mm in length and is pumped by a single 1.2 Watt laser diode. The output is frequency-doubled to take advantage of higher detector counting efficiencies and narrower spectral filters available at 532 nm. The transmitter produces a few microjoules of green energy in a subnanosecond pulse at several kilohertz rates. The illuminated ground area is imaged by a 14 cm diameter, diffraction-limited, off-axis telescope onto a segmented anode photomultiplier with up to 16 pixels (4 x4). Each anode segment is input to one channel of "fine" range receiver (5 cm detector-limited resolution), which records the times-of-flight of the individual photons. A parallel "coarse" receiver provides a lower resolution (>75 cm) histogram of atmospheric scatterers between the aircraft and ground and centers the "fine" receiver gate on the last set of returns, permitting the fine receiver to lock onto ground features with no a priori range knowledge. Many scientists have expressed a desire for globally contiguous maps of planetary bodies with few meter horizontal spatial resolutions and decimeter vertical resolutions. By sequentially overcoming various technical hurdles to globally contiguous mapping from space, we are led to a conceptual point design for a spaceborne, 3D imaging lidar, which utilizes low energy, high repetition rate lasers, photon-counting detector arrays, multi-channel timing receivers, and a unique optical scanner.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017APS..DMP.T9007K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017APS..DMP.T9007K"><span>Photon Shot Noise Limited Radio Frequency Electric Field Sensing Using Rydberg Atoms in Vapor Cells</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kumar, Santosh; Jahangiri, Akbar J.; Fan, Haoquan; Kuebler, Harald; Shaffer, James P.</p> <p>2017-04-01</p> <p>We report Rydberg atom-based radio frequency (RF) electrometry measurements at a sensitivity limited by probe laser photon shot noise. By utilizing the phenomena of electromagnetically induced transparency (EIT) in room temperature atomic vapor cells, Rydberg atoms can be used for absolute electric field measurements that significantly surpass conventional methods in utility, sensitivity and accuracy. We show that by using a Mach-Zehnder interferometer with homodyne detection or using frequency modulation spectroscopy with active control of residual amplitude modulation we can achieve a RF electric field detection sensitivity of 3 μVcm-1Hz/2. The sensitivity is limited by photon shot noise on the detector used to readout the probe laser of the EIT scheme. We suggest a new multi-photon scheme that can mitigate the effect of photon shot noise. The multi-photon approach allows an increase in probe laser power without decreasing atomic coherence times that result from collisions caused by an increase in Rydberg atom excitation. The multi-photon scheme also reduces Residual Doppler broadening enabling more accurate measurements to be carried out. This work is supported by DARPA, and NRO.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SPIE10187E..0IP','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SPIE10187E..0IP"><span>Multi-energy x-ray detectors to improve air-cargo security</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Paulus, Caroline; Moulin, Vincent; Perion, Didier; Radisson, Patrick; Verger, Loïck</p> <p>2017-05-01</p> <p>X-ray based systems have been used for decades to screen luggage or cargo to detect illicit material. The advent of energy-sensitive photon-counting x-ray detectors mainly based on Cd(Zn)Te semi-conductor technology enables to improve discrimination between materials compared to single or dual energy technology. The presented work is part of the EUROSKY European project to develop a Single European Secure Air-Cargo Space. "Cargo" context implies the presence of relatively heavy objects and with potentially high atomic number. All the study is conducted on simulations with three different detectors: a typical dual energy sandwich detector, a realistic model of the commercial ME100 multi-energy detector marketed by MULTIX, and a ME100 "Cargo": a not yet existing modified multi-energy version of the ME100 more suited to air freight cargo inspection. Firstly, a comparison on simulated measurements shows the performances improvement of the new multi-energy detectors compared to the current dual-energy one. The relative performances are evaluated according to different criteria of separability or contrast-to-noise ratio and the impact of different parameters is studied (influence of channel number, type of materials and tube voltage). Secondly, performances of multi-energy detectors for overlaps processing in a dual-view system is accessed: the case of orthogonal projections has been studied, one giving dimensional values, the other one providing spectral data to assess effective atomic number. A method of overlap correction has been proposed and extended to multi-layer objects case. Therefore, Calibration and processing based on bi-material decomposition have been adapted for this purpose.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017NIMPA.841..117S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017NIMPA.841..117S"><span>Depth-of-interaction estimates in pixelated scintillator sensors using Monte Carlo techniques</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sharma, Diksha; Sze, Christina; Bhandari, Harish; Nagarkar, Vivek; Badano, Aldo</p> <p>2017-01-01</p> <p>Image quality in thick scintillator detectors can be improved by minimizing parallax errors through depth-of-interaction (DOI) estimation. A novel sensor for low-energy single photon imaging having a thick, transparent, crystalline pixelated micro-columnar CsI:Tl scintillator structure has been described, with possible future application in small-animal single photon emission computed tomography (SPECT) imaging when using thicker structures under development. In order to understand the fundamental limits of this new structure, we introduce cartesianDETECT2, an open-source optical transport package that uses Monte Carlo methods to obtain estimates of DOI for improving spatial resolution of nuclear imaging applications. Optical photon paths are calculated as a function of varying simulation parameters such as columnar surface roughness, bulk, and top-surface absorption. We use scanning electron microscope images to estimate appropriate surface roughness coefficients. Simulation results are analyzed to model and establish patterns between DOI and photon scattering. The effect of varying starting locations of optical photons on the spatial response is studied. Bulk and top-surface absorption fractions were varied to investigate their effect on spatial response as a function of DOI. We investigated the accuracy of our DOI estimation model for a particular screen with various training and testing sets, and for all cases the percent error between the estimated and actual DOI over the majority of the detector thickness was ±5% with a maximum error of up to ±10% at deeper DOIs. In addition, we found that cartesianDETECT2 is computationally five times more efficient than MANTIS. Findings indicate that DOI estimates can be extracted from a double-Gaussian model of the detector response. We observed that our model predicts DOI in pixelated scintillator detectors reasonably well.