Sample records for gain photon detection

  1. Controlling gain one photon at a time

    PubMed Central

    Schwartz, Gregory W; Rieke, Fred

    2013-01-01

    Adaptation is a salient property of sensory processing. All adaptational or gain control mechanisms face the challenge of obtaining a reliable estimate of the property of the input to be adapted to and obtaining this estimate sufficiently rapidly to be useful. Here, we explore how the primate retina balances the need to change gain rapidly and reliably when photons arrive rarely at individual rod photoreceptors. We find that the weakest backgrounds that decrease the gain of the retinal output signals are similar to those that increase human behavioral threshold, and identify a novel site of gain control in the retinal circuitry. Thus, surprisingly, the gain of retinal signals begins to decrease essentially as soon as background lights are detectable; under these conditions, gain control does not rely on a highly averaged estimate of the photon count, but instead signals from individual photon absorptions trigger changes in gain. DOI: http://dx.doi.org/10.7554/eLife.00467.001 PMID:23682314

  2. Direct detection of a single photon by humans

    PubMed Central

    Tinsley, Jonathan N.; Molodtsov, Maxim I.; Prevedel, Robert; Wartmann, David; Espigulé-Pons, Jofre; Lauwers, Mattias; Vaziri, Alipasha

    2016-01-01

    Despite investigations for over 70 years, the absolute limits of human vision have remained unclear. Rod cells respond to individual photons, yet whether a single-photon incident on the eye can be perceived by a human subject has remained a fundamental open question. Here we report that humans can detect a single-photon incident on the cornea with a probability significantly above chance. This was achieved by implementing a combination of a psychophysics procedure with a quantum light source that can generate single-photon states of light. We further discover that the probability of reporting a single photon is modulated by the presence of an earlier photon, suggesting a priming process that temporarily enhances the effective gain of the visual system on the timescale of seconds. PMID:27434854

  3. Single photons from a gain medium below threshold

    NASA Astrophysics Data System (ADS)

    Ghosh, Sanjib; Liew, Timothy C. H.

    2018-06-01

    The emission from a nonlinear photonic mode coupled weakly to a gain medium operating below threshold is predicted to exhibit antibunching. In the steady state regime, analytical solutions for the relevant observable quantities are found in accurate agreement with exact numerical results. Under pulsed excitation, the unequal time second-order correlation function demonstrates the triggered probabilistic generation of single photons well separated in time.

  4. Brillouin gain enhancement in nano-scale photonic waveguide

    NASA Astrophysics Data System (ADS)

    Nouri Jouybari, Soodabeh

    2018-05-01

    The enhancement of stimulated Brillouin scattering in nano-scale waveguides has a great contribution in the improvement of the photonic devices technology. The key factors in Brillouin gain are the electrostriction force and radiation pressure generated by optical waves in the waveguide. In this article, we have proposed a new scheme of nano-scale waveguide in which the Brillouin gain is considerably improved compared to the previously-reported schemes. The role of radiation pressure in the Brillouin gain was much higher than the role of the electrostriction force. The Brillouin gain strongly depends on the structural parameters of the waveguide and the maximum value of 12127 W-1 m-1 is obtained for the Brillouin gain.

  5. Photon counting, censor corrections, and lifetime imaging for improved detection in two-photon microscopy

    PubMed Central

    Driscoll, Jonathan D.; Shih, Andy Y.; Iyengar, Satish; Field, Jeffrey J.; White, G. Allen; Squier, Jeffrey A.; Cauwenberghs, Gert

    2011-01-01

    We present a high-speed photon counter for use with two-photon microscopy. Counting pulses of photocurrent, as opposed to analog integration, maximizes the signal-to-noise ratio so long as the uncertainty in the count does not exceed the gain-noise of the photodetector. Our system extends this improvement through an estimate of the count that corrects for the censored period after detection of an emission event. The same system can be rapidly reconfigured in software for fluorescence lifetime imaging, which we illustrate by distinguishing between two spectrally similar fluorophores in an in vivo model of microstroke. PMID:21471395

  6. Channel-capacity gain in entanglement-assisted communication protocols based exclusively on linear optics, single-photon inputs, and coincidence photon counting

    DOE PAGES

    Lougovski, P.; Uskov, D. B.

    2015-08-04

    Entanglement can effectively increase communication channel capacity as evidenced by dense coding that predicts a capacity gain of 1 bit when compared to entanglement-free protocols. However, dense coding relies on Bell states and when implemented using photons the capacity gain is bounded by 0.585 bits due to one's inability to discriminate between the four optically encoded Bell states. In this research we study the following question: Are there alternative entanglement-assisted protocols that rely only on linear optics, coincidence photon counting, and separable single-photon input states and at the same time provide a greater capacity gain than 0.585 bits? In thismore » study, we show that besides the Bell states there is a class of bipartite four-mode two-photon entangled states that facilitate an increase in channel capacity. We also discuss how the proposed scheme can be generalized to the case of two-photon N-mode entangled states for N=6,8.« less

  7. Random Photon Absorption Model Elucidates How Early Gain Control in Fly Photoreceptors Arises from Quantal Sampling

    PubMed Central

    Song, Zhuoyi; Zhou, Yu; Juusola, Mikko

    2016-01-01

    Many diurnal photoreceptors encode vast real-world light changes effectively, but how this performance originates from photon sampling is unclear. A 4-module biophysically-realistic fly photoreceptor model, in which information capture is limited by the number of its sampling units (microvilli) and their photon-hit recovery time (refractoriness), can accurately simulate real recordings and their information content. However, sublinear summation in quantum bump production (quantum-gain-nonlinearity) may also cause adaptation by reducing the bump/photon gain when multiple photons hit the same microvillus simultaneously. Here, we use a Random Photon Absorption Model (RandPAM), which is the 1st module of the 4-module fly photoreceptor model, to quantify the contribution of quantum-gain-nonlinearity in light adaptation. We show how quantum-gain-nonlinearity already results from photon sampling alone. In the extreme case, when two or more simultaneous photon-hits reduce to a single sublinear value, quantum-gain-nonlinearity is preset before the phototransduction reactions adapt the quantum bump waveform. However, the contribution of quantum-gain-nonlinearity in light adaptation depends upon the likelihood of multi-photon-hits, which is strictly determined by the number of microvilli and light intensity. Specifically, its contribution to light-adaptation is marginal (≤ 1%) in fly photoreceptors with many thousands of microvilli, because the probability of simultaneous multi-photon-hits on any one microvillus is low even during daylight conditions. However, in cells with fewer sampling units, the impact of quantum-gain-nonlinearity increases with brightening light. PMID:27445779

  8. Stimulated Raman spectroscopy and nanoscopy of molecules using near field photon induced forces without resonant electronic enhancement gain

    NASA Astrophysics Data System (ADS)

    Tamma, Venkata Ananth; Huang, Fei; Nowak, Derek; Kumar Wickramasinghe, H.

    2016-06-01

    We report on stimulated Raman spectroscopy and nanoscopy of molecules, excited without resonant electronic enhancement gain, and recorded using near field photon induced forces. Photon-induced interaction forces between the sharp metal coated silicon tip of an Atomic Force Microscope (AFM) and a sample resulting from stimulated Raman excitation were detected. We controlled the tip to sample spacing using the higher order flexural eigenmodes of the AFM cantilever, enabling the tip to come very close to the sample. As a result, the detection sensitivity was increased compared with previous work on Raman force microscopy. Raman vibrational spectra of azobenzene thiol and l-phenylalanine were measured and found to agree well with published results. Near-field force detection eliminates the need for far-field optical spectrometer detection. Recorded images show spatial resolution far below the optical diffraction limit. Further optimization and use of ultrafast pulsed lasers could push the detection sensitivity towards the single molecule limit.

  9. Stimulated Raman spectroscopy and nanoscopy of molecules using near field photon induced forces without resonant electronic enhancement gain

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

    Tamma, Venkata Ananth; Huang, Fei; Kumar Wickramasinghe, H., E-mail: hkwick@uci.edu

    We report on stimulated Raman spectroscopy and nanoscopy of molecules, excited without resonant electronic enhancement gain, and recorded using near field photon induced forces. Photon-induced interaction forces between the sharp metal coated silicon tip of an Atomic Force Microscope (AFM) and a sample resulting from stimulated Raman excitation were detected. We controlled the tip to sample spacing using the higher order flexural eigenmodes of the AFM cantilever, enabling the tip to come very close to the sample. As a result, the detection sensitivity was increased compared with previous work on Raman force microscopy. Raman vibrational spectra of azobenzene thiol andmore » l-phenylalanine were measured and found to agree well with published results. Near-field force detection eliminates the need for far-field optical spectrometer detection. Recorded images show spatial resolution far below the optical diffraction limit. Further optimization and use of ultrafast pulsed lasers could push the detection sensitivity towards the single molecule limit.« less

  10. Development of a Photon Counting System for Differential Lidar Signal Detection

    NASA Technical Reports Server (NTRS)

    Elsayed-Ali, Hani

    1997-01-01

    Photon counting has been chosen as a means to extend the detection range of current airborne DIAL ozone measurements. Lidar backscattered return signals from the on and off-line lasers experience a significant exponential decay. To extract further data from the decaying ozone return signals, photon counting will be used to measure the low light levels, thus extending the detection range. In this application, photon counting will extend signal measurement where the analog return signal is too weak. The current analog measurement range is limited to approximately 25 kilometers from an aircraft flying at 12 kilometers. Photon counting will be able to exceed the current measurement range so as to follow the mid-latitude model of ozone density as a function of height. This report describes the development of a photon counting system. The initial development phase begins with detailed evaluation of individual photomultiplier tubes. The PMT qualities investigated are noise count rates, single electron response peaks, voltage versus gain values, saturation effects, and output signal linearity. These evaluations are followed by analysis of two distinctive tube base gating schemes. The next phase is to construct and operate a photon counting system in a laboratory environment. The laboratory counting simulations are used to determine optimum discriminator setpoints and to continue further evaluations of PMT properties. The final step in the photon counting system evaluation process is the compiling of photon counting measurements on the existing ozone DIAL laser system.

  11. Range detection using entangled optical photons

    NASA Astrophysics Data System (ADS)

    Brandsema, Matthew J.; Narayanan, Ram M.; Lanzagorta, Marco

    2015-05-01

    Quantum radar is an emerging field that shows a lot of promise in providing significantly improved resolution compared to its classical radar counterpart. The key to this kind of resolution lies in the correlations created from the entanglement of the photons being used. Currently, the technology available only supports quantum radar implementation and validation in the optical regime, as opposed to the microwave regime, because microwave photons have very low energy compared to optical photons. Furthermore, there currently do not exist practical single photon detectors and generators in the microwave spectrum. Viable applications in the optical regime include deep sea target detection and high resolution detection in space. In this paper, we propose a conceptual architecture of a quantum radar which uses entangled optical photons based on Spontaneous Parametric Down Conversion (SPDC) methods. After the entangled photons are created and emerge from the crystal, the idler photon is detected very shortly thereafter. At the same time, the signal photon is sent out towards the target and upon its reflection will impinge on the detector of the radar. From these two measurements, correlation data processing is done to obtain the distance of the target away from the radar. Various simulations are then shown to display the resolution that is possible.

  12. 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.

  13. Photon Counting Using Edge-Detection Algorithm

    NASA Technical Reports Server (NTRS)

    Gin, Jonathan W.; Nguyen, Danh H.; Farr, William H.

    2010-01-01

    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

  14. COMPACT NON-CONTACT TOTAL EMISSION DETECTION FOR IN-VIVO MULTI-PHOTON EXCITATION MICROSCOPY

    PubMed Central

    Glancy, Brian; Karamzadeh, Nader S.; Gandjbakhche, Amir H.; Redford, Glen; Kilborn, Karl; Knutson, Jay R.; Balaban, Robert S.

    2014-01-01

    Summary We describe a compact, non-contact design for a Total Emission Detection (c-TED) system for intra-vital multi-photon imaging. To conform to a standard upright two-photon microscope design, this system uses a parabolic mirror surrounding a standard microscope objective in concert with an optical path that does not interfere with normal microscope operation. The non-contact design of this device allows for maximal light collection without disrupting the physiology of the specimen being examined. Tests were conducted on exposed tissues in live animals to examine the emission collection enhancement of the c-TED device compared to heavily optimized objective-based emission collection. The best light collection enhancement was seen from murine fat (5×-2× gains as a function of depth), while murine skeletal muscle and rat kidney showed gains of over two and just under two-fold near the surface, respectively. Gains decreased with imaging depth (particularly in the kidney). Zebrafish imaging on a reflective substrate showed close to a two-fold gain throughout the entire volume of an intact embryo (approximately 150 μm deep). Direct measurement of bleaching rates confirmed that the lower laser powers (enabled by greater light collection efficiency) yielded reduced photobleaching in vivo. The potential benefits of increased light collection in terms of speed of imaging and reduced photo-damage, as well as the applicability of this device to other multi-photon imaging methods is discussed. PMID:24251437

  15. Bio-Photonic Detection of Various Cellular Cultures

    NASA Astrophysics Data System (ADS)

    Hann, Patrick; Garzon, Maria; Pfeiffer, Erik; Lofland, Samuel; Knoesel, Ernst

    2008-03-01

    Since it is non-invasive, there has been increased research in the field of bio-optics. Many biological systems display an unusual phenomenon, delayed luminescence, produced by what is known as bio-photons. We present an apparatus and procedure for the detection of these ultra-weak photonic emissions using a single photon detection device. The results of bread yeast, saccramyces, and algae will be presented and compared to other reports in the literature

  16. 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.

  17. Hybrid AlGaN-SiC Avalanche Photodiode for Deep-UV Photon Detection

    NASA Technical Reports Server (NTRS)

    Aslam, Shahid; Herrero, Federico A.; Sigwarth, John; Goldsman, Neil; Akturk, Akin

    2010-01-01

    The proposed device is capable of counting ultraviolet (UV) photons, is compatible for inclusion into space instruments, and has applications as deep- UV detectors for calibration systems, curing systems, and crack detection. The device is based on a Separate Absorption and Charge Multiplication (SACM) structure. It is based on aluminum gallium nitride (AlGaN) absorber on a silicon carbide APD (avalanche photodiode). The AlGaN layer absorbs incident UV photons and injects photogenerated carriers into an underlying SiC APD that is operated in Geiger mode and provides current multiplication via avalanche breakdown. The solid-state detector is capable of sensing 100-to-365-nanometer wavelength radiation at a flux level as low as 6 photons/pixel/s. Advantages include, visible-light blindness, operation in harsh environments (e.g., high temperatures), deep-UV detection response, high gain, and Geiger mode operation at low voltage. Furthermore, the device can also be designed in array formats, e.g., linear arrays or 2D arrays (micropixels inside a superpixel).

  18. Two-dimensional photonic crystal bandedge laser with hybrid perovskite thin film for optical gain

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

    Cha, Hyungrae; Inter-University Semiconductor Research Center, Seoul National University, Seoul 08826; Bae, Seunghwan

    2016-05-02

    We report optically pumped room temperature single mode laser that contains a thin film of hybrid perovskite, an emerging photonic material, as gain medium. Two-dimensional square lattice photonic crystal (PhC) backbone structure enables single mode laser operation via a photonic bandedge mode, while a thin film of methyl-ammonium lead iodide (CH{sub 3}NH{sub 3}PbI{sub 3}) spin-coated atop provides optical gain for lasing. Two kinds of bandedge modes, Γ and M, are employed, and both devices laser in single mode at similar laser thresholds of ∼200 μJ/cm{sup 2} in pulse energy density. Polarization dependence measurements reveal a clear difference between the two kindsmore » of bandedge lasers: isotropic for the Γ-point laser and highly anisotropic for the M-point laser. These observations are consistent with expected modal properties, confirming that the lasing actions indeed originate from the corresponding PhC bandedge modes.« less

  19. TCPD: A micropattern photon detector hybrid for RICH applications

    NASA Astrophysics Data System (ADS)

    Hamar, G.; Varga, D.

    2017-03-01

    A micropattern and wire chamber hybrid has been constructed for UV photon detection, and its performance evaluated. It is revealed that such combination retains some key advantages of both the Thick-GEM primary and CCC secondary amplification stages, and results in a high gain gaseous photon detector with outstanding stability. Key features such as MIP suppression, detection efficiency and photon cluster size are discussed. The capability of the detector for UV photon detection has been established and proven with Cherenkov photons in particle beam tests.

  20. Atom-atom entanglement by single-photon detection.

    PubMed

    Slodička, L; Hétet, G; Röck, N; Schindler, P; Hennrich, M; Blatt, R

    2013-02-22

    A scheme for entangling distant atoms is realized, as proposed in the seminal paper by [C. Cabrillo et al., Phys. Rev. A 59, 1025 (1999)]. The protocol is based on quantum interference and detection of a single photon scattered from two effectively one meter distant laser cooled and trapped atomic ions. The detection of a single photon heralds entanglement of two internal states of the trapped ions with high rate and with a fidelity limited mostly by atomic motion. Control of the entangled state phase is demonstrated by changing the path length of the single-photon interferometer.

  1. [Study on spectral gain characterization of FWM processes with multi-frequency pumps in photonic crystal fiber].

    PubMed

    Hui, Zhan-Qiang

    2011-10-01

    Spectral gain induced by four-wave-mixing with multi-frequency pump was investigated by exploiting the data signal and continue lights co-propagation in dispersion flattened high nonlinear photonic crystal fiber (PCF). The effects of wavelength drift of pump lights, polarization state of orthogonal or parallel of pump lights, polarization mismatch of signal light versus orthogonal pump lights, total power of signal and probe light on the spectrum gain were analyzed. The results show that good FWM gain effects with multi-frequency pump can be obtained in 36.4 nm wavelength range when power ratio of pump to probe light is appropriate and with identical polarization. Furthermore, the gain of FWM with multi-frequency pump is very sensitive to polarization fluctuation and the different idle waves obtain different gain with the variation in signal polarization state. Moreover, the impact of pump numbers was investigated. The obtained results would be helpful for further research on ultrahigh-speed all optical signal processing devices exploiting the FWM with multi-frequency pump in PCF for future photonics network.

  2. Photonic Crystal Enhanced Fluorescence for Early Breast Cancer Biomarker Detection

    PubMed Central

    Cunningham, Brian T.; Zangar, Richard C.

    2013-01-01

    Photonic crystal surfaces offer a compelling platform for improving the sensitivity of surface-based fluorescent assays used in disease diagnostics. Through the complementary processes of photonic crystal enhanced excitation and enhanced extraction, a periodic dielectric-based nanostructured surface can simultaneously increase the electric field intensity experienced by surface-bound fluorophores and increase the collection efficiency of emitted fluorescent photons. Through the ability to inexpensively fabricate photonic crystal surfaces over substantial surface areas, they are amenable to single-use applications in biological sensing, such as disease biomarker detection in serum. In this review, we will describe the motivation for implementing high-sensitivity, multiplexed biomarker detection in the context of breast cancer diagnosis. We will summarize recent efforts to improve the detection limits of such assays though the use of photonic crystal surfaces. Reduction of detection limits is driven by low autofluorescent substrates for photonic crystal fabrication, and detection instruments that take advantage of their unique features. PMID:22736539

  3. Efficient and robust quantum random number generation by photon number detection

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

    Applegate, M. J.; Cavendish Laboratory, University of Cambridge, 19 JJ Thomson Avenue, Cambridge CB3 0HE; Thomas, O.

    2015-08-17

    We present an efficient and robust quantum random number generator based upon high-rate room temperature photon number detection. We employ an electric field-modulated silicon avalanche photodiode, a type of device particularly suited to high-rate photon number detection with excellent photon number resolution to detect, without an applied dead-time, up to 4 photons from the optical pulses emitted by a laser. By both measuring and modeling the response of the detector to the incident photons, we are able to determine the illumination conditions that achieve an optimal bit rate that we show is robust against variation in the photon flux. Wemore » extract random bits from the detected photon numbers with an efficiency of 99% corresponding to 1.97 bits per detected photon number yielding a bit rate of 143 Mbit/s, and verify that the extracted bits pass stringent statistical tests for randomness. Our scheme is highly scalable and has the potential of multi-Gbit/s bit rates.« less

  4. 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.

  5. Hot-Electron Photon Counters for Detecting Terahertz Photons

    NASA Technical Reports Server (NTRS)

    Karasik, Boris; Sergeyev, Andrei

    2005-01-01

    A document proposes the development of hot-electron photon counters (HEPCs) for detecting terahertz photons in spaceborne far-infrared astronomical instruments. These would be superconducting- transition-edge devices: they would contain superconducting bridges that would have such low heat capacities that single terahertz photons would cause transient increases in their electron temperatures through the superconducting- transition range, thereby yielding measurable increases in electrical resistance. Single devices or imaging arrays of the devices would be fabricated as submicron-sized bridges made from films of disordered Ti (which has a superconducting- transition temperature of .0.35 K) between Nb contacts on bulk silicon or sapphire substrates. In operation, these devices would be cooled to a temperature of .0.3 K. The proposed devices would cost less to fabricate and operate, relative to integrating bolometers of equal sensitivity, which must be operated at a temperature of approx. = 0.1 K.

  6. Target Detection of Quantum Illumination Receiver Based on Photon-subtracted Entanglement State

    NASA Astrophysics Data System (ADS)

    Chi, Jiao; Liu, HongJun; Huang, Nan; Wang, ZhaoLu

    2017-12-01

    We theoretically propose a quantum illumination receiver based on the ideal photon-subtracted two-mode squeezed state (PSTMSS) to efficiently detect the noise-hidden target. This receiver is generated by applying an optical parametric amplifier (OPA) to the cross correlation detection. With analyzing the output performance, it is found that OPA as a preposition technology of the receiver can contribute to the PSTMSS by significantly reducing the error probability than that of the general two-mode squeezed state (TMSS). Comparing with TMSS, the signal-to-noise ratio of quantum illumination based on ideal PSTMSS and OPA is improved more than 4 dB under an optimal gain of OPA. This work may provide a potential improvement in the application of accurate target detection when two kinds of resource have the identical real squeezing parameter.

  7. Detective quantum efficiency of photon-counting x-ray detectors.

    PubMed

    Tanguay, Jesse; Yun, Seungman; Kim, Ho Kyung; Cunningham, Ian A

    2015-01-01

    Single-photon-counting (SPC) x-ray imaging has the potential to improve image quality and enable novel energy-dependent imaging methods. Similar to conventional detectors, optimizing image SPC quality will require systems that produce the highest possible detective quantum efficiency (DQE). This paper builds on the cascaded-systems analysis (CSA) framework to develop a comprehensive description of the DQE of SPC detectors that implement adaptive binning. The DQE of SPC systems can be described using the CSA approach by propagating the probability density function (PDF) of the number of image-forming quanta through simple quantum processes. New relationships are developed to describe PDF transfer through serial and parallel cascades to accommodate scatter reabsorption. Results are applied to hypothetical silicon and selenium-based flat-panel SPC detectors including the effects of reabsorption of characteristic/scatter photons from photoelectric and Compton interactions, stochastic conversion of x-ray energy to secondary quanta, depth-dependent charge collection, and electronic noise. Results are compared with a Monte Carlo study. Depth-dependent collection efficiency can result in substantial broadening of photopeaks that in turn may result in reduced DQE at lower x-ray energies (20-45 keV). Double-counting interaction events caused by reabsorption of characteristic/scatter photons may result in falsely inflated image signal-to-noise ratio and potential overestimation of the DQE. The CSA approach is extended to describe signal and noise propagation through photoelectric and Compton interactions in SPC detectors, including the effects of escape and reabsorption of emission/scatter photons. High-performance SPC systems can be achieved but only for certain combinations of secondary conversion gain, depth-dependent collection efficiency, electronic noise, and reabsorption characteristics.

  8. 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.

  9. Detecting Dark Photons with Reactor Neutrino Experiments

    NASA Astrophysics Data System (ADS)

    Park, H. K.

    2017-08-01

    We propose to search for light U (1 ) dark photons, A', produced via kinetically mixing with ordinary photons via the Compton-like process, γ e-→A'e-, in a nuclear reactor and detected by their interactions with the material in the active volumes of reactor neutrino experiments. We derive 95% confidence-level upper limits on ɛ , the A'-γ mixing parameter, ɛ , for dark-photon masses below 1 MeV of ɛ <1.3 ×10-5 and ɛ <2.1 ×10-5, from NEOS and TEXONO experimental data, respectively. This study demonstrates the applicability of nuclear reactors as potential sources of intense fluxes of low-mass dark photons.

  10. Molecular detection via hybrid peptide-semiconductor photonic devices

    NASA Astrophysics Data System (ADS)

    Estephan, E.; Saab, M.-b.; Martin, M.; Cloitre, T.; Larroque, C.; Cuisinier, F. J. G.; Malvezzi, A. M.; Gergely, C.

    2011-03-01

    The aim of this work was to investigate the possibilities to support device functionality that includes strongly confined and localized light emission and detection processes within nano/micro-structured semiconductors for biosensing applications. The interface between biological molecules and semiconductor surfaces, yet still under-explored is a key issue for improving biomolecular recognition in devices. We report on the use of adhesion peptides, elaborated via combinatorial phage-display libraries for controlled placement of biomolecules, leading to user-tailored hybrid photonic systems for molecular detection. An M13 bacteriophage library has been used to screen 1010 different peptides against various semiconductors to finally isolate specific peptides presenting a high binding capacity for the target surfaces. When used to functionalize porous silicon microcavities (PSiM) and GaAs/AlGaAs photonic crystals, we observe the formation of extremely thin (<1nm) peptide layers, hereby preserving the nanostructuration of the crystals. This is important to assure the photonic response of these tiny structures when they are functionalized by a biotinylated peptide layer and then used to capture streptavidin. Molecular detection was monitored via both linear and nonlinear optical measurements. Our linear reflectance spectra demonstrate an enhanced detection resolution via PSiM devices, when functionalized with the Si-specific peptide. Molecular capture at even lower concentrations (femtomols) is possible via the second harmonic generation of GaAs/AlGaAs photonic crystals when functionalized with GaAs-specific peptides. Our work demonstrates the outstanding value of adhesion peptides as interface linkers between semiconductors and biological molecules. They assure an enhanced molecular detection via both linear and nonlinear answers of photonic crystals.

  11. Surface plasmon induced direct detection of long wavelength photons.

    PubMed

    Tong, Jinchao; Zhou, Wei; Qu, Yue; Xu, Zhengji; Huang, Zhiming; Zhang, Dao Hua

    2017-11-21

    Millimeter and terahertz wave photodetectors have long been of great interest due to a wide range of applications, but they still face challenges in detection performance. Here, we propose a new strategy for the direct detection of millimeter and terahertz wave photons based on localized surface-plasmon-polariton (SPP)-induced non-equilibrium electrons in antenna-assisted subwavelength ohmic metal-semiconductor-metal (OMSM) structures. The subwavelength OMSM structure is used to convert the absorbed photons into localized SPPs, which then induce non-equilibrium electrons in the structure, while the antenna increases the number of photons coupled into the OMSM structure. When the structure is biased and illuminated, the unidirectional flow of the SPP-induced non-equilibrium electrons forms a photocurrent. The energy of the detected photons is determined by the structure rather than the band gap of the semiconductor. The detection scheme is confirmed by simulation and experimental results from the devices, made of gold and InSb, and a room temperature noise equivalent power (NEP) of 1.5 × 10 -13 W Hz -1/2 is achieved.

  12. 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.

  13. 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

  14. 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.

  15. Detecting Dark Photons with Reactor Neutrino Experiments.

    PubMed

    Park, H K

    2017-08-25

    We propose to search for light U(1) dark photons, A^{'}, produced via kinetically mixing with ordinary photons via the Compton-like process, γe^{-}→A^{'}e^{-}, in a nuclear reactor and detected by their interactions with the material in the active volumes of reactor neutrino experiments. We derive 95% confidence-level upper limits on ε, the A^{'}-γ mixing parameter, ε, for dark-photon masses below 1 MeV of ε<1.3×10^{-5} and ε<2.1×10^{-5}, from NEOS and TEXONO experimental data, respectively. This study demonstrates the applicability of nuclear reactors as potential sources of intense fluxes of low-mass dark photons.

  16. Detective quantum efficiency of photon-counting x-ray detectors

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

    Tanguay, Jesse, E-mail: jessetan@mail.ubc.ca; Yun, Seungman; Kim, Ho Kyung

    Purpose: Single-photon-counting (SPC) x-ray imaging has the potential to improve image quality and enable novel energy-dependent imaging methods. Similar to conventional detectors, optimizing image SPC quality will require systems that produce the highest possible detective quantum efficiency (DQE). This paper builds on the cascaded-systems analysis (CSA) framework to develop a comprehensive description of the DQE of SPC detectors that implement adaptive binning. Methods: The DQE of SPC systems can be described using the CSA approach by propagating the probability density function (PDF) of the number of image-forming quanta through simple quantum processes. New relationships are developed to describe PDF transfermore » through serial and parallel cascades to accommodate scatter reabsorption. Results are applied to hypothetical silicon and selenium-based flat-panel SPC detectors including the effects of reabsorption of characteristic/scatter photons from photoelectric and Compton interactions, stochastic conversion of x-ray energy to secondary quanta, depth-dependent charge collection, and electronic noise. Results are compared with a Monte Carlo study. Results: Depth-dependent collection efficiency can result in substantial broadening of photopeaks that in turn may result in reduced DQE at lower x-ray energies (20–45 keV). Double-counting interaction events caused by reabsorption of characteristic/scatter photons may result in falsely inflated image signal-to-noise ratio and potential overestimation of the DQE. Conclusions: The CSA approach is extended to describe signal and noise propagation through photoelectric and Compton interactions in SPC detectors, including the effects of escape and reabsorption of emission/scatter photons. High-performance SPC systems can be achieved but only for certain combinations of secondary conversion gain, depth-dependent collection efficiency, electronic noise, and reabsorption characteristics.« less

  17. Barium Qubit State Detection and Ba Ion-Photon Entanglement

    NASA Astrophysics Data System (ADS)

    Sosnova, Ksenia; Inlek, Ismail Volkan; Crocker, Clayton; Lichtman, Martin; Monroe, Christopher

    2016-05-01

    A modular ion-trap network is a promising framework for scalable quantum-computational devices. In this architecture, different ion-trap modules are connected via photonic buses while within one module ions interact locally via phonons. To eliminate cross-talk between photonic-link qubits and memory qubits, we use different atomic species for quantum information storage (171 Yb+) and intermodular communication (138 Ba+). Conventional deterministic Zeeman-qubit state detection schemes require additional stabilized narrow-linewidth lasers. Instead, we perform fast probabilistic state detection utilizing efficient detectors and high-NA lenses to detect emitted photons from circularly polarized 493 nm laser excitation. Our method is not susceptible to intensity and frequency noise, and we show single-shot detection efficiency of ~ 2%, meaning that we can discriminate between the two qubits states with 99% confidence after as little as 50 ms of averaging. Using this measurement technique, we report entanglement between a single 138 Ba+ ion and its emitted photon with 86% fidelity. This work is supported by the ARO with funding from the IARPA MQCO program, the DARPA Quiness program, the AFOSR MURI on Quantum Transduction, and the ARL Center for Distributed Quantum Information.

  18. 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.

  19. 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.

  20. Waveguide-integrated single- and multi-photon detection at telecom wavelengths using superconducting nanowires

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

    Ferrari, Simone; Kahl, Oliver; Kovalyuk, Vadim

    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.

  1. First photon detection in time-resolved transillumination imaging: a theoretical evaluation.

    PubMed

    Behin-Ain, S; van Doorn, T; Patterson, J R

    2004-09-07

    First photon detection, as a special case of time-resolved transillumination imaging, is studied through the derivation of the temporal probability density function (pdf) for the first arriving photon. The pdf for different laser intensities, media and second and later arriving photons were generated. The arrival time of the first detected photon reduced as the laser power increased and also when the scattering and absorption coefficients decreased. The pdf for an imbedded totally absorbing 3 mm inhomogeneity may be distinguished from the pdf of a homogeneous turbid medium similar to that of human breast in dimensions and optical properties.

  2. The effect of microchannel plate gain depression on PAPA photon counting cameras

    NASA Astrophysics Data System (ADS)

    Sams, Bruce J., III

    1991-03-01

    PAPA (precision analog photon address) cameras are photon counting imagers which employ microchannel plates (MCPs) for image intensification. They have been used extensively in astronomical speckle imaging. The PAPA camera can produce artifacts when light incident on its MCP is highly concentrated. The effect is exacerbated by adjusting the strobe detection level too low, so that the camera accepts very small MCP pulses. The artifacts can occur even at low total count rates if the image has highly a concentrated bright spot. This paper describes how to optimize PAPA camera electronics, and describes six techniques which can avoid or minimize addressing errors.

  3. Single photon detection in a waveguide-coupled Ge-on-Si lateral avalanche photodiode.

    PubMed

    Martinez, Nicholas J D; Gehl, Michael; Derose, Christopher T; Starbuck, Andrew L; Pomerene, Andrew T; Lentine, Anthony L; Trotter, Douglas C; Davids, Paul S

    2017-07-10

    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.

  4. Multiplying and detecting propagating microwave photons using inelastic Cooper-pair tunneling

    NASA Astrophysics Data System (ADS)

    Leppäkangas, Juha; Marthaler, Michael; Hazra, Dibyendu; Jebari, Salha; Albert, Romain; Blanchet, Florian; Johansson, Göran; Hofheinz, Max

    2018-01-01

    The interaction between propagating microwave fields and Cooper-pair tunneling across a DC-voltage-biased Josephson junction can be highly nonlinear. We show theoretically that this nonlinearity can be used to convert an incoming single microwave photon into an outgoing n -photon Fock state in a different mode. In this process, the electrostatic energy released in a Cooper-pair tunneling event is transferred to the outgoing Fock state, providing energy gain. The created multiphoton Fock state is frequency entangled and highly bunched. The conversion can be made reflectionless (impedance matched) so that all incoming photons are converted to n -photon states. With realistic parameters, multiplication ratios n >2 can be reached. By two consecutive multiplications, the outgoing Fock-state number can get sufficiently large to accurately discriminate it from vacuum with linear postamplification and power measurement. Therefore, this amplification scheme can be used as a single-photon detector without dead time.

  5. Photon Counting Imaging with an Electron-Bombarded Pixel Image Sensor

    PubMed Central

    Hirvonen, Liisa M.; Suhling, Klaus

    2016-01-01

    Electron-bombarded pixel image sensors, where a single photoelectron is accelerated directly into a CCD or CMOS sensor, allow wide-field imaging at extremely low light levels as they are sensitive enough to detect single photons. This technology allows the detection of up to hundreds or thousands of photon events per frame, depending on the sensor size, and photon event centroiding can be employed to recover resolution lost in the detection process. Unlike photon events from electron-multiplying sensors, the photon events from electron-bombarded sensors have a narrow, acceleration-voltage-dependent pulse height distribution. Thus a gain voltage sweep during exposure in an electron-bombarded sensor could allow photon arrival time determination from the pulse height with sub-frame exposure time resolution. We give a brief overview of our work with electron-bombarded pixel image sensor technology and recent developments in this field for single photon counting imaging, and examples of some applications. PMID:27136556

  6. 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

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

    NASA Technical Reports Server (NTRS)

    Krainak, M. A.; Yang, G.; Sun, X.; Lu, W.; Merritt, S.; Beck, J.

    2016-01-01

    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.

  8. 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.

  9. Complete chirp analysis of a gain-switched pulse using an interferometric two-photon absorption autocorrelation.

    PubMed

    Chin, Sang Hoon; Kim, Young Jae; Song, Ho Seong; Kim, Dug Young

    2006-10-10

    We propose a simple but powerful scheme for the complete analysis of the frequency chirp of a gain-switched optical pulse using a fringe-resolved interferometric two-photon absorption autocorrelator. A frequency chirp imposed on the gain-switched pulse from a laser diode was retrieved from both the intensity autocorrelation trace and the envelope of the second-harmonic interference fringe pattern. To verify the accuracy of the proposed phase retrieval method, we have performed an optical pulse compression experiment by using dispersion-compensating fibers with different lengths. We have obtained close agreement by less than a 1% error between the compressed pulse widths and numerically calculated pulse widths.

  10. Merged beam laser design for reduction of gain-saturation and two-photon absorption in high power single mode semiconductor lasers.

    PubMed

    Lysevych, M; Tan, H H; Karouta, F; Fu, L; Jagadish, C

    2013-04-08

    In this paper we report a method to overcome the limitations of gain-saturation and two-photon absorption faced by developers of high power single mode InP-based lasers and semiconductor optical amplifiers (SOA) including those based on wide-waveguide or slab-coupled optical waveguide laser (SCOWL) technology. The method is based on Y-coupling design of the laser cavity. The reduction in gain-saturation and two-photon absorption in the merged beam laser structures (MBL) are obtained by reducing the intensity of electromagnetic field in the laser cavity. Standard ridge-waveguide lasers and MBLs were fabricated, tested and compared. Despite a slightly higher threshold current, the reduced gain-saturation in MBLs results in higher output power. The MBLs also produced a single spatial mode, as well as a strongly dominating single spectral mode which is the inherent feature of MBL-type cavity.

  11. Target molecules detection by waveguiding in a photonic silicon membrane

    DOEpatents

    Letant, Sonia; Van Buuren, Anthony; Terminello, Louis

    2004-08-31

    Disclosed herein is a photonic silicon filter capable of binding and detecting biological and chemical target molecules in liquid or gas samples. A photonic waveguiding silicon filter with chemical and/or biological anchors covalently attached to the pore walls selectively bind target molecules. The system uses transmission curve engineering principles to allow measurements to be made in situ and in real time to detect the presence of various target molecules and determine the concentration of bound target.

  12. 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.

  13. 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

  14. High-speed low-power photonic transistor devices based on optically-controlled gain or absorption to affect optical interference.

    PubMed

    Huang, Yingyan; Ho, Seng-Tiong

    2008-10-13

    We show that a photonic transistor device can be realized via the manipulation of optical interference by optically controlled gain or absorption in novel ways, resulting in efficient transistor signal gain and switching action. Exemplary devices illustrate two complementary device types with high operating speed, microm size, microW switching power, and switching gain. They can act in tandem to provide a wide variety of operations including wavelength conversion, pulse regeneration, and logical operations. These devices could have a Transistor Figure-of-Merits >10(5) times higher than current chi((3)) approaches and are highly attractive.

  15. Hybrid inorganic/organic photonic crystal biochips for cancer biomarkers detection

    NASA Astrophysics Data System (ADS)

    Sinibaldi, Alberto; Danz, Norbert; Munzert, Peter; Michelotti, Francesco

    2018-06-01

    We report on hybrid inorganic/organic one-dimensional photonic crystal biochips sustaining Bloch surface waves. The biochips were used, together with an optical platform operating in a label-free and fluorescence configuration simultaneously, to detect the cancer biomarker Angiopoietin 2 in a protein base buffer. The hybrid photonic crystals embed in their geometry a thin functionalization poly-acrylic acid layer deposited by plasma polymerization, which is used to immobilize a monoclonal antibody for highly specific biological recognition. The fluorescence operation mode is described in detail, putting into evidence the role of field enhancement and localization at the photonic crystal surface in the shaping and intensification of the angular fluorescence pattern. In the fluorescence operation mode, the hybrid biochips can attain the limit of detection 6 ng/ml.