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017APS..MARA31007I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017APS..MARA31007I"><span>Single photon generation through exciton-exciton annihilation in air-suspended carbon nanotubes</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ishii, Akihiro; Uda, Takushi; Kato, Yuichiro K.</p> <p></p> <p>Carbon nanotubes have great potential for single photon sources as they have stable exciton states even at room temperature and their emission wavelengths cover the telecommunication bands. In recent years, single photon emission from carbon nanotubes has been achieved by creating localized states of excitons. In contrast to such an approach, here we utilize mobile excitons and show that single photons can be generated in air-suspended carbon nanotubes, where exciton diffusion length is as long as several hundred nanometers and exciton-exciton annihilation is efficient. We perform photoluminescence microscopy on as-grown air-suspended carbon nanotubes in order to determine their chirality and suspended length. Photon correlation measurements are performed on nanotube emission at room temperature using a Hanbury-Brown-Twiss setup with InGaAs/InP single photon detectors. We observe antibunching with a clear excitation power dependence, where we obtain g (2) (0) value less than 0.5 at low excitation powers, indicating single photon generation. We show such g (2) (0) data with different chiralities and suspended lengths, and the effects of exciton diffusion on single photon generation processes are discussed. Work supported by KAKENHI (26610080, 16H05962), The Canon Foundation, and MEXT (Photon Frontier Network Program, Nanotechnology Platform). A.I. is supported by MERIT and JSPS Research Fellowship, and T.U. is supported by ALPS.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/867759','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/867759"><span>Method and apparatus for measuring lung density by Compton backscattering</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Loo, Billy W.; Goulding, Frederick S.</p> <p>1991-01-01</p> <p>The density of the lung of a patient suffering from pulmonary edema is monitored by irradiating the lung by a single collimated beam of monochromatic photons and measuring the energies of photons Compton backscattered from the lung by a single high-resolution, high-purity germanium detector. A compact system geometry and a unique data extraction scheme are utilized to monimize systematic errors due to the presence of the chestwall and multiple scattering.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvB..96s5433H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvB..96s5433H"><span>High-energy x-ray diffraction from surfaces and nanoparticles</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hejral, U.; Müller, P.; Shipilin, M.; Gustafson, J.; Franz, D.; Shayduk, R.; Rütt, U.; Zhang, C.; Merte, L. R.; Lundgren, E.; Vonk, V.; Stierle, A.</p> <p>2017-11-01</p> <p>High-energy surface-sensitive x-ray diffraction (HESXRD) is a powerful high-energy photon technique (E > 70 keV) that has in recent years proven to allow a fast data acquisition for the 3D structure determination of surfaces and nanoparticles under in situ and operando conditions. The use of a large-area detector facilitates the direct collection of nearly distortion-free diffraction patterns over a wide q range, including crystal truncation rods perpendicular to the surface and large-area reciprocal space maps from epitaxial nanoparticles, which is not possible in the conventional low-photon energy approach (E =10 -20 keV ). Here, we present a comprehensive mathematical approach, explaining the working principle of HESXRD for both single-crystal surfaces and epitaxial nanostructures on single-crystal supports. The angular calculations used in conventional crystal truncation rod measurements at low-photon energies are adopted for the high-photon-energy regime, illustrating why and to which extent large reciprocal-space areas can be probed in stationary geometry with fixed sample rotation. We discuss how imperfections such as mosaicity and finite domain size aid in sampling a substantial part of reciprocal space without the need of rotating the sample. An exact account is given of the area probed in reciprocal space using such a stationary mode, which is essential for in situ or operando time-resolved experiments on surfaces and nanostructures.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013APS..APR.R9005C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013APS..APR.R9005C"><span>Prompt photon measurements with the PHENIX MPC-EX detector</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Campbell, Sarah</p> <p>2013-04-01</p> <p>The MPC-EX detector is a preshower extension to PHENIX's Muon Piston Calorimeter (MPC). It consists of eight layers of alternating W absorber and Si mini-pad sensors. Located at forward rapidity, 3.1<|η|<3.8, the MPC and MPC-EX access low-x partons in the Au nucleus in p+Au collisions and high-x partons in the projectile in polarized p+p collisions. With the MPC-EX, photon and ^0 separation extends to E>80 GeV, allowing the measurement of prompt photons using the double ratio method. At forward rapidities, prompt photons are dominated by direct photons produced by quark-gluon Compton scattering. In transversely polarized p+p collisions, the prompt photon single spin asymmetry measurement, AN, will resolve the sign discrepancy between the Sivers and twist-3 extractions of AN. In p+Au collisions, the prompt photon RpAu will quantify the level of gluon saturation in the Au nucleus at low-x, 10-3, with a projected systematic error band a factor of four smaller than EPS09's current allowable range. The MPC-EX detector will expand our understanding of gluon nuclear parton distribution functions, providing information about the initial state of heavy ion collisions, and clarify how valence parton's pT and spin correlate to the proton spin.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5090602','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5090602"><span>Mid-infrared materials and devices on a Si platform for optical sensing</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Singh, Vivek; Lin, Pao Tai; Patel, Neil; Lin, Hongtao; Li, Lan; Zou, Yi; Deng, Fei; Ni, Chaoying; Hu, Juejun; Giammarco, James; Soliani, Anna Paola; Zdyrko, Bogdan; Luzinov, Igor; Novak, Spencer; Novak, Jackie; Wachtel, Peter; Danto, Sylvain; Musgraves, J David; Richardson, Kathleen; Kimerling, Lionel C; Agarwal, Anuradha M</p> <p>2014-01-01</p> <p>In this article, we review our recent work on mid-infrared (mid-IR) photonic materials and devices fabricated on silicon for on-chip sensing applications. Pedestal waveguides based on silicon are demonstrated as broadband mid-IR sensors. Our low-loss mid-IR directional couplers demonstrated in SiNx waveguides are useful in differential sensing applications. Photonic crystal cavities and microdisk resonators based on chalcogenide glasses for high sensitivity are also demonstrated as effective mid-IR sensors. Polymer-based functionalization layers, to enhance the sensitivity and selectivity of our sensor devices, are also presented. We discuss the design of mid-IR chalcogenide waveguides integrated with polycrystalline PbTe detectors on a monolithic silicon platform for optical sensing, wherein the use of a low-index spacer layer enables the evanescent coupling of mid-IR light from the waveguides to the detector. Finally, we show the successful fabrication processing of our first prototype mid-IR waveguide-integrated detectors. PMID:27877641</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1415445','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1415445"><span>Method and apparatus for detecting dilute concentrations of radioactive xenon in samples of xenon extracted from the atmosphere</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Warburton, William K.; Hennig, Wolfgang G.</p> <p></p> <p>A method and apparatus for measuring the concentrations of radioxenon isotopes in a gaseous sample wherein the sample cell is surrounded by N sub-detectors that are sensitive to both electrons and to photons from radioxenon decays. Signal processing electronics are provided that can detect events within the sub-detectors, measure their energies, determine whether they arise from electrons or photons, and detect coincidences between events within the same or different sub-detectors. The energies of detected two or three event coincidences are recorded as points in associated two or three-dimensional histograms. Counts within regions of interest in the histograms are then usedmore » to compute estimates of the radioxenon isotope concentrations. The method achieves lower backgrounds and lower minimum detectable concentrations by using smaller detector crystals, eliminating interference between double and triple coincidence decay branches, and segregating double coincidences within the same sub-detector from those occurring between different sub-detectors.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22620873-photon-counting-hexagonal-pixel-array-cdte-detector-spatial-resolution-characteristics-image-guided-interventional-applications','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22620873-photon-counting-hexagonal-pixel-array-cdte-detector-spatial-resolution-characteristics-image-guided-interventional-applications"><span></span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Vedantham, Srinivasan; Shrestha, Suman; Karellas, Andrew, E-mail: andrew.karellas@umassmed.edu</p> <p></p> <p>Purpose: High-resolution, photon-counting, energy-resolved detector with fast-framing capability can facilitate simultaneous acquisition of precontrast and postcontrast images for subtraction angiography without pixel registration artifacts and can facilitate high-resolution real-time imaging during image-guided interventions. Hence, this study was conducted to determine the spatial resolution characteristics of a hexagonal pixel array photon-counting cadmium telluride (CdTe) detector. Methods: A 650 μm thick CdTe Schottky photon-counting detector capable of concurrently acquiring up to two energy-windowed images was operated in a single energy-window mode to include photons of 10 keV or higher. The detector had hexagonal pixels with apothem of 30 μm resulting in pixelmore » pitch of 60 and 51.96 μm along the two orthogonal directions. The detector was characterized at IEC-RQA5 spectral conditions. Linear response of the detector was determined over the air kerma rate relevant to image-guided interventional procedures ranging from 1.3 nGy/frame to 91.4 μGy/frame. Presampled modulation transfer was determined using a tungsten edge test device. The edge-spread function and the finely sampled line spread function accounted for hexagonal sampling, from which the presampled modulation transfer function (MTF) was determined. Since detectors with hexagonal pixels require resampling to square pixels for distortion-free display, the optimal square pixel size was determined by minimizing the root-mean-squared-error of the aperture functions for the square and hexagonal pixels up to the Nyquist limit. Results: At Nyquist frequencies of 8.33 and 9.62 cycles/mm along the apothem and orthogonal to the apothem directions, the modulation factors were 0.397 and 0.228, respectively. For the corresponding axis, the limiting resolution defined as 10% MTF occurred at 13.3 and 12 cycles/mm, respectively. Evaluation of the aperture functions yielded an optimal square pixel size of 54 μm. After resampling to 54 μm square pixels using trilinear interpolation, the presampled MTF at Nyquist frequency of 9.26 cycles/mm was 0.29 and 0.24 along the orthogonal directions and the limiting resolution (10% MTF) occurred at approximately 12 cycles/mm. Visual analysis of a bar pattern image showed the ability to resolve close to 12 line-pairs/mm and qualitative evaluation of a neurovascular nitinol-stent showed the ability to visualize its struts at clinically relevant conditions. Conclusions: Hexagonal pixel array photon-counting CdTe detector provides high spatial resolution in single-photon counting mode. After resampling to optimal square pixel size for distortion-free display, the spatial resolution is preserved. The dual-energy capabilities of the detector could allow for artifact-free subtraction angiography and basis material decomposition. The proposed high-resolution photon-counting detector with energy-resolving capability can be of importance for several image-guided interventional procedures as well as for pediatric applications.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29856401','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29856401"><span>In vivo time-gated diffuse correlation spectroscopy at quasi-null source-detector separation.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pagliazzi, M; Sekar, S Konugolu Venkata; Di Sieno, L; Colombo, L; Durduran, T; Contini, D; Torricelli, A; Pifferi, A; Mora, A Dalla</p> <p>2018-06-01</p> <p>We demonstrate time domain diffuse correlation spectroscopy at quasi-null source-detector separation by using a fast time-gated single-photon avalanche diode without the need of time-tagging electronics. This approach allows for increased photon collection, simplified real-time instrumentation, and reduced probe dimensions. Depth discriminating, quasi-null distance measurement of blood flow in a human subject is presented. We envision the miniaturization and integration of matrices of optical sensors of increased spatial resolution and the enhancement of the contrast of local blood flow changes.