  16. The study of electromagnetic wave propagation in photonic crystals via planewave based transfer (scattering) matrix method with active gain material applications

    NASA Astrophysics Data System (ADS)

    Li, Ming

    In this dissertation, a set of numerical simulation tools are developed under previous work to efficiently and accurately study one-dimensional (1D), two-dimensional (2D), 2D slab and three-dimensional (3D) photonic crystal structures and their defects effects by means of spectrum (transmission, reflection, absorption), band structure (dispersion relation), and electric and/or magnetic fields distribution (mode profiles). Further more, the lasing property and spontaneous emission behaviors are studied when active gain materials are presented in the photonic crystal structures. First, the planewave based transfer (scattering) matrix method (TMM) is described in every detail along with a brief review of photonic crystal history (Chapter 1 and 2). As a frequency domain method, TMM has the following major advantages over other numerical methods: (1) the planewave basis makes Maxwell's Equations a linear algebra problem and there are mature numerical package to solve linear algebra problem such as Lapack and Scalapack (for parallel computation). (2) Transfer (scattering) matrix method make 3D problem into 2D slices and link all slices together via the scattering matrix (S matrix) which reduces computation time and memory usage dramatically and makes 3D real photonic crystal devices design possible; and this also makes the simulated domain no length limitation along the propagation direction (ideal for waveguide simulation). (3) It is a frequency domain method and calculation results are all for steady state, without the influences of finite time span convolution effects and/or transient effects. (4) TMM can treat dispersive material (such as metal at visible light) naturally without introducing any additional computation; and meanwhile TMM can also deal with anisotropic material and magnetic material (such as perfectly matched layer) naturally from its algorithms. (5) Extension of TMM to deal with active gain material can be done through an iteration procedure with gain

  17. The physics of heterodyne detection in the far-infrared: Transition from electric-field to photon-absorption detection in a simple system

    NASA Technical Reports Server (NTRS)

    Teich, M. C.

    1980-01-01

    The history of heterodyne detection is reviewed from the radiowave to the optical regions of the electromagnetic spectrum with emphasion the submillimeter/far infrared. The transition from electric field to photon absorption detection in a simple system is investigated. The response of an isolated two level detector to a coherent source of incident radiation is calculated for both heterodyne and video detection. When the processes of photon absorption and photon emission cannot be distinguished, the relative detected power at double- and sum-frequencies is found to be multiplied by a coefficient, which is less than or equal to unity, and which depends on the incident photon energy and on the effective temperature of the system.

  18. Direct detection constraints on dark photon dark matter

    NASA Astrophysics Data System (ADS)

    An, Haipeng; Pospelov, Maxim; Pradler, Josef; Ritz, Adam

    2015-07-01

    Dark matter detectors built primarily to probe elastic scattering of WIMPs on nuclei are also precise probes of light, weakly coupled, particles that may be absorbed by the detector material. In this paper, we derive constraints on the minimal model of dark matter comprised of long-lived vector states V (dark photons) in the 0.01- 100 keV mass range. The absence of an ionization signal in direct detection experiments such as XENON10 and XENON100 places a very strong constraint on the dark photon mixing angle, down to O (10-15), assuming that dark photons comprise the dominant fraction of dark matter. This sensitivity to dark photon dark matter exceeds the indirect bounds derived from stellar energy loss considerations over a significant fraction of the available mass range. We also revisit indirect constraints from V → 3 γ decay and show that limits from modifications to the cosmological ionization history are comparable to the updated limits from the diffuse γ-ray flux.

  19. Observation of two-photon interference with continuous variables by homodyne detection

    NASA Astrophysics Data System (ADS)

    Wu, Daohua; Kawamoto, Kota; Guo, Xiaomin; Kasai, Katsuyuki; Watanabe, Masayoshi; Zhang, Yun

    2017-10-01

    We experimentally observed a two-photon interference between a squeezed vacuum state from an optical parametric amplifier and a weak coherent state on a beam splitter with continuous variables. The photon statistics properties of the mixed field were investigated by calculating the correlations among four permutations of measured quadratures components, which were obtained by two homodyne detection systems. This also means that the two-photon interference occurred at analysis frequency differing from the previous two-photon interference reports. The nonclassical effect of photon anti-bunching occurred when an amplitude squeezed vacuum state acted as one of interference sources. On the other hand, the photon bunching effect appeared when a phase squeezed vacuum state was employed.

  20. Enhancement of Rydberg-mediated single-photon nonlinearities by electrically tuned Förster resonances

    PubMed Central

    Gorniaczyk, H.; Tresp, C.; Bienias, P.; Paris-Mandoki, A.; Li, W.; Mirgorodskiy, I.; Büchler, H. P.; Lesanovsky, I.; Hofferberth, S.

    2016-01-01

    Mapping the strong interaction between Rydberg atoms onto single photons via electromagnetically induced transparency enables manipulation of light at the single-photon level and few-photon devices such as all-optical switches and transistors operated by individual photons. Here we demonstrate experimentally that Stark-tuned Förster resonances can substantially increase this effective interaction between individual photons. This technique boosts the gain of a single-photon transistor to over 100, enhances the non-destructive detection of single Rydberg atoms to a fidelity beyond 0.8, and enables high-precision spectroscopy on Rydberg pair states. On top, we achieve a gain larger than 2 with gate photon read-out after the transistor operation. Theory models for Rydberg polariton propagation on Förster resonance and for the projection of the stored spin-wave yield excellent agreement to our data and successfully identify the main decoherence mechanism of the Rydberg transistor, paving the way towards photonic quantum gates. PMID:27515278

  1. Two-Photon Excitation STED Microscopy with Time-Gated Detection

    PubMed Central

    Coto Hernández, Iván; Castello, Marco; Lanzanò, Luca; d’Amora, Marta; Bianchini, Paolo; Diaspro, Alberto; Vicidomini, Giuseppe

    2016-01-01

    We report on a novel two-photon excitation stimulated emission depletion (2PE-STED) microscope based on time-gated detection. The time-gated detection allows for the effective silencing of the fluorophores using moderate stimulated emission beam intensity. This opens the possibility of implementing an efficient 2PE-STED microscope with a stimulated emission beam running in a continuous-wave. The continuous-wave stimulated emission beam tempers the laser architecture’s complexity and cost, but the time-gated detection degrades the signal-to-noise ratio (SNR) and signal-to-background ratio (SBR) of the image. We recover the SNR and the SBR through a multi-image deconvolution algorithm. Indeed, the algorithm simultaneously reassigns early-photons (normally discarded by the time-gated detection) to their original positions and removes the background induced by the stimulated emission beam. We exemplify the benefits of this implementation by imaging sub-cellular structures. Finally, we discuss of the extension of this algorithm to future all-pulsed 2PE-STED implementationd based on time-gated detection and a nanosecond laser source. PMID:26757892

  2. 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.

  3. Detection of endotoxin using a photonic crystal nanolaser

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

    Takahashi, Daichi; Hachuda, Shoji; Watanabe, Takumi

    Fast and reliable detection of endotoxin (ET) in medical equipment and pharmaceutical products is an essential precursor to clinical treatment. In this study, we demonstrate the use of shifts in wavelength of photonic crystal nanolasers for sensing the Limulus amebocyte lysate reaction, which is a standard method for detecting ET. From working curves of wavelength shift vs ET concentration, whose correlation factors were as high as 98%, we detected a required concentration of 0.001 EU/ml within 33 min and detected a low concentration of 0.0001 EU/ml.

  4. Detection of endotoxin using a photonic crystal nanolaser

    NASA Astrophysics Data System (ADS)

    Takahashi, Daichi; Hachuda, Shoji; Watanabe, Takumi; Nishijima, Yoshiaki; Baba, Toshihiko

    2015-03-01

    Fast and reliable detection of endotoxin (ET) in medical equipment and pharmaceutical products is an essential precursor to clinical treatment. In this study, we demonstrate the use of shifts in wavelength of photonic crystal nanolasers for sensing the Limulus amebocyte lysate reaction, which is a standard method for detecting ET. From working curves of wavelength shift vs ET concentration, whose correlation factors were as high as 98%, we detected a required concentration of 0.001 EU/ml within 33 min and detected a low concentration of 0.0001 EU/ml.

  5. 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.

  6. High rate tests of the photon detection system for the LHCb RICH Upgrade

    NASA Astrophysics Data System (ADS)

    Blago, M. P.; Keizer, F.

    2017-12-01

    The photon detection system for the LHCb RICH Upgrade consists of an array of multianode photomultiplier tubes (MaPMTs) read out by custom-built modular electronics. The behaviour of the whole chain was studied at CERN using a pulsed laser. Threshold scans were performed in order to study the MaPMT pulse-height spectra at high event rates and different photon intensities. The results show a reduction in photon detection efficiency at 900 V bias voltage, marked by a 20% decrease in the single-photon peak height, when increasing the event rate from 100 kHz to 20 MHz. This reduction was not observed at 1000 V bias voltage.

  7. Nanostructured Surfaces and Detection Instrumentation for Photonic Crystal Enhanced Fluorescence

    PubMed Central

    Chaudhery, Vikram; George, Sherine; Lu, Meng; Pokhriyal, Anusha; Cunningham, Brian T.

    2013-01-01

    Photonic crystal (PC) surfaces have been demonstrated as a compelling platform for improving the sensitivity of surface-based fluorescent assays used in disease diagnostics and life science research. PCs can be engineered to support optical resonances at specific wavelengths at which strong electromagnetic fields are utilized to enhance the intensity of surface-bound fluorophore excitation. Meanwhile, the leaky resonant modes of PCs can be used to direct emitted photons within a narrow range of angles for more efficient collection by a fluorescence detection system. The multiplicative effects of enhanced excitation combined with enhanced photon extraction combine to provide improved signal-to-noise ratios for detection of fluorescent emitters, which in turn can be used to reduce the limits of detection of low concentration analytes, such as disease biomarker proteins. Fabrication of PCs using inexpensive manufacturing methods and materials that include replica molding on plastic, nano-imprint lithography on quartz substrates result in devices that are practical for single-use disposable applications. In this review, we will describe the motivation for implementing high-sensitivity fluorescence detection in the context of molecular diagnosis and gene expression analysis though the use of PC surfaces. Recent efforts to improve the design and fabrication of PCs and their associated detection instrumentation are summarized, including the use of PCs coupled with Fabry-Perot cavities and external cavity lasers. PMID:23624689

  8. Bio-inspired photon detection using chromophore/nanotube hybrids (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Léonard, François

    2017-05-01

    The human eye is an exquisite optical system with the ability to detect individual photons at room temperature. However, the complexity of this system, optimized over millions of years, has been difficult to reproduce using synthetic techniques. Here we discuss a bio-inspired approach for photon detection based on chromophore/nanotube hybrids, where the chromophore plays a similar role to the retinal molecule in the human eye, and the signal transduction is provided by electronic transport in the carbon nanotube. In this presentation, I will present the concept and discuss our progress in realizing this type of photodetection mechanism.

  9. Selective photon counter for digital x-ray mammography tomosynthesis

    NASA Astrophysics Data System (ADS)

    Goldan, Amir H.; Karim, Karim S.; Rowlands, J. A.

    2006-03-01

    Photon counting is an emerging detection technique that is promising for mammography tomosynthesis imagers. In photon counting systems, the value of each image pixel is equal to the number of photons that interact with the detector. In this research, we introduce the design and implementation of a low noise, novel selective photon counting pixel for digital mammography tomosynthesis in crystalline silicon CMOS (complementary metal oxide semiconductor) 0.18 micron technology. The design comprises of a low noise charge amplifier (CA), two low offset voltage comparators, a decision-making unit (DMU), a mode selector, and a pseudo-random counter. Theoretical calculations and simulation results of linearity, gain, and noise of the photon counting pixel are presented.

  10. 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.

  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. Direct detection constraints on dark photon dark matter

    DOE PAGES

    An, Haipeng; Pospelov, Maxim; Pradler, Josef; ...

    2015-06-11

    Dark matter detectors built primarily to probe elastic scattering of WIMPs on nuclei are also precise probes of light, weakly coupled, particles that may be absorbed by the detector material. In this paper, we derive constraints on the minimal model of dark matter comprised of long-lived vector states V (dark photons) in the 0.01–100KeV mass range. The absence of an ionization signal in direct detection experiments such as XENON10 and XENON100 places a very strong constraint on the dark photon mixing angle, down to Ο(10 –15), assuming that dark photons comprise the dominant fraction of dark matter. This sensitivity tomore » dark photon dark matter exceeds the indirect bounds derived from stellar energy loss considerations over a significant fraction of the available mass range. As a result, we also revisit indirect constraints from V → 3γ decay and show that limits from modifications to the cosmological ionization history are comparable to the updated limits from the diffuse γ-ray flux.« less

  13. Ultrabroadband direct detection of nonclassical photon statistics at telecom wavelength.

    PubMed

    Wakui, Kentaro; Eto, Yujiro; Benichi, Hugo; Izumi, Shuro; Yanagida, Tetsufumi; Ema, Kazuhiro; Numata, Takayuki; Fukuda, Daiji; Takeoka, Masahiro; Sasaki, Masahide

    2014-04-03

    Broadband light sources play essential roles in diverse fields, such as high-capacity optical communications, optical coherence tomography, optical spectroscopy, and spectrograph calibration. Although a nonclassical state from spontaneous parametric down-conversion may serve as a quantum counterpart, its detection and characterization have been a challenging task. Here we demonstrate the direct detection of photon numbers of an ultrabroadband (110 nm FWHM) squeezed state in the telecom band centred at 1535 nm wavelength, using a superconducting transition-edge sensor. The observed photon-number distributions violate Klyshko's criterion for the nonclassicality. From the observed photon-number distribution, we evaluate the second- and third-order correlation functions, and characterize a multimode structure, which implies that several tens of orthonormal modes of squeezing exist in the single optical pulse. Our results and techniques open up a new possibility to generate and characterize frequency-multiplexed nonclassical light sources for quantum info-communications technology.

  14. Monolithically integrated quantum dot optical gain modulator with semiconductor optical amplifier for 10-Gb/s photonic transmission

    NASA Astrophysics Data System (ADS)

    Yamamoto, Naokatsu; Akahane, Kouichi; Umezawa, Toshimasa; Kawanishi, Tetsuya

    2015-03-01

    Short-range interconnection and/or data center networks require high capacity and a large number of channels in order to support numerous connections. Solutions employed to meet these requirements involve the use of alternative wavebands to increase the usable optical frequency range. We recently proposed the use of the T- and O-bands (Thousand band: 1000-1260 nm, Original band: 1260-1360 nm) as alternative wavebands because large optical frequency resources (>60 THz) can be easily employed. In addition, a simple and compact Gb/s-order high-speed optical modulator is a critical photonic device for short-range communications. Therefore, to develop an optical modulator that acts as a highfunctional photonic device, we focused on the use of self-assembled quantum dots (QDs) as a three-dimensional (3D) confined structure because QD structures are highly suitable for realizing broadband optical gain media in the T+O bands. In this study, we use the high-quality broadband QD optical gain to develop a monolithically integrated QD optical gain modulator (QD-OGM) device that has a semiconductor optical amplifier (QD-SOA) for Gb/s-order highspeed optical data generation in the 1.3-μm waveband. The insertion loss of the device can be compensated through the SOA, and we obtained an optical gain change of up to ~7 dB in the OGM section. Further, we successfully demonstrate a 10-Gb/s clear eye opening using the QD-OGM/SOA device with a clock-data recovery sequence at the receiver end. These results suggest that the monolithic QD-EOM/SOA is suitable for increasing the number of wavelength channels for smart short-range communications.

  15. Single-photon technique for the detection of periodic extraterrestrial laser pulses.

    PubMed

    Leeb, W R; Poppe, A; Hammel, E; Alves, J; Brunner, M; Meingast, S

    2013-06-01

    To draw humankind's attention to its existence, an extraterrestrial civilization could well direct periodic laser pulses toward Earth. We developed a technique capable of detecting a quasi-periodic light signal with an average of less than one photon per pulse within a measurement time of a few tens of milliseconds in the presence of the radiation emitted by an exoplanet's host star. Each of the electronic events produced by one or more single-photon avalanche detectors is tagged with precise time-of-arrival information and stored. From this we compute a histogram displaying the frequency of event-time differences in classes with bin widths on the order of a nanosecond. The existence of periodic laser pulses manifests itself in histogram peaks regularly spaced at multiples of the-a priori unknown-pulse repetition frequency. With laser sources simulating both the pulse source and the background radiation, we tested a detection system in the laboratory at a wavelength of 850 nm. We present histograms obtained from various recorded data sequences with the number of photons per pulse, the background photons per pulse period, and the recording time as main parameters. We then simulated a periodic signal hypothetically generated on a planet orbiting a G2V-type star (distance to Earth 500 light-years) and show that the technique is capable of detecting the signal even if the received pulses carry as little as one photon on average on top of the star's background light.

  16. A novel pixellated solid-state photon detector for enhancing the Everhart-Thornley detector.

    PubMed

    Chuah, Joon Huang; Holburn, David

    2013-06-01

    This article presents a pixellated solid-state photon detector designed specifically to improve certain aspects of the existing Everhart-Thornley detector. The photon detector was constructed and fabricated in an Austriamicrosystems 0.35 µm complementary metal-oxide-semiconductor process technology. This integrated circuit consists of an array of high-responsivity photodiodes coupled to corresponding low-noise transimpedance amplifiers, a selector-combiner circuit and a variable-gain postamplifier. Simulated and experimental results show that the photon detector can achieve a maximum transimpedance gain of 170 dBΩ and minimum bandwidth of 3.6 MHz. It is able to detect signals with optical power as low as 10 nW and produces a minimum signal-to-noise ratio (SNR) of 24 dB regardless of gain configuration. The detector has been proven to be able to effectively select and combine signals from different pixels. The key advantages of this detector are smaller dimensions, higher cost effectiveness, lower voltage and power requirements and better integration. The photon detector supports pixel-selection configurability which may improve overall SNR and also potentially generate images for different analyses. This work has contributed to the future research of system-level integration of a pixellated solid-state detector for secondary electron detection in the scanning electron microscope. Copyright © 2013 Wiley Periodicals, Inc.

  17. Ultrabroadband direct detection of nonclassical photon statistics at telecom wavelength

    PubMed Central

    Wakui, Kentaro; Eto, Yujiro; Benichi, Hugo; Izumi, Shuro; Yanagida, Tetsufumi; Ema, Kazuhiro; Numata, Takayuki; Fukuda, Daiji; Takeoka, Masahiro; Sasaki, Masahide

    2014-01-01

    Broadband light sources play essential roles in diverse fields, such as high-capacity optical communications, optical coherence tomography, optical spectroscopy, and spectrograph calibration. Although a nonclassical state from spontaneous parametric down-conversion may serve as a quantum counterpart, its detection and characterization have been a challenging task. Here we demonstrate the direct detection of photon numbers of an ultrabroadband (110 nm FWHM) squeezed state in the telecom band centred at 1535 nm wavelength, using a superconducting transition-edge sensor. The observed photon-number distributions violate Klyshko's criterion for the nonclassicality. From the observed photon-number distribution, we evaluate the second- and third-order correlation functions, and characterize a multimode structure, which implies that several tens of orthonormal modes of squeezing exist in the single optical pulse. Our results and techniques open up a new possibility to generate and characterize frequency-multiplexed nonclassical light sources for quantum info-communications technology. PMID:24694515

  18. Coincidence detection of spatially correlated photon pairs with a monolithic time-resolving detector array.

    PubMed

    Unternährer, Manuel; Bessire, Bänz; Gasparini, Leonardo; Stoppa, David; Stefanov, André

    2016-12-12

    We demonstrate coincidence measurements of spatially entangled photons by means of a multi-pixel based detection array. The sensor, originally developed for positron emission tomography applications, is a fully digital 8×16 silicon photomultiplier array allowing not only photon counting but also per-pixel time stamping of the arrived photons with an effective resolution of 265 ps. Together with a frame rate of 500 kfps, this property exceeds the capabilities of conventional charge-coupled device cameras which have become of growing interest for the detection of transversely correlated photon pairs. The sensor is used to measure a second-order correlation function for various non-collinear configurations of entangled photons generated by spontaneous parametric down-conversion. The experimental results are compared to theory.

  19. Fiber-pigtailed silicon photonic sensors for methane leak detection

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

    Teng, Chu; Xiong, Chi; Zhang, Eric

    We present comprehensive characterization of silicon photonic sensors for methane leak detection. Sensitivity of 40 ppmv after 1 second integration is reported. Fourier domain characterization of on-chip etalon drifts is used for further sensor improvement.

  20. Label-free virus detection using silicon photonic microring resonators

    PubMed Central

    McClellan, Melinda S.; Domier, Leslie L; Bailey, Ryan C.

    2013-01-01

    Viruses represent a continual threat to humans through a number of mechanisms, which include disease, bioterrorism, and destruction of both plant and animal food resources. Many contemporary techniques used for the detection of viruses and viral infections suffer from limitations such as the need for extensive sample preparation or the lengthy window between infection and measurable immune response, for serological methods. In order to develop a method that is fast, cost-effective, and features reduced sample preparation compared to many other virus detection methods, we report the application of silicon photonic microring resonators for the direct, label-free detection of intact viruses in both purified samples as well as in a complex, real-world analytical matrix. As a model system, we demonstrate the quantitative detection of Bean pod mottle virus, a pathogen of great agricultural importance, with a limit of detection of 10 ng/mL. By simply grinding a small amount of leaf sample in buffer with a mortar and pestle, infected leaves can be identified over a healthy control with a total analysis time of less than 45 min. Given the inherent scalability and multiplexing capability of the semiconductor-based technology, we feel that silicon photonic microring resonators are well-positioned as a promising analytical tool for a number of viral detection applications. PMID:22138465

  1. Label-free virus detection using silicon photonic microring resonators.

    PubMed

    McClellan, Melinda S; Domier, Leslie L; Bailey, Ryan C

    2012-01-15

    Viruses represent a continual threat to humans through a number of mechanisms, which include disease, bioterrorism, and destruction of both plant and animal food resources. Many contemporary techniques used for the detection of viruses and viral infections suffer from limitations such as the need for extensive sample preparation or the lengthy window between infection and measurable immune response, for serological methods. In order to develop a method that is fast, cost-effective, and features reduced sample preparation compared to many other virus detection methods, we report the application of silicon photonic microring resonators for the direct, label-free detection of intact viruses in both purified samples as well as in a complex, real-world analytical matrix. As a model system, we demonstrate the quantitative detection of Bean pod mottle virus, a pathogen of great agricultural importance, with a limit of detection of 10 ng/mL. By simply grinding a small amount of leaf sample in buffer with a mortar and pestle, infected leaves can be identified over a healthy control with a total analysis time of less than 45 min. Given the inherent scalability and multiplexing capability of the semiconductor-based technology, we feel that silicon photonic microring resonators are well-positioned as a promising analytical tool for a number of viral detection applications. Copyright © 2011 Elsevier B.V. All rights reserved.

  2. Using Quasiparticle Poisoning To Detect Photons

    NASA Technical Reports Server (NTRS)

    Echternach, Pierre; Day, Peter

    2006-01-01

    According to a proposal, a phenomenon associated with excitation of quasiparticles in certain superconducting quantum devices would be exploited as a means of detecting photons with exquisite sensitivity. The phenomenon could also be exploited to perform medium-resolution spectroscopy. The proposal was inspired by the observation that Coulomb blockade devices upon which some quantum logic gates are based are extremely sensitive to quasiparticles excited above the superconducting gaps in their leads. The presence of quasiparticles in the leads can be easily detected via the charge states. If quasiparticles could be generated in the leads by absorption of photons, then the devices could be used as very sensitive detectors of electromagnetic radiation over the spectral range from x-rays to submillimeter waves. The devices in question are single-Cooper-pair boxes (SCBs), which are mesoscopic superconducting devices developed for quantum computing. An SCB consists of a small superconducting island connected to a reservoir via a small tunnel junction and connected to a voltage source through a gate capacitor. An SCB is an artificial two-level quantum system, the Hamiltonian of which can be controlled by the gate voltage. One measures the expected value of the charge of the eigenvectors of this quantum system by use of a radio-frequency single-electron transistor. A plot of this expected value of charge as a function of gate voltage resembles a staircase that, in the ideal case, consists of steps of height 2 e (where e is the charge of one electron). Experiments have shown that depending on the parameters of the device, quasiparticles in the form of "broken" Cooper pairs present in the reservoir can tunnel to the island, giving rise to steps of 1 e. This effect is sometimes called "poisoning." Simulations have shown that an extremely small average number of quasiparticles can generate a 1-e periodic signal. In a device according to the proposal, this poisoning would be

  3. The application of microwave photonic detection in quantum communication

    NASA Astrophysics Data System (ADS)

    Diao, Wenting; Zhuang, Yongyong; Song, Xuerui; Wang, Liujun; Duan, Chongdi

    2018-03-01

    Quantum communication has attracted much attention in recent years, provides an ultimate level of security, and uniquely it is one of the most likely practical quantum technologies at present. In order to realize global coverage of quantum communication networks, not only need the help of satellite to realize wide area quantum communication, need implementation of optical fiber system to realize city to city quantum communication, but also, it is necessary to implement end-to-end quantum communications intercity and wireless quantum communications that can be received by handheld devices. Because of the limitation of application of light in buildings, it needs quantum communication with microwave band to achieve quantum reception of wireless handheld devices. The single microwave photon energy is very low, it is difficult to directly detect, which become a difficulty in microwave quantum detection. This paper summarizes the mode of single microwave photon detection methods and the possibility of application in microwave quantum communication, and promotes the development of quantum communication in microwave band and quantum radar.

  4. Detection of TNT using a sensitive two-photon organic dendrimer for remote sensing

    NASA Astrophysics Data System (ADS)

    Narayanan, Aditya; Varnavski, Oleg; Mongin, Oliver; Majoral, Jean-Pierre; Blanchard-Desce, Mireille; Goodson, Theodore, III

    2008-03-01

    There is currently a need for superior stand-off detection schemes for protection against explosive weapons of mass destruction. Fluorescence detection at small distances from the target has proven to be attractive. A novel unexplored route in fluorescence chemical sensing that utilizes the exceptional spectroscopic capabilities of nonlinear optical methods is two-photon excited fluorescence. This approach utilizes infra-red light for excitation of remote sensors. Infra-red light suffers less scattering in porous materials which is beneficial for vapor sensing and has greater depth of penetration through the atmosphere, and there are fewer concerns regarding eye safety in remote detection schemes. We demonstrate this method using a novel dendritic system which possesses both excellent fluorescence sensitivity to the presence of TNT with infra-red pulses of light and high two-photon absorption (TPA) response. This illustrates the use of TPA for potential stand-off detection of energetic materials in the infra-red spectral regions in a highly two-photon responsive dendrimer.

  5. Efficient single photon detection by quantum dot resonant tunneling diodes.

    PubMed

    Blakesley, J C; See, P; Shields, A J; Kardynał, B E; Atkinson, P; Farrer, I; Ritchie, D A

    2005-02-18

    We demonstrate that the resonant tunnel current through a double-barrier structure is sensitive to the capture of single photoexcited holes by an adjacent layer of quantum dots. This phenomenon could allow the detection of single photons with low dark count rates and high quantum efficiencies. The magnitude of the sensing current may be controlled via the thickness of the tunnel barriers. Larger currents give improved signal to noise and allow sub-mus photon time resolution.

  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 me

  7. Intensity fluctuations in bimodal micropillar lasers enhanced by quantum-dot gain competition

    NASA Astrophysics Data System (ADS)

    Leymann, H. A. M.; Hopfmann, C.; Albert, F.; Foerster, A.; Khanbekyan, M.; Schneider, C.; Höfling, S.; Forchel, A.; Kamp, M.; Wiersig, J.; Reitzenstein, S.

    2013-05-01

    We investigate correlations between orthogonally polarized cavity modes of a bimodal micropillar laser with a single layer of self-assembled quantum dots in the active region. While one emission mode of the microlaser demonstrates a characteristic S-shaped input-output curve, the output intensity of the second mode saturates and even decreases with increasing injection current above threshold. Measuring the photon autocorrelation function g(2)(τ) of the light emission confirms the onset of lasing in the first mode with g(2)(0) approaching unity above threshold. In contrast, strong photon bunching associated with superthermal values of g(2)(0) is detected for the other mode for currents above threshold. This behavior is attributed to gain competition of the two modes induced by the common gain material, which is confirmed by photon cross-correlation measurements revealing a clear anticorrelation between emission events of the two modes. The experimental studies are in qualitative agreement with theoretical studies based on a microscopic semiconductor theory, which we extend to the case of two modes interacting with the common gain medium. Moreover, we treat the problem by a phenomenological birth-death model extended to two interacting modes, which reveals that the photon probability distribution of each mode has a double-peak structure, indicating switching behavior of the modes for pump rates around threshold.

  8. Smart detection of microRNAs through fluorescence enhancement on a photonic crystal.

    PubMed

    Pasquardini, L; Potrich, C; Vaghi, V; Lunelli, L; Frascella, F; Descrovi, E; Pirri, C F; Pederzolli, C

    2016-04-01

    The detection of low abundant biomarkers, such as circulating microRNAs, demands innovative detection methods with increased resolution, sensitivity and specificity. Here, a biofunctional surface was implemented for the selective capture of microRNAs, which were detected through fluorescence enhancement directly on a photonic crystal. To set up the optimal biofunctional surface, epoxy-coated commercially available microscope slides were spotted with specific anti-microRNA probes. The optimal concentration of probe as well as of passivating agent were selected and employed for titrating the microRNA hybridization. Cross-hybridization of different microRNAs was also tested, resulting negligible. Once optimized, the protocol was adapted to the photonic crystal surface, where fluorescent synthetic miR-16 was hybridized and imaged with a dedicated equipment. The photonic crystal consists of a dielectric multilayer patterned with a grating structure. In this way, it is possible to take advantage from both a resonant excitation of fluorophores and an angularly redirection of the emitted radiation. As a result, a significant fluorescence enhancement due to the resonant structure is collected from the patterned photonic crystal with respect to the outer non-structured surface. The dedicated read-out system is compact and based on a wide-field imaging detection, with little or no optical alignment issues, which makes this approach particularly interesting for further development such as for example in microarray-type bioassays. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Picosecond timing resolution detection of ggr-photons utilizing microchannel-plate detectors: experimental tests of quantum nonlocality and photon localization

    NASA Astrophysics Data System (ADS)

    Irby, Victor D.

    2004-09-01

    The concept and subsequent experimental verification of the proportionality between pulse amplitude and detector transit time for microchannel-plate detectors is presented. This discovery has led to considerable improvement in the overall timing resolution for detection of high-energy ggr-photons. Utilizing a 22Na positron source, a full width half maximum (FWHM) timing resolution of 138 ps has been achieved. This FWHM includes detector transit-time spread for both chevron-stack-type detectors, timing spread due to uncertainties in annihilation location, all electronic uncertainty and any remaining quantum mechanical uncertainty. The first measurement of the minimum quantum uncertainty in the time interval between detection of the two annihilation photons is reported. The experimental results give strong evidence against instantaneous spatial localization of ggr-photons due to measurement-induced nonlocal quantum wavefunction collapse. The experimental results are also the first that imply momentum is conserved only after the quantum uncertainty in time has elapsed (Yukawa H 1935 Proc. Phys. Math. Soc. Japan 17 48).

  10. Low concentration biomolecular detection using liquid core photonic crystal fiber (LCPCF) SERS sensor

    NASA Astrophysics Data System (ADS)

    Shi, Chao; Zhang, Yi; Gu, Claire; Seballos, Leo; Zhang, Jin Z.

    2008-02-01

    This work demonstrates the use of a highly sensitive Liquid Core Photonic Crystal Fiber (LCPCF) Surface Enhanced Raman Scattering (SERS) sensor in detecting biological and biochemical molecules. The Photonic Crystal Fiber (PCF) probe was prepared by carefully sealing the cladding holes using a fusion splicer while leaving the central hollow core open, which ensures that the liquid mixture of the analyte and silver nanoparticles only fills in the hollow core of the PCF, therefore preserving the photonic bandgap. The dependence of the SERS signal on the excitation power and sample concentration was fully characterized using Rhodamine 6G (R6G) molecules. The result shows that the LCPCF sensor has significant advantages over flat surface SERS detections at lower concentrations. This is attributed to the lower absorption at lower concentration leading to a longer effective interaction length inside the LCPCF, which in turn, results in a stronger SERS signal. Several biomolecules, such as Prostate Specific Antigen (PSA) and alpha-synuclein, which are indicators of prostate cancer and Parkinson's disease, respectively, and fail to be detected directly, are successfully detected by the LCPCF sensor. Our results demonstrate the potential of the LCPCF SERS sensor for biomedical detection at low concentrations.

  11. Density of photon states in dye-doped chiral nematic liquid crystal cells in the presence of losses and gain.

    PubMed

    Mavrogordatos, Th K; Morris, S M; Castles, F; Hands, P J W; Ford, A D; Coles, H J; Wilkinson, T D

    2012-07-01

    We calculate the density of photon states (DOS) of the normal modes in dye-doped chiral nematic liquid crystal (LC) cells in the presence of various loss mechanisms. Losses and gain are incorporated into the transmission characteristics through the introduction of a small imaginary part in the dielectric constant perpendicular and along the director, for which we assume no frequency dispersion. Theoretical results are presented on the DOS in the region of the photonic band gap for a range of values of the loss coefficient and different values of the optical anisotropy. The obtained values of the DOS at the photonic band gap edges predict a reversal of the dominant modes in the structure. Our results are found to be in good agreement with the experimentally obtained excitation thresholds in chiral nematic LC lasers. The behavior of the DOS is also discussed for amplifying LC cells providing additional insight to the lasing mechanism of these structures.

  12. Solid-state Image Sensor with Focal-plane Digital Photon-counting Pixel Array

    NASA Technical Reports Server (NTRS)

    Fossum, Eric R.; Pain, Bedabrata

    1997-01-01

    A solid-state focal-plane imaging system comprises an NxN array of high gain. low-noise unit cells. each unit cell being connected to a different one of photovoltaic detector diodes, one for each unit cell, interspersed in the array for ultra low level image detection and a plurality of digital counters coupled to the outputs of the unit cell by a multiplexer(either a separate counter for each unit cell or a row of N of counters time shared with N rows of digital counters). Each unit cell includes two self-biasing cascode amplifiers in cascade for a high charge-to-voltage conversion gain (greater than 1mV/e(-)) and an electronic switch to reset input capacitance to a reference potential in order to be able to discriminate detection of an incident photon by the photoelectron (e(-))generated in the detector diode at the input of the first cascode amplifier in order to count incident photons individually in a digital counter connected to the output of the second cascade amplifier. Reseting the input capacitance and initiating self-biasing of the amplifiers occurs every clock cycle of an integratng period to enable ultralow light level image detection by the may of photovoltaic detector diodes under such ultralow light level conditions that the photon flux will statistically provide only a single photon at a time incident on anyone detector diode during any clock cycle.

  13. Hierarchically structured photonic crystals for integrated chemical separation and colorimetric detection.

    PubMed

    Fu, Qianqian; Zhu, Biting; Ge, Jianping

    2017-02-16

    A SiO 2 colloidal photonic crystal film with a hierarchical porous structure is fabricated to demonstrate an integrated separation and colorimetric detection of chemical species for the first time. This new photonic crystal based thin layer chromatography process requires no dyeing, developing and UV irradiation compared to the traditional TLC. The assembling of mesoporous SiO 2 particles via a supersaturation-induced-precipitation process forms uniform and hierarchical photonic crystals with micron-scale cracks and mesopores, which accelerate the diffusion of developers and intensify the adsorption/desorption between the analytes and silica for efficient separation. Meanwhile, the chemical substances infiltrated to the voids of photonic crystals cause an increase of the refractive index and a large contrast of structural colors towards the unloaded part, so that the sample spots can be directly recognized with the naked eye before and after separation.

  14. Photon-detections via probing the switching current shifts of Josephson junctions

    NASA Astrophysics Data System (ADS)

    Wang, Yiwen; Zhou, Pinjia; Wei, Lianfu; Zhang, Beihong; Wei, Qiang; Zhai, Jiquan; Xu, Weiwei; Cao, Chunhai

    2015-08-01

    Phenomenally, Cooper pairs can be broken up by external energy and thus the Cooper-pair density in the superconducting electrodes of a Josephson junction (JJ) under radiation can be lowered accordingly. Therefore, by probing the shift of the switching current through the junction, the radiation power absorbed by the superconductors can be detected. Here, we experimentally demonstrate weak optical detections in two types of JJs: Al/AlOx/Al junction (Al-J) and Nb/AlOx/Nb junction (Nb-J), with the superconducting transition temperatures Tc ≈ 1.2K and 6.8 K respectively. The photon-induced switching current shifts are measured at ultra-low temperature (T ≈ 16mK) in order to significantly suppress thermal noises. It is observed that the Al-J has a higher sensitivity than the Nb-J, which is expected since Al has a smaller superconducting gap energy than Nb. The minimum detectable optical powers (at 1550 nm) with the present Al-J and Nb-J are measured as 8 pW and 2 nW respectively, and the noise equivalent power (NEP) are estimated to be 7 ×10-11W /√{ Hz } (for Nb-J) and 3 ×10-12W /√{ Hz } (for Al-J). We also find that the observed switching current responses are dominated by the photon-induced thermal effects. Several methods are proposed to further improve the device sensitivity, so that the JJ based devices can be applicable in photon detections.

  15. Photon gating in four-dimensional ultrafast electron microscopy.

    PubMed

    Hassan, Mohammed T; Liu, Haihua; Baskin, John Spencer; Zewail, Ahmed H

    2015-10-20

    Ultrafast electron microscopy (UEM) is a pivotal tool for imaging of nanoscale structural dynamics with subparticle resolution on the time scale of atomic motion. Photon-induced near-field electron microscopy (PINEM), a key UEM technique, involves the detection of electrons that have gained energy from a femtosecond optical pulse via photon-electron coupling on nanostructures. PINEM has been applied in various fields of study, from materials science to biological imaging, exploiting the unique spatial, energy, and temporal characteristics of the PINEM electrons gained by interaction with a "single" light pulse. The further potential of photon-gated PINEM electrons in probing ultrafast dynamics of matter and the optical gating of electrons by invoking a "second" optical pulse has previously been proposed and examined theoretically in our group. Here, we experimentally demonstrate this photon-gating technique, and, through diffraction, visualize the phase transition dynamics in vanadium dioxide nanoparticles. With optical gating of PINEM electrons, imaging temporal resolution was improved by a factor of 3 or better, being limited only by the optical pulse widths. This work enables the combination of the high spatial resolution of electron microscopy and the ultrafast temporal response of the optical pulses, which provides a promising approach to attain the resolution of few femtoseconds and attoseconds in UEM.