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_24 --> <div id="page_25" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="481"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013APS..MARA26005S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013APS..MARA26005S"><span>Observation of quantum entanglement between a photon and a single electron spin confined to an InAs quantum dot</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schaibley, John; Burgers, Alex; McCracken, Greg; Duan, Luming; Berman, Paul; Steel, Duncan; Bracker, Allan; Gammon, Daniel; Sham, Lu</p> <p>2013-03-01</p> <p>A single electron spin confined to a single InAs quantum dot (QD) can serve as a qubit for quantum information processing. By utilizing the QD's optically excited trion states in the presence of an externally applied magnetic field, the QD spin can be rapidly initialized, manipulated and read out. A key resource for quantum information is the ability to entangle distinct QD spins. One approach relies on intermediate spin-photon entanglement to mediate the entanglement between distant QD spin qubits. We report a demonstration of quantum entanglement between a photon's polarization state and the spin state of a single electron confined to a single QD. Here, the photon is spontaneously emitted from one of the QD's trion states. The emitted photon's polarization along the detection axis is entangled with the resulting spin state of the QD. By performing projective measurements on the photon's polarization state and correlating these measurements with the state of the QD spin in two different bases, we obtain a lower bound on the entanglement fidelity of 0.59 (after background correction). The fidelity bound is limited almost entirely by the timing resolution of our single photon detector. The spin-photon entanglement generation rate is 3 ×103 s-1. Supported by: NSF, MURI, AFOSR, DARPA, ARO.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017OptCo.402..193K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017OptCo.402..193K"><span>Coherent state amplification using frequency conversion and a single photon source</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kasture, Sachin</p> <p>2017-11-01</p> <p>Quantum state discrimination lies at the heart of quantum communication and quantum cryptography protocols. Quantum Key Distribution (QKD) using coherent states and homodyne detection has been shown to be a feasible method for quantum communication over long distances. However, this method is still limited because of optical losses. Noiseless coherent state amplification has been proposed as a way to overcome this. Photon addition using stimulated Spontaneous Parametric Down-conversion followed by photon subtraction has been used as a way to implement amplification. However, this process occurs with very low probability which makes it very difficult to implement cascaded stages of amplification due to dark count probability in the single photon detectors used to herald the addition and subtraction of single photons. We discuss a scheme using the χ (2) and χ (3) optical non-linearity and frequency conversion (sum and difference frequency generation) along with a single photon source to implement photon addition. Unlike the photon addition scheme using SPDC, this scheme allows us to tune the success probability at the cost of reduced amplification. The photon statistics of the converted field can be controlled using the power of the pump field and the interaction time.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29497080','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29497080"><span>Quantum Secure Group Communication.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Li, Zheng-Hong; Zubairy, M Suhail; Al-Amri, M</p> <p>2018-03-01</p> <p>We propose a quantum secure group communication protocol for the purpose of sharing the same message among multiple authorized users. Our protocol can remove the need for key management that is needed for the quantum network built on quantum key distribution. Comparing with the secure quantum network based on BB84, we show our protocol is more efficient and securer. Particularly, in the security analysis, we introduce a new way of attack, i.e., the counterfactual quantum attack, which can steal information by "invisible" photons. This invisible photon can reveal a single-photon detector in the photon path without triggering the detector. Moreover, the photon can identify phase operations applied to itself, thereby stealing information. To defeat this counterfactual quantum attack, we propose a quantum multi-user authorization system. It allows us to precisely control the communication time so that the attack can not be completed in time.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013NIMPA.697...59H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013NIMPA.697...59H"><span>Neutron detection with a NaI spectrometer using high-energy photons</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Holm, Philip; Peräjärvi, Kari; Sihvonen, Ari-Pekka; Siiskonen, Teemu; Toivonen, Harri</p> <p>2013-01-01</p> <p>Neutrons can be indirectly detected by high-energy photons. The performance of a 4″×4″×16″ NaI portal monitor was compared to a 3He-based portal monitor with a comparable cross-section of the active volume. Measurements were performed with bare and shielded 252Cf and AmBe sources. With an optimum converter and moderator structure for the NaI detector, the detection efficiencies and minimum detectable activities of the portal monitors were similar. The NaI portal monitor preserved its detection efficiency much better with shielded sources, making the method very interesting for security applications. For heavily shielded sources, the NaI detector was 2-3 times more sensitive than the 3He-based detector.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvP...8b4021M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvP...8b4021M"><span>High-Efficiency Plug-and-Play Source of Heralded Single Photons</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Montaut, Nicola; Sansoni, Linda; Meyer-Scott, Evan; Ricken, Raimund; Quiring, Viktor; Herrmann, Harald; Silberhorn, Christine</p> <p>2017-08-01</p> <p>Reliable generation of single photons is of key importance for fundamental physical experiments and to demonstrate quantum protocols. Waveguide-based photon-pair sources have shown great promise in this regard due to their large spectral tunability, high generation rates, and long temporal coherence of the photon wave packet. However, integrating such sources with fiber-optic networks often results in a strong degradation of performance. We answer this challenge by presenting an alignment-free source of photon pairs in the telecommunications band that maintains heralding efficiency >50 % even after fiber pigtailing, photon separation, and pump suppression. The source combines this outstanding performance in heralding efficiency with a compact, stable, and easy-to-use "plug-and-play" package: one simply connects a laser to the input and detectors to the output, and the source is ready to use. This high performance can be achieved even outside the lab without the need for alignment which makes the source extremely useful for any experiment or demonstration needing heralded single photons.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016FrMat...3...33F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016FrMat...3...33F"><span>Advances on Sensitive Electron-injection based Cameras for Low-Flux, Short-Wave-Infrared Applications</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fathipour, Vala; Bonakdar, Alireza; Mohseni, Hooman</p> <p>2016-08-01</p> <p>Short-wave infrared (SWIR) photon detection has become an essential technology in the modern world. Sensitive SWIR detector arrays with high pixel density, low noise levels and high signal-to-noise-ratios are highly desirable for a variety of applications including biophotonics, light detection and ranging, optical tomography, and astronomical imaging. As such many efforts in infrared detector research are directed towards improving the performance of the photon detectors operating in this wavelength range. We review the history, principle of operation, present status and possible future developments of a sensitive SWIR detector technology, which has demonstrated to be one of the most promising paths to high pixel density focal plane arrays for low flux applications. The so-called electron-injection (EI) detector was demonstrated for the first time (in 2007). It offers an overall system-level sensitivity enhancement compared to the p-i-n diode due to a stable internal avalanche-free gain. The amplification method is inherently low noise, and devices exhibit an excess noise of unity. The detector operates in linear-mode and requires only bias voltage of a few volts. The stable detector characteristics, makes formation of high yield large-format, and high pixel density focal plane arrays less challenging compared to other detector technologies such as avalanche photodetectors. Detector is based on the mature InP material system (InP/InAlAs/GaAsSb/InGaAs), and has a cutoff wavelength of 1700 nm. It takes advantage of a unique three-dimensional geometry and combines the efficiency of a large absorbing volume with the sensitivity of a low-dimensional switch (injector) to sense and amplify signals. Current devices provide high-speed response ~ 5 ns rise time, and low jitter ~ 12 ps at room temperature. The internal dark current density is ~ 1 μA/cm2 at room temperature decreasing to 0.1 nA/cm2 at 160 K. EI detectors have been designed, fabricated, and tested during two generations of development and optimization cycles. We review our imager results using the first-generation detectors. In the second-generation devices, the dark current is reduced by two orders of magnitude, and bandwidth is improved by 4 orders of magnitude. The dark current density of the EI detector is shown to outperform the state-of-the-art technology, the</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120011888','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120011888"><span>Blocking Losses With a Photon Counter</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Moision, Burce E.; Piazzolla, Sabino</p> <p>2012-01-01</p> <p>It was not known how to assess accurately losses in a communications link due to photodetector blocking, a phenomenon wherein a detector is rendered inactive for a short time after the detection of a photon. When used to detect a communications signal, blocking leads to losses relative to an ideal detector, which may be measured as a reduction in the communications rate for a given received signal power, or an increase in the signal power required to support the same communications rate. This work involved characterizing blocking losses for single detectors and arrays of detectors. Blocking may be mitigated by spreading the signal intensity over an array of detectors, reducing the count rate on any one detector. A simple approximation was made to the blocking loss as a function of the probability that a detector is unblocked at a given time, essentially treating the blocking probability as a scaling of the detection efficiency. An exact statistical characterization was derived for a single detector, and an approximation for multiple detectors. This allowed derivation of several accurate approximations to the loss. Methods were also derived to account for a rise time in recovery, and non-uniform illumination due to diffraction and atmospheric distortion of the phase front. It was assumed that the communications signal is intensity modulated and received by an array of photon-counting photodetectors. For the purpose of this analysis, it was assumed that the detectors are ideal, in that they produce a signal that allows one to reproduce the arrival times of electrons, produced either as photoelectrons or from dark noise, exactly. For single detectors, the performance of the maximum-likelihood (ML) receiver in blocking is illustrated, as well as a maximum-count (MC) receiver, that, when receiving a pulse-position-modulated (PPM) signal, selects the symbol corresponding to the slot with the largest electron count. Whereas the MC receiver saturates at high count rates, the ML receiver may not. The loss in capacity, symbol-error-rate (SER), and count-rate were numerically computed. It was shown that the capacity and symbol-error-rate losses track, whereas the count-rate loss does not generally reflect the SER or capacity loss, as the slot-statistics at the detector output are no longer Poisson. It is also shown that the MC receiver loss may be accurately predicted for dead times on the order of a slot.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19820011244','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19820011244"><span>A photon-counting photodiode array detector for far ultraviolet (FUV) astronomy</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hartig, G. F.; Moos, H. W.; Pembroke, R.; Bowers, C.</p> <p>1982-01-01</p> <p>A compact, stable, single-stage intensified photodiode array detector designed for photon-counting, far ultraviolet astronomy applications employs a saturable, 'C'-type MCP (Galileo S. MCP 25-25) to produce high gain pulses with a narrowly peaked pulse height distribution. The P-20 output phosphor exhibits a very short decay time, due to the high current density of the electron pulses. This intensifier is being coupled to a self-scanning linear photodiode array which has a fiber optic input window which allows direct, rigid mechanical coupling with minimal light loss. The array was scanned at a 250 KHz pixel rate. The detector exhibits more than adequate signal-to-noise ratio for pulse counting and event location.