  16. Photonic sensor devices for explosive detection.

    PubMed

    Willer, Ulrike; Schade, Wolfgang

    2009-09-01

    For the sensitive online and in situ detection of gaseous species, optical methods are ideally suited. In contrast to chemical analysis, no sample preparation is necessary and therefore spectroscopic methods should be favorable both in respect of a fast signal recovery and economically because no disposal is needed. However, spectroscopic methods are currently not widely used for security applications. We review photonic sensor devices for the detection of explosives in the gas phase as well as the condensed phase and the underlying spectroscopic techniques with respect to their adaptability for security applications, where high sensitivity, high selectivity, and a low false-alarm rate are of importance. The measurements have to be performed under ambient conditions and often remote handling or even operation in standoff configuration is needed. For handheld and portable equipment, special attention is focused on the miniaturization and examples for already-available sensor devices are given.

  17. Two-Photon Raman Gain in a Laser Driven Potassium Vapor

    DTIC Science & Technology

    1996-02-01

    between light and matter becomes highly nonlinear and the light and matter strongly couple, the systems become much more difficult to understand both...theoretically and experimentally. One example of a strongly coupled, highly nonlinear system is the two-photon laser that is based on the two-photon

  18. A TLD-based few-channel spectrometer for mixed photon, electron, and ion fields with high fluence rates.

    PubMed

    Behrens, R; Ambrosi, P

    2002-01-01

    A few-channel spectrometer for mixed photon, electron and ion radiation fields has been developed. It consists of a front layer of an etched-track detector foil for detecting protons and ions, a stack of PMMA with thermoluminescent detectors at different depths for gaining spectral information about electrons, and a stack of metallic filters with increasing cut-off photon energies, interspersed with thermoluminescent detectors for gaining spectral information about photons. From the reading of the TL detectors the spectral fluence of the electrons (400 keV to 9 MeV) and photons (20 keV to 2 MeV) can be determined by an unfolding procedure. The spectrometer can be used in pulsed radiation fields with extremely high momentary values of the fluence rate. Design and calibration of the spectrometer are described.

  19. Characterization of x-ray framing cameras for the National Ignition Facility using single photon pulse height analysis.

    PubMed

    Holder, J P; Benedetti, L R; Bradley, D K

    2016-11-01

    Single hit pulse height analysis is applied to National Ignition Facility x-ray framing cameras to quantify gain and gain variation in a single micro-channel plate-based instrument. This method allows the separation of gain from detectability in these photon-detecting devices. While pulse heights measured by standard-DC calibration methods follow the expected exponential distribution at the limit of a compound-Poisson process, gain-gated pulse heights follow a more complex distribution that may be approximated as a weighted sum of a few exponentials. We can reproduce this behavior with a simple statistical-sampling model.

  20. 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.

  1. Detection of orbital angular momentum using a photonic integrated circuit.

    PubMed

    Rui, Guanghao; Gu, Bing; Cui, Yiping; Zhan, Qiwen

    2016-06-20

    Orbital angular momentum (OAM) state of photons offer an attractive additional degree of freedom that has found a variety of applications. Measurement of OAM state, which is a critical task of these applications, demands photonic integrated devices for improved fidelity, miniaturization, and reconfiguration. Here we report the design of a silicon-integrated OAM receiver that is capable of detecting distinct and variable OAM states. Furthermore, the reconfiguration capability of the detector is achieved by applying voltage to the GeSe film to form gratings with alternate states. The resonant wavelength for arbitrary OAM state is demonstrated to be tunable in a quasi-linear manner through adjusting the duty cycle of the gratings. This work provides a viable approach for the realization of a compact integrated OAM detection device with enhanced functionality that may find important applications in optical communications and information processing with OAM states.

  2. 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.

  3. Multicolor photonic crystal laser array

    DOEpatents

    Wright, Jeremy B; Brener, Igal; Subramania, Ganapathi S; Wang, George T; Li, Qiming

    2015-04-28

    A multicolor photonic crystal laser array comprises pixels of monolithically grown gain sections each with a different emission center wavelength. As an example, two-dimensional surface-emitting photonic crystal lasers comprising broad gain-bandwidth III-nitride multiple quantum well axial heterostructures were fabricated using a novel top-down nanowire fabrication method. Single-mode lasing was obtained in the blue-violet spectral region with 60 nm of tuning (or 16% of the nominal center wavelength) that was determined purely by the photonic crystal geometry. This approach can be extended to cover the entire visible spectrum.

  4. Methodology for the Determination of the Photon Detection Efficiency of Large-Area Multi-Pixel Photon Counters

    NASA Astrophysics Data System (ADS)

    Beattie, T.; Lolos, G. J.; Papandreou, Z.; Semenov, A. Yu.; Teigrob, L. A.

    2015-08-01

    Large-area, multi-pixel photon counters will be used for the electromagnetic Barrel Calorimeter of the GlueX experiment at Jefferson Lab. These photo sensors are based on a 3 ×3 mm2 cell populated by 50 μm pixels, with 16 such cells tiled in a 4 ×4 arrangement in the array. The 16 cells are summed electronically and the signals are amplified. The photon detection efficiency of a group of first-article units at room temperature under conditions similar to those of the experiment was extracted to be (28 ±2(stat) ±2(syst))%, by employing an analysis methodology based on Poisson statistics carried out on the summed energy signals from the units.

  5. Two-Photon Absorption and Two-Photon-Induced Gain in Perovskite Quantum Dots.

    PubMed

    Nagamine, Gabriel; Rocha, Jaqueline O; Bonato, Luiz G; Nogueira, Ana F; Zaharieva, Zhanet; Watt, Andrew A R; de Brito Cruz, Carlos H; Padilha, Lazaro A

    2018-06-21

    Perovskite quantum dots (PQDs) emerged as a promising class of material for applications in lighting devices, including light emitting diodes and lasers. In this work, we explore nonlinear absorption properties of PQDs showing the spectral signatures and the size dependence of their two-photon absorption (2PA) cross-section, which can reach values higher than 10 6 GM. The large 2PA cross section allows for low threshold two-photon induced amplified spontaneous emission (ASE), which can be as low as 1.6 mJ/cm 2 . We also show that the ASE properties are strongly dependent on the nanomaterial size, and that the ASE threshold, in terms of the average number of excitons, decreases for smaller PQDs. Investigating the PQDs biexciton binding energy, we observe strong correlation between the increasing on the biexciton binding energy and the decreasing on the ASE threshold, suggesting that ASE in PQDs is a biexciton-assisted process.

  6. Crossed-coil detection of two-photon excited nuclear quadrupole resonance

    NASA Astrophysics Data System (ADS)

    Eles, Philip T.; Michal, Carl A.

    2005-08-01

    Applying a recently developed theoretical framework for determining two-photon excitation Hamiltonians using average Hamiltonian theory, we calculate the excitation produced by half-resonant irradiation of the pure quadrupole resonance of a spin-3/2 system. This formalism provides expressions for the single-quantum and double-quantum nutation frequencies as well as the Bloch-Siegert shift. The dependence of the excitation strength on RF field orientation and the appearance of the free-induction signal along an axis perpendicular to the excitation field provide an unmistakable signature of two-photon excitation. We demonstrate single- and double-quantum excitation in an axially symmetric system using 35Cl in a single crystal of potassium chlorate ( ωQ = 28 MHz) with crossed-coil detection. A rotation plot verifies the orientation dependence of the two-photon excitation, and double-quantum coherences are observed directly with the application of a static external magnetic field.

  7. Detection of fissionable materials in cargoes using monochromatic photon radiography

    NASA Astrophysics Data System (ADS)

    Danagoulian, Areg; Lanza, Richard; O'Day, Buckley; LNSP Team

    2015-04-01

    The detection of Special Nuclear Materials (e.g. Pu and U) and nuclear devices in the commercial cargo traffic is one of the challenges posed by the threat of nuclear terrorism. Radiography and active interrogation of heavily loaded cargoes require ~ 1 - 10MeV photons for penetration. In a proof-of-concept system under development at MIT, the interrogating monochromatic photon beam is produced via a 11B(d , nγ) 12C reaction. To achieve this, a boron target is used along with the 3 MeV d+ RFQ accelerator at MIT-Bates. The reactions results in the emission of very narrow 4.4 MeV and 15.1 MeV gammas lines. The photons, after traversing the cargo, are detected by an array of NaI(Tl) detectors. A spectral analysis of the transmitted gammas allows to independently determine the areal density and the atomic number (Z) of the cargo. The proposed approach could revolutionize cargo inspection, which, in its current fielded form has to rely on simple but high dose bremsstrahlung sources. Use of monochromatic sources would significantly reduce the necessary dose and allow for better determination of the cargo's atomic number. The general methodology will be described and the preliminary results from the proof-of-concept system will be presented and discussed. Supported by NSF/DNDO Collaborative Research ARI-LA Award ECCS-1348328.

  8. Target molecules detection by waveguiding in a photonic silicon membrane

    DOEpatents

    Letant, Sonia E [Livermore, CA; Van Buuren, Anthony [Livermore, CA; Terminello, Louis [Danville, CA; Hart, Bradley R [Brentwood, CA

    2006-12-26

    Disclosed herein is a porous silicon filter capable of binding and detecting biological and chemical target molecules in liquid or gas samples. A photonic waveguiding silicon filter with chemical and/or biological anchors covalently attached to the pore walls bind target molecules. The system uses transmission curve engineering principles to allow measurements to be made in situ and in real time to detect the presence of various target molecules and calculate the concentration of bound target.

  9. Three-photon N00N states generated by photon subtraction from double photon pairs.

    PubMed

    Kim, Heonoh; Park, Hee Su; Choi, Sang-Kyung

    2009-10-26

    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.

  10. 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.

  11. Physical mechanisms of timing jitter in photon detection by current-carrying superconducting nanowires

    NASA Astrophysics Data System (ADS)

    Sidorova, Mariia; Semenov, Alexej; Hübers, Heinz-Wilhelm; Charaev, Ilya; Kuzmin, Artem; Doerner, Steffen; Siegel, Michael

    2017-11-01

    We studied timing jitter in the appearance of photon counts in meandering nanowires with different fractional amount of bends. Intrinsic timing jitter, which is the probability density function of the random time delay between photon absorption in current-carrying superconducting nanowire and appearance of the normal domain, reveals two different underlying physical mechanisms. In the deterministic regime, which is realized at large photon energies and large currents, jitter is controlled by position-dependent detection threshold in straight parts of meanders. It decreases with the increase in the current. At small photon energies, jitter increases and its current dependence disappears. In this probabilistic regime jitter is controlled by Poisson process in that magnetic vortices jump randomly across the wire in areas adjacent to the bends.

  12. 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.

  13. Improved Signal Control: An Analysis of the Effects of Automatic Gain Control for Optical Signal Detection.

    DTIC Science & Technology

    1982-12-01

    period f T - switching period a - AGC control parameter q - quantum efficiency of photon to electron conversions "I - binary "one" given in terms of the...of the photons striking the surface of the detector. This rate is defined as: X(t) = (np(t)A) / hf 0 (21) where n - quantum efficiency of the photon...mw to 10 mw [Ref 5, Table 1] for infrared wavelengths. 30 Assuming all of the source’s output power is detected, the rate is calculated to be an order

  14. Detection of X-ray photons by solution-processed organic-inorganic perovskites

    PubMed Central

    Yakunin, Sergii; Sytnyk, Mykhailo; Kriegner, Dominik; Shrestha, Shreetu; Richter, Moses; Matt, Gebhard J.; Azimi, Hamed; Brabec, Christoph J.; Stangl, Julian; Kovalenko, Maksym V.; Heiss, Wolfgang

    2017-01-01

    The evolution of real-time medical diagnostic tools such as angiography and computer tomography from radiography based on photographic plates was enabled by the development of integrated solid-state X-ray photon detectors, based on conventional solid-state semiconductors. Recently, for optoelectronic devices operating in the visible and near infrared spectral regions, solution-processed organic and inorganic semiconductors have also attracted immense attention. Here we demonstrate a possibility to use such inexpensive semiconductors for sensitive detection of X-ray photons by direct photon-to-current conversion. In particular, methylammonium lead iodide perovskite (CH3NH3PbI3) offers a compelling combination of fast photoresponse and a high absorption cross-section for X-rays, owing to the heavy Pb and I atoms. Solution processed photodiodes as well as photoconductors are presented, exhibiting high values of X-ray sensitivity (up to 25 µC mGyair-1 cm-3) and responsivity (1.9×104 carriers/photon), which are commensurate with those obtained by the current solid-state technology. PMID:28553368

  15. Towards hybrid pixel detectors for energy-dispersive or soft X-ray photon science

    PubMed Central

    Jungmann-Smith, J. H.; Bergamaschi, A.; Brückner, M.; Cartier, S.; Dinapoli, R.; Greiffenberg, D.; Huthwelker, T.; Maliakal, D.; Mayilyan, D.; Medjoubi, K.; Mezza, D.; Mozzanica, A.; Ramilli, M.; Ruder, Ch.; Schädler, L.; Schmitt, B.; Shi, X.; Tinti, G.

    2016-01-01

    JUNGFRAU (adJUstiNg Gain detector FoR the Aramis User station) is a two-dimensional hybrid pixel detector for photon science applications at free-electron lasers and synchrotron light sources. The JUNGFRAU 0.4 prototype presented here is specifically geared towards low-noise performance and hence soft X-ray detection. The design, geometry and readout architecture of JUNGFRAU 0.4 correspond to those of other JUNGFRAU pixel detectors, which are charge-integrating detectors with 75 µm × 75 µm pixels. Main characteristics of JUNGFRAU 0.4 are its fixed gain and r.m.s. noise of as low as 27 e− electronic noise charge (<100 eV) with no active cooling. The 48 × 48 pixels JUNGFRAU 0.4 prototype can be combined with a charge-sharing suppression mask directly placed on the sensor, which keeps photons from hitting the charge-sharing regions of the pixels. The mask consists of a 150 µm tungsten sheet, in which 28 µm-diameter holes are laser-drilled. The mask is aligned with the pixels. The noise and gain characterization, and single-photon detection as low as 1.2 keV are shown. The performance of JUNGFRAU 0.4 without the mask and also in the charge-sharing suppression configuration (with the mask, with a ‘software mask’ or a ‘cluster finding’ algorithm) is tested, compared and evaluated, in particular with respect to the removal of the charge-sharing contribution in the spectra, the detection efficiency and the photon rate capability. Energy-dispersive and imaging experiments with fluorescence X-ray irradiation from an X-ray tube and a synchrotron light source are successfully demonstrated with an r.m.s. energy resolution of 20% (no mask) and 14% (with the mask) at 1.2 keV and of 5% at 13.3 keV. The performance evaluation of the JUNGFRAU 0.4 prototype suggests that this detection system could be the starting point for a future detector development effort for either applications in the soft X-ray energy regime or for an energy

  16. 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.

  17. The detective quantum efficiency of photon-counting x-ray detectors using cascaded-systems analyses

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

    Tanguay, Jesse; Yun, Seungman; School of Mechanical Engineering, Pusan National University, Jangjeon-dong, Geumjeong-gu, Busan 609-735

    Purpose: Single-photon counting (SPC) x-ray imaging has the potential to improve image quality and enable new advanced energy-dependent methods. The purpose of this study is to extend cascaded-systems analyses (CSA) to the description of image quality and the detective quantum efficiency (DQE) of SPC systems. Methods: Point-process theory is used to develop a method of propagating the mean signal and Wiener noise-power spectrum through a thresholding stage (required to identify x-ray interaction events). The new transfer relationships are used to describe the zero-frequency DQE of a hypothetical SPC detector including the effects of stochastic conversion of incident photons to secondarymore » quanta, secondary quantum sinks, additive noise, and threshold level. Theoretical results are compared with Monte Carlo calculations assuming the same detector model. Results: Under certain conditions, the CSA approach can be applied to SPC systems with the additional requirement of propagating the probability density function describing the total number of image-forming quanta through each stage of a cascaded model. Theoretical results including DQE show excellent agreement with Monte Carlo calculations under all conditions considered. Conclusions: Application of the CSA method shows that false counts due to additive electronic noise results in both a nonlinear image signal and increased image noise. There is a window of allowable threshold values to achieve a high DQE that depends on conversion gain, secondary quantum sinks, and additive noise.« less

  18. Improvement of antigen detection efficiency with the use of two-dimensional photonic crystal as a substrate

    NASA Astrophysics Data System (ADS)

    Dovzhenko, Dmitriy; Terekhin, Vladimir; Vokhmincev, Kirill; Sukhanova, Alyona; Nabiev, Igor

    2017-01-01

    Multiplex detection of different antigens in human serum in order to reveal diseases at the early stage is of interest nowadays. There are a lot of biosensors, which use the fluorescent labels for specific detection of analytes. For instance, common method for detection of antigens in human serum samples is enzyme-linked immunosorbent assay (ELISA). One of the most effective ways to improve the sensitivity of this detection method is the use of a substrate that could enhance the fluorescent signal and make it easier to collect. Two-dimensional (2D) photonic crystals are very suitable structures for these purposes because of the ability to enhance the luminescent signal, control the light propagation and perform the analysis directly on its surface. In our study we have calculated optimal parameters for 2D-dimensional photonic crystal consisting of the array of silicon nano-rods, fabricated such photonic crystal on a silicon substrate using reactive ion etching and showed the possibility of its efficient application as a substrate for ELISA detection of human cancer antigens.

  19. Multi-channel photon counting DOT system based on digital lock-in detection technique

    NASA Astrophysics Data System (ADS)

    Wang, Tingting; Zhao, Huijuan; Wang, Zhichao; Hou, Shaohua; Gao, Feng

    2011-02-01

    Relying on deeper penetration of light in the tissue, Diffuse Optical Tomography (DOT) achieves organ-level tomography diagnosis, which can provide information on anatomical and physiological features. DOT has been widely used in imaging of breast, neonatal cerebral oxygen status and blood oxygen kinetics observed by its non-invasive, security and other advantages. Continuous wave DOT image reconstruction algorithms need the measurement of the surface distribution of the output photon flow inspired by more than one driving source, which means that source coding is necessary. The most currently used source coding in DOT is time-division multiplexing (TDM) technology, which utilizes the optical switch to switch light into optical fiber of different locations. However, in case of large amounts of the source locations or using the multi-wavelength, the measurement time with TDM and the measurement interval between different locations within the same measurement period will therefore become too long to capture the dynamic changes in real-time. In this paper, a frequency division multiplexing source coding technology is developed, which uses light sources modulated by sine waves with different frequencies incident to the imaging chamber simultaneously. Signal corresponding to an individual source is obtained from the mixed output light using digital phase-locked detection technology at the detection end. A digital lock-in detection circuit for photon counting measurement system is implemented on a FPGA development platform. A dual-channel DOT photon counting experimental system is preliminary established, including the two continuous lasers, photon counting detectors, digital lock-in detection control circuit, and codes to control the hardware and display the results. A series of experimental measurements are taken to validate the feasibility of the system. This method developed in this paper greatly accelerates the DOT system measurement, and can also obtain the

  20. Tunable photonic cavities for in-situ spectroscopic trace gas detection

    DOEpatents

    Bond, Tiziana; Cole, Garrett; Goddard, Lynford

    2012-11-13

    Compact tunable optical cavities are provided for in-situ NIR spectroscopy. MEMS-tunable VCSEL platforms represents a solid foundation for a new class of compact, sensitive and fiber compatible sensors for fieldable, real-time, multiplexed gas detection systems. Detection limits for gases with NIR cross-sections such as O.sub.2, CH.sub.4, CO.sub.x and NO.sub.x have been predicted to approximately span from 10.sup.ths to 10s of parts per million. Exemplary oxygen detection design and a process for 760 nm continuously tunable VCSELS is provided. This technology enables in-situ self-calibrating platforms with adaptive monitoring by exploiting Photonic FPGAs.

  1. Technologic developments in the field of photonics for the detection of urinary bladder cancer.

    PubMed

    Palmer, Scott; Sokolovski, Sergei G; Rafailov, Edik; Nabi, Ghulam

    2013-12-01

    Bladder cancer is a common cause of morbidity and mortality worldwide in an aging population. Each year, thousands of people, mostly men, are diagnosed with this disease, but many of them present too late to receive optimal treatment. As with all cancers, early diagnosis of bladder cancer significantly improves the efficacy of therapy and increases survival and recurrence-free survival rates. Ongoing research has identified many limitations about the sensitivity of standard diagnostic procedures in detecting early-stage tumors and precancerous changes. The consequences of this are often tumor progression and increased tumor burden, leading to a decrease in patient quality of life and a vast increase in treatment costs. The necessity for improved early detection of bladder cancer has spurred on research into novel methods that use a wide range of biological and photonic phenomena. This review will broadly discuss standard detection methodologies and their major limitations before covering novel photonic techniques for early tumor detection and staging, assessing their diagnostic accuracy for flat and precancerous changes. We will do so in the context of both cystoscopic examination and the screening of voided urine and will also touch on the concept of using photonic technology as a surgical tool for tumor ablation. Copyright © 2013 Elsevier Inc. All rights reserved.

  2. Photon gating in four-dimensional ultrafast electron microscopy

    PubMed Central

    Hassan, Mohammed T.; Liu, Haihua; Baskin, John Spencer; Zewail, Ahmed H.

    2015-01-01

    Ultrafast electron microscopy (UEM) is a pivotal tool for imaging of nanoscale structural dynamics with subparticle resolution on the time scale of atomic motion. Photon-induced near-field electron microscopy (PINEM), a key UEM technique, involves the detection of electrons that have gained energy from a femtosecond optical pulse via photon–electron coupling on nanostructures. PINEM has been applied in various fields of study, from materials science to biological imaging, exploiting the unique spatial, energy, and temporal characteristics of the PINEM electrons gained by interaction with a “single” light pulse. The further potential of photon-gated PINEM electrons in probing ultrafast dynamics of matter and the optical gating of electrons by invoking a “second” optical pulse has previously been proposed and examined theoretically in our group. Here, we experimentally demonstrate this photon-gating technique, and, through diffraction, visualize the phase transition dynamics in vanadium dioxide nanoparticles. With optical gating of PINEM electrons, imaging temporal resolution was improved by a factor of 3 or better, being limited only by the optical pulse widths. This work enables the combination of the high spatial resolution of electron microscopy and the ultrafast temporal response of the optical pulses, which provides a promising approach to attain the resolution of few femtoseconds and attoseconds in UEM. PMID:26438835

  3. Design of Silicon Photonic Crystal Waveguides for High Gain Raman Amplification Using Two Symmetric Transvers-Electric-Like Slow-Light Modes

    NASA Astrophysics Data System (ADS)

    Hsiao, Yi-Hua; Iwamoto, Satoshi; Arakawa, Yasuhiko

    2013-04-01

    We designed silicon photonic crystal (PhC) waveguides (WGs) for efficient silicon Raman amplifiers and lasers. We adopted narrow-width WGs to utilize two symmetric transvers-electric-like (TE-like) guided modes, which permit efficient external coupling for both the pump and Stokes waves. Modifying the size and shape of air holes surrounding the line-defect WG structures could tune the frequency difference between these two modes, at the Brillouin-zone edge, to match the Raman shift of silicon. Thus, small group velocities are also available both for pump and Stokes waves simultaneously, which results in a large enhancement of Raman gain. The enhancement factor of the Raman gain in the designed structure is more than 100 times that reported previously.

  4. Measuring temporal summation in visual detection with a single-photon source.

    PubMed

    Holmes, Rebecca; Victora, Michelle; Wang, Ranxiao Frances; Kwiat, Paul G

    2017-11-01

    Temporal summation is an important feature of the visual system which combines visual signals that arrive at different times. Previous research estimated complete summation to last for 100ms for stimuli judged "just detectable." We measured the full range of temporal summation for much weaker stimuli using a new paradigm and a novel light source, developed in the field of quantum optics for generating small numbers of photons with precise timing characteristics and reduced variance in photon number. Dark-adapted participants judged whether a light was presented to the left or right of their fixation in each trial. In Experiment 1, stimuli contained a stream of photons delivered at a constant rate while the duration was systematically varied. Accuracy should increase with duration as long as the later photons can be integrated with the proceeding ones into a single signal. The temporal integration window was estimated as the point that performance no longer improved, and was found to be 650ms on average. In Experiment 2, the duration of the visual stimuli was kept short (100ms or <30ms) while the number of photons was varied to explore the efficiency of summation over the integration window compared to Experiment 1. There was some indication that temporal summation remains efficient over the integration window, although there is variation between individuals. The relatively long integration window measured in this study may be relevant to studies of the absolute visual threshold, i.e., tests of single-photon vision, where "single" photons should be separated by greater than the integration window to avoid summation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Real-Time Fluorescence Detection in Aqueous Systems by Combined and Enhanced Photonic and Surface Effects in Patterned Hollow Sphere Colloidal Photonic Crystals.

    PubMed

    Zhong, Kuo; Wang, Ling; Li, Jiaqi; Van Cleuvenbergen, Stijn; Bartic, Carmen; Song, Kai; Clays, Koen

    2017-05-16

    Hollow sphere colloidal photonic crystals (HSCPCs) exhibit the ability to maintain a high refractive index contrast after infiltration of water, leading to extremely high-quality photonic band gap effects, even in an aqueous (physiological) environment. Superhydrophilic pinning centers in a superhydrophobic environment can be used to strongly confine and concentrate water-soluble analytes. We report a strategy to realize real-time ultrasensitive fluorescence detection in patterned HSCPCs based on strongly enhanced fluorescence due to the photonic band-edge effect combined with wettability differentiation in the superhydrophobic/superhydrophilic pattern. The orthogonal nature of the two strategies allows for a multiplicative effect, resulting in an increase of two orders of magnitude in fluorescence.

  6. 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.

  7. Single photon detection and timing in the Lunar Laser Ranging Experiment.

    NASA Technical Reports Server (NTRS)

    Poultney, S. K.

    1972-01-01

    The goals of the Lunar Laser Ranging Experiment lead to the need for the measurement of a 2.5 sec time interval to an accuracy of a nanosecond or better. The systems analysis which included practical retroreflector arrays, available laser systems, and large telescopes led to the necessity of single photon detection. Operation under all background illumination conditions required auxiliary range gates and extremely narrow spectral and spatial filters in addition to the effective gate provided by the time resolution. Nanosecond timing precision at relatively high detection efficiency was obtained using the RCA C31000F photomultiplier and Ortec 270 constant fraction of pulse-height timing discriminator. The timing accuracy over the 2.5 sec interval was obtained using a digital interval with analog vernier ends. Both precision and accuracy are currently checked internally using a triggerable, nanosecond light pulser. Future measurements using sub-nanosecond laser pulses will be limited by the time resolution of single photon detectors.

  8. A new method for spatial structure detection of complex inner cavities based on 3D γ-photon imaging

    NASA Astrophysics Data System (ADS)

    Xiao, Hui; Zhao, Min; Liu, Jiantang; Liu, Jiao; Chen, Hao

    2018-05-01

    This paper presents a new three-dimensional (3D) imaging method for detecting the spatial structure of a complex inner cavity based on positron annihilation and γ-photon detection. This method first marks carrier solution by a certain radionuclide and injects it into the inner cavity where positrons are generated. Subsequently, γ-photons are released from positron annihilation, and the γ-photon detector ring is used for recording the γ-photons. Finally, the two-dimensional (2D) image slices of the inner cavity are constructed by the ordered-subset expectation maximization scheme and the 2D image slices are merged to the 3D image of the inner cavity. To eliminate the artifact in the reconstructed image due to the scattered γ-photons, a novel angle-traversal model is proposed for γ-photon single-scattering correction, in which the path of the single scattered γ-photon is analyzed from a spatial geometry perspective. Two experiments are conducted to verify the effectiveness of the proposed correction model and the advantage of the proposed testing method in detecting the spatial structure of the inner cavity, including the distribution of gas-liquid multi-phase mixture inside the inner cavity. The above two experiments indicate the potential of the proposed method as a new tool for accurately delineating the inner structures of industrial complex parts.

  9. Photon theory hypothesis about photon tunneling microscope's subwavelength resolution

    NASA Astrophysics Data System (ADS)

    Zhu, Yanbin; Ma, Junfu

    1995-09-01

    The foundation for the invention of the photon scanning tunneling microscope (PSTM) are the near field scanning optical microscope, the optical fiber technique, the total internal reflection, high sensitive opto-electronic detecting technique and computer technique etc. Recent research results show the subwavelength resolution of 1 - 3 nm is obtained. How to explain the PSTM has got such high subwavelength resolution? What value is the PSTM's limiting of subwavelength resolution? For resolving these problems this paper presented a photon theory hypothesis about PSTM that is based on the following two basic laws: (1) Photon is not only a carrier bringing energy and optical information, but also is a particle occupied fixed space size. (2) When a photon happened reflection, refraction, scattering, etc., only changed its energy and optical information carried, its particle size doesn't change. g (DOT) pphoton equals constant. Using these two basic laws to PSTM, the `evanescent field' is practically a weak photon distribution field and the detecting fiber tip diameter is practically a `gate' which size controlled the photon numbers into fiber tip. Passing through some calculation and inference, the following three conclusions can be given: (1) Under the PSTM's detection system sensitivity is high enough, the diameter D of detecting fiber tip and the near field detecting distance Z are the two most important factors to decide the subwavelength resolution of PSTM. (2) The limiting of PSTM's resolution will be given upon the conditions of D equals pphoton and Z equals pphoton, where pphoton is one photon size. (2) The final resolution limit R of PSTM will be lim R equals pphoton, D yields pphoton, Z yields pphoton.

  10. Detection of anthrax lef with DNA-based photonic crystal sensors

    NASA Astrophysics Data System (ADS)

    Zhang, Bailin; Dallo, Shatha; Peterson, Ralph; Hussain, Syed; Weitao, Tao; Ye, Jing Yong

    2011-12-01

    Bacillus anthracis has posed a threat of becoming biological weapons of mass destruction due to its virulence factors encoded by the plasmid-borne genes, such as lef for lethal factor. We report the development of a fast and sensitive anthrax DNA biosensor based on a photonic crystal structure used in a total-internal-reflection configuration. For the detection of the lef gene, a single-stranded DNA lef probe was biotinylated and immobilized onto the sensor via biotin-streptavidin interactions. A positive control, lef-com, was the complementary strand of the probe, while a negative control was an unrelated single-stranded DNA fragment from the 16S rRNA gene of Acinetobacter baumannii. After addition of the biotinylated lef probe onto the sensor, significant changes in the resonance wavelength of the sensor were observed, resulting from binding of the probe to streptavidin on the sensor. The addition of lef-com led to another significant increase as a result of hybridization between the two DNA strands. The detection sensitivity for the target DNA reached as low as 0.1 nM. In contrast, adding the unrelated DNAs did not cause an obvious shift in the resonant wavelength. These results demonstrate that detection of the anthrax lef by the photonic crystal structure in a total-internal-reflection sensor is highly specific and sensitive.

  11. Selective and reversible ammonia gas detection with nanoporous film functionalized silicon photonic micro-ring resonator.

    PubMed

    Yebo, Nebiyu A; Sree, Sreeprasanth Pulinthanathu; Levrau, Elisabeth; Detavernier, Christophe; Hens, Zeger; Martens, Johan A; Baets, Roel

    2012-05-21

    Portable, low cost and real-time gas sensors have a considerable potential in various biomedical and industrial applications. For such applications, nano-photonic gas sensors based on standard silicon fabrication technology offer attractive opportunities. Deposition of high surface area nano-porous coatings on silicon photonic sensors is a means to achieve selective, highly sensitive and multiplexed gas detection on an optical chip. Here we demonstrate selective and reversible ammonia gas detection with functionalized silicon-on-insulator optical micro-ring resonators. The micro-ring resonators are coated with acidic nano-porous aluminosilicate films for specific ammonia sensing, which results in a reversible response to NH(3)with selectivity relative to CO(2). The ammonia detection limit is estimated at about 5 ppm. The detectors reach a steady response to NH(3) within 30 and return to their base level within 60 to 90 seconds. The work opens perspectives on development of nano-photonic sensors for real-time, non-invasive, low cost and light weight biomedical and industrial sensing applications.

  12. Direct Generation and Detection of Quantum Correlated Photons with 3.2 um Wavelength Spacing.

    PubMed

    Sua, Yong Meng; Fan, Heng; Shahverdi, Amin; Chen, Jia-Yang; Huang, Yu-Ping

    2017-12-13

    Quantum correlated, highly non-degenerate photons can be used to synthesize disparate quantum nodes and link quantum processing over incompatible wavelengths, thereby constructing heterogeneous quantum systems for otherwise unattainable superior performance. Existing techniques for correlated photons have been concentrated in the visible and near-IR domains, with the photon pairs residing within one micron. Here, we demonstrate direct generation and detection of high-purity photon pairs at room temperature with 3.2 um wavelength spacing, one at 780 nm to match the rubidium D2 line, and the other at 3950 nm that falls in a transparent, low-scattering optical window for free space applications. The pairs are created via spontaneous parametric downconversion in a lithium niobate waveguide with specially designed geometry and periodic poling. The 780 nm photons are measured with a silicon avalanche photodiode, and the 3950 nm photons are measured with an upconversion photon detector using a similar waveguide, which attains 34% internal conversion efficiency. Quantum correlation measurement yields a high coincidence-to-accidental ratio of 54, which indicates the strong correlation with the extremely non-degenerate photon pairs. Our system bridges existing quantum technology to the challenging mid-IR regime, where unprecedented applications are expected in quantum metrology and sensing, quantum communications, medical diagnostics, and so on.

  13. First Direct-Detection Constraints on eV-Scale Hidden-Photon Dark Matter with DAMIC at SNOLAB

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

    Aguilar-Arevalo, A.; Amidei, D.; Bertou, X.

    We present direct detection constraints on the absorption of hidden-photon dark matter with particle masses in the range 1.2-30 eVmore » $$c^{-2}$$ with the DAMIC experiment at SNOLAB. Under the assumption that the local dark matter is entirely constituted of hidden photons, the sensitivity to the kinetic mixing parameter $$\\kappa$$ is competitive with constraints from solar emission, reaching a minimum value of 2.2$$\\times$$$10^{-14}$$ at 17 eV$$c^{-2}$$. These results are the most stringent direct detection constraints on hidden-photon dark matter with masses 3-12 eV$$c^{-2}$$ and the first demonstration of direct experimental sensitivity to ionization signals $<$12 eV from dark matter interactions.« less

  14. Authenticated Quantum Key Distribution with Collective Detection using Single Photons

    NASA Astrophysics Data System (ADS)

    Huang, Wei; Xu, Bing-Jie; Duan, Ji-Tong; Liu, Bin; Su, Qi; He, Yuan-Hang; Jia, Heng-Yue

    2016-10-01

    We present two authenticated quantum key distribution (AQKD) protocols by utilizing the idea of collective (eavesdropping) detection. One is a two-party AQKD protocol, the other is a multiparty AQKD protocol with star network topology. In these protocols, the classical channels need not be assumed to be authenticated and the single photons are used as the quantum information carriers. To achieve mutual identity authentication and establish a random key in each of the proposed protocols, only one participant should be capable of preparing and measuring single photons, and the main quantum ability that the rest of the participants should have is just performing certain unitary operations. Security analysis shows that these protocols are free from various kinds of attacks, especially the impersonation attack and the man-in-the-middle (MITM) attack.

  15. 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.

  16. 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

  17. Active integrated filters for RF-photonic channelizers.

    PubMed

    El Nagdi, Amr; Liu, Ke; LaFave, Tim P; Hunt, Louis R; Ramakrishna, Viswanath; Dabkowski, Mieczyslaw; MacFarlane, Duncan L; Christensen, Marc P

    2011-01-01

    A theoretical study of RF-photonic channelizers using four architectures formed by active integrated filters with tunable gains is presented. The integrated filters are enabled by two- and four-port nano-photonic couplers (NPCs). Lossless and three individual manufacturing cases with high transmission, high reflection, and symmetric couplers are assumed in the work. NPCs behavior is dependent upon the phenomenon of frustrated total internal reflection. Experimentally, photonic channelizers are fabricated in one single semiconductor chip on multi-quantum well epitaxial InP wafers using conventional microelectronics processing techniques. A state space modeling approach is used to derive the transfer functions and analyze the stability of these filters. The ability of adapting using the gains is demonstrated. Our simulation results indicate that the characteristic bandpass and notch filter responses of each structure are the basis of channelizer architectures, and optical gain may be used to adjust filter parameters to obtain a desired frequency magnitude response, especially in the range of 1-5 GHz for the chip with a coupler separation of ∼9 mm. Preliminarily, the measurement of spectral response shows enhancement of quality factor by using higher optical gains. The present compact active filters on an InP-based integrated photonic circuit hold the potential for a variety of channelizer applications. Compared to a pure RF channelizer, photonic channelizers may perform both channelization and down-conversion in an optical domain.

  18. Atom detection and photon production in a scalable, open, optical microcavity.

    PubMed

    Trupke, M; Goldwin, J; Darquié, B; Dutier, G; Eriksson, S; Ashmore, J; Hinds, E A

    2007-08-10

    A microfabricated Fabry-Perot optical resonator has been used for atom detection and photon production with less than 1 atom on average in the cavity mode. Our cavity design combines the intrinsic scalability of microfabrication processes with direct coupling of the cavity field to single-mode optical waveguides or fibers. The presence of the atom is seen through changes in both the intensity and the noise characteristics of probe light reflected from the cavity input mirror. An excitation laser passing transversely through the cavity triggers photon emission into the cavity mode and hence into the single-mode fiber. These are first steps toward building an optical microcavity network on an atom chip for applications in quantum information processing.

  19. Strongly Iridescent Hybrid Photonic Sensors Based on Self-Assembled Nanoparticles for Hazardous Solvent Detection.

    PubMed

    Sato, Ayaka; Ikeda, Yuya; Yamaguchi, Koichi; Vohra, Varun

    2018-03-16

    Facile detection and the identification of hazardous organic solvents are essential for ensuring global safety and avoiding harm to the environment caused by industrial wastes. Here, we present a simple method for the fabrication of silver-coated monodisperse polystyrene nanoparticle photonic structures that are embedded into a polydimethylsiloxane (PDMS) matrix. These hybrid materials exhibit a strong green iridescence with a reflectance peak at 550 nm that originates from the close-packed arrangement of the nanoparticles. This reflectance peak measured under Wulff-Bragg conditions displays a 20 to 50 nm red shift when the photonic sensors are exposed to five commonly employed and highly hazardous organic solvents. These red-shifts correlate well with PDMS swelling ratios using the various solvents, which suggests that the observable color variations result from an increase in the photonic crystal lattice parameter with a similar mechanism to the color modulation of the chameleon skin. Dynamic reflectance measurements enable the possibility of clearly identifying each of the tested solvents. Furthermore, as small amounts of hazardous solvents such as tetrahydrofuran can be detected even when mixed with water, the nanostructured solvent sensors we introduce here could have a major impact on global safety measures as innovative photonic technology for easily visualizing and identifying the presence of contaminants in water.

  20. Detection of single nano-defects in photonic crystals between crossed polarizers.

    PubMed

    Grepstad, Jon Olav; Kaspar, Peter; Johansen, Ib-Rune; Solgaard, Olav; Sudbø, Aasmund

    2013-12-16

    We investigate, by simulations and experiments, the light scattering of small particles trapped in photonic crystal membranes supporting guided resonance modes. Our results show that, due to amplified Rayleigh small particle scattering, such membranes can be utilized to make a sensor that can detect single nano-particles. We have designed a biomolecule sensor that uses cross-polarized excitation and detection for increased sensitivity. Estimated using Rayleigh scattering theory and simulation results, the current fabricated sensor has a detection limit of 26 nm, corresponding to the size of a single virus. The sensor can potentially be made both cheap and compact, to facilitate use at point-of-care.