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008SPIE.6976E..07S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008SPIE.6976E..07S"><span>High bit rate germanium single photon detectors for 1310nm</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Seamons, J. A.; Carroll, M. S.</p> <p>2008-04-01</p> <p>There is increasing interest in development of high speed, low noise and readily fieldable near infrared (NIR) single photon detectors. InGaAs/InP Avalanche photodiodes (APD) operated in Geiger mode (GM) are a leading choice for NIR due to their preeminence in optical networking. After-pulsing is, however, a primary challenge to operating InGaAs/InP single photon detectors at high frequencies1. After-pulsing is the effect of charge being released from traps that trigger false ("dark") counts. To overcome this problem, hold-off times between detection windows are used to allow the traps to discharge to suppress after-pulsing. The hold-off time represents, however, an upper limit on detection frequency that shows degradation beginning at frequencies of ~100 kHz in InGaAs/InP. Alternatively, germanium (Ge) single photon avalanche photodiodes (SPAD) have been reported to have more than an order of magnitude smaller charge trap densities than InGaAs/InP SPADs2, which allowed them to be successfully operated with passive quenching2 (i.e., no gated hold off times necessary), which is not possible with InGaAs/InP SPADs, indicating a much weaker dark count dependence on hold-off time consistent with fewer charge traps. Despite these encouraging results suggesting a possible higher operating frequency limit for Ge SPADs, little has been reported on Ge SPAD performance at high frequencies presumably because previous work with Ge SPADs has been discouraged by a strong demand to work at 1550 nm. NIR SPADs require cooling, which in the case of Ge SPADs dramatically reduces the quantum efficiency of the Ge at 1550 nm. Recently, however, advantages to working at 1310 nm have been suggested which combined with a need to increase quantum bit rates for quantum key distribution (QKD) motivates examination of Ge detectors performance at very high detection rates where InGaAs/InP does not perform as well. Presented in this paper are measurements of a commercially available Ge APD operated at relatively short GM hold-off times to examine whether there are potential advantages to using Ge for 1310 nm single photon detection. A weaker after-pulsing dependence on frequency is observed offering initial indications of the potential that Ge APDs might provide better high frequency performance.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PhRvL.113s0501T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PhRvL.113s0501T"><span>Measurement-Device-Independent Quantum Key Distribution over 200 km</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tang, Yan-Lin; Yin, Hua-Lei; Chen, Si-Jing; Liu, Yang; Zhang, Wei-Jun; Jiang, Xiao; Zhang, Lu; Wang, Jian; You, Li-Xing; Guan, Jian-Yu; Yang, Dong-Xu; Wang, Zhen; Liang, Hao; Zhang, Zhen; Zhou, Nan; Ma, Xiongfeng; Chen, Teng-Yun; Zhang, Qiang; Pan, Jian-Wei</p> <p>2014-11-01</p> <p>Measurement-device-independent quantum key distribution (MDIQKD) protocol is immune to all attacks on detection and guarantees the information-theoretical security even with imperfect single-photon detectors. Recently, several proof-of-principle demonstrations of MDIQKD have been achieved. Those experiments, although novel, are implemented through limited distance with a key rate less than 0.1 bit /s . Here, by developing a 75 MHz clock rate fully automatic and highly stable system and superconducting nanowire single-photon detectors with detection efficiencies of more than 40%, we extend the secure transmission distance of MDIQKD to 200 km and achieve a secure key rate 3 orders of magnitude higher. These results pave the way towards a quantum network with measurement-device-independent security.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015SPIE.9639E..1HM','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015SPIE.9639E..1HM"><span>G-MAP: a novel night vision system for satellites</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Miletti, Thomas; Maresi, Luca; Zuccaro Marchi, Alessandro; Pontetti, Giorgia</p> <p>2015-10-01</p> <p>The recent developments of single-photon counting array detectors opens the door to a novel type of systems that could be used on satellites in low Earth orbit. One possible application is the detection of non-cooperative vessels or illegal fishing activities. Currently only surveillance operations conducted by Navy or coast guard address this topic, operations by nature costly and with limited coverage. This paper aims to describe the architectural design of a system based on a novel single-photon counting detector, which works mainly in the visible and features fast readout, low noise and a 256x256 matrix of 64 μm-pixels. This detector is positioned in the focal plane of a fully aspheric reflective f/6 telescope, to guarantee state of the art performance. The combination of the two grants optimal ground sampling distance, compatible with the average dimension of a vessel, and overall performance. A radiative analysis of the light transmitted from emission to detection is presented, starting from models of lamps used for attracting fishes and illuminating the deck of the boats. A radiative transfer model is used to estimate the amount of photons emitted by such vessels reaching the detector. Since the novel detector features high framerate and low noise, the system as it is envisaged is able to properly serve the proposed goal. The paper shows the results of a trade-off between instrument parameters and spacecraft operations to maximize the detection probability and the covered sea surface. The status of development of both detector and telescope are also described.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22351157-high-flux-ptychographic-imaging-using-new-pixel-detector-lambda-based-medipix3-readout-chip','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22351157-high-flux-ptychographic-imaging-using-new-pixel-detector-lambda-based-medipix3-readout-chip"><span></span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Wilke, R. N., E-mail: rwilke@gwdg.de; Wallentin, J.; Osterhoff, M.</p> <p></p> <p>The Large Area Medipix-Based Detector Array (Lambda) has been used in a ptychographic imaging experiment on solar-cell nanowires. By using a semi-transparent central stop, the high flux density provided by nano-focusing Kirkpatrick–Baez mirrors can be fully exploited for high-resolution phase reconstructions. Suitable detection systems that are capable of recording high photon count rates with single-photon detection are instrumental for coherent X-ray imaging. The new single-photon-counting pixel detector ‘Lambda’ has been tested in a ptychographic imaging experiment on solar-cell nanowires using Kirkpatrick–Baez-focused 13.8 keV X-rays. Taking advantage of the high count rate of the Lambda and dynamic range expansion by themore » semi-transparent central stop, a high-dynamic-range diffraction signal covering more than seven orders of magnitude has been recorded, which corresponds to a photon flux density of about 10{sup 5} photons nm{sup −2} s{sup −1} or a flux of ∼10{sup 10} photons s{sup −1} on the sample. By comparison with data taken without the semi-transparent central stop, an increase in resolution by a factor of 3–4 is determined: from about 125 nm to about 38 nm for the nanowire and from about 83 nm to about 21 nm for the illuminating wavefield.