  1. First Direct-Detection Constraints on eV-Scale Hidden-Photon Dark Matter with DAMIC at SNOLAB.

    PubMed

    Aguilar-Arevalo, A; Amidei, D; Bertou, X; Butner, M; Cancelo, G; Castañeda Vázquez, A; Cervantes Vergara, B A; Chavarria, A E; Chavez, C R; de Mello Neto, J R T; D'Olivo, J C; Estrada, J; Fernandez Moroni, G; Gaïor, R; Guardincerri, Y; Hernández Torres, K P; Izraelevitch, F; Kavner, A; Kilminster, B; Lawson, I; Letessier-Selvon, A; Liao, J; Matalon, A; Mello, V B B; Molina, J; Privitera, P; Ramanathan, K; Sarkis, Y; Schwarz, T; Settimo, M; Sofo Haro, M; Thomas, R; Tiffenberg, J; Tiouchichine, E; Torres Machado, D; Trillaud, F; You, X; Zhou, J

    2017-04-07

    We present direct detection constraints on the absorption of hidden-photon dark matter with particle masses in the range 1.2-30  eV c^{-2} with the DAMIC experiment at SNOLAB. Under the assumption that the local dark matter is entirely constituted of hidden photons, the sensitivity to the kinetic mixing parameter κ is competitive with constraints from solar emission, reaching a minimum value of 2.2×10^{-14} at 17  eV c^{-2}. These results are the most stringent direct detection constraints on hidden-photon dark matter in the galactic halo with masses 3-12  eV c^{-2} and the first demonstration of direct experimental sensitivity to ionization signals <12  eV from dark matter interactions.

  2. 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.

  3. Neutron detection with a NaI spectrometer using high-energy photons

    NASA Astrophysics Data System (ADS)

    Holm, Philip; Peräjärvi, Kari; Sihvonen, Ari-Pekka; Siiskonen, Teemu; Toivonen, Harri

    2013-01-01

    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.

  4. CMOS-compatible photonic devices for single-photon generation

    NASA Astrophysics Data System (ADS)

    Xiong, Chunle; Bell, Bryn; Eggleton, Benjamin J.

    2016-09-01

    Sources of single photons are one of the key building blocks for quantum photonic technologies such as quantum secure communication and powerful quantum computing. To bring the proof-of-principle demonstration of these technologies from the laboratory to the real world, complementary metal-oxide-semiconductor (CMOS)-compatible photonic chips are highly desirable for photon generation, manipulation, processing and even detection because of their compactness, scalability, robustness, and the potential for integration with electronics. In this paper, we review the development of photonic devices made from materials (e.g., silicon) and processes that are compatible with CMOS fabrication facilities for the generation of single photons.

  5. Photon correlation in single-photon frequency upconversion.

    PubMed

    Gu, Xiaorong; Huang, Kun; Pan, Haifeng; Wu, E; Zeng, Heping

    2012-01-30

    We experimentally investigated the intensity cross-correlation between the upconverted photons and the unconverted photons in the single-photon frequency upconversion process with multi-longitudinal mode pump and signal sources. In theoretical analysis, with this multi-longitudinal mode of both signal and pump sources system, the properties of the signal photons could also be maintained as in the single-mode frequency upconversion system. Experimentally, based on the conversion efficiency of 80.5%, the joint probability of simultaneously detecting at upconverted and unconverted photons showed an anti-correlation as a function of conversion efficiency which indicated the upconverted photons were one-to-one from the signal photons. While due to the coherent state of the signal photons, the intensity cross-correlation function g(2)(0) was shown to be equal to unity at any conversion efficiency, agreeing with the theoretical prediction. This study will benefit the high-speed wavelength-tunable quantum state translation or photonic quantum interface together with the mature frequency tuning or longitudinal mode selection techniques.

  6. Photonic crystal waveguide-based biosensor for detection of diseases

    NASA Astrophysics Data System (ADS)

    Chopra, Harshita; Kaler, Rajinder S.; Painam, Balveer

    2016-07-01

    A biosensor is a device that is used to detect the analytes or molecules of a sample by means of a binding mechanism. A two-dimensional photonic crystal waveguide-based biosensor is designed with a diamond-shaped ring resonator and two waveguides: a bus waveguide and a drop waveguide. The sensing mechanism is based on change in refractive index of the analytes, leading to a shift in the peak resonant wavelength. This mechanism can be used in the field of biomedical treatment where different body fluids such as blood, tears, saliva, or urine can be used as the analyte in which different components of the fluid can be detected. It can also be used to differentiate between the cell lines of a normal and an unhealthy human being. Average value of quality factor for this device comes out to be 1082.2063. For different analytes used, the device exhibits enhanced sensitivity and, hence, it is useful for the detection of diseases.

  7. Method for universal detection of two-photon polarization entanglement

    NASA Astrophysics Data System (ADS)

    Bartkiewicz, Karol; Horodecki, Paweł; Lemr, Karel; Miranowicz, Adam; Życzkowski, Karol

    2015-03-01

    Detecting and quantifying quantum entanglement of a given unknown state poses problems that are fundamentally important for quantum information processing. Surprisingly, no direct (i.e., without quantum tomography) universal experimental implementation of a necessary and sufficient test of entanglement has been designed even for a general two-qubit state. Here we propose an experimental method for detecting a collective universal witness, which is a necessary and sufficient test of two-photon polarization entanglement. It allows us to detect entanglement for any two-qubit mixed state and to establish tight upper and lower bounds on its amount. A different element of this method is the sequential character of its main components, which allows us to obtain relatively complicated information about quantum correlations with the help of simple linear-optical elements. As such, this proposal realizes a universal two-qubit entanglement test within the present state of the art of quantum optics. We show the optimality of our setup with respect to the minimal number of measured quantities.

  8. Single photon counting fluorescence lifetime detection of pericellular oxygen concentrations

    NASA Astrophysics Data System (ADS)

    Hosny, Neveen A.; Lee, David A.; Knight, Martin M.

    2012-01-01

    Fluorescence lifetime imaging microscopy offers a non-invasive method for quantifying local oxygen concentrations. However, existing methods are either invasive, require custom-made systems, or show limited spatial resolution. Therefore, these methods are unsuitable for investigation of pericellular oxygen concentrations. This study describes an adaptation of commercially available equipment which has been optimized for quantitative extracellular oxygen detection with high lifetime accuracy and spatial resolution while avoiding systematic photon pile-up. The oxygen sensitive fluorescent dye, tris(2,2'-bipyridyl)ruthenium(II) chloride hexahydrate [Ru(bipy)3]2+, was excited using a two-photon excitation laser. Lifetime was measured using a Becker & Hickl time-correlated single photon counting, which will be referred to as a TCSPC card. [Ru(bipy)3]2+ characterization studies quantified the influences of temperature, pH, cellular culture media and oxygen on the fluorescence lifetime measurements. This provided a precisely calibrated and accurate system for quantification of pericellular oxygen concentration based on measured lifetimes. Using this technique, quantification of oxygen concentrations around isolated viable chondrocytes, seeded in three-dimensional agarose gel, revealed a subpopulation of cells that exhibited significant spatial oxygen gradients such that oxygen concentration reduced with increasing proximity to the cell. This technique provides a powerful tool for quantifying spatial oxygen gradients within three-dimensional cellular models.

  9. Single photon counting fluorescence lifetime detection of pericellular oxygen concentrations.

    PubMed

    Hosny, Neveen A; Lee, David A; Knight, Martin M

    2012-01-01

    Fluorescence lifetime imaging microscopy offers a non-invasive method for quantifying local oxygen concentrations. However, existing methods are either invasive, require custom-made systems, or show limited spatial resolution. Therefore, these methods are unsuitable for investigation of pericellular oxygen concentrations. This study describes an adaptation of commercially available equipment which has been optimized for quantitative extracellular oxygen detection with high lifetime accuracy and spatial resolution while avoiding systematic photon pile-up. The oxygen sensitive fluorescent dye, tris(2,2'-bipyridyl)ruthenium(II) chloride hexahydrate [Ru(bipy)(3)](2+), was excited using a two-photon excitation laser. Lifetime was measured using a Becker & Hickl time-correlated single photon counting, which will be referred to as a TCSPC card. [Ru(bipy)(3)](2+) characterization studies quantified the influences of temperature, pH, cellular culture media and oxygen on the fluorescence lifetime measurements. This provided a precisely calibrated and accurate system for quantification of pericellular oxygen concentration based on measured lifetimes. Using this technique, quantification of oxygen concentrations around isolated viable chondrocytes, seeded in three-dimensional agarose gel, revealed a subpopulation of cells that exhibited significant spatial oxygen gradients such that oxygen concentration reduced with increasing proximity to the cell. This technique provides a powerful tool for quantifying spatial oxygen gradients within three-dimensional cellular models.

  10. Self-assembled block copolymer photonic crystal for selective fructose detection.

    PubMed

    Ayyub, Omar B; Ibrahim, Michael B; Briber, Robert M; Kofinas, Peter

    2013-08-15

    The use of one-dimensional photonic crystals fabricated from a self-assembled lamellar block copolymer as a sensitive and selective fructose sensor is investigated. The polystyrene-b-poly(2-vinyl pyridine) (PS-b-P2VP) films are functionalized with 2-(bromomethyl)phenylboronic acid. The boronic acid moiety confined within the lamellar morphology can reversibly bind to sugars such as fructose, imparting the photonic properties of the PS-b-P2VP film. The films exhibit a detection limit of 500 μM in water and 1mM in phosphate buffered saline. Exposure to a 50 mM solution of fructose invokes a highly visible color change from blue to orange. The films are also able to selectively recognize and respond to fructose in competitive studies in the presence of glucose, mannose and sucrose. Copyright © 2013 Elsevier B.V. All rights reserved.

  11. National Photonics Skills Standard for Technicians.

    ERIC Educational Resources Information Center

    Center for Occupational Research and Development, Inc., Waco, TX.

    This document defines "photonics" as the generation, manipulation, transport, detection, and use of light information and energy whose quantum unit is the photon. The range of applications of photonics extends from energy generation to detection to communication and information processing. Photonics is at the heart of today's…

  12. Supramolecular assembly affording a ratiometric two-photon fluorescent nanoprobe for quantitative detection and bioimaging.

    PubMed

    Wang, Peng; Zhang, Cheng; Liu, Hong-Wen; Xiong, Mengyi; Yin, Sheng-Yan; Yang, Yue; Hu, Xiao-Xiao; Yin, Xia; Zhang, Xiao-Bing; Tan, Weihong

    2017-12-01

    Fluorescence quantitative analyses for vital biomolecules are in great demand in biomedical science owing to their unique detection advantages with rapid, sensitive, non-damaging and specific identification. However, available fluorescence strategies for quantitative detection are usually hard to design and achieve. Inspired by supramolecular chemistry, a two-photon-excited fluorescent supramolecular nanoplatform ( TPSNP ) was designed for quantitative analysis with three parts: host molecules (β-CD polymers), a guest fluorophore of sensing probes (Np-Ad) and a guest internal reference (NpRh-Ad). In this strategy, the TPSNP possesses the merits of (i) improved water-solubility and biocompatibility; (ii) increased tissue penetration depth for bioimaging by two-photon excitation; (iii) quantitative and tunable assembly of functional guest molecules to obtain optimized detection conditions; (iv) a common approach to avoid the limitation of complicated design by adjustment of sensing probes; and (v) accurate quantitative analysis by virtue of reference molecules. As a proof-of-concept, we utilized the two-photon fluorescent probe NHS-Ad-based TPSNP-1 to realize accurate quantitative analysis of hydrogen sulfide (H 2 S), with high sensitivity and good selectivity in live cells, deep tissues and ex vivo -dissected organs, suggesting that the TPSNP is an ideal quantitative indicator for clinical samples. What's more, TPSNP will pave the way for designing and preparing advanced supramolecular sensors for biosensing and biomedicine.

  13. Comparison of detection limit in fiber-based conventional, amplified, and gain-clamped cavity ring-down techniques

    NASA Astrophysics Data System (ADS)

    Sharma, K.; Abdul Khudus, M. I. M.; Alam, S. U.; Bhattacharya, S.; Venkitesh, D.; Brambilla, G.

    2018-01-01

    Relative performance and detection limit of conventional, amplified, and gain-clamped cavity ring-down techniques (CRDT) in all-fiber configurations are compared experimentally for the first time. Refractive index measurement using evanescent field in tapered fibers is used as a benchmark for the comparison. The systematic optimization of a nested-loop configuration in gain-clamped CRDT is also discussed, which is crucial for achieving a constant gain in a CRDT experiment. It is found that even though conventional CRDT has the lowest standard error in ring-down time (Δτ), the value of ring-down time (τ) is very small, thus leading to poor detection limit. Amplified CRDT provides an improvement in τ, albeit with two orders of magnitude higher Δτ due to amplifier noise. The nested-loop configuration in gain-clamped CRDT helps in reducing Δτ by an order of magnitude as compared to amplified CRDT whilst retaining the improvement in τ. A detection limit of 1 . 03 × 10-4 RIU at refractive index of 1.322 with a 3 mm long and 4.5 μm diameter tapered fiber is demonstrated with the gain-clamped CRDT.

  14. Gun muzzle flash detection using a CMOS single photon avalanche diode

    NASA Astrophysics Data System (ADS)

    Merhav, Tomer; Savuskan, Vitali; Nemirovsky, Yael

    2013-10-01

    Si based sensors, in particular CMOS Image sensors, have revolutionized low cost imaging systems but to date have hardly been considered as possible candidates for gun muzzle flash detection, due to performance limitations, and low SNR in the visible spectrum. In this study, a CMOS Single Photon Avalanche Diode (SPAD) module is used to record and sample muzzle flash events in the visible spectrum, from representative weapons, common on the modern battlefield. SPADs possess two crucial properties for muzzle flash imaging - Namely, very high photon detection sensitivity, coupled with a unique ability to convert the optical signal to a digital signal at the source pixel, thus practically eliminating readout noise. This enables high sampling frequencies in the kilohertz range without SNR degradation, in contrast to regular CMOS image sensors. To date, the SPAD has not been utilized for flash detection in an uncontrolled environment, such as gun muzzle flash detection. Gun propellant manufacturers use alkali salts to suppress secondary flashes ignited during the muzzle flash event. Common alkali salts are compounds based on Potassium or Sodium, with spectral emission lines around 769nm and 589nm, respectively. A narrow band filter around the Potassium emission doublet is used in this study to favor the muzzle flash signal over solar radiation. This research will demonstrate the SPAD's ability to accurately sample and reconstruct the temporal behavior of the muzzle flash in the visible wavelength under the specified imaging conditions. The reconstructed signal is clearly distinguishable from background clutter, through exploitation of flash temporal characteristics.

  15. Ideal-observer detectability in photon-counting differential phase-contrast imaging using a linear-systems approach

    PubMed Central

    Fredenberg, Erik; Danielsson, Mats; Stayman, J. Webster; Siewerdsen, Jeffrey H.; Åslund, Magnus

    2012-01-01

    Purpose: To provide a cascaded-systems framework based on the noise-power spectrum (NPS), modulation transfer function (MTF), and noise-equivalent number of quanta (NEQ) for quantitative evaluation of differential phase-contrast imaging (Talbot interferometry) in relation to conventional absorption contrast under equal-dose, equal-geometry, and, to some extent, equal-photon-economy constraints. The focus is a geometry for photon-counting mammography. Methods: Phase-contrast imaging is a promising technology that may emerge as an alternative or adjunct to conventional absorption contrast. In particular, phase contrast may increase the signal-difference-to-noise ratio compared to absorption contrast because the difference in phase shift between soft-tissue structures is often substantially larger than the absorption difference. We have developed a comprehensive cascaded-systems framework to investigate Talbot interferometry, which is a technique for differential phase-contrast imaging. Analytical expressions for the MTF and NPS were derived to calculate the NEQ and a task-specific ideal-observer detectability index under assumptions of linearity and shift invariance. Talbot interferometry was compared to absorption contrast at equal dose, and using either a plane wave or a spherical wave in a conceivable mammography geometry. The impact of source size and spectrum bandwidth was included in the framework, and the trade-off with photon economy was investigated in some detail. Wave-propagation simulations were used to verify the analytical expressions and to generate example images. Results: Talbot interferometry inherently detects the differential of the phase, which led to a maximum in NEQ at high spatial frequencies, whereas the absorption-contrast NEQ decreased monotonically with frequency. Further, phase contrast detects differences in density rather than atomic number, and the optimal imaging energy was found to be a factor of 1.7 higher than for absorption

  16. Radio for hidden-photon dark matter detection

    DOE PAGES

    Chaudhuri, Saptarshi; Graham, Peter W.; Irwin, Kent; ...

    2015-10-08

    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

  17. Demonstration of optical parametric gain generation in the 1 μm regime based on a photonic crystal fiber pumped by a picosecond mode-locked ytterbium-doped fiber laser

    NASA Astrophysics Data System (ADS)

    Zhang, Lei; Yang, Si-Gang; Wang, Xiao-Jian; Gou, Dou-Dou; Chen, Hong-Wei; Chen, Ming-Hua; Xie, Shi-Zhong

    2014-01-01

    We report the experimental demonstration of the optical parametric gain generation in the 1 μm regime based on a photonic crystal fiber (PCF) with a zero group velocity dispersion (GVD) wavelength of 1062 nm pumped by a homemade tunable picosecond mode-locked ytterbium-doped fiber laser. A broad parametric gain band is obtained by pumping the PCF in the anomalous GVD regime with a relatively low power. Two separated narrow parametric gain bands are observed by pumping the PCF in the normal GVD regime. The peak of the parametric gain profile can be tuned from 927 to 1038 nm and from 1099 to 1228 nm. This widely tunable parametric gain band can be used for a broad band optical parametric amplifier, large span wavelength conversion or a tunable optical parametric oscillator.

  18. Two-Photon Probes for Lysosomes and Mitochondria: Simultaneous Detection of Lysosomes and Mitochondria in Live Tissues by Dual-Color Two-Photon Microscopy Imaging.

    PubMed

    Lim, Chang Su; Hong, Seung Taek; Ryu, Seong Shick; Kang, Dong Eun; Cho, Bong Rae

    2015-10-01

    Novel two-photon (TP) probes were developed for lysosomes (PLT-yellow) and mitochondria (BMT-blue and PMT-yellow). These probes emitted strong TP-excited fluorescence in cells at widely separated wavelength regions and displayed high organelle selectivity, good cell permeability, low cytotoxicity, and pH insensitivity. The BMT-blue and PLT-yellow probes could be utilized to detect lysosomes and mitochondria simultaneously in live tissues by using dual-color two-photon microscopy, with minimum interference from each other. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Gain modulation by graphene plasmons in aperiodic lattice lasers

    NASA Astrophysics Data System (ADS)

    Chakraborty, S.; Marshall, O. P.; Folland, T. G.; Kim, Y.-J.; Grigorenko, A. N.; Novoselov, K. S.

    2016-01-01

    Two-dimensional graphene plasmon-based technologies will enable the development of fast, compact, and inexpensive active photonic elements because, unlike plasmons in other materials, graphene plasmons can be tuned via the doping level. Such tuning is harnessed within terahertz quantum cascade lasers to reversibly alter their emission. This is achieved in two key steps: first, by exciting graphene plasmons within an aperiodic lattice laser and, second, by engineering photon lifetimes, linking graphene’s Fermi energy with the round-trip gain. Modal gain and hence laser spectra are highly sensitive to the doping of an integrated, electrically controllable, graphene layer. Demonstration of the integrated graphene plasmon laser principle lays the foundation for a new generation of active, programmable plasmonic metamaterials with major implications across photonics, material sciences, and nanotechnology.

  20. Photon counting detector for the personal radiography inspection system "SIBSCAN"

    NASA Astrophysics Data System (ADS)

    Babichev, E. A.; Baru, S. E.; Grigoriev, D. N.; Leonov, V. V.; Oleynikov, V. P.; Porosev, V. V.; Savinov, G. A.

    2017-02-01

    X-ray detectors operating in the energy integrating mode are successfully used in many different applications. Nevertheless the direct photon counting detectors, having the superior parameters in comparison with the integrating ones, are rarely used yet. One of the reasons for this is the low value of the electrical signal generated by a detected photon. Silicon photomultiplier (SiPM) based scintillation counters have a high detection efficiency, high electronic gain and compact dimensions. This makes them a very attractive candidate to replace routinely used detectors in many fields. More than 10 years ago the digital scanning radiography system based on multistrip ionization chamber (MIC) was suggested at Budker Institute of Nuclear Physics. The detector demonstrates excellent radiation resistance and parameter stability after 5 year operations and an imaging of up to 1000 persons per day. Currently, the installations operate at several Russian airports and at subway stations in some cities. At the present time we design a new detector operating in the photon counting mode, having superior parameters than the gas one, based on scintillator - SiPM assemblies. This detector has close to zero noise, higher quantum efficiency and a count rate capability of more than 5 MHz per channel (20% losses), which leads to better image quality and improved detection capability. The suggested detector technology could be expanded to medical applications.

  1. Silicon photonics for high-performance interconnection networks

    NASA Astrophysics Data System (ADS)

    Biberman, Aleksandr

    2011-12-01

    We assert in the course of this work that silicon photonics has the potential to be a key disruptive technology in computing and communication industries. The enduring pursuit of performance gains in computing, combined with stringent power constraints, has fostered the ever-growing computational parallelism associated with chip multiprocessors, memory systems, high-performance computing systems, and data centers. Sustaining these parallelism growths introduces unique challenges for on- and off-chip communications, shifting the focus toward novel and fundamentally different communication approaches. This work showcases that chip-scale photonic interconnection networks, enabled by high-performance silicon photonic devices, enable unprecedented bandwidth scalability with reduced power consumption. We demonstrate that the silicon photonic platforms have already produced all the high-performance photonic devices required to realize these types of networks. Through extensive empirical characterization in much of this work, we demonstrate such feasibility of waveguides, modulators, switches, and photodetectors. We also demonstrate systems that simultaneously combine many functionalities to achieve more complex building blocks. Furthermore, we leverage the unique properties of available silicon photonic materials to create novel silicon photonic devices, subsystems, network topologies, and architectures to enable unprecedented performance of these photonic interconnection networks and computing systems. We show that the advantages of photonic interconnection networks extend far beyond the chip, offering advanced communication environments for memory systems, high-performance computing systems, and data centers. Furthermore, we explore the immense potential of all-optical functionalities implemented using parametric processing in the silicon platform, demonstrating unique methods that have the ability to revolutionize computation and communication. Silicon photonics

  2. Two-photon interference of polarization-entangled photons in a Franson interferometer.

    PubMed

    Kim, Heonoh; Lee, Sang Min; Kwon, Osung; Moon, Han Seb

    2017-07-18

    We present two-photon interference experiments with polarization-entangled photon pairs in a polarization-based Franson-type interferometer. Although the two photons do not meet at a common beamsplitter, a phase-insensitive Hong-Ou-Mandel type two-photon interference peak and dip fringes are observed, resulting from the two-photon interference effect between two indistinguishable two-photon probability amplitudes leading to a coincidence detection. A spatial quantum beating fringe is also measured for nondegenerate photon pairs in the same interferometer, although the two-photon states have no frequency entanglement. When unentangled polarization-correlated photons are used as an input state, the polarization entanglement is successfully recovered through the interferometer via delayed compensation.

  3. Detection of Myoglobin with an Open-Cavity-Based Label-Free Photonic Crystal Biosensor.

    PubMed

    Zhang, Bailin; Tamez-Vela, Juan Manuel; Solis, Steven; Bustamante, Gilbert; Peterson, Ralph; Rahman, Shafiqur; Morales, Andres; Tang, Liang; Ye, Jing Yong

    2013-01-01

    The label-free detection of one of the cardiac biomarkers, myoglobin, using a photonic-crystal-based biosensor in a total-internal-reflection configuration (PC-TIR) is presented in this paper. The PC-TIR sensor possesses a unique open optical microcavity that allows for several key advantages in biomolecular assays. In contrast to a conventional closed microcavity, the open configuration allows easy functionalization of the sensing surface for rapid biomolecular binding assays. Moreover, the properties of PC structures make it easy to be designed and engineered for operating at any optical wavelength. Through fine design of the photonic crystal structure, biochemical modification of the sensor surface, and integration with a microfluidic system, we have demonstrated that the detection sensitivity of the sensor for myoglobin has reached the clinically significant concentration range, enabling potential usage of this biosensor for diagnosis of acute myocardial infarction. The real-time response of the sensor to the myoglobin binding may potentially provide point-of-care monitoring of patients and treatment effects.

  4. Terahertz detection of alcohol using a photonic crystal fiber sensor.

    PubMed

    Sultana, Jakeya; Islam, Md Saiful; Ahmed, Kawsar; Dinovitser, Alex; Ng, Brian W-H; Abbott, Derek

    2018-04-01

    Ethanol is widely used in chemical industrial processes as well as in the food and beverage industry. Therefore, methods of detecting alcohol must be accurate, precise, and reliable. In this content, a novel Zeonex-based photonic crystal fiber (PCF) has been modeled and analyzed for ethanol detection in terahertz frequency range. A finite-element-method-based simulation of the PCF sensor shows a high relative sensitivity of 68.87% with negligible confinement loss of 7.79×10 -12    cm -1 at 1 THz frequency and x -polarization mode. Moreover, the core power fraction, birefringence, effective material loss, dispersion, and numerical aperture are also determined in the terahertz frequency range. Owing to the simple fiber structure, existing fabrication methods are feasible. With the outstanding waveguiding properties, the proposed sensor can potentially be used in ethanol detection, as well as polarization-preserving applications of terahertz waves.

  5. Excess noise in gain-guided amplifiers

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

    Deutsch, I.H.; Garrison, J.C.; Wright, E.M.

    1991-06-01

    A second-quantized theory of the radiation field is used to study the origin of the excess noise observed in gain-guided amplifiers. We find that the reduction of the signal-to-noise ratio is a function of the length of the amplifier, and thus the enhancement of the noise is a propagation effect arising from longitudinally inhomogeneous gain of the noise rather than from an excess of local spontaneous emission. We confirm this conclusion by showing that the microscopic rate of spontaneous emission into a given non-power-orthogonal cavity mode is not enhanced by the Petermann factor. In addition, we illustrate the difficulties associatedmore » with photon statistics for this and other open systems by showing that no acceptable family of photon-number operators corresponds to a set of non-power-orthogonal cavity modes.« less

  6. Quantum imaging with undetected photons.

    PubMed

    Lemos, Gabriela Barreto; Borish, Victoria; Cole, Garrett D; Ramelow, Sven; Lapkiewicz, Radek; Zeilinger, Anton

    2014-08-28

    Information is central to quantum mechanics. In particular, quantum interference occurs only if there exists no information to distinguish between the superposed states. The mere possibility of obtaining information that could distinguish between overlapping states inhibits quantum interference. Here we introduce and experimentally demonstrate a quantum imaging concept based on induced coherence without induced emission. Our experiment uses two separate down-conversion nonlinear crystals (numbered NL1 and NL2), each illuminated by the same pump laser, creating one pair of photons (denoted idler and signal). If the photon pair is created in NL1, one photon (the idler) passes through the object to be imaged and is overlapped with the idler amplitude created in NL2, its source thus being undefined. Interference of the signal amplitudes coming from the two crystals then reveals the image of the object. The photons that pass through the imaged object (idler photons from NL1) are never detected, while we obtain images exclusively with the signal photons (from NL1 and NL2), which do not interact with the object. Our experiment is fundamentally different from previous quantum imaging techniques, such as interaction-free imaging or ghost imaging, because now the photons used to illuminate the object do not have to be detected at all and no coincidence detection is necessary. This enables the probe wavelength to be chosen in a range for which suitable detectors are not available. To illustrate this, we show images of objects that are either opaque or invisible to the detected photons. Our experiment is a prototype in quantum information--knowledge can be extracted by, and about, a photon that is never detected.

  7. Heat Capacity and Thermal Conductance Measurements of a Superconducting-Normal Mixed State by Detection of Single 3 eV Photons in a Magnetic Penetration Thermometer

    NASA Technical Reports Server (NTRS)

    Stevenson, T. R.; Balvin, M. A.; Bandler, S. R.; Denis, K. L.; Lee, S.-J.; Nagler, P. C.; Smith, S. J.

    2015-01-01

    We report on measurements of the detected signal pulses in a molybdenum-gold Magnetic Penetration Thermometer (MPT) in response to absorption of one or more 3 eV photons. We designed and used this MPT sensor for x-ray microcalorimetry. In this device, the diamagnetic response of a superconducting MoAu bilayer is used to sense temperature changes in response to absorbed photons, and responsivity is enhanced by a Meissner transition in which the magnetic flux penetrating the sensor changes rapidly to minimize free energy in a mixed superconducting normal state. We have previously reported on use of our MPT to study a thermal phonon energy loss to the substrate when absorbing x-rays. We now describe results of extracting heat capacity C and thermal conductance G values from pulse height and decay time of MPT pulses generated by 3 eV photons. The variation in C and G at temperatures near the Meissner transition temperature (set by an internal magnetic bias field) allow us to probe the behavior in superconducting normal mixed state of the condensation energy and the electron cooling power resulting from quasi-particle recombination and phonon emission. The information gained on electron cooling power is also relevant to the operation of other superconducting detectors, such as Microwave Kinetic Inductance Detectors.

  8. Photonic crystal surface-emitting lasers

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

    Chua, Song Liang; Lu, Ling; Soljacic, Marin

    2015-06-23

    A photonic-crystal surface-emitting laser (PCSEL) includes a gain medium electromagnetically coupled to a photonic crystal whose energy band structure exhibits a Dirac cone of linear dispersion at the center of the photonic crystal's Brillouin zone. This Dirac cone's vertex is called a Dirac point; because it is at the Brillouin zone center, it is called an accidental Dirac point. Tuning the photonic crystal's band structure (e.g., by changing the photonic crystal's dimensions or refractive index) to exhibit an accidental Dirac point increases the photonic crystal's mode spacing by orders of magnitudes and reduces or eliminates the photonic crystal's distributed in-planemore » feedback. Thus, the photonic crystal can act as a resonator that supports single-mode output from the PCSEL over a larger area than is possible with conventional PCSELs, which have quadratic band edge dispersion. Because output power generally scales with output area, this increase in output area results in higher possible output powers.« less

  9. Sentinel lymph node detection by an optical method using scattered photons

    PubMed Central

    Tellier, Franklin; Ravelo, Rasata; Simon, Hervé; Chabrier, Renée; Steibel, Jérôme; Poulet, Patrick

    2010-01-01

    We present a new near infrared optical probe for the sentinel lymph node detection, based on the recording of scattered photons. A two wavelengths setup was developed to improve the detection threshold of an injected dye: the Patent Blue V dye. The method used consists in modulating each laser diode at a given frequency. A Fast Fourier Transform of the recorded signal separates both components. The signal amplitudes are used to compute relative Patent Blue V concentration. Results on the probe using phantoms model and small animal experimentation exhibit a sensitivity threshold of 3.2 µmol/L, which is thirty fold better than the eye visible threshold. PMID:21258517

  10. Deterministically swapping frequency-bin entanglement from photon-photon to atom-photon hybrid systems

    NASA Astrophysics Data System (ADS)

    Ou, Bao-Quan; Liu, Chang; Sun, Yuan; Chen, Ping-Xing

    2018-02-01

    Inspired by the recent developments of the research on the atom-photon quantum interface and energy-time entanglement between single-photon pulses, we are motivated to study the deterministic protocol for the frequency-bin entanglement of the atom-photon hybrid system, which is analogous to the frequency-bin entanglement between single-photon pulses. We show that such entanglement arises naturally in considering the interaction between a frequency-bin entangled single-photon pulse pair and a single atom coupled to an optical cavity, via straightforward atom-photon phase gate operations. Its anticipated properties and preliminary examples of its potential application in quantum networking are also demonstrated. Moreover, we construct a specific quantum entanglement witness tool to detect such extended frequency-bin entanglement from a reasonably general set of separable states, and prove its capability theoretically. We focus on the energy-time considerations throughout the analysis.

  11. Novel design of inherently gain-flattened discrete highly nonlinear photonic crystal fiber Raman amplifier and dispersion compensation using a single pump in C-band.

    PubMed

    Varshney, Shailendra; Fujisawa, Takeshi; Saitoh, Kunimasa; Koshiba, Masanori

    2005-11-14

    In this paper, we report, for the first time, an inherently gain-flattened discrete highly nonlinear photonic crystal fiber (HNPCF) Raman amplifier (HNPCF-RA) design which shows 13.7 dB of net gain (with +/-0.85-dB gain ripple) over 28-nm bandwidth. The wavelength dependent leakage loss property of HNPCF is used to flatten the Raman gain of the amplifier module. The PCF structural design is based on W-shaped refractive index profile where the fiber parameters are well optimized by homely developed genetic algorithm optimization tool integrated with an efficient vectorial finite element method (V-FEM). The proposed fiber design has a high Raman gain efficiency of 4.88 W(-1) . km(-1) at a frequency shift of 13.1 THz, which is precisely evaluated through V-FEM. Additionally, the designed module, which shows ultra-wide single mode operation, has a slowly varying negative dispersion coefficient (-107.5 ps/nm/km at 1550 nm) over the operating range of wavelengths. Therefore, our proposed HNPCF-RA module acts as a composite amplifier with dispersion compensator functionality in a single component using a single pump.

  12. Single photon counting linear mode avalanche photodiode technologies

    NASA Astrophysics Data System (ADS)

    Williams, George M.; Huntington, Andrew S.

    2011-10-01

    The false count rate of a single-photon-sensitive photoreceiver consisting of a high-gain, low-excess-noise linear-mode InGaAs avalanche photodiode (APD) and a high-bandwidth transimpedance amplifier (TIA) is fit to a statistical model. The peak height distribution of the APD's multiplied dark current is approximated by the weighted sum of McIntyre distributions, each characterizing dark current generated at a different location within the APD's junction. The peak height distribution approximated in this way is convolved with a Gaussian distribution representing the input-referred noise of the TIA to generate the statistical distribution of the uncorrelated sum. The cumulative distribution function (CDF) representing count probability as a function of detection threshold is computed, and the CDF model fit to empirical false count data. It is found that only k=0 McIntyre distributions fit the empirically measured CDF at high detection threshold, and that false count rate drops faster than photon count rate as detection threshold is raised. Once fit to empirical false count data, the model predicts the improvement of the false count rate to be expected from reductions in TIA noise and APD dark current. Improvement by at least three orders of magnitude is thought feasible with further manufacturing development and a capacitive-feedback TIA (CTIA).

  13. Highly sensitive detection of cancer cells using femtosecond dual-wavelength near-IR two-photon imaging.

    PubMed

    Starkey, Jean R; Makarov, Nikolay S; Drobizhev, Mikhail; Rebane, Aleksander

    2012-07-01

    We describe novel imaging protocols that allow detection of small cancer cell colonies deep inside tissue phantoms with high sensitivity and specificity. We compare fluorescence excited in Styryl-9M molecules by femtosecond pulses at near IR wavelengths, where Styryl-9M shows the largest dependence of the two-photon absorption (2PA) cross section on the local environment. We show that by calculating the normalized ratio of the two-photon excited fluorescence (2PEF) intensity at 1200 nm and 1100 nm excitation wavelengths we can achieve high sensitivity and specificity for determining the location of cancer cells surrounded by normal cells. The 2PEF results showed a positive correlation with the levels of MDR1 proteins expressed by the cells, and, for high MDR1 expressors, as few as ten cancer cells could be detected. Similar high sensitivity is also demonstrated for tumor colonies induced in mouse external ears. This technique could be useful in early cancer detection, and, perhaps, also in monitoring dormant cancer deposits.

  14. HgCdTe APD-based linear-mode photon counting components and ladar receivers

    NASA Astrophysics Data System (ADS)

    Jack, Michael; Wehner, Justin; Edwards, John; Chapman, George; Hall, Donald N. B.; Jacobson, Shane M.

    2011-05-01

    Linear mode photon counting (LMPC) provides significant advantages in comparison with Geiger Mode (GM) Photon Counting including absence of after-pulsing, nanosecond pulse to pulse temporal resolution and robust operation in the present of high density obscurants or variable reflectivity objects. For this reason Raytheon has developed and previously reported on unique linear mode photon counting components and modules based on combining advanced APDs and advanced high gain circuits. By using HgCdTe APDs we enable Poisson number preserving photon counting. A metric of photon counting technology is dark count rate and detection probability. In this paper we report on a performance breakthrough resulting from improvement in design, process and readout operation enabling >10x reduction in dark counts rate to ~10,000 cps and >104x reduction in surface dark current enabling long 10 ms integration times. Our analysis of key dark current contributors suggest that substantial further reduction in DCR to ~ 1/sec or less can be achieved by optimizing wavelength, operating voltage and temperature.

  15. Proposal and proof-of-principle demonstration of non-destructive detection of photonic qubits using a Tm:LiNbO3 waveguide

    PubMed Central

    Sinclair, N.; Heshami, K.; Deshmukh, C.; Oblak, D.; Simon, C.; Tittel, W.

    2016-01-01

    Non-destructive detection of photonic qubits is an enabling technology for quantum information processing and quantum communication. For practical applications, such as quantum repeaters and networks, it is desirable to implement such detection in a way that allows some form of multiplexing as well as easy integration with other components such as solid-state quantum memories. Here, we propose an approach to non-destructive photonic qubit detection that promises to have all the mentioned features. Mediated by an impurity-doped crystal, a signal photon in an arbitrary time-bin qubit state modulates the phase of an intense probe pulse that is stored during the interaction. Using a thulium-doped waveguide in LiNbO3, we perform a proof-of-principle experiment with macroscopic signal pulses, demonstrating the expected cross-phase modulation as well as the ability to preserve the coherence between temporal modes. Our findings open the path to a new key component of quantum photonics based on rare-earth-ion-doped crystals. PMID:27853153

  16. Anti-dynamic-crosstalk method for single photon LIDAR detection

    NASA Astrophysics Data System (ADS)

    Zhang, Fan; Liu, Qiang; Gong, Mali; Fu, Xing

    2017-11-01

    With increasing number of vehicles equipped with light detection and ranging (LIDAR), crosstalk is identified as a critical and urgent issue in the range detection for active collision avoidance. Chaotic pulse position modulation (CPPM) applied in the transmitting pulse train has been shown to prevent crosstalk as well as range ambiguity. However, static and unified strategy on discrimination threshold and the number of accumulated pulse is not valid against crosstalk with varying number of sources and varying intensity of each source. This paper presents an adaptive algorithm to distinguish the target echo from crosstalk with dynamic and unknown level of intensity in the context of intelligent vehicles. New strategy is given based on receiver operating characteristics (ROC) curves that consider the detection requirements of the probability of detection and false alarm for the scenario with varying crosstalk. In the adaptive algorithm, the detected results are compared by the new strategy with both the number of accumulated pulses and the threshold being raised step by step, so that the target echo can be exactly identified from crosstalk with the dynamic and unknown level of intensity. The validity of the algorithm has been verified through the experiments with a single photon detector and the time correlated single photo counting (TCSPC) technique, demonstrating a marked drop in required shots for identifying the target compared with static and unified strategy

  17. Progress in low light-level InAs detectors- towards Geiger-mode detection

    NASA Astrophysics Data System (ADS)

    Tan, Chee Hing; Ng, Jo Shien; Zhou, Xinxin; David, John; Zhang, Shiyong; Krysa, Andrey

    2017-05-01

    InAs avalanche photodiodes (APDs) can be designed such that only electrons are allowed to initiate impact ionization, leading to the lowest possible excess noise factor. Optimization of wet chemical etching and surface passivation produced mesa APDs with bulk dominated dark current and responsivity that are comparable and higher, respectively, than a commercial InAs detector. Our InAs electron-APDs also show high stability with fluctuation of 0.1% when operated at a gain of 11.2 over 60 s. These InAs APDs can detect very weak signal down to 35 photons per pulse. Fabrication of planar InAs by Be implantation produced planar APDs with bulk dominated dark current. Annealing at 550 °C was necessary to remove implantation damage and to activate Be dopants. Due to minimal diffusion of Be, thick depletion of 8 μm was achieved. Since the avalanche gain increases exponentially with the thickness of avalanche region, our planar APD achieved high gain > 300 at 200 K. Our work suggest that both mesa and planar InAs APDs can exhibit high gain. When combined with a suitable preamplifier, single photon detection using InAs electron-APDs could be achieved.