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24759983','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24759983"><span>Performance of a Medipix3RX spectroscopic pixel detector with a high resistivity gallium arsenide sensor.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hamann, Elias; Koenig, Thomas; Zuber, Marcus; Cecilia, Angelica; Tyazhev, Anton; Tolbanov, Oleg; Procz, Simon; Fauler, Alex; Baumbach, Tilo; Fiederle, Michael</p> <p>2015-03-01</p> <p>High resistivity gallium arsenide is considered a suitable sensor material for spectroscopic X-ray imaging detectors. These sensors typically have thicknesses between a few hundred μm and 1 mm to ensure a high photon detection efficiency. However, for small pixel sizes down to several tens of μm, an effect called charge sharing reduces a detector's spectroscopic performance. The recently developed Medipix3RX readout chip overcomes this limitation by implementing a charge summing circuit, which allows the reconstruction of the full energy information of a photon interaction in a single pixel. In this work, we present the characterization of the first Medipix3RX detector assembly with a 500 μm thick high resistivity, chromium compensated gallium arsenide sensor. We analyze its properties and demonstrate the functionality of the charge summing mode by means of energy response functions recorded at a synchrotron. Furthermore, the imaging properties of the detector, in terms of its modulation transfer functions and signal-to-noise ratios, are investigated. After more than one decade of attempts to establish gallium arsenide as a sensor material for photon counting detectors, our results represent a breakthrough in obtaining detector-grade material. The sensor we introduce is therefore suitable for high resolution X-ray imaging applications.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014SPIE.9033E..3LP','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014SPIE.9033E..3LP"><span>Energy-resolved CT imaging with a photon-counting silicon-strip detector</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Persson, Mats; Huber, Ben; Karlsson, Staffan; Liu, Xuejin; Chen, Han; Xu, Cheng; Yveborg, Moa; Bornefalk, Hans; Danielsson, Mats</p> <p>2014-03-01</p> <p>Photon-counting detectors are promising candidates for use in the next generation of x-ray CT scanners. Among the foreseen benefits are higher spatial resolution, better trade-off between noise and dose, and energy discriminating capabilities. Silicon is an attractive detector material because of its low cost, mature manufacturing process and high hole mobility. However, it is sometimes claimed to be unsuitable for use in computed tomography because of its low absorption efficiency and high fraction of Compton scatter. The purpose of this work is to demonstrate that high-quality energy-resolved CT images can nonetheless be acquired with clinically realistic exposure parameters using a photon-counting silicon-strip detector with eight energy thresholds developed in our group. We use a single detector module, consisting of a linear array of 50 0.5 × 0.4 mm detector elements, to image a phantom in a table-top lab setup. The phantom consists of a plastic cylinder with circular inserts containing water, fat and aqueous solutions of calcium, iodine and gadolinium, in different concentrations. We use basis material decomposition to obtain water, calcium, iodine and gadolinium basis images and demonstrate that these basis images can be used to separate the different materials in the inserts. We also show results showing that the detector has potential for quantitative measurements of substance concentrations.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018ApPhL.112i3106S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018ApPhL.112i3106S"><span>On-demand generation of background-free single photons from a solid-state source</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schweickert, Lucas; Jöns, Klaus D.; Zeuner, Katharina D.; Covre da Silva, Saimon Filipe; Huang, Huiying; Lettner, Thomas; Reindl, Marcus; Zichi, Julien; Trotta, Rinaldo; Rastelli, Armando; Zwiller, Val</p> <p>2018-02-01</p> <p>True on-demand high-repetition-rate single-photon sources are highly sought after for quantum information processing applications. However, any coherently driven two-level quantum system suffers from a finite re-excitation probability under pulsed excitation, causing undesirable multi-photon emission. Here, we present a solid-state source of on-demand single photons yielding a raw second-order coherence of g(2 )(0 )=(7.5 ±1.6 )×10-5 without any background subtraction or data processing. To this date, this is the lowest value of g(2 )(0 ) reported for any single-photon source even compared to the previously reported best background subtracted values. We achieve this result on GaAs/AlGaAs quantum dots embedded in a low-Q planar cavity by employing (i) a two-photon excitation process and (ii) a filtering and detection setup featuring two superconducting single-photon detectors with ultralow dark-count rates of (0.0056 ±0.0007 ) s-1 and (0.017 ±0.001 ) s-1, respectively. Re-excitation processes are dramatically suppressed by (i), while (ii) removes false coincidences resulting in a negligibly low noise floor.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009NIMPA.604..221P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009NIMPA.604..221P"><span>Reborn quadrant anode image sensor</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Prokazov, Yury; Turbin, Evgeny; Vitali, Marco; Herzog, Andreas; Michaelis, Bernd; Zuschratter, Werner; Kemnitz, Klaus</p> <p>2009-06-01</p> <p>We describe a position sensitive photon counting microchannel plate based detector with an improved quadrant anode (QA) readout system. The technique relies on a combination of the four planar elements pattern and an additional fifth electrode. The charge cloud induced by single particle detection is split between the electrodes. The measured charge values uniquely define the position of the initial event. QA has been first published in 1976 by Lampton and Malina. This anode configuration was undeservedly forgotten and its potential has been hardly underestimated. The presented approach extends the operating spatial range to the whole sensitive area of the microchannel plate surface and demonstrates good linearity over the field of view. Therefore, the novel image sensor results in spatial resolution better then 50 μm and count rates up to one million events per second.