  18. Brillouin Amplification--A Powerful New Scheme for Microwave Photonic Communications

    NASA Technical Reports Server (NTRS)

    Yao, S.; Maleki, L.

    1997-01-01

    We introduce the Brillouin selective sideband amplification technique and demonstrate many important applications of this technique in photonic microwave systems, including efficient phase modulation to amplitude modulation conversion, photonic frequency multiplication, photonic signal mixing with gain, and frequency multiplied signal up conversion.

  19. A novel photonic oscillator

    NASA Technical Reports Server (NTRS)

    Yao, X. S.; Maleki, L.

    1995-01-01

    We report a novel oscillator for photonic RF systems. This oscillator is capable of generating high-frequency signals up to 70 GHz in both electrical and optical domains and is a special voltage-controlled oscillator with an optical output port. It can be used to make a phase-locked loop (PLL) and perform all functions that a PLL is capable of for photonic systems. It can be synchronized to a reference source by means of optical injection locking, electrical injection locking, and PLL. It can also be self-phase locked and self-injection locked to generate a high-stability photonic RF reference. Its applications include high-frequency reference regeneration and distribution, high-gain frequency multiplication, comb-frequecy and square-wave generation, carrier recovery, and clock recovery. We anticipate that such photonic voltage-controlled oscillators (VCOs) will be as important to photonic RF systems as electrical VCOs are to electrical RF systems.

  20. Particle and Photon Detection: Counting and Energy Measurement

    PubMed Central

    Janesick, James; Tower, John

    2016-01-01

    Fundamental limits for photon counting and photon energy measurement are reviewed for CCD and CMOS imagers. The challenges to extend photon counting into the visible/nIR wavelengths and achieve energy measurement in the UV with specific read noise requirements are discussed. Pixel flicker and random telegraph noise sources are highlighted along with various methods used in reducing their contribution on the sensor’s read noise floor. Practical requirements for quantum efficiency, charge collection efficiency, and charge transfer efficiency that interfere with photon counting performance are discussed. Lastly we will review current efforts in reducing flicker noise head-on, in hopes to drive read noise substantially below 1 carrier rms. PMID:27187398

  1. Performance simulation of a detector for 4th generation photon sources: The AGIPD

    NASA Astrophysics Data System (ADS)

    Potdevin, G.; Trunk, U.; Graafsma, H.; Agipd Consortium

    2009-08-01

    Future 4th generation photon sources, such as the European XFEL based in Hamburg, will deliver around 1012 X-ray photons in less than 100 fs with full lateral coherence. These new sources will offer unprecedented possibilities in photon science. The high peak brilliance, combined with a 5 MHz repetition rate poses very high demands for the 2D detectors. In order to provide appropriate detectors during XFEL startup, three dedicated development projects have been initiated, one of them being the Adaptive Gain Integrating Pixel Detector (AGIPD) project which is a collaborative effort between DESY, PSI, University of Bonn, and University of Hamburg. An essential part of the AGIPD project is the development of a simulation tool for the complete detection system. The simulation tool as well as preliminary simulations of the detector characteristics is presented.

  2. Iodine-131 imaging using 284 keV photons with a small animal CZT-SPECT system dedicated to low-medium-energy photon detection.

    PubMed

    Kojima, Akihiro; Gotoh, Kumiko; Shimamoto, Masako; Hasegawa, Koki; Okada, Seiji

    2016-02-01

    Iodine-131 is widely used for radionuclide therapy because of its β-particle and for diagnostic imaging employing its principal gamma ray. Since that principal gamma ray has the relatively high energy of 364 keV, small animal single-photon emission computed tomography (SPECT) imaging systems may be required to possess the ability to image such higher energy photons. The aim of this study was to investigate the possibility of imaging I-131 using its 284 keV photons instead of its 364 keV photons in a small animal SPECT imaging system dedicated to the detection of low-medium-energy photons (below 300 keV). The imaging system used was a commercially available preclinical SPECT instrument with CZT detectors that was equipped with multi-pinhole collimators and was accompanied by a CT imager. An energy window for I-131 imaging was set to a photopeak of 284 keV with a low abundance compared with 364 keV photons. Small line sources and two mice, one of each of two types, that were injected with NaI-131 were scanned. Although higher counts occurred at the peripheral region of the reconstructed images due to the collimator penetration by the 364 keV photons, the shape of the small line sources could be well visualized. The measured spatial resolution was relatively poor (~1.9 mm for full width at half maximum and ~3.9 mm for full width at tenth maximum). However, a good linear correlation between SPECT values and the level of I-131 radioactivity was observed. Furthermore, the uptake of NaI-131 to the thyroid gland for the two mice was clearly identified in the 3D-SPECT image fused with the X-ray CT image. We conclude that the use of an energy window set on the photopeak of 284 keV and the multi-pinhole collimator may permit I-131 imaging for a preclinical CZT-SPECT system that does not have the ability to acquire images using the 364 keV photons.

  3. Adaptation without parameter change: Dynamic gain control in motion detection

    PubMed Central

    Borst, Alexander; Flanagin, Virginia L.; Sompolinsky, Haim

    2005-01-01

    Many sensory systems adapt their input-output relationship to changes in the statistics of the ambient stimulus. Such adaptive behavior has been measured in a motion detection sensitive neuron of the fly visual system, H1. The rapid adaptation of the velocity response gain has been interpreted as evidence of optimal matching of the H1 response to the dynamic range of the stimulus, thereby maximizing its information transmission. Here, we show that correlation-type motion detectors, which are commonly thought to underlie fly motion vision, intrinsically possess adaptive properties. Increasing the amplitude of the velocity fluctuations leads to a decrease of the effective gain and the time constant of the velocity response without any change in the parameters of these detectors. The seemingly complex property of this adaptation turns out to be a straightforward consequence of the multidimensionality of the stimulus and the nonlinear nature of the system. PMID:15833815

  4. Indirect-detection single-photon-counting x-ray detector for breast tomosynthesis

    NASA Astrophysics Data System (ADS)

    Jiang, Hao; Kaercher, Joerg; Durst, Roger

    2016-03-01

    X-ray mammography is a crucial screening tool for early identification of breast cancer. However, the overlap of anatomical features present in projection images often complicates the task of correctly identifying suspicious masses. As a result, there has been increasing interest in acquisition of volumetric information through digital breast tomosynthesis (DBT) which, compared to mammography, offers the advantage of depth information. Since DBT requires acquisition of many projection images, it is desirable that the noise in each projection image be dominated by the statistical noise of the incident x-ray quanta and not by the additive noise of the imaging system (referred to as quantum-limited imaging) and that the cumulative dose be as low as possible (e.g., no more than for a mammogram). Unfortunately, the electronic noise (~2000 electrons) present in current DBT systems based on active matrix, flat-panel imagers (AMFPIs) is still relatively high compared with modest x-ray gain of the a-Se and CsI:Tl x-ray converters often used. To overcome the modest signal-to-noise ratio (SNR) limitations of current DBT systems, we have developed a large-area x-ray imaging detector with the combination of an extremely low noise (~20 electrons) active-pixel CMOS and a specially designed high resolution scintillator. The high sensitivity and low noise of such system provides better SNR by at least an order of magnitude than current state-of-art AMFPI systems and enables x-ray indirect-detection single photon counting (SPC) at mammographic energies with the potential of dose reduction.

  5. Linear Mode HgCdTe Avalanche Photodiodes for Photon Counting Applications

    NASA Technical Reports Server (NTRS)

    Sullivan, William, III; Beck, Jeffrey; Scritchfield, Richard; Skokan, Mark; Mitra, Pradip; Sun, Xiaoli; Abshire, James; Carpenter, Darren; Lane, Barry

    2015-01-01

    An overview of recent improvements in the understanding and maturity of linear mode photon counting with HgCdTe electron-initiated avalanche photodiodes is presented. The first HgCdTe LMPC 2x8 format array fabricated in 2011 with 64 micron pitch was a remarkable success in terms of demonstrating a high single photon signal to noise ratio of 13.7 with an excess noise factor of 1.3-1.4, a 7 ns minimum time between events, and a broad spectral response extending from 0.4 micron to 4.2 micron. The main limitations were a greater than 10x higher false event rate than expected of greater than 1 MHz, a 5-7x lower than expected APD gain, and a photon detection efficiency of only 50% when greater than 60% was expected. This paper discusses the reasons behind these limitations and the implementation of their mitigations with new results.

  6. Photon detector system

    DOEpatents

    Ekstrom, Philip A.

    1981-01-01

    A photon detector includes a semiconductor device, such as a Schottky barrier diode, which has an avalanche breakdown characteristic. The diode is cooled to cryogenic temperatures to eliminate thermally generated charge carriers from the device. The diode is then biased to a voltage level exceeding the avalanche breakdown threshold level such that, upon receipt of a photon, avalanche breakdown occurs. This breakdown is detected by appropriate circuitry which thereafter reduces the diode bias potential to a level below the avalanche breakdown threshold level to terminate the avalanche condition. Subsequently, the bias potential is reapplied to the diode in preparation for detection of a subsequently received photon.

  7. Facile detection of toxic ingredients in seafood using biologically enabled photonic crystal materials

    NASA Astrophysics Data System (ADS)

    Kong, Xianming; Squire, Kenneth; Wang, Alan X.

    2018-02-01

    Surface-enhanced Raman scattering (SERS) spectroscopy has attracted considerable attention recently as a powerful detection platform in biosensing because of the wealth of inherent information ascertained about the chemical and molecular composition of a sample. However, real-world samples are often composed of many components, which renders the detection of constitutes of mixed samples very challenging for SERS sensing. Accordingly, separation techniques are needed before SERS measurements. Thin layer chromatography (TLC) is a simple, fast and costeffective technique for analyte separation and can a play pivotal role for on-site sensing. However, combining TLC with SERS is only successful to detect a limited number of analytes that have large Raman scattering cross sections. As a kind of biogenic amine, histamine (2-(4-imidazolyl)-ethylamine) has a relationship with many health problems resulting from seafood consumption occurring worldwide. Diatomaceous earth consists of fossilized remains of diatoms, a type of hard-shelled algae. As a kind of natural photonic biosilica from geological deposits, it has a variety of unique properties including highly porous structure, excellent adsorption capacity, and low cost. In addition, the two dimensional periodic pores on diatomite earth with hierarchical nanoscale photonic crystal features can enhance the localized optical field. Herein, we fabricate TLC plates from diatomite as the stationary phase combining with SERS to separate and detect histamine from seafood samples. We have proved that the diatomite on the TLC plate not only functions as stationary phase, but also provides additional Raman enhancement, in which the detection limit of 2 ppm was achieved for pyrene in mixture.

  8. Dramatic Raman Gain Suppression in the Vicinity of the Zero Dispersion Point in a Gas-Filled Hollow-Core Photonic Crystal Fiber.

    PubMed

    Bauerschmidt, S T; Novoa, D; Russell, P St J

    2015-12-11

    In 1964 Bloembergen and Shen predicted that Raman gain could be suppressed if the rates of phonon creation and annihilation (by inelastic scattering) exactly balance. This is only possible if the momentum required for each process is identical, i.e., phonon coherence waves created by pump-to-Stokes scattering are identical to those annihilated in pump-to-anti-Stokes scattering. In bulk gas cells, this can only be achieved over limited interaction lengths at an oblique angle to the pump axis. Here we report a simple system that provides dramatic Raman gain suppression over long collinear path lengths in hydrogen. It consists of a gas-filled hollow-core photonic crystal fiber whose zero dispersion point is pressure adjusted to lie close to the pump laser wavelength. At a certain precise pressure, stimulated generation of Stokes light in the fundamental mode is completely suppressed, allowing other much weaker phenomena such as spontaneous Raman scattering to be explored at high pump powers.

  9. Long-range depth profiling of camouflaged targets using single-photon detection

    NASA Astrophysics Data System (ADS)

    Tobin, Rachael; Halimi, Abderrahim; McCarthy, Aongus; Ren, Ximing; McEwan, Kenneth J.; McLaughlin, Stephen; Buller, Gerald S.

    2018-03-01

    We investigate the reconstruction of depth and intensity profiles from data acquired using a custom-designed time-of-flight scanning transceiver based on the time-correlated single-photon counting technique. The system had an operational wavelength of 1550 nm and used a Peltier-cooled InGaAs/InP single-photon avalanche diode detector. Measurements were made of human figures, in plain view and obscured by camouflage netting, from a stand-off distance of 230 m in daylight using only submilliwatt average optical powers. These measurements were analyzed using a pixelwise cross correlation approach and compared to analysis using a bespoke algorithm designed for the restoration of multilayered three-dimensional light detection and ranging images. This algorithm is based on the optimization of a convex cost function composed of a data fidelity term and regularization terms, and the results obtained show that it achieves significant improvements in image quality for multidepth scenarios and for reduced acquisition times.

  10. Broadband mixing of [Formula: see text]-symmetric and [Formula: see text]-broken phases in photonic heterostructures with a one-dimensional loss/gain bilayer.

    PubMed

    Özgün, Ege; Serebryannikov, Andriy E; Ozbay, Ekmel; Soukoulis, Costas M

    2017-11-14

    Combining loss and gain components in one photonic heterostructure opens a new route to efficient manipulation by radiation, transmission, absorption, and scattering of electromagnetic waves. Therefore, loss/gain structures enabling [Formula: see text]-symmetric and [Formula: see text]-broken phases for eigenvalues have extensively been studied in the last decade. In particular, translation from one phase to another, which occurs at the critical point in the two-channel structures with one-dimensional loss/gain components, is often associated with one-way transmission. In this report, broadband mixing of the [Formula: see text]-symmetric and [Formula: see text]-broken phases for eigenvalues is theoretically demonstrated in heterostructures with four channels obtained by combining a one-dimensional loss/gain bilayer and one or two thin polarization-converting components (PCCs). The broadband phase mixing in the four-channel case is expected to yield advanced transmission and absorption regimes. Various configurations are analyzed, which are distinguished in symmetry properties and polarization conversion regime of PCCs. The conditions necessary for phase mixing are discussed. The simplest two-component configurations with broadband mixing are found, as well as the more complex three-component configurations wherein symmetric and broken sets are not yet mixed and appear in the neighbouring frequency ranges. Peculiarities of eigenvalue behaviour are considered for different permittivity ranges of loss/gain medium, i.e., from epsilon-near-zero to high-epsilon regime.

  11. Measuring mouse retina response near the detection threshold to direct stimulation of photons with sub-poisson statistics

    NASA Astrophysics Data System (ADS)

    Tavala, Amir; Dovzhik, Krishna; Schicker, Klaus; Koschak, Alexandra; Zeilinger, Anton

    Probing the visual system of human and animals at very low photon rate regime has recently attracted the quantum optics community. In an experiment on the isolated photoreceptor cells of Xenopus, the cell output signal was measured while stimulating it by pulses with sub-poisson distributed photons. The results showed single photon detection efficiency of 29 +/-4.7% [1]. Another behavioral experiment on human suggests a less detection capability at perception level with the chance of 0.516 +/-0.01 (i.e. slightly better than random guess) [2]. Although the species are different, both biological models and experimental observations with classical light stimuli expect that a fraction of single photon responses is filtered somewhere within the retina network and/or during the neural processes in the brain. In this ongoing experiment, we look for a quantitative answer to this question by measuring the output signals of the last neural layer of WT mouse retina using microelectrode arrays. We use a heralded downconversion single-photon source. We stimulate the retina directly since the eye lens (responsible for 20-50% of optical loss and scattering [2]) is being removed. Here, we demonstrate our first results that confirms the response to the sub-poisson distributied pulses. This project was supported by Austrian Academy of Sciences, SFB FoQuS F 4007-N23 funded by FWF and ERC QIT4QAD 227844 funded by EU Commission.

  12. Fixed forced detection for fast SPECT Monte-Carlo simulation

    NASA Astrophysics Data System (ADS)

    Cajgfinger, T.; Rit, S.; Létang, J. M.; Halty, A.; Sarrut, D.

    2018-03-01

    Monte-Carlo simulations of SPECT images are notoriously slow to converge due to the large ratio between the number of photons emitted and detected in the collimator. This work proposes a method to accelerate the simulations based on fixed forced detection (FFD) combined with an analytical response of the detector. FFD is based on a Monte-Carlo simulation but forces the detection of a photon in each detector pixel weighted by the probability of emission (or scattering) and transmission to this pixel. The method was evaluated with numerical phantoms and on patient images. We obtained differences with analog Monte Carlo lower than the statistical uncertainty. The overall computing time gain can reach up to five orders of magnitude. Source code and examples are available in the Gate V8.0 release.

  13. Fixed forced detection for fast SPECT Monte-Carlo simulation.

    PubMed

    Cajgfinger, T; Rit, S; Létang, J M; Halty, A; Sarrut, D

    2018-03-02

    Monte-Carlo simulations of SPECT images are notoriously slow to converge due to the large ratio between the number of photons emitted and detected in the collimator. This work proposes a method to accelerate the simulations based on fixed forced detection (FFD) combined with an analytical response of the detector. FFD is based on a Monte-Carlo simulation but forces the detection of a photon in each detector pixel weighted by the probability of emission (or scattering) and transmission to this pixel. The method was evaluated with numerical phantoms and on patient images. We obtained differences with analog Monte Carlo lower than the statistical uncertainty. The overall computing time gain can reach up to five orders of magnitude. Source code and examples are available in the Gate V8.0 release.

  14. Photon statistics in scintillation crystals

    NASA Astrophysics Data System (ADS)

    Bora, Vaibhav Joga Singh

    Scintillation based gamma-ray detectors are widely used in medical imaging, high-energy physics, astronomy and national security. Scintillation gamma-ray detectors are eld-tested, relatively inexpensive, and have good detection eciency. Semi-conductor detectors are gaining popularity because of their superior capability to resolve gamma-ray energies. However, they are relatively hard to manufacture and therefore, at this time, not available in as large formats and much more expensive than scintillation gamma-ray detectors. Scintillation gamma-ray detectors consist of: a scintillator, a material that emits optical (scintillation) photons when it interacts with ionization radiation, and an optical detector that detects the emitted scintillation photons and converts them into an electrical signal. Compared to semiconductor gamma-ray detectors, scintillation gamma-ray detectors have relatively poor capability to resolve gamma-ray energies. This is in large part attributed to the "statistical limit" on the number of scintillation photons. The origin of this statistical limit is the assumption that scintillation photons are either Poisson distributed or super-Poisson distributed. This statistical limit is often dened by the Fano factor. The Fano factor of an integer-valued random process is dened as the ratio of its variance to its mean. Therefore, a Poisson process has a Fano factor of one. The classical theory of light limits the Fano factor of the number of photons to a value greater than or equal to one (Poisson case). However, the quantum theory of light allows for Fano factors to be less than one. We used two methods to look at the correlations between two detectors looking at same scintillation pulse to estimate the Fano factor of the scintillation photons. The relationship between the Fano factor and the correlation between the integral of the two signals detected was analytically derived, and the Fano factor was estimated using the measurements for SrI2:Eu, YAP

  15. Visual signal detection in structured backgrounds. II. Effects of contrast gain control, background variations, and white noise

    NASA Technical Reports Server (NTRS)

    Eckstein, M. P.; Ahumada, A. J. Jr; Watson, A. B.

    1997-01-01

    Studies of visual detection of a signal superimposed on one of two identical backgrounds show performance degradation when the background has high contrast and is similar in spatial frequency and/or orientation to the signal. To account for this finding, models include a contrast gain control mechanism that pools activity across spatial frequency, orientation and space to inhibit (divisively) the response of the receptor sensitive to the signal. In tasks in which the observer has to detect a known signal added to one of M different backgrounds grounds due to added visual noise, the main sources of degradation are the stochastic noise in the image and the suboptimal visual processing. We investigate how these two sources of degradation (contrast gain control and variations in the background) interact in a task in which the signal is embedded in one of M locations in a complex spatially varying background (structured background). We use backgrounds extracted from patient digital medical images. To isolate effects of the fixed deterministic background (the contrast gain control) from the effects of the background variations, we conduct detection experiments with three different background conditions: (1) uniform background, (2) a repeated sample of structured background, and (3) different samples of structured background. Results show that human visual detection degrades from the uniform background condition to the repeated background condition and degrades even further in the different backgrounds condition. These results suggest that both the contrast gain control mechanism and the background random variations degrade human performance in detection of a signal in a complex, spatially varying background. A filter model and added white noise are used to generate estimates of sampling efficiencies, an equivalent internal noise, an equivalent contrast-gain-control-induced noise, and an equivalent noise due to the variations in the structured background.

  16. Detecting explosive molecules from nanoliter solution: A new paradigm of SERS sensing on hydrophilic photonic crystal biosilica.

    PubMed

    Kong, Xianming; Xi, Yuting; Le Duff, Paul; Chong, Xinyuan; Li, Erwen; Ren, Fanghui; Rorrer, Gregory L; Wang, Alan X

    2017-02-15

    We demonstrate a photonic crystal biosilica surface-enhanced Raman scattering (SERS) substrate based on a diatom frustule with in-situ synthesized silver nanoparticles (Ag NPs) to detect explosive molecules from nanoliter (nL) solution. By integrating high density Ag NPs inside the nanopores of diatom biosilica, which is not achievable by traditional self-assembly techniques, we obtained ultra-high SERS sensitivity due to dual enhancement mechanisms. First, the hybrid plasmonic-photonic crystal biosilica with three dimensional morphologies was obtained by electroless-deposited Ag seeds at nanometer sized diatom frustule surface, which provides high density hot spots as well as strongly coupled optical resonances with the photonic crystal structure of diatom frustules. Second, we discovered that the evaporation-driven microscopic flow combined with the strong hydrophilic surface of diatom frustules is capable of concentrating the analyte molecules, which offers a simple yet effective mechanism to accelerate the mass transport into the SERS substrate. Using the inkjet printing technology, we are able to deliver multiple 100pico-liter (pL) volume droplets with pinpoint accuracy into a single diatom frustule with dimension around 30µm×7µm×5µm, which allows for label-free detection of explosive molecules such as trinitrotoluene (TNT) down to 10 -10 M in concentration and 2.7×10 -15 g in mass from 120nL solution. Our research illustrates a new paradigm of SERS sensing to detect trace level of chemical compounds from minimum volume of analyte using nature created photonic crystal biosilica materials. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Detecting explosive molecules from nanoliter solution: A new paradigm of SERS sensing on hydrophilic photonic crystal biosilica

    PubMed Central

    Kong, Xianming; Xi, Yuting; Le Duff, Paul; Chong, Xinyuan; Li, Erwen; Ren, Fanghui; Rorrer, Gregory L.; Wang, Alan X.

    2017-01-01

    We demonstrate a photonic crystal biosilica surface-enhanced Raman scattering (SERS) substrate based on a diatom frustule with in-situ synthesized silver nanoparticles (Ag NPs) to detect explosive molecules from nanoliter (nL) solution. By integrating high density Ag NPs inside the nanopores of diatom biosilica, which is not achievable by traditional self-assembly techniques, we obtained ultra-high SERS sensitivity due to dual enhancement mechanisms. First, the hybrid plasmonic-photonic crystal biosilica with three dimensional morphologies was obtained by electroless-deposited Ag seeds at nanometer sized diatom frustule surface, which provides high density hot spots as well as strongly coupled optical resonances with the photonic crystal structure of diatom frustules. Second, we discovered that the evaporation-driven microscopic flow combined with the strong hydrophilic surface of diatom frustules is capable of concentrating the analyte molecules, which offers a simple yet effective mechanism to accelerate the mass transport into the SERS substrate. Using the inkjet printing technology, we are able to deliver multiple 100 pico-liter (pL) volume droplets with pinpoint accuracy into a single diatom frustule with dimension around 30 μm × 7 μm × 5 μm, which allows for label-free detection of explosive molecules such as trinitrotoluene (TNT) down to 10−10 M in concentration and 2.7 × 10−15 g in mass from 120 nL solution. Our research illustrates a new paradigm of SERS sensing to detect trace level of chemical compounds from minimum volume of analyte using nature created photonic crystal biosilica materials. PMID:27471144

  18. pnCCD for photon detection from near-infrared to X-rays

    NASA Astrophysics Data System (ADS)

    Meidinger, Norbert; Andritschke, Robert; Hartmann, Robert; Herrmann, Sven; Holl, Peter; Lutz, Gerhard; Strüder, Lothar

    2006-09-01

    A pnCCD is a special type of charge-coupled device developed for spectroscopy and imaging of X-rays with high time resolution and quantum efficiency. Its most famous application is the operation on the XMM-Newton satellite, an X-ray astronomy mission that was launched by the European space agency in 1999. The excellent performance of the focal plane camera has been maintained for more than 6 years in orbit. The energy resolution in particular has shown hardly any degradation since launch. In order to satisfy the requirements of future X-ray astronomy missions as well as those of ground-based experiments, a new type of pnCCD has been developed. This ‘frame-store pnCCD’ shows an enhanced performance compared to the XMM-Newton type of pnCCD. Now, more options in device design and operation are available to tailor the detector to its respective application. Part of this concept is a programmable analog signal processor, which has been developed for the readout of the CCD signals. The electronic noise of the new detector has a value of only 2 electrons equivalent noise charge (ENC), which is less than half of the figure achieved for the XMM-Newton-type pnCCD. The energy resolution for the Mn-Kα line at 5.9 keV is approximately 130 eV FWHM. We have close to 100% quantum efficiency for both low- and high-energy photon detection (e.g. the C-K line at 277 eV, and the Ge-Kα line at 10 keV, respectively). Very high frame rates of 1000 images/s have been achieved due to the ultra-fast readout accomplished by the parallel architecture of the pnCCD and the analog signal processor. Excellent spectroscopic performance is shown even at the relatively high operating temperature of -25 °C that can be achieved by a Peltier cooler. The applications of the low-noise and fast pnCCD detector are not limited to the detection of X-rays. With an anti-reflective coating deposited on the photon entrance window, we achieve high quantum efficiency also for near-infrared and optical

  19. Experiment to Detect Accelerating Modes in a Photonic Bandgap Fiber

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

    England, R.J.; /SLAC; Colby, E.R.

    An experimental effort is currently underway at the E-163 test beamline at Stanford Linear Accelerator Center to use a hollow-core photonic bandgap (PBG) fiber as a high-gradient laser-based accelerating structure for electron bunches. For the initial stage of this experiment, a 50pC, 60 MeV electron beam will be coupled into the fiber core and the excited modes will be detected using a spectrograph to resolve their frequency signatures in the wakefield radiation generated by the beam. They will describe the experimental plan and recent simulation studies of candidate fibers.

  20. Living in a digital world: features and applications of FPGA in photon detection

    NASA Astrophysics Data System (ADS)

    Arnesano, Cosimo

    signal processing in a digital fashion avoiding RF emission and it is extremely inexpensive. This development is the result of a systematic study carried on a previous design known as the FLIMBox developed as part of a thesis of another graduate student. The extensive work done in maximizing the performance of the original FLIMBox led us to develop a new hardware solution with exciting and promising results and potential that were not possible in the previous hardware realization, where the signal harmonic content was limited by the FPGA technology. The new design permits acquisition of a much larger harmonic content of the sample response when it is excited with a pulsed light source in one single measurement using the digital mixing principle that was developed in the original design. Furthermore, we used the parallel digital FD principle to perform tissue imaging through Diffuse Optical Spectroscopy (DOS) measurements. We integrated the FLIMBox in a new system that uses a supercontinuum white laser with high brightness as a single light source and photomultipliers with large detection area, both allowing a high penetration depth with extremely low power at the sample. The parallel acquisition, achieved by using the FlimBox, decreases the time required for standard serial systems that scan through all modulation frequencies. Furthermore, the all-digital acquisition avoids analog noise, removes the analog mixer of the conventional frequency domain approach, and it does not generate radio-frequencies, normally present in current analog systems. We are able to obtain a very sensitive acquisition due to the high signal to noise ratio (S/N). The successful results obtained by utilizing digital technology in photon acquisition and processing, prompted us to extend the use of FPGA to other applications, such as phosphorescence detection. Using the FPGA concept we proposed possible solutions to outstanding problems with the current technology. In this thesis I discuss new

  1. Spatially selective photonic crystal enhanced fluorescence and application to background reduction for biomolecule detection assays

    PubMed Central

    Chaudhery, Vikram; Huang, Cheng-Sheng; Pokhriyal, Anusha; Polans, James; Cunningham, Brian T.

    2011-01-01

    By combining photonic crystal label-free biosensor imaging with photonic crystal enhanced fluorescence, it is possible to selectively enhance the fluorescence emission from regions of the PC surface based upon the density of immobilized capture molecules. A label-free image of the capture molecules enables determination of optimal coupling conditions of the laser used for fluorescence imaging of the photonic crystal surface on a pixel-by-pixel basis, allowing maximization of fluorescence enhancement factor from regions incorporating a biomolecule capture spot and minimization of background autofluorescence from areas between capture spots. This capability significantly improves the contrast of enhanced fluorescent images, and when applied to an antibody protein microarray, provides a substantial advantage over conventional fluorescence microscopy. Using the new approach, we demonstrate detection limits as low as 0.97 pg/ml for a representative protein biomarker in buffer. PMID:22109210

  2. Spatially selective photonic crystal enhanced fluorescence and application to background reduction for biomolecule detection assays.

    PubMed

    Chaudhery, Vikram; Huang, Cheng-Sheng; Pokhriyal, Anusha; Polans, James; Cunningham, Brian T

    2011-11-07

    By combining photonic crystal label-free biosensor imaging with photonic crystal enhanced fluorescence, it is possible to selectively enhance the fluorescence emission from regions of the PC surface based upon the density of immobilized capture molecules. A label-free image of the capture molecules enables determination of optimal coupling conditions of the laser used for fluorescence imaging of the photonic crystal surface on a pixel-by-pixel basis, allowing maximization of fluorescence enhancement factor from regions incorporating a biomolecule capture spot and minimization of background autofluorescence from areas between capture spots. This capability significantly improves the contrast of enhanced fluorescent images, and when applied to an antibody protein microarray, provides a substantial advantage over conventional fluorescence microscopy. Using the new approach, we demonstrate detection limits as low as 0.97 pg/ml for a representative protein biomarker in buffer.

  3. Time-resolved single-photon detection module based on silicon photomultiplier: A novel building block for time-correlated measurement systems

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

    Martinenghi, E., E-mail: edoardo.martinenghi@polimi.it; Di Sieno, L.; Contini, D.

    2016-07-15

    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

  4. Time-resolved single-photon detection module based on silicon photomultiplier: A novel building block for time-correlated measurement systems

    NASA Astrophysics Data System (ADS)

    Martinenghi, E.; Di Sieno, L.; Contini, D.; Sanzaro, M.; Pifferi, A.; Dalla Mora, A.

    2016-07-01

    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).

  5. 10-fold detection range increase in quadrant-photodiode position sensing for photonic force microscope

    NASA Astrophysics Data System (ADS)

    Perrone, Sandro; Volpe, Giovanni; Petrov, Dmitri

    2008-10-01

    We propose a technique that permits one to increase by one order of magnitude the detection range of position sensing for the photonic force microscope with quadrant photodetectors (QPDs). This technique takes advantage of the unavoidable cross-talk between output signals of the QPD and does not assume that the output signals are linear in the probe displacement. We demonstrate the increase in the detection range from 150 to 1400 nm for a trapped polystyrene sphere with radius of 300 nm as probe.

  6. 10-fold detection range increase in quadrant-photodiode position sensing for photonic force microscope

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

    Perrone, Sandro; Volpe, Giovanni; Petrov, Dmitri

    2008-10-15

    We propose a technique that permits one to increase by one order of magnitude the detection range of position sensing for the photonic force microscope with quadrant photodetectors (QPDs). This technique takes advantage of the unavoidable cross-talk between output signals of the QPD and does not assume that the output signals are linear in the probe displacement. We demonstrate the increase in the detection range from 150 to 1400 nm for a trapped polystyrene sphere with radius of 300 nm as probe.

  7. 10-fold detection range increase in quadrant-photodiode position sensing for photonic force microscope.

    PubMed

    Perrone, Sandro; Volpe, Giovanni; Petrov, Dmitri

    2008-10-01

    We propose a technique that permits one to increase by one order of magnitude the detection range of position sensing for the photonic force microscope with quadrant photodetectors (QPDs). This technique takes advantage of the unavoidable cross-talk between output signals of the QPD and does not assume that the output signals are linear in the probe displacement. We demonstrate the increase in the detection range from 150 to 1400 nm for a trapped polystyrene sphere with radius of 300 nm as probe.

  8. Detection of Zak phases and topological invariants in a chiral quantum walk of twisted photons.

    PubMed

    Cardano, Filippo; D'Errico, Alessio; Dauphin, Alexandre; Maffei, Maria; Piccirillo, Bruno; de Lisio, Corrado; De Filippis, Giulio; Cataudella, Vittorio; Santamato, Enrico; Marrucci, Lorenzo; Lewenstein, Maciej; Massignan, Pietro

    2017-06-01

    Topological insulators are fascinating states of matter exhibiting protected edge states and robust quantized features in their bulk. Here we propose and validate experimentally a method to detect topological properties in the bulk of one-dimensional chiral systems. We first introduce the mean chiral displacement, an observable that rapidly approaches a value proportional to the Zak phase during the free evolution of the system. Then we measure the Zak phase in a photonic quantum walk of twisted photons, by observing the mean chiral displacement in its bulk. Next, we measure the Zak phase in an alternative, inequivalent timeframe and combine the two windings to characterize the full phase diagram of this Floquet system. Finally, we prove the robustness of the measure by introducing dynamical disorder in the system. This detection method is extremely general and readily applicable to all present one-dimensional platforms simulating static or Floquet chiral systems.

  9. Detection of Zak phases and topological invariants in a chiral quantum walk of twisted photons

    PubMed Central

    Cardano, Filippo; D’Errico, Alessio; Dauphin, Alexandre; Maffei, Maria; Piccirillo, Bruno; de Lisio, Corrado; De Filippis, Giulio; Cataudella, Vittorio; Santamato, Enrico; Marrucci, Lorenzo; Lewenstein, Maciej; Massignan, Pietro

    2017-01-01

    Topological insulators are fascinating states of matter exhibiting protected edge states and robust quantized features in their bulk. Here we propose and validate experimentally a method to detect topological properties in the bulk of one-dimensional chiral systems. We first introduce the mean chiral displacement, an observable that rapidly approaches a value proportional to the Zak phase during the free evolution of the system. Then we measure the Zak phase in a photonic quantum walk of twisted photons, by observing the mean chiral displacement in its bulk. Next, we measure the Zak phase in an alternative, inequivalent timeframe and combine the two windings to characterize the full phase diagram of this Floquet system. Finally, we prove the robustness of the measure by introducing dynamical disorder in the system. This detection method is extremely general and readily applicable to all present one-dimensional platforms simulating static or Floquet chiral systems. PMID:28569741

  10. Non-classical photon correlation in a two-dimensional photonic lattice.

    PubMed

    Gao, Jun; Qiao, Lu-Feng; Lin, Xiao-Feng; Jiao, Zhi-Qiang; Feng, Zhen; Zhou, Zheng; Gao, Zhen-Wei; Xu, Xiao-Yun; Chen, Yuan; Tang, Hao; Jin, Xian-Min

    2016-06-13

    Quantum interference and quantum correlation, as two main features of quantum optics, play an essential role in quantum information applications, such as multi-particle quantum walk and boson sampling. While many experimental demonstrations have been done in one-dimensional waveguide arrays, it remains unexplored in higher dimensions due to tight requirement of manipulating and detecting photons in large-scale. Here, we experimentally observe non-classical correlation of two identical photons in a fully coupled two-dimensional structure, i.e. photonic lattice manufactured by three-dimensional femtosecond laser writing. Photon interference consists of 36 Hong-Ou-Mandel interference and 9 bunching. The overlap between measured and simulated distribution is up to 0.890 ± 0.001. Clear photon correlation is observed in the two-dimensional photonic lattice. Combining with controllably engineered disorder, our results open new perspectives towards large-scale implementation of quantum simulation on integrated photonic chips.

  11. Silicon photonic integrated circuit swept-source optical coherence tomography receiver with dual polarization, dual balanced, in-phase and quadrature detection.

    PubMed

    Wang, Zhao; Lee, Hsiang-Chieh; Vermeulen, Diedrik; Chen, Long; Nielsen, Torben; Park, Seo Yeon; Ghaemi, Allan; Swanson, Eric; Doerr, Chris; Fujimoto, James

    2015-07-01

    Optical coherence tomography (OCT) is a widely used three-dimensional (3D) optical imaging method with many biomedical and non-medical applications. Miniaturization, cost reduction, and increased functionality of OCT systems will be critical for future emerging clinical applications. We present a silicon photonic integrated circuit swept-source OCT (SS-OCT) coherent receiver with dual polarization, dual balanced, in-phase and quadrature (IQ) detection. We demonstrate multiple functional capabilities of IQ polarization resolved detection including: complex-conjugate suppressed full-range OCT, polarization diversity detection, and polarization-sensitive OCT. To our knowledge, this is the first demonstration of a silicon photonic integrated receiver for OCT. The integrated coherent receiver provides a miniaturized, low-cost solution for SS-OCT, and is also a key step towards a fully integrated high speed SS-OCT system with good performance and multi-functional capabilities. With further performance improvement and cost reduction, photonic integrated technology promises to greatly increase penetration of OCT systems in existing applications and enable new applications.

  12. Silicon photonic integrated circuit swept-source optical coherence tomography receiver with dual polarization, dual balanced, in-phase and quadrature detection

    PubMed Central

    Wang, Zhao; Lee, Hsiang-Chieh; Vermeulen, Diedrik; Chen, Long; Nielsen, Torben; Park, Seo Yeon; Ghaemi, Allan; Swanson, Eric; Doerr, Chris; Fujimoto, James

    2015-01-01

    Optical coherence tomography (OCT) is a widely used three-dimensional (3D) optical imaging method with many biomedical and non-medical applications. Miniaturization, cost reduction, and increased functionality of OCT systems will be critical for future emerging clinical applications. We present a silicon photonic integrated circuit swept-source OCT (SS-OCT) coherent receiver with dual polarization, dual balanced, in-phase and quadrature (IQ) detection. We demonstrate multiple functional capabilities of IQ polarization resolved detection including: complex-conjugate suppressed full-range OCT, polarization diversity detection, and polarization-sensitive OCT. To our knowledge, this is the first demonstration of a silicon photonic integrated receiver for OCT. The integrated coherent receiver provides a miniaturized, low-cost solution for SS-OCT, and is also a key step towards a fully integrated high speed SS-OCT system with good performance and multi-functional capabilities. With further performance improvement and cost reduction, photonic integrated technology promises to greatly increase penetration of OCT systems in existing applications and enable new applications. PMID:26203382

  13. Remote air lasing for trace detection

    NASA Astrophysics Data System (ADS)

    Dogariu, Arthur; Michael, James B.; Miles, Richard B.

    2011-05-01

    We demonstrate coherent light propagating backwards from a remotely generated high gain air laser. A short ultraviolet laser pulse tuned to a two-photon atomic oxygen electronic resonance at 226 nm simultaneously dissociates the oxygen molecules in air and excites the resulting atomic oxygen fragments. Due to the focal depth of the pumping laser, a millimeter long region of high gain is created in air for the atomic oxygen stimulated emission at 845nm. We demonstrate that the gain in excess of 60 cm-1 is responsible for both forward and backwards emission of a strong, collimated, coherent laser beam. We present evidence for coherent emission and characterize the backscattered laser beam while varying the pumping conditions. The optical gain and directional emission allows for six orders of magnitude enhancement for the backscattered emission when compared with the fluorescence emission collected into the same solid angle. . This opens new opportunities for the remote detection capabilities of trace species, and provides much greater range for the detection of optical molecular and atomic features from a distant target.

  14. Photonic crystal based biosensor for the detection of glucose concentration in urine

    NASA Astrophysics Data System (ADS)

    Robinson, Savarimuthu; Dhanlaksmi, Nagaraj

    2017-03-01

    Photonic sensing technology is a new and accurate measurement technology for bio-sensing applications. In this paper, a two-dimensional photonic crystal ring resonator based sensor is proposed and designed to detect the glucose concentration in urine over the range of 0 gm/dl-15 gm/dl. The proposed sensor is consisted of two inverted "L" waveguides and a ring resonator. If the glucose concentration in urine is varied, the refractive index of the urine is varied, which in turn the output response of sensor will be varied. By having the aforementioned principle, the glucose concentration in urine, glucose concentration in blood, albumin, urea, and bilirubin concentration in urine are predicted. The size of the proposed sensor is about 11.4 µm×11.4 µm, and the sensor can predict the result very accurately without any delay, hence, this attempt could be implemented for medical applications.