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4677301','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4677301"><span>A squeezed light source operated under high vacuum</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Wade, Andrew R.; Mansell, Georgia L.; Chua, Sheon S. Y.; Ward, Robert L.; Slagmolen, Bram J. J.; Shaddock, Daniel A.; McClelland, David E.</p> <p>2015-01-01</p> <p>Non-classical squeezed states of light are becoming increasingly important to a range of metrology and other quantum optics applications in cryptography, quantum computation and biophysics. Applications such as improving the sensitivity of advanced gravitational wave detectors and the development of space-based metrology and quantum networks will require robust deployable vacuum-compatible sources. To date non-linear photonics devices operated under high vacuum have been simple single pass systems, testing harmonic generation and the production of classically correlated photon pairs for space-based applications. Here we demonstrate the production under high-vacuum conditions of non-classical squeezed light with an observed 8.6 dB of quantum noise reduction down to 10 Hz. Demonstration of a resonant non-linear optical device, for the generation of squeezed light under vacuum, paves the way to fully exploit the advantages of in-vacuum operations, adapting this technology for deployment into new extreme environments. PMID:26657616</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015NatSR...518052W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015NatSR...518052W"><span>A squeezed light source operated under high vacuum</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wade, Andrew R.; Mansell, Georgia L.; Chua, Sheon S. Y.; Ward, Robert L.; Slagmolen, Bram J. J.; Shaddock, Daniel A.; McClelland, David E.</p> <p>2015-12-01</p> <p>Non-classical squeezed states of light are becoming increasingly important to a range of metrology and other quantum optics applications in cryptography, quantum computation and biophysics. Applications such as improving the sensitivity of advanced gravitational wave detectors and the development of space-based metrology and quantum networks will require robust deployable vacuum-compatible sources. To date non-linear photonics devices operated under high vacuum have been simple single pass systems, testing harmonic generation and the production of classically correlated photon pairs for space-based applications. Here we demonstrate the production under high-vacuum conditions of non-classical squeezed light with an observed 8.6 dB of quantum noise reduction down to 10 Hz. Demonstration of a resonant non-linear optical device, for the generation of squeezed light under vacuum, paves the way to fully exploit the advantages of in-vacuum operations, adapting this technology for deployment into new extreme environments.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3703459','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3703459"><span>Design study of a high-resolution breast-dedicated PET system built from cadmium zinc telluride detectors</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Peng, Hao; Levin, Craig S</p> <p>2013-01-01</p> <p>We studied the performance of a dual-panel positron emission tomography (PET) camera dedicated to breast cancer imaging using Monte Carlo simulation. The proposed system consists of two 4 cm thick 12 × 15 cm2 area cadmium zinc telluride (CZT) panels with adjustable separation, which can be put in close proximity to the breast and/or axillary nodes. Unique characteristics distinguishing the proposed system from previous efforts in breast-dedicated PET instrumentation are the deployment of CZT detectors with superior spatial and energy resolution, using a cross-strip electrode readout scheme to enable 3D positioning of individual photon interaction coordinates in the CZT, which includes directly measured photon depth-of-interaction (DOI), and arranging the detector slabs edge-on with respect to incoming 511 keV photons for high photon sensitivity. The simulation results show that the proposed CZT dual-panel PET system is able to achieve superior performance in terms of photon sensitivity, noise equivalent count rate, spatial resolution and lesion visualization. The proposed system is expected to achieve ~32% photon sensitivity for a point source at the center and a 4 cm panel separation. For a simplified breast phantom adjacent to heart and torso compartments, the peak noise equivalent count (NEC) rate is predicted to be ~94.2 kcts s−1 (breast volume: 720 cm3 and activity concentration: 3.7 kBq cm−3) for a ~10% energy window around 511 keV and ~8 ns coincidence time window. The system achieves 1 mm intrinsic spatial resolution anywhere between the two panels with a 4 cm panel separation if the detectors have DOI resolution less than 2 mm. For a 3 mm DOI resolution, the system exhibits excellent sphere resolution uniformity (σrms/mean) ≤ 10%) across a 4 cm width FOV. Simulation results indicate that the system exhibits superior hot sphere visualization and is expected to visualize 2 mm diameter spheres with a 5:1 activity concentration ratio within roughly 7 min imaging time. Furthermore, we observe that the degree of spatial resolution degradation along the direction orthogonal to the two panels that is typical of a limited angle tomography configuration is mitigated by having high-resolution DOI capabilities that enable more accurate positioning of oblique response lines. PMID:20400807</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..APRU17001I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..APRU17001I"><span>First Results from the DUNE 35-ton Prototype using Cosmics</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Insler, Jonathan; DUNE Collaboration</p> <p>2016-03-01</p> <p>The 35-ton prototype for the Deep Underground Neutrino Experiment (DUNE) Far Detector is a single-phase liquid argon time projection chamber (LAr-TPC) integrated detector that will take cosmics data for a two month run beginning in February 2016. The 35-ton prototype will characterize DUNE's Far Detector technology performance and provide a sample of real data for DUNE reconstruction algorithms. The 35-ton prototype has two drift volumes of lengths 2.23 m and 0.23 m on either side of its anode plane assembly (APA) and makes use of wire planes with wrapped wires and a photon detection system (PDS) utilizing photon detection panels read out by silicon photomultipliers (SiPMs). Data from the 35-ton LAr detector are expected to provide rich information on scintillation light and charged particle tracks. We present a preliminary analysis of cosmics data taken with the 35-ton detector with a focus on stopping muons.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_25 --> <div class="footer-extlink text-muted" style="margin-bottom:1rem; text-align:center;">Some links on this page may take you to non-federal websites. 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