  15. 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 <span class="hlt">photon</span> detectors are regarded as the key enabling elements in many applications. Due to the low <span class="hlt">photon</span> energy at the short-wave infrared (SWIR), <span class="hlt">photon</span> <span class="hlt">detection</span> and imaging at this band are very challenging. As such, many efforts in <span class="hlt">photon</span> detector research are directed toward improving the performance of the <span class="hlt">photon</span> detectors operating in this wavelength range. To solve these problems, we have developed an electron-injection (EI) technique. The significance of this <span class="hlt">detection</span> 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 <span class="hlt">gain</span>. 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 <span class="hlt">detection</span> 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</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26133636','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26133636"><span>Microcalcification <span class="hlt">detectability</span> using a bench-top prototype <span class="hlt">photon</span>-counting breast CT based on a Si strip detector.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cho, Hyo-Min; Ding, Huanjun; Barber, William C; Iwanczyk, Jan S; Molloi, Sabee</p> <p>2015-07-01</p> <p>To investigate the feasibility of <span class="hlt">detecting</span> breast microcalcification (μCa) with a dedicated breast computed tomography (CT) system based on energy-resolved <span class="hlt">photon</span>-counting silicon (Si) strip detectors. The proposed <span class="hlt">photon</span>-counting breast CT system and a bench-top prototype <span class="hlt">photon</span>-counting breast CT system were simulated using a simulation package written in matlab to determine the smallest <span class="hlt">detectable</span> μCa. A 14 cm diameter cylindrical phantom made of breast tissue with 20% glandularity was used to simulate an average-sized breast. Five different size groups of calcium carbonate grains, from 100 to 180 μm in diameter, were simulated inside of the cylindrical phantom. The images were acquired with a mean glandular dose (MGD) in the range of 0.7-8 mGy. A total of 400 images was used to perform a reader study. Another simulation study was performed using a 1.6 cm diameter cylindrical phantom to validate the experimental results from a bench-top prototype breast CT system. In the experimental study, a bench-top prototype CT system was constructed using a tungsten anode x-ray source and a single line 256-pixels Si strip <span class="hlt">photon</span>-counting detector with a pixel pitch of 100 μm. Calcium carbonate grains, with diameter in the range of 105-215 μm, were embedded in a cylindrical plastic resin phantom to simulate μCas. The physical phantoms were imaged at 65 kVp with an entrance exposure in the range of 0.6-8 mGy. A total of 500 images was used to perform another reader study. The images were displayed in random order to three blinded observers, who were asked to give a 4-point confidence rating on each image regarding the presence of μCa. The μCa <span class="hlt">detectability</span> for each image was evaluated by using the average area under the receiver operating characteristic curve (AUC) across the readers. The simulation results using a 14 cm diameter breast phantom showed that the proposed <span class="hlt">photon</span>-counting breast CT system can achieve high <span class="hlt">detection</span> accuracy with an average AUC greater</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27069647','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27069647"><span>InGaAs/InAlAs single <span class="hlt">photon</span> avalanche diode for 1550 nm <span class="hlt">photons</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Meng, Xiao; Xie, Shiyu; Zhou, Xinxin; Calandri, Niccolò; Sanzaro, Mirko; Tosi, Alberto; Tan, Chee Hing; Ng, Jo Shien</p> <p>2016-03-01</p> <p>A single <span class="hlt">photon</span> avalanche diode (SPAD) with an InGaAs absorption region, and an InAlAs avalanche region was designed and demonstrated to <span class="hlt">detect</span> 1550 nm wavelength <span class="hlt">photons</span>. The characterization included leakage current, dark count rate and single <span class="hlt">photon</span> <span class="hlt">detection</span> efficiency as functions of temperature from 210 to 294 K. The SPAD exhibited good temperature stability, with breakdown voltage dependence of approximately 45 mV K(-1). Operating at 210 K and in a gated mode, the SPAD achieved a <span class="hlt">photon</span> <span class="hlt">detection</span> probability of 26% at 1550 nm with a dark count rate of 1 × 10(8) Hz. The time response of the SPAD showed decreasing timing jitter (full width at half maximum) with increasing overbias voltage, with 70 ps being the smallest timing jitter measured.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4821258','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4821258"><span>InGaAs/InAlAs single <span class="hlt">photon</span> avalanche diode for 1550 nm <span class="hlt">photons</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Xie, Shiyu; Zhou, Xinxin; Calandri, Niccolò; Sanzaro, Mirko; Tosi, Alberto; Tan, Chee Hing; Ng, Jo Shien</p> <p>2016-01-01</p> <p>A single <span class="hlt">photon</span> avalanche diode (SPAD) with an InGaAs absorption region, and an InAlAs avalanche region was designed and demonstrated to <span class="hlt">detect</span> 1550 nm wavelength <span class="hlt">photons</span>. The characterization included leakage current, dark count rate and single <span class="hlt">photon</span> <span class="hlt">detection</span> efficiency as functions of temperature from 210 to 294 K. The SPAD exhibited good temperature stability, with breakdown voltage dependence of approximately 45 mV K−1. Operating at 210 K and in a gated mode, the SPAD achieved a <span class="hlt">photon</span> <span class="hlt">detection</span> probability of 26% at 1550 nm with a dark count rate of 1 × 108 Hz. The time response of the SPAD showed decreasing timing jitter (full width at half maximum) with increasing overbias voltage, with 70 ps being the smallest timing jitter measured. PMID:27069647</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29131361','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29131361"><span>Modeling the frequency-dependent <span class="hlt">detective</span> quantum efficiency of <span class="hlt">photon</span>-counting x-ray detectors.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Stierstorfer, Karl</p> <p>2018-01-01</p> <p>To find a simple model for the frequency-dependent <span class="hlt">detective</span> quantum efficiency (DQE) of <span class="hlt">photon</span>-counting detectors in the low flux limit. Formula for the spatial cross-talk, the noise power spectrum and the DQE of a <span class="hlt">photon</span>-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 <span class="hlt">photon</span>-counting detectors as a function of spatial frequency is calculated for various pixel sizes, <span class="hlt">photon</span> energies, and thresholds. The frequency-dependent DQE of a <span class="hlt">photon</span>-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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006PhDT........55J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006PhDT........55J"><span>Terahertz <span class="hlt">photonic</span> crystals</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jian, Zhongping</p> <p></p> <p>This thesis describes the study of two-dimensional <span class="hlt">photonic</span> crystals slabs with terahertz time domain spectroscopy. In our study we first demonstrate the realization of planar <span class="hlt">photonic</span> components to manipulate terahertz waves, and then characterize <span class="hlt">photonic</span> crystals using terahertz pulses. <span class="hlt">Photonic</span> crystal slabs at the scale of micrometers are first designed and fabricated free of defects. Terahertz time domain spectrometer generates and <span class="hlt">detects</span> the electric fields of single-cycle terahertz pulses. By putting <span class="hlt">photonic</span> crystals into waveguide geometry, we successfully demonstrate planar <span class="hlt">photonic</span> components such as transmission filters, reflection frequency-selective filters, defects modes as well as superprisms. In the characterization study of out-of-plane properties of <span class="hlt">photonic</span> crystal slabs, we observe very strong dispersion at low frequencies, guided resonance modes at middle frequencies, and a group velocity anomaly at high frequencies. We employ Finite Element Method and Finite-Difference Time-Domain method to simulate the <span class="hlt">photonic</span> crystals, and excellent agreement is achieved between simulation results and experimental results.</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_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_11 --> <div id="page_12" 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_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> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="221"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26816373','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26816373"><span>Applied optics. <span class="hlt">Gain</span> modulation by graphene plasmons in aperiodic lattice lasers.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chakraborty, S; Marshall, O P; Folland, T G; Kim, Y-J; Grigorenko, A N; Novoselov, K S</p> <p>2016-01-15</p> <p>Two-dimensional graphene plasmon-based technologies will enable the development of fast, compact, and inexpensive active <span class="hlt">photonic</span> elements because, unlike plasmons in other materials, graphene plasmons can be tuned via the doping level. Such tuning is harnessed within terahertz quantum cascade lasers to reversibly alter their emission. This is achieved in two key steps: first, by exciting graphene plasmons within an aperiodic lattice laser and, second, by engineering <span class="hlt">photon</span> lifetimes, linking graphene's Fermi energy with the round-trip <span class="hlt">gain</span>. Modal <span class="hlt">gain</span> and hence laser spectra are highly sensitive to the doping of an integrated, electrically controllable, graphene layer. Demonstration of the integrated graphene plasmon laser principle lays the foundation for a new generation of active, programmable plasmonic metamaterials with major implications across <span class="hlt">photonics</span>, material sciences, and nanotechnology. Copyright © 2016, American Association for the Advancement of Science.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20090041691','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20090041691"><span>Interferometric Quantum-Nondemolition Single-<span class="hlt">Photon</span> Detectors</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kok, Peter; Lee, Hwang; Dowling, Jonathan</p> <p>2007-01-01</p> <p>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 <span class="hlt">photons</span>, whereas the polarization-preserving device works on a superposition of vacuum and single- <span class="hlt">photon</span> 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 <span class="hlt">photon</span>, in which case its output mode would also be populated by a single <span class="hlt">photon</span>. 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, <span class="hlt">detection</span> 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 <span class="hlt">detecting</span> a <span class="hlt">photon</span> without destroying it. The only prior single- <span class="hlt">photon-detecting</span> QND device is based on quantum electrodynamics in a resonant cavity and, as such, it depends on the <span class="hlt">photon</span> frequency. Moreover, the prior device can distinguish only between one <span class="hlt">photon</span> and no <span class="hlt">photon</span>. The proposed interferometric QND devices would not depend on frequency and could distinguish between (a) one <span class="hlt">photon</span> and (b) zero or two <span class="hlt">photons</span>. 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-<span class="hlt">photon</span> 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 <span class="hlt">photon</span>, in which case its output mode also would be populated by a single <span class="hlt">photon</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016OptCo.370....1H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016OptCo.370....1H"><span>Microwave <span class="hlt">photonic</span> link with improved phase noise using a balanced <span class="hlt">detection</span> scheme</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hu, Jingjing; Gu, Yiying; Tan, Wengang; Zhu, Wenwu; Wang, Linghua; Zhao, Mingshan</p> <p>2016-07-01</p> <p>A microwave <span class="hlt">photonic</span> link (MPL) with improved phase noise performance using a dual output Mach-Zehnder modulator (DP-MZM) and balanced <span class="hlt">detection</span> is proposed and experimentally demonstrated. The fundamental concept of the approach is based on the two complementary outputs of DP-MZM and the destructive combination of the photocurrent in balanced photodetector (BPD). Theoretical analysis is performed to numerical evaluate the additive phase noise performance and shows a good agreement with the experiment. Experimental results are presented for 4 GHz, 8 GHz and 12 GHz transmission link and an 11 dB improvement of phase noise performance at 10 MHz offset is achieved compared to the conventional intensity-modulation and direct-<span class="hlt">detection</span> (IMDD) MPL.</p> </li> <li> <p><a target="_blank" 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, <span class="hlt">photon</span>-number-resolving, telecommunication-band detectors for scalable <span class="hlt">photonic</span> information processing</span></a></p> <p><a target="_blank" 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 <span class="hlt">photonic</span> quantum processing devices that are sufficiently complex to be genuinely useful in computing, metrology, and simulation. Embedded on-chip <span class="hlt">detection</span> will be critical to such devices. We demonstrate an integrated <span class="hlt">photon</span>-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 <span class="hlt">photons</span> are resolved in the guided optical mode via absorption from the evanescent field into a tungsten transition-edge sensor. The <span class="hlt">detection</span> 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 <span class="hlt">detection</span> efficiencies.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/11101255','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/11101255"><span>Electrophoretically mediated microanalysis of leucine aminopeptidase using two-<span class="hlt">photon</span> excited fluorescence <span class="hlt">detection</span> on a microchip.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zugel, S A; Burke, B J; Regnier, F E; Lytle, F E</p> <p>2000-11-15</p> <p>Two-<span class="hlt">photon</span> excited fluorescence <span class="hlt">detection</span> was performed on a microfabricated electrophoresis chip. A calibration curve of the fluorescent tag beta-naphthylamine was performed, resulting in a sensitivity of 2.5 x 10(9) counts M(-1) corresponding to a <span class="hlt">detection</span> limit of 60 nM. Additionally, leucine aminopeptidase was assayed on the chip using electrophoretically mediated microanalysis. The differential electroosmotic mobilities of the enzyme and substrate, L-leucine beta-naphthylamide, allowed for efficient mixing in an open channel, resulting in the <span class="hlt">detection</span> of a 30 nM enzyme solution under constant potential. A zero potential incubation for 1 min yielded a calculated <span class="hlt">detection</span> limit of 4 nM enzyme.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JOpt...19d4005B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JOpt...19d4005B"><span>Orbital angular momentum modes of high-<span class="hlt">gain</span> parametric down-conversion</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Beltran, Lina; Frascella, Gaetano; Perez, Angela M.; Fickler, Robert; Sharapova, Polina R.; Manceau, Mathieu; Tikhonova, Olga V.; Boyd, Robert W.; Leuchs, Gerd; Chekhova, Maria V.</p> <p>2017-04-01</p> <p>Light beams with orbital angular momentum (OAM) are convenient carriers of quantum information. They can also be used for imparting rotational motion to particles and providing high resolution in imaging. Due to the conservation of OAM in parametric down-conversion (PDC), signal and idler <span class="hlt">photons</span> generated at low <span class="hlt">gain</span> have perfectly anti-correlated OAM values. It is interesting to study the OAM properties of high-<span class="hlt">gain</span> PDC, where the same OAM modes can be populated with large, but correlated, numbers of <span class="hlt">photons</span>. Here we investigate the OAM spectrum of high-<span class="hlt">gain</span> PDC and show that the OAM mode content can be controlled by varying the pump power and the configuration of the source. In our experiment, we use a source consisting of two nonlinear crystals separated by an air gap. We discuss the OAM properties of PDC radiation emitted by this source and suggest possible modifications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2945739','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2945739"><span>A solid-state amorphous selenium avalanche technology for low <span class="hlt">photon</span> flux imaging applications</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Wronski, M. M.; Zhao, W.; Reznik, A.; Tanioka, K.; DeCrescenzo, G.; Rowlands, J. A.</p> <p>2010-01-01</p> <p>Purpose: The feasibility of a practical solid-state technology for low <span class="hlt">photon</span> flux imaging applications was investigated. The technology is based on an amorphous selenium photoreceptor with a voltage-controlled avalanche multiplication <span class="hlt">gain</span>. If this photoreceptor can provide sufficient internal <span class="hlt">gain</span>, it will be useful for an extensive range of diagnostic imaging systems. Methods: The avalanche photoreceptor under investigation is referred to as HARP-DRL. This is a novel concept in which a high-<span class="hlt">gain</span> avalanche rushing photoconductor (HARP) is integrated with a distributed resistance layer (DRL) and sandwiched between two electrodes. The avalanche <span class="hlt">gain</span> and leakage current characteristics of this photoreceptor were measured. Results: HARP-DRL has been found to sustain very high electric field strengths without electrical breakdown. It has shown avalanche multiplication <span class="hlt">gains</span> as high as 104 and a very low leakage current (≤20 pA∕mm2). Conclusions: This is the first experimental demonstration of a solid-state amorphous photoreceptor which provides sufficient internal avalanche <span class="hlt">gain</span> for <span class="hlt">photon</span> counting and <span class="hlt">photon</span> starved imaging applications. PMID:20964217</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3260923','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3260923"><span>Practical guidelines for interpreting copy number <span class="hlt">gains</span> <span class="hlt">detected</span> by high-resolution array in routine diagnostics</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Hanemaaijer, Nicolien M; Sikkema-Raddatz, Birgit; van der Vries, Gerben; Dijkhuizen, Trijnie; Hordijk, Roel; van Essen, Anthonie J; Veenstra-Knol, Hermine E; Kerstjens-Frederikse, Wilhelmina S; Herkert, Johanna C; Gerkes, Erica H; Leegte, Lamberta K; Kok, Klaas; Sinke, Richard J; van Ravenswaaij-Arts, Conny M A</p> <p>2012-01-01</p> <p>The correct interpretation of copy number <span class="hlt">gains</span> in patients with developmental delay and multiple congenital anomalies is hampered by the large number of copy number variations (CNVs) encountered in healthy individuals. The variable phenotype associated with copy number <span class="hlt">gains</span> makes interpretation even more difficult. Literature shows that inheritence, size and presence in healthy individuals are commonly used to decide whether a certain copy number <span class="hlt">gain</span> is pathogenic, but no general consensus has been established. We aimed to develop guidelines for interpreting <span class="hlt">gains</span> <span class="hlt">detected</span> by array analysis using array CGH data of 300 patients analysed with the 105K Agilent oligo array in a diagnostic setting. We evaluated the guidelines in a second, independent, cohort of 300 patients. In the first 300 patients 797 <span class="hlt">gains</span> of four or more adjacent oligonucleotides were observed. Of these, 45.4% were de novo and 54.6% were familial. In total, 94.8% of all de novo <span class="hlt">gains</span> and 87.1% of all familial <span class="hlt">gains</span> were concluded to be benign CNVs. Clinically relevant <span class="hlt">gains</span> ranged from 288 to 7912 kb in size, and were significantly larger than benign <span class="hlt">gains</span> and <span class="hlt">gains</span> of unknown clinical relevance (P<0.001). Our study showed that a threshold of 200 kb is acceptable in a clinical setting, whereas heritability does not exclude a pathogenic nature of a <span class="hlt">gain</span>. Evaluation of the guidelines in the second cohort of 300 patients revealed that the interpretation guidelines were clear, easy to follow and efficient. PMID:21934709</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3014427','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3014427"><span>Color changing <span class="hlt">photonic</span> crystals <span class="hlt">detect</span> blast exposure</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Cullen, D. Kacy; Xu, Yongan; Reneer, Dexter V.; Browne, Kevin D.; Geddes, James W.; Yang, Shu; Smith, Douglas H.</p> <p>2010-01-01</p> <p>Blast-induced traumatic brain injury (bTBI) is the “signature wound” of the current wars in Iraq and Afghanistan. However, with no objective information of relative blast exposure, warfighters with bTBI may not receive appropriate medical care and are at risk of being returned to the battlefield. Accordingly, we have created a colorimetric blast injury dosimeter (BID) that exploits material failure of <span class="hlt">photonic</span> crystals to <span class="hlt">detect</span> blast exposure. Appearing like a colored sticker, the BID is fabricated in photosensitive polymers via multi-beam interference lithography. Although very stable in the presence of heat, cold or physical impact, sculpted micro- and nano-structures of the BID are physically altered in a precise manner by blast exposure, resulting in color changes that correspond with blast intensity. This approach offers a lightweight, power-free sensor that can be readily interpreted by the naked eye. Importantly, with future refinement this technology may be deployed to identify soldiers exposed to blast at levels suggested to be supra-threshold for non-impact blast-induced mild TBI. PMID:21040795</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/20888220-detection-cherenkov-photons-multi-anode-photomultipliers','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/20888220-detection-cherenkov-photons-multi-anode-photomultipliers"><span><span class="hlt">Detection</span> of Cherenkov <span class="hlt">Photons</span> with Multi-Anode Photomultipliers</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Salazar, H.; Moreno, E.; Murrieta, T.</p> <p>2006-09-25</p> <p>The present paper describes the laboratory course given at the X Mexican Workshop on Particles and Fields. We describe the setup and procedure used to measure the Cherenkov circles produced by cosmic muons upon traversal of a simple glass radiator system. The main purpose of this exercise is to introduce the students to work with multi-anode photomultipliers such as the one used for this experiment (Hamamatsu R5900-M64), with which measurements requiring position sensitive <span class="hlt">detection</span> of single <span class="hlt">photons</span> can be successfully performed. We present a short introduction to multi-anode photomultipliers (MAPMT) and describe the setup and the procedure used to measuremore » the response of a MAPMT to a uniform source of light. Finally, we describe the setup and procedure used to measure the Cherenkov circles produced by cosmic muons upon traversal of a simple glass radiator system.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3319679','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3319679"><span>Phospholipase C mediated Suppression of Dark Noise Enables Single <span class="hlt">Photon</span> <span class="hlt">Detection</span> in Drosophila Photoreceptors</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Katz, Ben; Minke, Baruch</p> <p>2012-01-01</p> <p>Drosophila photoreceptor cells use the ubiquitous G-protein-mediated phospholipase C (PLC) cascade to achieve ultimate single <span class="hlt">photon</span> sensitivity. This is manifested in the single <span class="hlt">photon</span> responses (quantum bumps). In photoreceptor cells, dark activation of Gqα molecules occurs spontaneously and produces unitary dark events (dark bumps). A high rate of spontaneous Gqα activation and dark bump production potentially hampers single <span class="hlt">photon</span> <span class="hlt">detection</span>. We found that in wild type flies the in vivo rate of spontaneous Gqα activation is very high. Nevertheless, this high rate is not manifested in a substantially high rate of dark bumps. Therefore, it is unclear how phototransduction suppresses dark bump production, arising from spontaneous Gqα activation, while still maintaining high-fidelity representation of single <span class="hlt">photons</span>. In this study we show that reduced PLC catalytic activity selectively suppressed production of dark bumps but not light-induced bumps. Manipulations of PLC activity using PLC mutant flies and Ca2+ modulations revealed that a critical level of PLC activity is required to induce bump production. The required minimal level of PLC activity, selectively suppressed random production of single Gqα-activated dark bumps despite a high rate of spontaneous Gqα activation. This minimal PLC activity level is reliably obtained by <span class="hlt">photon</span> induced synchronized activation of several neighboring Gqα molecules activating several PLC molecules, but not by random activation of single Gqα molecules. We thus demonstrate how a G-protein-mediated transduction system, with PLC as its target, selectively suppresses its intrinsic noise while preserving reliable signaling. PMID:22357856</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22945141','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22945141"><span>Back-focal-plane position <span class="hlt">detection</span> with extended linear range for <span class="hlt">photonic</span> force microscopy.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Martínez, Ignacio A; Petrov, Dmitri</p> <p>2012-09-01</p> <p>In <span class="hlt">photonic</span> force microscopes, the position <span class="hlt">detection</span> with high temporal and spatial resolution is usually implemented by a quadrant position detector placed in the back focal plane of a condenser. An objective with high numerical aperture (NA) for the optical trap has also been used to focus a <span class="hlt">detection</span> beam. In that case the displacement of the probe at a fixed position of the detector produces a unique and linear response only in a restricted region of the probe displacement, usually several hundred nanometers. There are specific experiments where the absolute position of the probe is a relevant measure together with the probe position relative the optical trap focus. In our scheme we introduce the <span class="hlt">detection</span> beam into the condenser with low NA through a pinhole with tunable size. This combination permits us to create a wide <span class="hlt">detection</span> spot and to achieve the linear range of several micrometers by the probe position <span class="hlt">detection</span> without reducing the trapping force.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18754045','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18754045"><span>Time-resolved methods in biophysics. 7. <span class="hlt">Photon</span> counting vs. analog time-resolved singlet oxygen phosphorescence <span class="hlt">detection</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jiménez-Banzo, Ana; Ragàs, Xavier; Kapusta, Peter; Nonell, Santi</p> <p>2008-09-01</p> <p>Two recent advances in optoelectronics, namely novel near-IR sensitive photomultipliers and inexpensive yet powerful diode-pumped solid-state lasers working at kHz repetition rate, enable the time-resolved <span class="hlt">detection</span> of singlet oxygen (O2(a1Deltag)) phosphorescence in <span class="hlt">photon</span> counting mode, thereby boosting the time-resolution, sensitivity, and dynamic range of this well-established <span class="hlt">detection</span> technique. Principles underlying this novel approach and selected examples of applications are provided in this perspective, which illustrate the advantages over the conventional analog <span class="hlt">detection</span> mode.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19820024663','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19820024663"><span>The 2.5 bit/<span class="hlt">detected</span> <span class="hlt">photon</span> demonstration program: Phase 2 and 3 experimental results</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Katz, J.</p> <p>1982-01-01</p> <p>The experimental program for laboratory demonstration of and energy efficient optical communication channel operating at a rate of 2.5 bits/<span class="hlt">detected</span> <span class="hlt">photon</span> is described. Results of the uncoded PPM channel performance are presented. It is indicated that the throughput efficiency can be achieved not only with a Reed-Solomon code as originally predicted, but with a less complex code as well.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SPIE10212E..0SQ','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SPIE10212E..0SQ"><span>The ultraviolet <span class="hlt">detection</span> component based on Te-Cs image intensifier</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Qian, Yunsheng; Zhou, Xiaoyu; Wu, Yujing; Wang, Yan; Xu, Hua</p> <p>2017-05-01</p> <p>Ultraviolet <span class="hlt">detection</span> technology has been widely focused and adopted in the fields of ultraviolet warning and corona <span class="hlt">detection</span> for its significant value and practical meaning. The component structure of ultraviolet ICMOS, imaging driving and the <span class="hlt">photon</span> counting algorithm are studied in this paper. Firstly, the one-inch and wide dynamic range CMOS chip with the coupling optical fiber panel is coupled to the ultraviolet image intensifier. The photocathode material in ultraviolet image intensifier is Te-Cs, which contributes to the solar blind characteristic, and the dual micro-channel plates (MCP) structure ensures the sufficient <span class="hlt">gain</span> to achieve the single <span class="hlt">photon</span> counting. Then, in consideration of the ultraviolet <span class="hlt">detection</span> demand, the drive circuit of the CMOS chip is designed and the corresponding program based on Verilog language is written. According to the characteristics of ultraviolet imaging, the histogram equalization method is applied to enhance the ultraviolet image and the connected components labeling way is utilized for the ultraviolet single <span class="hlt">photon</span> counting. Moreover, one visible light video channel is reserved in the ultraviolet ICOMS camera, which can be used for the fusion of ultraviolet and visible images. Based upon the module, the ultraviolet optical lens and the deep cut-off solar blind filter are adopted to construct the ultraviolet detector. At last, the <span class="hlt">detection</span> experiment of the single <span class="hlt">photon</span> signal is carried out, and the test results are given and analyzed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20020040876&hterms=ophthalmology&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dophthalmology','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20020040876&hterms=ophthalmology&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dophthalmology"><span>Parafoveal Target <span class="hlt">Detectability</span> Reversal Predicted by Local Luminance and Contrast <span class="hlt">Gain</span> Control</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ahumada, Albert J., Jr.; Beard, Bettina L.; Null, Cynthia H. (Technical Monitor)</p> <p>1996-01-01</p> <p>This project is part of a program to develop image discrimination models for the prediction of the <span class="hlt">detectability</span> of objects in a range of backgrounds. We wanted to see if the models could predict parafoveal object <span class="hlt">detection</span> as well as they predict <span class="hlt">detection</span> in foveal vision. We also wanted to make our simplified models more general by local computation of luminance and contrast <span class="hlt">gain</span> control. A signal image (0.78 x 0.17 deg) was made by subtracting a simulated airport runway scene background image (2.7 deg square) from the same scene containing an obstructing aircraft. Signal visibility contrast thresholds were measured in a fully crossed factorial design with three factors: eccentricity (0 deg or 4 deg), background (uniform or runway scene background), and fixed-pattern white noise contrast (0%, 5%, or 10%). Three experienced observers responded to three repetitions of 60 2IFC trials in each condition and thresholds were estimated by maximum likelihood probit analysis. In the fovea the average <span class="hlt">detection</span> contrast threshold was 4 dB lower for the runway background than for the uniform background, but in the parafovea, the average threshold was 6 dB higher for the runway background than for the uniform background. This interaction was similar across the different noise levels and for all three observers. A likely reason for the runway background giving a lower threshold in the fovea is the low luminance near the signal in that scene. In our model, the local luminance computation is controlled by a spatial spread parameter. When this parameter and a corresponding parameter for the spatial spread of contrast <span class="hlt">gain</span> were increased for the parafoveal predictions, the model predicts the interaction of background with eccentricity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29247218','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29247218"><span>Wavevector multiplexed atomic quantum memory via spatially-resolved single-<span class="hlt">photon</span> <span class="hlt">detection</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Parniak, Michał; Dąbrowski, Michał; Mazelanik, Mateusz; Leszczyński, Adam; Lipka, Michał; Wasilewski, Wojciech</p> <p>2017-12-15</p> <p>Parallelized quantum information processing requires tailored quantum memories to simultaneously handle multiple <span class="hlt">photons</span>. The spatial degree of freedom is a promising candidate to facilitate such <span class="hlt">photonic</span> multiplexing. Using a single-<span class="hlt">photon</span> resolving camera, we demonstrate a wavevector multiplexed quantum memory based on a cold atomic ensemble. Observation of nonclassical correlations between Raman scattered <span class="hlt">photons</span> is confirmed by an average value of the second-order correlation function [Formula: see text] in 665 separated modes simultaneously. The proposed protocol utilizing the multimode memory along with the camera will facilitate generation of multi-<span class="hlt">photon</span> states, which are a necessity in quantum-enhanced sensing technologies and as an input to <span class="hlt">photonic</span> quantum circuits.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4880548','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4880548"><span><span class="hlt">Photonic</span> quantum information: science and technology</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>TAKEUCHI, Shigeki</p> <p>2016-01-01</p> <p>Recent technological progress in the generation, manipulation and <span class="hlt">detection</span> of individual single <span class="hlt">photons</span> has opened a new scientific field of <span class="hlt">photonic</span> quantum information. This progress includes the realization of single <span class="hlt">photon</span> switches, <span class="hlt">photonic</span> quantum circuits with specific functions, and the application of novel <span class="hlt">photonic</span> states to novel optical metrology beyond the limits of standard optics. In this review article, the recent developments and current status of <span class="hlt">photonic</span> quantum information technology are overviewed based on the author’s past and recent works. PMID:26755398</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26755398','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26755398"><span><span class="hlt">Photonic</span> quantum information: science and technology.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Takeuchi, Shigeki</p> <p>2016-01-01</p> <p>Recent technological progress in the generation, manipulation and <span class="hlt">detection</span> of individual single <span class="hlt">photons</span> has opened a new scientific field of <span class="hlt">photonic</span> quantum information. This progress includes the realization of single <span class="hlt">photon</span> switches, <span class="hlt">photonic</span> quantum circuits with specific functions, and the application of novel <span class="hlt">photonic</span> states to novel optical metrology beyond the limits of standard optics. In this review article, the recent developments and current status of <span class="hlt">photonic</span> quantum information technology are overviewed based on the author's past and recent works.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..DMP.B2001V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..DMP.B2001V"><span>Entanglement of 3000 atoms by <span class="hlt">detecting</span> one <span class="hlt">photon</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vuletic, Vladan</p> <p>2016-05-01</p> <p>Quantum-mechanically correlated (entangled) states of many particles are of interest in quantum information, quantum computing and quantum metrology. In particular, entangled states of many particles can be used to overcome limits on measurements performed with ensembles of independent atoms (standard quantum limit). Metrologically useful entangled states of large atomic ensembles (spin squeezed states) have been experimentally realized. These states display Gaussian spin distribution functions with a non-negative Wigner quasiprobability distribution function. We report the generation of entanglement in a large atomic ensemble via an interaction with a very weak laser pulse; remarkably, the <span class="hlt">detection</span> of a single <span class="hlt">photon</span> prepares several thousand atoms in an entangled state. We reconstruct a negative-valued Wigner function, and verify an entanglement depth (the minimum number of mutually entangled atoms) that comprises 90% of the atomic ensemble containing 3100 atoms. Further technical improvement should allow the generation of more complex Schrödinger cat states, and of states the overcome the standard quantum limit.</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" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013PhDT.......265B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013PhDT.......265B"><span>Photodiode radiation hardness, lyman-alpha emitting galaxies and <span class="hlt">photon</span> <span class="hlt">detection</span> in liquid argon neutrino detectors</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Baptista, Brian</p> <p>2013-12-01</p> <p>My dissertation is comprised of three projects: 1) studies of Lyman-alpha Emitting galaxies (LAEs), 2) radiation hardness studies of InGaAs photodiodes (PDs), and 3) scintillation <span class="hlt">photon</span> <span class="hlt">detection</span> in liquid argon (LAr) neutrino detectors. I began work on the project that has now become WFIRST, developing a science case that would use WFIRST after launch for the observation of LAEs. The radiation hardness of PDs was as an effort to support the WFIRST calibration team. When WFIRST was significantly delayed, I joined an R&D effort that applied my skills to work on <span class="hlt">photon</span> <span class="hlt">detection</span> in LAr neutrino detectors. I report results on a broadband selection method developed to <span class="hlt">detect</span> high equivalent width (EW) LAEs. Using photometry from the CFHT-Legacy Survey Deep 2 and 3 fields, I have spectroscopically confirmed 63 z=2.5-3.5 LAEs using the WIYN/Hydra spectrograph. Using UV continuum-fitting techniques I computed properties such as EWs, internal reddening and star formation rates. 62 of my LAEs show evidence to be normal dust-free LAEs. Second, I present an investigation into the effects of ionizing proton radiation on commercial off-the-shelf InGaAs PDs. I developed a monochromator-based test apparatus that utilized NIST-calibrated reference PDs. I tested the PDs for changes to their dark current, relative responsivity as a function of wavelength, and absolute responsivity. I irradiated the test PDs using 30, 52, and 98 MeV protons at the IU Cyclotron Facility. I found the InGaAs PDs showed increased dark current as the fluence increased with no evidence of broadband response degradation at the fluences expected at an L2 orbit and a 10-year mission lifetime. Finally, I detail my efforts on technology development of both optical detector technologies and waveshifting light guide construction for LAr vacuum UV scintillation light. Cryogenic neutrino detectors use <span class="hlt">photon</span> <span class="hlt">detection</span> for both accelerator based science and for SNe neutrino <span class="hlt">detection</span> and proton decay. I have</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ascl.soft03004M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ascl.soft03004M"><span>g<span class="hlt">Photon</span>: Time-tagged GALEX <span class="hlt">photon</span> events analysis tools</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Million, Chase C.; Fleming, S. W.; Shiao, B.; Loyd, P.; Seibert, M.; Smith, M.</p> <p>2016-03-01</p> <p>Written in Python, g<span class="hlt">Photon</span> calibrates and sky-projects the ~1.1 trillion ultraviolet <span class="hlt">photon</span> events <span class="hlt">detected</span> by the microchannel plates on the Galaxy Evolution Explorer Spacecraft (GALEX), archives these events in a publicly accessible database at the Mikulski Archive for Space Telescopes (MAST), and provides tools for working with the database to extract scientific results, particularly over short time domains. The software includes a re-implementation of core functionality of the GALEX mission calibration pipeline to produce <span class="hlt">photon</span> list files from raw spacecraft data as well as a suite of command line tools to generate calibrated light curves, images, and movies from the MAST database.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5448902','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5448902"><span><span class="hlt">Photonic</span> Paint Developed with Metallic Three-Dimensional <span class="hlt">Photonic</span> Crystals</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Sun, Po; Williams, John D.</p> <p>2012-01-01</p> <p>This work details the design and simulation of an inconspicuous <span class="hlt">photonic</span> paint that can be applied onto an object for anticounterfeit and tag, track, and locate (TTL) applications. The paint consists of three-dimensional metallic tilted woodpile <span class="hlt">photonic</span> crystals embedded into a visible and infrared transparent polymer film, which can be applied to almost any surface. The tilted woodpile <span class="hlt">photonic</span> crystals are designed with a specific pass band <span class="hlt">detectable</span> at nearly all incident angles of light. When painted onto a surface, these crystals provide a unique reflective infra-red optical signature that can be easily observed and recorded to verify the location or contents of a package.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28072546','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28072546"><span>Three-Dimensional Integration of Black Phosphorus Photodetector with Silicon <span class="hlt">Photonics</span> and Nanoplasmonics.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chen, Che; Youngblood, Nathan; Peng, Ruoming; Yoo, Daehan; Mohr, Daniel A; Johnson, Timothy W; Oh, Sang-Hyun; Li, Mo</p> <p>2017-02-08</p> <p>We demonstrate the integration of a black phosphorus photodetector in a hybrid, three-dimensional architecture of silicon <span class="hlt">photonics</span> and metallic nanoplasmonics structures. This integration approach combines the advantages of the low propagation loss of silicon waveguides, high-field confinement of a plasmonic nanogap, and the narrow bandgap of black phosphorus to achieve high responsivity for <span class="hlt">detection</span> of telecom-band, near-infrared light. Benefiting from an ultrashort channel (∼60 nm) and near-field enhancement enabled by the nanogap structure, the photodetector shows an intrinsic responsivity as high as 10 A/W afforded by internal <span class="hlt">gain</span> mechanisms, and a 3 dB roll-off frequency of 150 MHz. This device demonstrates a promising approach for on-chip integration of three distinctive <span class="hlt">photonic</span> systems, which, as a generic platform, may lead to future nanophotonic applications for biosensing, nonlinear optics, and optical signal processing.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA614951','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA614951"><span><span class="hlt">Photonic</span> Generation and <span class="hlt">Detection</span> of Arbitrary MMW Waveform for High-Resolution MMW Radar Imaging</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2014-12-06</p> <p>20ft ~ 2cm Destribution A: Approved for public release. Distribution is unlimited. Fig. 1. The system setup for our MMW arbitrary waveform generation...IOA(AOARD) 11. SPONSOR/MONITOR’S REPORT NUMBER(S) AOARD-134088 12. DISTRIBUTION/AVAILABILITY STATEMENT Destribution A: Approved for public...traveling carrier photodiode (NBUTC-PD), advanced optical pulse shaper system , and ultrafast TDS system to demonstrate the <span class="hlt">photonic</span> generation and <span class="hlt">detection</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23202223','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23202223"><span>Recent advances in integrated <span class="hlt">photonic</span> sensors.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Passaro, Vittorio M N; de Tullio, Corrado; Troia, Benedetto; La Notte, Mario; Giannoccaro, Giovanni; De Leonardis, Francesco</p> <p>2012-11-09</p> <p>Nowadays, optical devices and circuits are becoming fundamental components in several application fields such as medicine, biotechnology, automotive, aerospace, food quality control, chemistry, to name a few. In this context, we propose a complete review on integrated <span class="hlt">photonic</span> sensors, with specific attention to materials, technologies, architectures and optical sensing principles. To this aim, sensing principles commonly used in optical <span class="hlt">detection</span> are presented, focusing on sensor performance features such as sensitivity, selectivity and rangeability. Since <span class="hlt">photonic</span> sensors provide substantial benefits regarding compatibility with CMOS technology and integration on chips characterized by micrometric footprints, design and optimization strategies of <span class="hlt">photonic</span> devices are widely discussed for sensing applications. In addition, several numerical methods employed in <span class="hlt">photonic</span> circuits and devices, simulations and design are presented, focusing on their advantages and drawbacks. Finally, recent developments in the field of <span class="hlt">photonic</span> sensing are reviewed, considering advanced <span class="hlt">photonic</span> sensor architectures based on linear and non-linear optical effects and to be employed in chemical/biochemical sensing, angular velocity and electric field <span class="hlt">detection</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3522976','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3522976"><span>Recent Advances in Integrated <span class="hlt">Photonic</span> Sensors</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Passaro, Vittorio M. N.; de Tullio, Corrado; Troia, Benedetto; La Notte, Mario; Giannoccaro, Giovanni; De Leonardis, Francesco</p> <p>2012-01-01</p> <p>Nowadays, optical devices and circuits are becoming fundamental components in several application fields such as medicine, biotechnology, automotive, aerospace, food quality control, chemistry, to name a few. In this context, we propose a complete review on integrated <span class="hlt">photonic</span> sensors, with specific attention to materials, technologies, architectures and optical sensing principles. To this aim, sensing principles commonly used in optical <span class="hlt">detection</span> are presented, focusing on sensor performance features such as sensitivity, selectivity and rangeability. Since <span class="hlt">photonic</span> sensors provide substantial benefits regarding compatibility with CMOS technology and integration on chips characterized by micrometric footprints, design and optimization strategies of <span class="hlt">photonic</span> devices are widely discussed for sensing applications. In addition, several numerical methods employed in <span class="hlt">photonic</span> circuits and devices, simulations and design are presented, focusing on their advantages and drawbacks. Finally, recent developments in the field of <span class="hlt">photonic</span> sensing are reviewed, considering advanced <span class="hlt">photonic</span> sensor architectures based on linear and non-linear optical effects and to be employed in chemical/biochemical sensing, angular velocity and electric field <span class="hlt">detection</span>. PMID:23202223</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22453468','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22453468"><span><span class="hlt">Photonic</span>-crystal membranes for optical <span class="hlt">detection</span> of single nano-particles, designed for biosensor application.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Grepstad, Jon Olav; Kaspar, Peter; Solgaard, Olav; Johansen, Ib-Rune; Sudbø, Aasmund S</p> <p>2012-03-26</p> <p>A sensor designed to <span class="hlt">detect</span> bio-molecules is presented. The sensor exploits a planar 2D <span class="hlt">photonic</span> crystal (PC) membrane with sub-micron thickness and through holes, to induce high optical fields that allow <span class="hlt">detection</span> of nano-particles smaller than the diffraction limit of an optical microscope. We report on our design and fabrication of a PC membrane with a nano-particle trapped inside. We have also designed and built an imaging system where an optical microscope and a CCD camera are used to take images of the PC membrane. Results show how the trapped nano-particle appears as a bright spot in the image. In a first experimental realization of the imaging system, single particles with a radius of 75 nm can be <span class="hlt">detected</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/939437','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/939437"><span>Search for chameleon particles via <span class="hlt">photon</span> regeneration</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Chou, Aaron S.; /CCPP, New York U.</p> <p>2008-09-01</p> <p>We report the first results from the GammeV search for chameleon particles, which may be created via <span class="hlt">photon-photon</span> interactions within a strong magnetic field. The chameleons are assumed to have matter effects sufficiently strong that they reflect from all solid surfaces of the apparatus, thus evading <span class="hlt">detection</span> in our previous search for weakly-interacting axion-like particles. We implement a novel technique to create and trap the reflective particles within a jar and to <span class="hlt">detect</span> them later via their afterglow as they slowly convert back into <span class="hlt">photons</span>. These measurements provide the first experimental constraints on the couplings of chameleons to <span class="hlt">photons</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SPIE10464E..0CQ','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SPIE10464E..0CQ"><span>Instrument for all-fiber structure measurement of ultra-low turbidity by using single <span class="hlt">photon</span> <span class="hlt">detection</span> technique</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Qin, Feihu; Hu, Juntao; Wang, Huanqin; Gui, Huaqiao; Liu, Jianguo; Lü, Liang; Kong, Deyi; Zhang, Jian; Han, Xia; Wang, Tianli</p> <p>2017-10-01</p> <p>An all-fiber structure <span class="hlt">detection</span> system based on single <span class="hlt">photon</span> <span class="hlt">detection</span> technique(SPDT) has been developed to measure the ultra-low turbidity ofliquids. To assure the measurement accuracy,the total intensity of transmission light has been <span class="hlt">detected</span> and quantified as number of <span class="hlt">photons</span> by avalanche photodiode (APD) which has the advantage of high sensitivity.A fresh all-fiber structure optical fiber probe based on SPDT is applied in the system to reduce the volume and fluctuation of traditional transmission-light measurement system,in which the all-fiber structure probe is used to delivery and collection of transmission light.On the basis of Beer-Lambert (B-L) transmission law,a test system has been established and carried out a series of experiments.By combining B-Llaw with the principle of SPDT,a novel model for <span class="hlt">detecting</span> turbidity has been proposed to explain the experimental results.The results have shown a well exponential relationship over the range of 0.01-1NTU (Nephelometric Turbidity Units).It also has showna good linear relationship with a resolution as high as 0.01NTUin the range of 0.01-0.09 NTU.When it is 1 secondofthe sampling time,the mean error of measurement result can be controlled within 5% of full scale.In addition,the new <span class="hlt">detection</span> structure proposed in this paper, which makes the system more compact and more suitable in the small special space.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23955230','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23955230"><span>Deterministic quantum teleportation of <span class="hlt">photonic</span> quantum bits by a hybrid technique.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Takeda, Shuntaro; Mizuta, Takahiro; Fuwa, Maria; van Loock, Peter; Furusawa, Akira</p> <p>2013-08-15</p> <p>Quantum teleportation allows for the transfer of arbitrary unknown quantum states from a sender to a spatially distant receiver, provided that the two parties share an entangled state and can communicate classically. It is the essence of many sophisticated protocols for quantum communication and computation. <span class="hlt">Photons</span> are an optimal choice for carrying information in the form of 'flying qubits', but the teleportation of <span class="hlt">photonic</span> quantum bits (qubits) has been limited by experimental inefficiencies and restrictions. Main disadvantages include the fundamentally probabilistic nature of linear-optics Bell measurements, as well as the need either to destroy the teleported qubit or attenuate the input qubit when the detectors do not resolve <span class="hlt">photon</span> numbers. Here we experimentally realize fully deterministic quantum teleportation of <span class="hlt">photonic</span> qubits without post-selection. The key step is to make use of a hybrid technique involving continuous-variable teleportation of a discrete-variable, <span class="hlt">photonic</span> qubit. When the receiver's feedforward <span class="hlt">gain</span> is optimally tuned, the continuous-variable teleporter acts as a pure loss channel, and the input dual-rail-encoded qubit, based on a single <span class="hlt">photon</span>, represents a quantum error <span class="hlt">detection</span> code against <span class="hlt">photon</span> loss and hence remains completely intact for most teleportation events. This allows for a faithful qubit transfer even with imperfect continuous-variable entangled states: for four qubits the overall transfer fidelities range from 0.79 to 0.82 and all of them exceed the classical limit of teleportation. Furthermore, even for a relatively low level of the entanglement, qubits are teleported much more efficiently than in previous experiments, albeit post-selectively (taking into account only the qubit subspaces), and with a fidelity comparable to the previously reported values.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19840025696','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19840025696"><span>Means and method for calibrating a <span class="hlt">photon</span> detector utilizing electron-<span class="hlt">photon</span> coincidence</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Srivastava, S. K. (Inventor)</p> <p>1984-01-01</p> <p>An arrangement for calibrating a <span class="hlt">photon</span> detector particularly applicable for the ultraviolet and vacuum ultraviolet regions is based on electron <span class="hlt">photon</span> coincidence utilizing crossed electron beam atom beam collisions. Atoms are excited by electrons which lose a known amount of energy and scatter with a known remaining energy, while the excited atoms emit <span class="hlt">photons</span> of known radiation. Electrons of the known remaining energy are separated from other electrons and are counted. <span class="hlt">Photons</span> emitted in a direction related to the particular direction of scattered electrons are <span class="hlt">detected</span> to serve as a standard. Each of the electrons is used to initiate the measurements of a time interval which terminates with the arrival of a <span class="hlt">photon</span> exciting the <span class="hlt">photon</span> detector. Only the number of time intervals related to the coincidence correlation and of electrons scattered in the particular direction with the known remaining energy and <span class="hlt">photons</span> of a particular radiation level emitted due to the collisions of such scattered electrons are counted. The detector calibration is related to the number of counted electrons and <span class="hlt">photons</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27254867','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27254867"><span>Noise Power Spectrum Measurements in Digital Imaging With <span class="hlt">Gain</span> Nonuniformity Correction.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kim, Dong Sik</p> <p>2016-08-01</p> <p>The noise power spectrum (NPS) of an image sensor provides the spectral noise properties needed to evaluate sensor performance. Hence, measuring an accurate NPS is important. However, the fixed pattern noise from the sensor's nonuniform <span class="hlt">gain</span> inflates the NPS, which is measured from images acquired by the sensor. Detrending the low-frequency fixed pattern is traditionally used to accurately measure NPS. However, detrending methods cannot remove high-frequency fixed patterns. In order to efficiently correct the fixed pattern noise, a <span class="hlt">gain</span>-correction technique based on the <span class="hlt">gain</span> map can be used. The <span class="hlt">gain</span> map is generated using the average of uniformly illuminated images without any objects. Increasing the number of images n for averaging can reduce the remaining <span class="hlt">photon</span> noise in the <span class="hlt">gain</span> map and yield accurate NPS values. However, for practical finite n , the <span class="hlt">photon</span> noise also significantly inflates NPS. In this paper, a nonuniform-<span class="hlt">gain</span> image formation model is proposed and the performance of the <span class="hlt">gain</span> correction is theoretically analyzed in terms of the signal-to-noise ratio (SNR). It is shown that the SNR is O(√n) . An NPS measurement algorithm based on the <span class="hlt">gain</span> map is then proposed for any given n . Under a weak nonuniform <span class="hlt">gain</span> assumption, another measurement algorithm based on the image difference is also proposed. For real radiography image detectors, the proposed algorithms are compared with traditional detrending and subtraction methods, and it is shown that as few as two images ( n=1 ) can provide an accurate NPS because of the compensation constant (1+1/n) .</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1422764','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1422764"><span>Broadband mixing of $${\\mathscr{P}}{\\mathscr{T}}$$-symmetric and $${\\mathscr{P}}{\\mathscr{T}}$$-broken phases in <span class="hlt">photonic</span> heterostructures with a one-dimensional loss/<span class="hlt">gain</span> bilayer</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Özgün, Ege; Serebryannikov, Andriy E.; Ozbay, Ekmel</p> <p></p> <p>Combining loss and <span class="hlt">gain</span> components in one <span class="hlt">photonic</span> heterostructure opens a new route to efficient manipulation by radiation, transmission, absorption, and scattering of electromagnetic waves. Therefore, loss/<span class="hlt">gain</span> structures enablingmore » $${\\mathscr{P}}{\\mathscr{T}}$$-symmetric and $${\\mathscr{P}}{\\mathscr{T}}$$-broken phases for eigenvalues have extensively been studied in the last decade. In particular, translation from one phase to another, which occurs at the critical point in the two-channel structures with one-dimensional loss/<span class="hlt">gain</span> components, is often associated with one-way transmission. In this report, broadband mixing of the $${\\mathscr{P}}{\\mathscr{T}}$$-symmetric and $${\\mathscr{P}}{\\mathscr{T}}$$-broken phases for eigenvalues is theoretically demonstrated in heterostructures with four channels obtained by combining a one-dimensional loss/<span class="hlt">gain</span> bilayer and one or two thin polarization-converting components (PCCs). The broadband phase mixing in the four-channel case is expected to yield advanced transmission and absorption regimes. Various configurations are analyzed, which are distinguished in symmetry properties and polarization conversion regime of PCCs. The conditions necessary for phase mixing are then discussed. The simplest two-component configurations with broadband mixing are found, as well as the more complex three-component configurations wherein symmetric and broken sets are not yet mixed and appear in the neighbouring frequency ranges. Peculiarities of eigenvalue behaviour are considered for different permittivity ranges of loss/<span class="hlt">gain</span> medium, i.e., from epsilon-near-zero to high-epsilon regime.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1422764-broadband-mixing-mathscr-mathscr-symmetric-mathscr-mathscr-broken-phases-photonic-heterostructures-one-dimensional-loss-gain-bilayer','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1422764-broadband-mixing-mathscr-mathscr-symmetric-mathscr-mathscr-broken-phases-photonic-heterostructures-one-dimensional-loss-gain-bilayer"><span>Broadband mixing of $${\\mathscr{P}}{\\mathscr{T}}$$-symmetric and $${\\mathscr{P}}{\\mathscr{T}}$$-broken phases in <span class="hlt">photonic</span> heterostructures with a one-dimensional loss/<span class="hlt">gain</span> bilayer</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Özgün, Ege; Serebryannikov, Andriy E.; Ozbay, Ekmel; ...</p> <p>2017-11-14</p> <p>Combining loss and <span class="hlt">gain</span> components in one <span class="hlt">photonic</span> heterostructure opens a new route to efficient manipulation by radiation, transmission, absorption, and scattering of electromagnetic waves. Therefore, loss/<span class="hlt">gain</span> structures enablingmore » $${\\mathscr{P}}{\\mathscr{T}}$$-symmetric and $${\\mathscr{P}}{\\mathscr{T}}$$-broken phases for eigenvalues have extensively been studied in the last decade. In particular, translation from one phase to another, which occurs at the critical point in the two-channel structures with one-dimensional loss/<span class="hlt">gain</span> components, is often associated with one-way transmission. In this report, broadband mixing of the $${\\mathscr{P}}{\\mathscr{T}}$$-symmetric and $${\\mathscr{P}}{\\mathscr{T}}$$-broken phases for eigenvalues is theoretically demonstrated in heterostructures with four channels obtained by combining a one-dimensional loss/<span class="hlt">gain</span> bilayer and one or two thin polarization-converting components (PCCs). The broadband phase mixing in the four-channel case is expected to yield advanced transmission and absorption regimes. Various configurations are analyzed, which are distinguished in symmetry properties and polarization conversion regime of PCCs. The conditions necessary for phase mixing are then discussed. The simplest two-component configurations with broadband mixing are found, as well as the more complex three-component configurations wherein symmetric and broken sets are not yet mixed and appear in the neighbouring frequency ranges. Peculiarities of eigenvalue behaviour are considered for different permittivity ranges of loss/<span class="hlt">gain</span> medium, i.e., from epsilon-near-zero to high-epsilon regime.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20070017487','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20070017487"><span>SiC-based Photo-detectors for UV, VUV, EUV and Soft X-ray <span class="hlt">Detection</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Yan, Feng</p> <p>2006-01-01</p> <p>A viewgraph presentation describing an ideal Silicon Carbide detector for ultraviolet, vacuum ultraviolet, extreme ultraviolet and soft x-ray <span class="hlt">detection</span> 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 <span class="hlt">gain</span>; 6) Excess noise; 7) SNR in single <span class="hlt">photon</span> counting mode; 8) Structure of SiC single <span class="hlt">photon</span> counting APD and testing structure; 9) Single <span class="hlt">photon</span> counting waveform and testing circuit; 10) Amplitude of SiC single <span class="hlt">photon</span> counter; 11) Dark count of SiC APD <span class="hlt">photon</span> 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 <span class="hlt">detection</span>; 23) Terrestrial solar spectra; and 24) Less than 1KeV soft x-ray <span class="hlt">detection</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018SPIE10510E..0IS','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018SPIE10510E..0IS"><span>Chemical sensors fabricated by a <span class="hlt">photonic</span> integrated circuit foundry</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stievater, Todd H.; Koo, Kee; Tyndall, Nathan F.; Holmstrom, Scott A.; Kozak, Dmitry A.; Goetz, Peter G.; McGill, R. Andrew; Pruessner, Marcel W.</p> <p>2018-02-01</p> <p>We describe the <span class="hlt">detection</span> of trace concentrations of chemical agents using waveguide-enhanced Raman spectroscopy in a <span class="hlt">photonic</span> integrated circuit fabricated by AIM <span class="hlt">Photonics</span>. The <span class="hlt">photonic</span> integrated circuit is based on a five-centimeter long silicon nitride waveguide with a trench etched in the top cladding to allow access to the evanescent field of the propagating mode by analyte molecules. This waveguide transducer is coated with a sorbent polymer to enhance <span class="hlt">detection</span> sensitivity and placed between low-loss edge couplers. The <span class="hlt">photonic</span> integrated circuit is laid-out using the AIM <span class="hlt">Photonics</span> Process Design Kit and fabricated on a Multi-Project Wafer. We <span class="hlt">detect</span> chemical warfare agent simulants at sub parts-per-million levels in times of less than a minute. We also discuss anticipated improvements in the level of integration for <span class="hlt">photonic</span> chemical sensors, as well as existing challenges.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1001991','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/1001991"><span>Monitoring molecular interactions using <span class="hlt">photon</span> arrival-time interval distribution analysis</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Laurence, Ted A [Livermore, CA; Weiss, Shimon [Los Angels, CA</p> <p>2009-10-06</p> <p>A method for analyzing/monitoring the properties of species that are labeled with fluorophores. A detector is used to <span class="hlt">detect</span> <span class="hlt">photons</span> emitted from species that are labeled with one or more fluorophores and located in a confocal <span class="hlt">detection</span> volume. The arrival time of each of the <span class="hlt">photons</span> is determined. The interval of time between various <span class="hlt">photon</span> pairs is then determined to provide <span class="hlt">photon</span> pair intervals. The number of <span class="hlt">photons</span> that have arrival times within the <span class="hlt">photon</span> pair intervals is also determined. The <span class="hlt">photon</span> pair intervals are then used in combination with the corresponding counts of intervening <span class="hlt">photons</span> to analyze properties and interactions of the molecules including brightness, concentration, coincidence and transit time. The method can be used for analyzing single <span class="hlt">photon</span> streams and multiple <span class="hlt">photon</span> streams.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20060041707&hterms=signal+amplification&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dsignal%2Bamplification','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20060041707&hterms=signal+amplification&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dsignal%2Bamplification"><span>Brillouin Selective Sideband Amplification of Microwave <span class="hlt">Photonic</span> Signals</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Yao, S.</p> <p>1997-01-01</p> <p>We introduce a powerful Brillouin selective sideband amplification technique and demonstrate its application for achieving <span class="hlt">gain</span> in photonix signal up- and down- conversions in microwave <span class="hlt">photonic</span> systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21996918','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21996918"><span>Analytical model and figures of merit for filtered Microwave <span class="hlt">Photonic</span> Links.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gasulla, Ivana; Capmany, José</p> <p>2011-09-26</p> <p>The concept of filtered Microwave <span class="hlt">Photonic</span> Links is proposed in order to provide the most general and versatile description of complex analog <span class="hlt">photonic</span> systems. We develop a field propagation model where a global optical filter, characterized by its optical transfer function, embraces all the intermediate optical components in a linear link. We assume a non-monochromatic light source characterized by an arbitrary spectral distribution which has a finite linewidth spectrum and consider both intensity modulation and phase modulation with balanced and single <span class="hlt">detection</span>. Expressions leading to the computation of the main figures of merit concerning the link <span class="hlt">gain</span>, noise and intermodulation distortion are provided which, to our knowledge, are not available in the literature. The usefulness of this derivation resides in the capability to directly provide performance criteria results for complex links just by substituting in the overall closed-form formulas the numerical or measured optical transfer function characterizing the link. This theory is presented thus as a potential tool for a wide range of relevant microwave <span class="hlt">photonic</span> application cases which is extendable to multiport radio over fiber systems. © 2011 Optical Society of America</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" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20632606','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20632606"><span>Fast simulation of yttrium-90 bremsstrahlung <span class="hlt">photons</span> with GATE.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rault, Erwann; Staelens, Steven; Van Holen, Roel; De Beenhouwer, Jan; Vandenberghe, Stefaan</p> <p>2010-06-01</p> <p>Multiple investigators have recently reported the use of yttrium-90 (90Y) bremsstrahlung single <span class="hlt">photon</span> emission computed tomography (SPECT) imaging for the dosimetry of targeted radionuclide therapies. Because Monte Carlo (MC) simulations are useful for studying SPECT imaging, this study investigates the MC simulation of 90Y bremsstrahlung <span class="hlt">photons</span> in SPECT. To overcome the computationally expensive simulation of electrons, the authors propose a fast way to simulate the emission of 90Y bremsstrahlung <span class="hlt">photons</span> based on prerecorded bremsstrahlung <span class="hlt">photon</span> probability density functions (PDFs). The accuracy of bremsstrahlung <span class="hlt">photon</span> simulation is evaluated in two steps. First, the validity of the fast bremsstrahlung <span class="hlt">photon</span> generator is checked. To that end, fast and analog simulations of <span class="hlt">photons</span> emitted from a 90Y point source in a water phantom are compared. The same setup is then used to verify the accuracy of the bremsstrahlung <span class="hlt">photon</span> simulations, comparing the results obtained with PDFs generated from both simulated and measured data to measurements. In both cases, the energy spectra and point spread functions of the <span class="hlt">photons</span> <span class="hlt">detected</span> in a scintillation camera are used. Results show that the fast simulation method is responsible for a 5% overestimation of the low-energy fluence (below 75 keV) of the bremsstrahlung <span class="hlt">photons</span> <span class="hlt">detected</span> using a scintillation camera. The spatial distribution of the <span class="hlt">detected</span> <span class="hlt">photons</span> is, however, accurately reproduced with the fast method and a computational acceleration of approximately 17-fold is achieved. When measured PDFs are used in the simulations, the simulated energy spectrum of <span class="hlt">photons</span> emitted from a point source of 90Y in a water phantom and <span class="hlt">detected</span> in a scintillation camera closely approximates the measured spectrum. The PSF of the <span class="hlt">photons</span> imaged in the 50-300 keV energy window is also accurately estimated with a 12.4% underestimation of the full width at half maximum and 4.5% underestimation of the full width at tenth maximum</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22250746-low-noise-low-jitter-pixels-cmos-single-photon-avalanche-diodes-array-single-photon-counting-from-nm-nm','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22250746-low-noise-low-jitter-pixels-cmos-single-photon-avalanche-diodes-array-single-photon-counting-from-nm-nm"><span>Low-noise low-jitter 32-pixels CMOS single-<span class="hlt">photon</span> avalanche diodes array for single-<span class="hlt">photon</span> counting from 300 nm to 900 nm</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Scarcella, Carmelo; Tosi, Alberto, E-mail: alberto.tosi@polimi.it; Villa, Federica</p> <p>2013-12-15</p> <p>We developed a single-<span class="hlt">photon</span> counting multichannel <span class="hlt">detection</span> system, based on a monolithic linear array of 32 CMOS SPADs (Complementary Metal-Oxide-Semiconductor Single-<span class="hlt">Photon</span> Avalanche Diodes). All channels achieve a timing resolution of 100 ps (full-width at half maximum) and a <span class="hlt">photon</span> <span class="hlt">detection</span> efficiency of 50% at 400 nm. Dark count rate is very low even at room temperature, being about 125 counts/s for 50 μm active area diameter SPADs. <span class="hlt">Detection</span> performance and microelectronic compactness of this CMOS SPAD array make it the best candidate for ultra-compact time-resolved spectrometers with single-<span class="hlt">photon</span> sensitivity from 300 nm to 900 nm.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29575398','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29575398"><span>Strong <span class="hlt">Photonic</span>-Band-Gap Effect on the Spontaneous Emission in 3D Lead Halide Perovskite <span class="hlt">Photonic</span> Crystals.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhou, Xue; Li, Mingzhu; Wang, Kang; Li, Huizeng; Li, Yanan; Li, Chang; Yan, Yongli; Zhao, Yongsheng; Song, Yanlin</p> <p>2018-03-25</p> <p>Stimulated emission in perovskite-embedded polymer opal structures is investigated. A polymer opal structure is filled with a perovskite, and perovskite <span class="hlt">photonic</span> crystals are prepared. The spontaneous emission of the perovskite embedded in the polymer opal structures exhibits clear signatures of amplified spontaneous emission (ASE) via <span class="hlt">gain</span> modulation. The difference in refractive-index contrast between the perovskite and the polymer opal is large enough for retaining <span class="hlt">photonic</span>-crystals properties. The <span class="hlt">photonic</span> band gap has a strong effect on the fluorescence emission intensity and lifetime. The stimulated emission spectrum exhibits a narrow ASE rather than a wide fluorescence peak in the thin film. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.</p> </li> <li> <p><a target="_blank" 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 <span class="hlt">Photon</span> Counters in liquid xenon</span></a></p> <p><a target="_blank" 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 <span class="hlt">Photon</span> 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 <span class="hlt">gain</span> equalization of photosensors operating at different voltages. The results show single <span class="hlt">photon</span> <span class="hlt">detection</span> 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" onclick="trackOutboundLink('http://hdl.handle.net/2060/19770025926','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19770025926"><span>Development and test of <span class="hlt">photon</span>-counting microchannel plate detector arrays for use on space telescopes</span></a></p> <p><a target="_blank" 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 <span class="hlt">photon</span>-counting <span class="hlt">detection</span> system for space operations. Components of the system include feedback-free MCP's for high <span class="hlt">gain</span> 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" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19408912','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19408912"><span>Trace <span class="hlt">detection</span> of organic compounds in complex sample matrixes by single <span class="hlt">photon</span> ionization ion trap mass spectrometry: real-time <span class="hlt">detection</span> of security-relevant compounds and online analysis of the coffee-roasting process.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Schramm, Elisabeth; Kürten, Andreas; Hölzer, Jasper; Mitschke, Stefan; Mühlberger, Fabian; Sklorz, Martin; Wieser, Jochen; Ulrich, Andreas; Pütz, Michael; Schulte-Ladbeck, Rasmus; Schultze, Rainer; Curtius, Joachim; Borrmann, Stephan; Zimmermann, Ralf</p> <p>2009-06-01</p> <p>An in-house-built ion trap mass spectrometer combined with a soft ionization source has been set up and tested. As ionization source, an electron beam pumped vacuum UV (VUV) excimer lamp (EBEL) was used for single-<span class="hlt">photon</span> ionization. It was shown that soft ionization allows the reduction of fragmentation of the target analytes and the suppression of most matrix components. Therefore, the combination of <span class="hlt">photon</span> ionization with the tandem mass spectrometry (MS/MS) capability of an ion trap yields a powerful tool for molecular ion peak <span class="hlt">detection</span> and identification of organic trace compounds in complex matrixes. This setup was successfully tested for two different applications. The first one is the <span class="hlt">detection</span> of security-relevant substances like explosives, narcotics, and chemical warfare agents. One test substance from each of these groups was chosen and <span class="hlt">detected</span> successfully with single <span class="hlt">photon</span> ionization ion trap mass spectrometry (SPI-ITMS) MS/MS measurements. Additionally, first tests were performed, demonstrating that this method is not influenced by matrix compounds. The second field of application is the <span class="hlt">detection</span> of process gases. Here, exhaust gas from coffee roasting was analyzed in real time, and some of its compounds were identified using MS/MS studies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018SPIE10697E..0NW','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018SPIE10697E..0NW"><span>Development and test of <span class="hlt">photon</span> counting lidar</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Chun-hui; Wang, Ao-you; Tao, Yu-liang; Li, Xu; Peng, Huan; Meng, Pei-bei</p> <p>2018-02-01</p> <p>In order to satisfy the application requirements of spaceborne three dimensional imaging lidar , a prototype of nonscanning multi-channel lidar based on receiver field of view segmentation was designed and developed. High repetition frequency micro-pulse lasers, optics fiber array and Geiger-mode APD, combination with time-correlated single <span class="hlt">photon</span> counting technology, were adopted to achieve multi-channel <span class="hlt">detection</span>. Ranging experiments were carried out outdoors. In low echo <span class="hlt">photon</span> condition, target <span class="hlt">photon</span> counting showed time correlated and noise <span class="hlt">photon</span> counting were random. <span class="hlt">Detection</span> probability and range precision versus threshold were described and range precision increased from 0.44 to 0.11 when threshold increased from 4 to 8.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017NaPho..11..752F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017NaPho..11..752F"><span>Non-Hermitian <span class="hlt">photonics</span> based on parity-time symmetry</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Feng, Liang; El-Ganainy, Ramy; Ge, Li</p> <p>2017-12-01</p> <p>Nearly one century after the birth of quantum mechanics, parity-time symmetry is revolutionizing and extending quantum theories to include a unique family of non-Hermitian Hamiltonians. While conceptually striking, experimental demonstration of parity-time symmetry remains unexplored in quantum electronic systems. The flexibility of <span class="hlt">photonics</span> allows for creating and superposing non-Hermitian eigenstates with ease using optical <span class="hlt">gain</span> and loss, which makes it an ideal platform to explore various non-Hermitian quantum symmetry paradigms for novel device functionalities. Such explorations that employ classical <span class="hlt">photonic</span> platforms not only deepen our understanding of fundamental quantum physics but also facilitate technological breakthroughs for <span class="hlt">photonic</span> applications. Research into non-Hermitian <span class="hlt">photonics</span> therefore advances and benefits both fields simultaneously.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28789132','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28789132"><span>Silicon <span class="hlt">photonic</span> dual-gas sensor for H2 and CO2 <span class="hlt">detection</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mi, Guangcan; Horvath, Cameron; Van, Vien</p> <p>2017-07-10</p> <p>We report a silicon <span class="hlt">photonic</span> dual-gas sensor based on a wavelength-multiplexed microring resonator array for simultaneous <span class="hlt">detection</span> of H 2 and CO 2 gases. The sensor uses Pd as the sensing layer for H 2 gas and a novel functional material based on the Polyhexamethylene Biguanide (PHMB) polymer for CO 2 gas sensing. Gas sensing experiments showed that the PHMB-functionalized microring exhibited high sensitivity to CO 2 gas and excellent selectivity against H 2 . However, the Pd-functionalized microring was found to exhibit sensitivity to both H 2 and CO 2 gases, rendering it ineffective for <span class="hlt">detecting</span> H 2 in a gas mixture containing CO 2 . We show that the dual-gas sensing scheme can allow for accurate measurement of H 2 concentration in the presence of CO 2 by accounting for the cross-sensitivity of Pd to the latter.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018AAS...23136104V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018AAS...23136104V"><span>Measuring the Velocity of Cosmic <span class="hlt">Photons</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vazquez, Gerardo Arturo</p> <p>2018-01-01</p> <p>The position of the JWST in space—close to the L2 point at a distance of 1.5 million kilometers from Earth—allows us a unique chance to measure the speed of cosmic <span class="hlt">photons</span> through a double <span class="hlt">detection</span> in two different telescopes. The speed of cosmic <span class="hlt">photons</span> has been considered constant as a matter of principle, but in the same way, the energy lost by these <span class="hlt">photons</span> could have a contribution due to a different nature such as dark matter. In this work, an experiment to measure the speed of <span class="hlt">photons</span> is proposed based on the <span class="hlt">detection</span> on two different telescopes located at a considerable distance. Some of the most important results of this experiment could be variations of the speed of light as it passes through dark matter and, as a consequence, the ability to map dark matter in the universe. Although JWST is not in the direction to measure the difference in time of 5 seconds, the fact that it can move up to a 50 arc degree angle will allow us to measure a difference in <span class="hlt">detection</span> between 3 to 4.5 seconds. The observations needed to do this experiment should come from the <span class="hlt">detection</span> of gamma ray bursts and then, the simultaneous <span class="hlt">detection</span> by the sudden pointing of JWST plus a secondary telescope—on ground or in space—to catch the afterglow of the GRB in longer wavelengths. The new technology in telescopes will allow us to catch a difference in magnitude between both telescopes or even to measure single <span class="hlt">photon</span> <span class="hlt">detection</span> in time in order to accomplish the purpose of the experiment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/6580022','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/biblio/6580022"><span><span class="hlt">Photon</span> beam position monitor</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Kuzay, T.M.; Shu, D.</p> <p>1995-02-07</p> <p>A <span class="hlt">photon</span> beam position monitor is disclosed for use in the front end of a beamline of a high heat flux and high energy <span class="hlt">photon</span> source such as a synchrotron radiation storage ring <span class="hlt">detects</span> and measures the position and, when a pair of such monitors are used in tandem, the slope of a <span class="hlt">photon</span> beam emanating from an insertion device such as a wiggler or an undulator inserted in the straight sections of the ring. The <span class="hlt">photon</span> beam position monitor includes a plurality of spaced blades for precisely locating the <span class="hlt">photon</span> beam, with each blade comprised of chemical vapor deposition (CVD) diamond with an outer metal coating of a <span class="hlt">photon</span> sensitive metal such as tungsten, molybdenum, etc., which combination emits electrons when a high energy <span class="hlt">photon</span> 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 <span class="hlt">photon</span> beam and limiting detector blade temperature during operation. 18 figs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/869742','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/869742"><span><span class="hlt">Photon</span> beam position monitor</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Kuzay, Tuncer M.; Shu, Deming</p> <p>1995-01-01</p> <p>A <span class="hlt">photon</span> beam position monitor for use in the front end of a beamline of a high heat flux and high energy <span class="hlt">photon</span> source such as a synchrotron radiation storage ring <span class="hlt">detects</span> and measures the position and, when a pair of such monitors are used in tandem, the slope of a <span class="hlt">photon</span> beam emanating from an insertion device such as a wiggler or an undulator inserted in the straight sections of the ring. The <span class="hlt">photon</span> beam position monitor includes a plurality of spaced blades for precisely locating the <span class="hlt">photon</span> beam, with each blade comprised of chemical vapor deposition (CVD) diamond with an outer metal coating of a <span class="hlt">photon</span> sensitive metal such as tungsten, molybdenum, etc., which combination emits electrons when a high energy <span class="hlt">photon</span> 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 <span class="hlt">photon</span> beam and limiting detector blade temperature during operation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009JOptA..11k0201C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009JOptA..11k0201C"><span>EDITORIAL: TaCoNa-<span class="hlt">Photonics</span> 2008 TaCoNa-<span class="hlt">Photonics</span> 2008</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chigrin, Dmitry N.; Busch, Kurt; Lavrinenko, Andrei V.</p> <p>2009-11-01</p> <p>This special section on theoretical and computational nano-<span class="hlt">photonics</span> features papers presented at the first International Workshop on Theoretical and Computational Nano-<span class="hlt">Photonics</span> (TaCoNa-<span class="hlt">Photonics</span> 2008) held in Bad Honnef, Germany, 3-5 December 2008. The workshop covered a broad range of topics related to current developments and achievements in this interdisciplinary area of research. Since the late 1960s, the word `<span class="hlt">photonics</span>' has been understood as the science of generating, controlling, and <span class="hlt">detecting</span> light. Nowadays, a routine fabrication of complex structures with micro- and nano-scale dimensions opens up many new and exciting possibilities in <span class="hlt">photonics</span>. The science of generating, routing and <span class="hlt">detecting</span> light in micro- and nano-structured matter, `nano-<span class="hlt">photonics</span>', is becoming more important both in research and technology and offers many promising applications. The inherently sub-wavelength character of the structures that nano-<span class="hlt">photonics</span> deals with challenges modern theoretical and computational physics and engineering with many nontrivial questions: Up to what length-scale can one use a macroscopic phenomenological description of matter? Where is the interface between the classical and quantum description of light in nano-scale structures? How can one combine different physical systems, different time- and length-scales in a single computational model? How can one engineer nano-structured materials in order to achieve the desired optical properties for particular applications? Any attempt at answering these kinds of questions is impossible without the joint efforts of physicists, engineers, applied mathematicians and programmers. This is the reason why the major goal of the TaCoNa-<span class="hlt">Photonics</span> workshops is to provide a forum where theoreticians and specialists in numerical methods from all branches of physics, engineering sciences and mathematics can compare their results, report on novel results and breakthroughs, and discuss new challenges ahead. In order to</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29124351','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29124351"><span>NeuroSeg: automated cell <span class="hlt">detection</span> and segmentation for in vivo two-<span class="hlt">photon</span> Ca2+ imaging data.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Guan, Jiangheng; Li, Jingcheng; Liang, Shanshan; Li, Ruijie; Li, Xingyi; Shi, Xiaozhe; Huang, Ciyu; Zhang, Jianxiong; Pan, Junxia; Jia, Hongbo; Zhang, Le; Chen, Xiaowei; Liao, Xiang</p> <p>2018-01-01</p> <p>Two-<span class="hlt">photon</span> Ca 2+ imaging has become a popular approach for monitoring neuronal population activity with cellular or subcellular resolution in vivo. This approach allows for the recording of hundreds to thousands of neurons per animal and thus leads to a large amount of data to be processed. In particular, manually drawing regions of interest is the most time-consuming aspect of data analysis. However, the development of automated image analysis pipelines, which will be essential for dealing with the likely future deluge of imaging data, remains a major challenge. To address this issue, we developed NeuroSeg, an open-source MATLAB program that can facilitate the accurate and efficient segmentation of neurons in two-<span class="hlt">photon</span> Ca 2+ imaging data. We proposed an approach using a generalized Laplacian of Gaussian filter to <span class="hlt">detect</span> cells and weighting-based segmentation to separate individual cells from the background. We tested this approach on an in vivo two-<span class="hlt">photon</span> Ca 2+ imaging dataset obtained from mouse cortical neurons with differently sized view fields. We show that this approach exhibits superior performance for cell <span class="hlt">detection</span> and segmentation compared with the existing published tools. In addition, we integrated the previously reported, activity-based segmentation into our approach and found that this combined method was even more promising. The NeuroSeg software, including source code and graphical user interface, is freely available and will be a useful tool for in vivo brain activity mapping.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017OExpr..2533514M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017OExpr..2533514M"><span>Electro-optic routing of <span class="hlt">photons</span> from a single quantum dot in <span class="hlt">photonic</span> integrated circuits</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Midolo, Leonardo; Hansen, Sofie L.; Zhang, Weili; Papon, Camille; Schott, Rüdiger; Ludwig, Arne; Wieck, Andreas D.; Lodahl, Peter; Stobbe, Søren</p> <p>2017-12-01</p> <p>Recent breakthroughs in solid-state <span class="hlt">photonic</span> quantum technologies enable generating and <span class="hlt">detecting</span> single <span class="hlt">photons</span> with near-unity efficiency as required for a range of <span class="hlt">photonic</span> quantum technologies. The lack of methods to simultaneously generate and control <span class="hlt">photons</span> within the same chip, however, has formed a main obstacle to achieving efficient multi-qubit gates and to harness the advantages of chip-scale quantum <span class="hlt">photonics</span>. Here we propose and demonstrate an integrated voltage-controlled phase shifter based on the electro-optic effect in suspended <span class="hlt">photonic</span> waveguides with embedded quantum emitters. The phase control allows building a compact Mach-Zehnder interferometer with two orthogonal arms, taking advantage of the anisotropic electro-optic response in gallium arsenide. <span class="hlt">Photons</span> emitted by single self-assembled quantum dots can be actively routed into the two outputs of the interferometer. These results, together with the observed sub-microsecond response time, constitute a significant step towards chip-scale single-<span class="hlt">photon</span>-source de-multiplexing, fiber-loop boson sampling, and linear optical quantum computing.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21197014','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21197014"><span>A <span class="hlt">photonic</span> chip based frequency discriminator for a high performance microwave <span class="hlt">photonic</span> link.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Marpaung, David; Roeloffzen, Chris; Leinse, Arne; Hoekman, Marcel</p> <p>2010-12-20</p> <p>We report a high performance phase modulation direct <span class="hlt">detection</span> microwave <span class="hlt">photonic</span> link employing a <span class="hlt">photonic</span> chip as a frequency discriminator. The <span class="hlt">photonic</span> chip consists of five optical ring resonators (ORRs) which are fully programmable using thermo-optical tuning. In this discriminator a drop-port response of an ORR is cascaded with a through response of another ORR to yield a linear phase modulation (PM) to intensity modulation (IM) conversion. The balanced <span class="hlt">photonic</span> link employing the PM to IM conversion exhibits high second-order and third-order input intercept points of + 46 dBm and + 36 dBm, respectively, which are simultaneously achieved at one bias point.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19940006117','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19940006117"><span><span class="hlt">Photon</span> number amplification/duplication through parametric conversion</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Dariano, G. M.; Macchiavello, C.; Paris, M.</p> <p>1993-01-01</p> <p>The performance of parametric conversion in achieving number amplification and duplication is analyzed. It is shown that the effective maximum <span class="hlt">gains</span> G(sub *) remain well below their integer ideal values, even for large signals. Correspondingly, one has output Fano factors F(sub *) which are increasing functions of the input <span class="hlt">photon</span> number. On the other hand, in the inverse (deamplifier/recombiner) operating mode quasi-ideal <span class="hlt">gains</span> G(sub *) and small factors F(sub *) approximately equal to 10 percent are obtained. Output noise and non-ideal <span class="hlt">gains</span> are ascribed to spontaneous parametric emission.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EPJST.226.2705B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EPJST.226.2705B"><span>Homodyne versus <span class="hlt">photon</span>-counting quantum trajectories for dissipative Kerr resonators with two-<span class="hlt">photon</span> driving</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bartolo, Nicola; Minganti, Fabrizio; Lolli, Jared; Ciuti, Cristiano</p> <p>2017-07-01</p> <p>We investigate two different kinds of quantum trajectories for a nonlinear <span class="hlt">photon</span> resonator subject to two-<span class="hlt">photon</span> pumping, a configuration recently studied for the generation of <span class="hlt">photonic</span> Schrödinger cat states. In the absence of feedback control and in the strong-driving limit, the steady-state density matrix is a statistical mixture of two states with equal weight. While along a single <span class="hlt">photon</span>-counting trajectory the systems intermittently switches between an odd and an even cat state, we show that upon homodyne <span class="hlt">detection</span> the situation is different. Indeed, homodyne quantum trajectories reveal switches between coherent states of opposite phase.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22093433-photon-number-discrimination-without-photon-counter-its-application-reconstructing-non-gaussian-states','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22093433-photon-number-discrimination-without-photon-counter-its-application-reconstructing-non-gaussian-states"><span><span class="hlt">Photon</span>-number discrimination without a <span class="hlt">photon</span> counter and its application to reconstructing non-Gaussian states</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Chrzanowski, H. M.; Bernu, J.; Sparkes, B. M.</p> <p>2011-11-15</p> <p>The nonlinearity of a conditional <span class="hlt">photon</span>-counting measurement can be used to ''de-Gaussify'' a Gaussian state of light. Here we present and experimentally demonstrate a technique for <span class="hlt">photon</span>-number resolution using only homodyne <span class="hlt">detection</span>. We then apply this technique to inform a conditional measurement, unambiguously reconstructing the statistics of the non-Gaussian one- and two-<span class="hlt">photon</span>-subtracted squeezed vacuum states. Although our <span class="hlt">photon</span>-number measurement relies on ensemble averages and cannot be used to prepare non-Gaussian states of light, its high efficiency, <span class="hlt">photon</span>-number-resolving capabilities, and compatibility with the telecommunications band make it suitable for quantum-information tasks relying on the outcomes of mean values.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/921316','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/921316"><span>Ion <span class="hlt">photon</span> emission microscope</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Doyle, Barney L.</p> <p>2003-04-22</p> <p>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 <span class="hlt">photons</span> emitted at that point with a signal from a detector that measures the interaction of that ion within the sample. The emitted <span class="hlt">photons</span> are collected in the lens system of a conventional optical microscope, and projected on the image plane of a high resolution single <span class="hlt">photon</span> position sensitive detector. Position signals from this <span class="hlt">photon</span> detector are then correlated in time with electrical effects, including the malfunction of digital circuits, <span class="hlt">detected</span> within the sample that were caused by the individual ion that created these <span class="hlt">photons</span> initially.</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" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016NatNa..11..857B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016NatNa..11..857B"><span>A semiconductor <span class="hlt">photon</span>-sorter</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bennett, A. J.; Lee, J. P.; Ellis, D. J. P.; Farrer, I.; Ritchie, D. A.; Shields, A. J.</p> <p>2016-10-01</p> <p>Obtaining substantial nonlinear effects at the single-<span class="hlt">photon</span> level is a considerable challenge that holds great potential for quantum optical measurements and information processing. Of the progress that has been made in recent years one of the most promising methods is to scatter coherent light from quantum emitters, imprinting quantum correlations onto the <span class="hlt">photons</span>. We report effective interactions between <span class="hlt">photons</span>, controlled by a single semiconductor quantum dot that is weakly coupled to a monolithic cavity. We show that the nonlinearity of a transition modifies the counting statistics of a Poissonian beam, sorting the <span class="hlt">photons</span> in number. This is used to create strong correlations between <span class="hlt">detection</span> events and to create polarization-correlated <span class="hlt">photons</span> from an uncorrelated stream using a single spin. These results pave the way for semiconductor optical switches operated by single quanta of light.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008APS..APRS19003H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008APS..APRS19003H"><span>Bio-<span class="hlt">Photons</span> of Various Cellular Cultures and Tissues</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hann, Patrick; Knoesel, Ernst; Garzon, Maria; Lofland, Samuel; Pfieffer, Erik</p> <p>2008-04-01</p> <p>Since it is non-invasive, there has been increased research in the field of bio-optics. Many biological systems display an unusual phenomenon, delayed luminescence, produced by what is known as bio-<span class="hlt">photons</span>. We present an apparatus and procedure for the <span class="hlt">detection</span> of these ultra-weak <span class="hlt">photonic</span> emissions using a single <span class="hlt">photon</span> <span class="hlt">detection</span> device. The results of bread yeast, saccramyces, and algae will be presented and compared to other reports in the literature.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4354036','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4354036"><span>Imaging with a small number of <span class="hlt">photons</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Morris, Peter A.; Aspden, Reuben S.; Bell, Jessica E. C.; Boyd, Robert W.; Padgett, Miles J.</p> <p>2015-01-01</p> <p>Low-light-level imaging techniques have application in many diverse fields, ranging from biological sciences to security. A high-quality digital camera based on a multi-megapixel array will typically record an image by collecting of order 105 <span class="hlt">photons</span> per pixel, but by how much could this <span class="hlt">photon</span> flux be reduced? In this work we demonstrate a single-<span class="hlt">photon</span> imaging system based on a time-gated intensified camera from which the image of an object can be inferred from very few <span class="hlt">detected</span> <span class="hlt">photons</span>. We show that a ghost-imaging configuration, where the image is obtained from <span class="hlt">photons</span> that have never interacted with the object, is a useful approach for obtaining images with high signal-to-noise ratios. The use of heralded single <span class="hlt">photons</span> ensures that the background counts can be virtually eliminated from the recorded images. By applying principles of image compression and associated image reconstruction, we obtain high-quality images of objects from raw data formed from an average of fewer than one <span class="hlt">detected</span> <span class="hlt">photon</span> per image pixel. PMID:25557090</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018NJPh...20f3008B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018NJPh...20f3008B"><span>Localization control of few-<span class="hlt">photon</span> states in parity-symmetric ‘<span class="hlt">photonic</span> molecules’ under balanced pumping</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bentley, C. D. B.; Celestino, A.; Yacomotti, A. M.; El-Ganainy, R.; Eisfeld, A.</p> <p>2018-06-01</p> <p>We theoretically investigate the problem of localization control of few-<span class="hlt">photon</span> states in driven-dissipative parity-symmetric <span class="hlt">photonic</span> molecules. <span class="hlt">Photonic</span> molecules are multi-cavity <span class="hlt">photonic</span> systems. We show that a quantum feedback loop can utilize the information of the spontaneously-emitted <span class="hlt">photons</span> from each cavity to induce asymmetric <span class="hlt">photon</span> population in the cavities, while maintaining a balanced pump that respects parity symmetry. To better understand the system’s behavior, we characterize the degree of asymmetry as a function of the coupling between the two optical cavities. Contrary to intuitive expectations, we find that in some regimes the coupling can enhance the population asymmetry. We also show that these results are robust against experimental imperfections and limitations such as <span class="hlt">detection</span> efficiency.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhyS...91b3006P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhyS...91b3006P"><span>Characterization of a remote optical element with bi-<span class="hlt">photons</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Puhlmann, D.; Henkel, C.; Heuer, A.; Pieplow, G.; Menzel, R.</p> <p>2016-02-01</p> <p>We present a simple setup that exploits the interference of entangled <span class="hlt">photon</span> pairs. ‘Signal’ <span class="hlt">photons</span> are sent through a Mach-Zehnder-like interferometer, while ‘idlers’ are <span class="hlt">detected</span> in a variable polarization state. Two-<span class="hlt">photon</span> interference (in coincidence <span class="hlt">detection</span>) is observed with very high contrast and for significant time delays between signal and idler <span class="hlt">detection</span> events. This is explained by quantum erasure of the polarization tag and a delayed choice protocol involving a non-local virtual polarizer. The phase of the two-<span class="hlt">photon</span> fringes is scanned by varying the path length in the signal beam or by rotating a birefringent crystal in the idler beam. We exploit this to characterize one beam splitter of the signal <span class="hlt">photon</span> interferometer (reflection and transmission amplitudes including losses), using only information about coincidences and control parameters in the idler path. This is possible because our bi-<span class="hlt">photon</span> state saturates the Greenberger-Yelin-Englert inequality between contrast and predictability.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018LaPhL..15a5201Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018LaPhL..15a5201Z"><span>Recyclable amplification for single-<span class="hlt">photon</span> entanglement from <span class="hlt">photon</span> loss and decoherence</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhou, Lan; Chen, Ling-Quan; Zhong, Wei; Sheng, Yu-Bo</p> <p>2018-01-01</p> <p>We put forward a highly efficient recyclable single-<span class="hlt">photon</span> assisted amplification protocol, which can protect single-<span class="hlt">photon</span> entanglement (SPE) from <span class="hlt">photon</span> loss and decoherence. Making use of quantum nondemolition <span class="hlt">detection</span> gates constructed with the help of cross-Kerr nonlinearity, our protocol has some attractive advantages. First, the parties can recover less-entangled SPE to be maximally entangled SPE, and reduce <span class="hlt">photon</span> loss simultaneously. Second, if the protocol fails, the parties can repeat the protocol to reuse some discarded items, which can increase the success probability. Third, when the protocol is successful, they can similarly repeat the protocol to further increase the fidelity of the SPE. Thereby, our protocol provides a possible way to obtain high entanglement, high fidelity and high success probability simultaneously. In particular, our protocol shows higher success probability in the practical high <span class="hlt">photon</span> loss channel. Based on the above features, our amplification protocol has potential for future application in long-distance quantum communication.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018OptCo.414..191N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018OptCo.414..191N"><span>Thermal and dynamic range characterization of a <span class="hlt">photonics</span>-based RF amplifier</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Noque, D. F.; Borges, R. M.; Muniz, A. L. M.; Bogoni, A.; Cerqueira S., Arismar, Jr.</p> <p>2018-05-01</p> <p>This work reports a thermal and dynamic range characterization of an ultra-wideband <span class="hlt">photonics</span>-based RF amplifier for microwave and mm-waves future 5G optical-wireless networks. The proposed technology applies the four-wave mixing nonlinear effect to provide RF amplification in analog and digital radio-over-fiber systems. The experimental analysis from 300 kHz to 50 GHz takes into account different figures of merit, such as RF <span class="hlt">gain</span>, spurious-free dynamic range and RF output power stability as a function of temperature. The thermal characterization from -10 to +70 °C demonstrates a 27 dB flat <span class="hlt">photonics</span>-assisted RF <span class="hlt">gain</span> over the entire frequency range under real operational conditions of a base station for illustrating the feasibility of the <span class="hlt">photonics</span>-assisted RF amplifier for 5G networks.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JInst..11C1078S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JInst..11C1078S"><span>SiPMs characterization and selection for the DUNE far detector <span class="hlt">photon</span> <span class="hlt">detection</span> system</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sun, Y.; Maricic, J.</p> <p>2016-01-01</p> <p>The Deep Underground Neutrino Experiment (DUNE) together with the Long Baseline Neutrino Facility (LBNF) hosted at the Fermilab will provide a unique, world-leading program for the exploration of key questions at the forefront of neutrino physics and astrophysics. CP violation in neutrino flavor mixing is one of its most important potential discoveries. Additionally, the experiment will determine the neutrino mass hierarchy and precisely measure the neutrino mixing parameters which may potentially reveal new fundamental symmetries of nature. Moreover, the DUNE is also designed for the observation of nucleon decay and supernova burst neutrinos. The <span class="hlt">photon</span> <span class="hlt">detection</span> (PD) system in the DUNE far detector provides trigger for cosmic backgrounds, enhances supernova burst trigger efficiency and improves the energy resolution of the detector. The DUNE adopts the technology of liquid argon time projection chamber (LArTPC) that requires the PD sensors, silicon photomultipliers (SiPM), to be carefully chosen to not only work properly in LAr temperature, but also meet certain specifications for the life of the experiment. A comprehensive testing of SiPMs in cryostat is necessary since the datasheet provided by the manufactures in the market does not cover this temperature regime. This paper gives the detailed characterization results of SenSL C-Series 60035 SiPMs, including <span class="hlt">gain</span>, dark count rate (DCR), cross-talk and after-pulse rate. Characteristic studies on SiPMs from other vendors are also discussed in order to avoid any potential problems associated with using a single source. Moreover, the results of the ongoing mechanical durability tests are shown for the current candidate, SenSL B/C-Series 60035 SiPMs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/909655','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/909655"><span>Apparatus for <span class="hlt">photon</span> activation positron annihilation analysis</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Akers, Douglas W [Idaho Falls, ID</p> <p>2007-06-12</p> <p>Non-destructive testing apparatus according to one embodiment of the invention comprises a <span class="hlt">photon</span> source. The <span class="hlt">photon</span> source produces <span class="hlt">photons</span> having predetermined energies and directs the <span class="hlt">photons</span> toward a specimen being tested. The <span class="hlt">photons</span> from the <span class="hlt">photon</span> source result in the creation of positrons within the specimen being tested. A detector positioned adjacent the specimen being tested <span class="hlt">detects</span> gamma rays produced by annihilation of positrons with electrons. A data processing system operatively associated with the detector produces output data indicative of a lattice characteristic of the specimen being tested.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29249833','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29249833"><span><span class="hlt">Photonic</span>-band-gap gyrotron amplifier with picosecond pulses.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nanni, Emilio A; Jawla, Sudheer; Lewis, Samantha M; Shapiro, Michael A; Temkin, Richard J</p> <p>2017-12-04</p> <p>We report the amplification of 250 GHz pulses as short as 260 ps without observation of pulse broadening using a <span class="hlt">photonic</span>-band-gap circuit gyrotron traveling-wave-amplifier. The gyrotron amplifier operates with a device <span class="hlt">gain</span> of 38 dB and an instantaneous bandwidth of 8 GHz. The operational bandwidth of the amplifier can be tuned over 16 GHz by adjusting the operating voltage of the electron beam and the magnetic field. The amplifier uses a 30 cm long <span class="hlt">photonic</span>-band-gap interaction circuit to confine the desired TE 03 -like operating mode while suppressing lower order modes which can result in undesired oscillations. The circuit <span class="hlt">gain</span> is >55 dB for a beam voltage of 23 kV and a current of 700 mA. These results demonstrate the wide bandwidths and a high <span class="hlt">gain</span> achievable with gyrotron amplifiers. The amplification of picosecond pulses of variable lengths, 260-800 ps, shows good agreement with the theory using the coupled dispersion relation and the <span class="hlt">gain</span>-spectrum of the amplifier as measured with quasi-CW input pulses.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PhRvB..97l5303B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PhRvB..97l5303B"><span>Microscopic theory of cavity-enhanced single-<span class="hlt">photon</span> emission from optical two-<span class="hlt">photon</span> Raman processes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Breddermann, Dominik; Praschan, Tom; Heinze, Dirk; Binder, Rolf; Schumacher, Stefan</p> <p>2018-03-01</p> <p>We consider cavity-enhanced single-<span class="hlt">photon</span> generation from stimulated two-<span class="hlt">photon</span> Raman processes in three-level systems. We compare four fundamental system configurations, one Λ -, one V-, and two ladder (Ξ -) configurations. These can be realized as subsystems of a single quantum dot or of quantum-dot molecules. For a new microscopic understanding of the Raman process, we analyze the Heisenberg equation of motion applying the cluster-expansion scheme. Within this formalism an exact and rigorous definition of a cavity-enhanced Raman <span class="hlt">photon</span> via its corresponding Raman correlation is possible. This definition for example enables us to systematically investigate the on-demand potential of Raman-transition-based single-<span class="hlt">photon</span> sources. The four system arrangements can be divided into two subclasses, Λ -type and V-type, which exhibit strongly different Raman-emission characteristics and Raman-emission probabilities. Moreover, our approach reveals whether the Raman path generates a single <span class="hlt">photon</span> or just induces destructive quantum interference with other excitation paths. Based on our findings and as a first application, we <span class="hlt">gain</span> a more detailed understanding of experimental data from the literature. Our analysis and results are also transferable to the case of atomic three-level-resonator systems and can be extended to more complicated multilevel schemes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29154310','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29154310"><span>Tutorial on X-ray <span class="hlt">photon</span> counting detector characterization.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ren, Liqiang; Zheng, Bin; Liu, Hong</p> <p>2018-01-01</p> <p>Recent advances in <span class="hlt">photon</span> counting <span class="hlt">detection</span> technology have led to significant research interest in X-ray imaging. As a tutorial level review, this paper covers a wide range of aspects related to X-ray <span class="hlt">photon</span> counting detector characterization. The tutorial begins with a detailed description of the working principle and operating modes of a pixelated X-ray <span class="hlt">photon</span> counting detector with basic architecture and <span class="hlt">detection</span> mechanism. Currently available methods and techniques for charactering major aspects including energy response, noise floor, energy resolution, count rate performance (detector efficiency), and charge sharing effect of <span class="hlt">photon</span> counting detectors are comprehensively reviewed. Other characterization aspects such as point spread function (PSF), line spread function (LSF), contrast transfer function (CTF), modulation transfer function (MTF), noise power spectrum (NPS), <span class="hlt">detective</span> quantum efficiency (DQE), bias voltage, radiation damage, and polarization effect are also remarked. A cadmium telluride (CdTe) pixelated <span class="hlt">photon</span> counting detector is employed for part of the characterization demonstration and the results are presented. This review can serve as a tutorial for X-ray imaging researchers and investigators to understand, operate, characterize, and optimize <span class="hlt">photon</span> counting detectors for a variety of applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5470468','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5470468"><span>Efficient Fluorescence Resonance Energy Transfer between Quantum Dots and Gold Nanoparticles Based on Porous Silicon <span class="hlt">Photonic</span> Crystal for DNA <span class="hlt">Detection</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Zhang, Hongyan; Lv, Jie; Jia, Zhenhong</p> <p>2017-01-01</p> <p>A novel assembled biosensor was prepared for <span class="hlt">detecting</span> 16S rRNA, a small-size persistent specific for Actinobacteria. The mechanism of the porous silicon (PS) <span class="hlt">photonic</span> crystal biosensor is based on the fluorescence resonance energy transfer (FRET) between quantum dots (QDs) and gold nanoparticles (AuNPs) through DNA hybridization, where QDs act as an emission donor and AuNPs serve as a fluorescence quencher. Results showed that the photoluminescence (PL) intensity of PS <span class="hlt">photonic</span> crystal was drastically increased when the QDs-conjugated probe DNA was adhered to the PS layer by surface modification using a standard cross-link chemistry method. The PL intensity of QDs was decreased when the addition of AuNPs-conjugated complementary 16S rRNA was dropped onto QDs-conjugated PS. Based on the analysis of different target DNA concentration, it was found that the decrease of the PL intensity showed a good linear relationship with complementary DNA concentration in a range from 0.25 to 10 μM, and the <span class="hlt">detection</span> limit was 328.7 nM. Such an optical FRET biosensor functions on PS-based <span class="hlt">photonic</span> crystal for DNA <span class="hlt">detection</span> that differs from the traditional FRET, which is used only in liquid. This method will benefit the development of a new optical FRET label-free biosensor on Si substrate and has great potential in biochips based on integrated optical devices. PMID:28489033</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28489033','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28489033"><span>Efficient Fluorescence Resonance Energy Transfer between Quantum Dots and Gold Nanoparticles Based on Porous Silicon <span class="hlt">Photonic</span> Crystal for DNA <span class="hlt">Detection</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhang, Hongyan; Lv, Jie; Jia, Zhenhong</p> <p>2017-05-10</p> <p>A novel assembled biosensor was prepared for <span class="hlt">detecting</span> 16S rRNA, a small-size persistent specific for Actinobacteria. The mechanism of the porous silicon (PS) <span class="hlt">photonic</span> crystal biosensor is based on the fluorescence resonance energy transfer (FRET) between quantum dots (QDs) and gold nanoparticles (AuNPs) through DNA hybridization, where QDs act as an emission donor and AuNPs serve as a fluorescence quencher. Results showed that the photoluminescence (PL) intensity of PS <span class="hlt">photonic</span> crystal was drastically increased when the QDs-conjugated probe DNA was adhered to the PS layer by surface modification using a standard cross-link chemistry method. The PL intensity of QDs was decreased when the addition of AuNPs-conjugated complementary 16S rRNA was dropped onto QDs-conjugated PS. Based on the analysis of different target DNA concentration, it was found that the decrease of the PL intensity showed a good linear relationship with complementary DNA concentration in a range from 0.25 to 10 μM, and the <span class="hlt">detection</span> limit was 328.7 nM. Such an optical FRET biosensor functions on PS-based <span class="hlt">photonic</span> crystal for DNA <span class="hlt">detection</span> that differs from the traditional FRET, which is used only in liquid. This method will benefit the development of a new optical FRET label-free biosensor on Si substrate and has great potential in biochips based on integrated optical devices.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AdSpR..56.1307V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AdSpR..56.1307V"><span>Single <span class="hlt">photon</span> laser altimeter data processing, analysis and experimental validation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vacek, Michael; Peca, Marek; Michalek, Vojtech; Prochazka, Ivan</p> <p>2015-10-01</p> <p>Spaceborne laser altimeters are common instruments on-board the rendezvous spacecraft. This manuscript deals with the altimeters using a single <span class="hlt">photon</span> approach, which belongs to the family of time-of-flight range measurements. Moreover, the single <span class="hlt">photon</span> receiver part of the altimeter may be utilized as an Earth-to-spacecraft link enabling one-way ranging, time transfer and data transfer. The single <span class="hlt">photon</span> altimeters evaluate actual altitude through the repetitive <span class="hlt">detections</span> of single <span class="hlt">photons</span> of the reflected laser pulses. We propose the single <span class="hlt">photon</span> altimeter signal processing and data mining algorithm based on the Poisson statistic filter (histogram method) and the modified Kalman filter, providing all common altimetry products (altitude, slope, background <span class="hlt">photon</span> flux and albedo). The Kalman filter is extended for the background noise filtering, the varying slope adaptation and the non-causal extension for an abrupt slope change. Moreover, the algorithm partially removes the major drawback of a single <span class="hlt">photon</span> altitude reading, namely that the <span class="hlt">photon</span> <span class="hlt">detection</span> measurement statistics must be gathered. The developed algorithm deduces the actual altitude on the basis of a single <span class="hlt">photon</span> <span class="hlt">detection</span>; thus, being optimal in the sense that each <span class="hlt">detected</span> signal <span class="hlt">photon</span> carrying altitude information is tracked and no altitude information is lost. The algorithm was tested on the simulated datasets and partially cross-probed with the experimental data collected using the developed single <span class="hlt">photon</span> altimeter breadboard based on the microchip laser with the pulse energy on the order of microjoule and the repetition rate of several kilohertz. We demonstrated that such an altimeter configuration may be utilized for landing or hovering a small body (asteroid, comet).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25121901','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25121901"><span>Extended parametric <span class="hlt">gain</span> range in <span class="hlt">photonic</span> crystal fibers with strongly frequency-dependent field distributions.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Petersen, Sidsel R; Alkeskjold, Thomas T; Olausson, Christina B; Lægsgaard, Jesper</p> <p>2014-08-15</p> <p>The parametric <span class="hlt">gain</span> range of a degenerate four-wave mixing process is determined in the undepleted pump regime. The <span class="hlt">gain</span> range is considered with and without taking the mode field distributions of the four-wave mixing components into account. It is found that the mode field distributions have to be included to evaluate the parametric <span class="hlt">gain</span> correctly in dispersion-tailored speciality fibers and that mode profile engineering can provide a way to increase the parametric <span class="hlt">gain</span> range.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016LaPhL..13h5204A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016LaPhL..13h5204A"><span>Realization of all-optical switch and diode via Raman <span class="hlt">gain</span> process using a Kerr field</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Abbas, Muqaddar; Qamar, Sajid; Qamar, Shahid</p> <p>2016-08-01</p> <p>The idea of optical <span class="hlt">photonic</span> crystal, which is generated using two counter-propagating fields, is revisited to study <span class="hlt">gain</span>-assisted all-optical switch and diode using Kerr field. Two counter-propagating fields with relative detuning Δ ν generate standing-wave field pattern which interacts with a four-level atomic system. The standing-wave field pattern acts like a static <span class="hlt">photonic</span> crystal for Δ ν =0 , however, it behaves as a moving <span class="hlt">photonic</span> crystal for Δ ν \</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29867085','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29867085"><span>A scalable multi-<span class="hlt">photon</span> coincidence detector based on superconducting nanowires.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhu, Di; Zhao, Qing-Yuan; Choi, Hyeongrak; Lu, Tsung-Ju; Dane, Andrew E; Englund, Dirk; Berggren, Karl K</p> <p>2018-06-04</p> <p>Coincidence <span class="hlt">detection</span> of single <span class="hlt">photons</span> is crucial in numerous quantum technologies and usually requires multiple time-resolved single-<span class="hlt">photon</span> 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-<span class="hlt">photon</span> and two-<span class="hlt">photon</span> coincidence events. We further explore the pulse shapes of the detector output and resolve up to four-<span class="hlt">photon</span> events in a four-element device, giving the detector <span class="hlt">photon</span>-number-resolving capability. This new detector architecture and operating scheme will be particularly useful for multi-<span class="hlt">photon</span> coincidence <span class="hlt">detection</span> in large-scale <span class="hlt">photonic</span> integrated circuits.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20040171398&hterms=microchip+laser&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dmicrochip%2Blaser','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20040171398&hterms=microchip+laser&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dmicrochip%2Blaser"><span>Prototype Test Results for the Single <span class="hlt">Photon</span> <span class="hlt">Detection</span> SLR2000 Satellite Laser Ranging System</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Zagwodzki, Thomas W.; McGarry, Jan F.; Degnan, John J.; Cheek, Jack W.; Dunn, Peter J.; Patterson, Don; Donovan, Howard</p> <p>2004-01-01</p> <p>NASA's aging Satellite Laser Ranging (SLR) network is scheduled to be replaced over the next few years with a fully automated single <span class="hlt">photon</span> <span class="hlt">detection</span> system. A prototype of this new system, called SLR2000, is currently undergoing field trials at the Goddard Space Flight Center in Greenbelt, Maryland to evaluate <span class="hlt">photon</span> counting techniques and determine system hardware, software, and control algorithm performance levels and limitations. Newly developed diode pumped microchip lasers and quadrant microchannel plate-based photomultiplier tubes have enabled the development of this high repetition rate single <span class="hlt">photon</span> <span class="hlt">detection</span> SLR system. The SLR2000 receiver threshold is set at the single photoelectron (pe) level but tracks satellites with an average signal level typically much less than 1 pe. The 2 kHz laser fire rate aids in satellite acquisition and tracking and will enable closed loop tracking by accumulating single <span class="hlt">photon</span> count statistics in a quadrant detector and using this information to correct for pointing errors. Laser transmitter beamwidths of 10 arcseconds (FWHM) or less are currently being used to maintain an adequate signal level for tracking while the receiver field of view (FOV) has been opened to 40 arcseconds to accommodate point ahead/look behind angular offsets. In the near future, the laser transmitter point ahead will be controlled by a pair of Risley prisms. This will allow the telescope to point behind and enable closure of the receiver FOV to roughly match the transmitter beam divergence. Bandpass filters (BPF) are removed for night tracking operations while 0.2 nm or 1 nm filters are used during daylight operation. Both day and night laser tracking of Low Earth Orbit (LEO) satellites has been achieved with a laser transmitter energy of only 65 microjoules per pulse. Satellite tracking is presently limited to LEO satellites until the brassboard laser transmitter can be upgraded or replaced. Simultaneous tracks have also been observed with NASA s</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JMoSt1114...65H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JMoSt1114...65H"><span>Theoretical investigation on ratiometric two-<span class="hlt">photon</span> fluorescent probe for Zn2+ <span class="hlt">detection</span> based on ICT mechanism</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Huang, Shuang; Yang, Bao-Zhu; Ren, Ai-Min</p> <p>2016-06-01</p> <p>OPA (one-<span class="hlt">photon</span> absorption), TPA (two-<span class="hlt">photon</span> absorption) and fluorescence properties of a free ligand L upon coordination with Zn2+, and the regeneration with CN- were investigated in theory. According to our research, OPA spectra of ligand L show red-shift binding with Zn2+ while blue-shift with CN-. The fluorescence spectra and TPA wavelength are shifted in the same situation as those of OPA spectra. The value of TPA cross-section decreased at first, and then increased to 1813 GM for [L-Zn(CN)4]2-. Intramolecular charge transfer (ICT) mechanism was investigated by natural bond orbital (NBO) analysis. It demonstrates that L is hopeful to be a good ratiometric fluorescent probe for zinc ion <span class="hlt">detection</span> in solution, and it can regenerate after CN- was introduced.</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" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20150010998&hterms=photon&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dphoton','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20150010998&hterms=photon&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dphoton"><span>Update on Linear Mode <span class="hlt">Photon</span> Counting with the HgCdTe Linear Mode Avalanche Photodiode</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Beck, Jeffrey D.; Kinch, Mike; Sun, Xiaoli</p> <p>2014-01-01</p> <p>The behavior of the <span class="hlt">gain</span>-voltage characteristic of the mid-wavelength infrared cutoff HgCdTe linear mode avalanche photodiode (e-APD) is discussed both experimentally and theoretically as a function of the width of the multiplication region. Data are shown that demonstrate a strong dependence of the <span class="hlt">gain</span> at a given bias voltage on the width of the n- <span class="hlt">gain</span> region. Geometrical and fundamental theoretical models are examined to explain this behavior. The geometrical model takes into account the <span class="hlt">gain</span>-dependent optical fill factor of the cylindrical APD. The theoretical model is based on the ballistic ionization model being developed for the HgCdTe APD. It is concluded that the fundamental theoretical explanation is the dominant effect. A model is developed that combines both the geometrical and fundamental effects. The model also takes into account the effect of the varying multiplication width in the low bias region of the <span class="hlt">gain</span>-voltage curve. It is concluded that the lower than expected <span class="hlt">gain</span> seen in the first 2 × 8 HgCdTe linear mode <span class="hlt">photon</span> counting APD arrays, and higher excess noise factor, was very likely due to the larger than typical multiplication region length in the <span class="hlt">photon</span> counting APD pixel design. The implications of these effects on device <span class="hlt">photon</span> counting performance are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA024027','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA024027"><span><span class="hlt">Photon</span> Limited Images and Their Restoration</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>1976-03-01</p> <p>arises from noise inherent in the <span class="hlt">detected</span> image data. In the first part of this report a model is developed which can be used to mathematically and...statistically describe an image <span class="hlt">detected</span> at low light levels. This rodel serves to clarify some basic properties of <span class="hlt">photon</span> noise , and provides a basis...for the analysi.s of image restoration. In the second part the problem of linear least-square restoration of imagery limited by <span class="hlt">photon</span> noise is</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JAP...120q3102M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JAP...120q3102M"><span>Safe and simple <span class="hlt">detection</span> of sparse hydrogen by Pd-Au alloy/air based 1D <span class="hlt">photonic</span> crystal sensor</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mitra, S.; Biswas, T.; Chattopadhyay, R.; Ghosh, J.; Bysakh, S.; Bhadra, S. K.</p> <p>2016-11-01</p> <p>A simple integrated hydrogen sensor using Pd-Au alloy/air based one dimensional <span class="hlt">photonic</span> crystal with an air defect layer is theoretically modeled. Structural parameters of the <span class="hlt">photonic</span> crystal are delicately scaled to generate <span class="hlt">photonic</span> band gap frequencies in a visible spectral regime. An optimized defect thickness permits a localized defect mode operating at a frequency within the <span class="hlt">photonic</span> band gap region. Hydrogen absorption causes modification in the band gap characteristics due to variation of refractive index and lattice parameters of the alloy. As a result, the transmission peak appeared due to the resonant defect state gets shifted. This peak shifting is utilized to <span class="hlt">detect</span> sparse amount of hydrogen present in the surrounding environment. A theoretical framework is built to calculate the refractive index profile of hydrogen loaded alloy using density functional theory and Bruggeman's effective medium approximation. The calculated refractive index variation of Pd3Au alloy film due to hydrogen loading is verified experimentally by measuring the reflectance characteristics. Lattice expansion properties of the alloy are studied through X-ray diffraction analyses. The proposed structure shows about 3 nm red shift of the transmission peak for a rise of 1% atomic hydrogen concentration in the alloy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22415912-coherent-photon-vs-incoherent-current-detection-multidimensional-optical-signals-from-single-molecules-open-junctions','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22415912-coherent-photon-vs-incoherent-current-detection-multidimensional-optical-signals-from-single-molecules-open-junctions"><span>Coherent (<span class="hlt">photon</span>) vs incoherent (current) <span class="hlt">detection</span> of multidimensional optical signals from single molecules in open junctions</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Agarwalla, Bijay Kumar; Hua, Weijie; Zhang, Yu</p> <p>2015-06-07</p> <p>The nonlinear optical response of a current-carrying single molecule coupled to two metal leads and driven by a sequence of impulsive optical pulses with controllable phases and time delays is calculated. Coherent (stimulated, heterodyne) <span class="hlt">detection</span> of <span class="hlt">photons</span> and incoherent <span class="hlt">detection</span> of the optically induced current are compared. Using a diagrammatic Liouville space superoperator formalism, the signals are recast in terms of molecular correlation functions which are then expanded in the many-body molecular states. Two dimensional signals in benzene-1,4-dithiol molecule show cross peaks involving charged states. The correlation between optical and charge current signal is also observed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/1417663-photonic-band-gap-gyrotron-amplifier-picosecond-pulses','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1417663-photonic-band-gap-gyrotron-amplifier-picosecond-pulses"><span><span class="hlt">Photonic</span>-band-gap gyrotron amplifier with picosecond pulses</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Nanni, Emilio A.; Jawla, Sudheer; Lewis, Samantha M.</p> <p></p> <p>Here, we report the amplification of 250 GHz pulses as short as 260 ps without observation of pulse broadening using a <span class="hlt">photonic</span>-band-gap circuit gyrotron traveling-wave-amplifier. The gyrotron amplifier operates with a device <span class="hlt">gain</span> of 38 dB and an instantaneous bandwidth of 8 GHz. The operational bandwidth of the amplifier can be tuned over 16 GHz by adjusting the operating voltage of the electron beam and the magnetic field. The amplifier uses a 30 cm long <span class="hlt">photonic</span>-band-gap interaction circuit to confine the desired TE 03-like operating mode while suppressing lower order modes which can result in undesired oscillations. The circuit gainmore » is >55 dB for a beam voltage of 23 kV and a current of 700 mA. These results demonstrate the wide bandwidths and a high <span class="hlt">gain</span> achievable with gyrotron amplifiers. The amplification of picosecond pulses of variable lengths, 260–800 ps, shows good agreement with the theory using the coupled dispersion relation and the <span class="hlt">gain</span>-spectrum of the amplifier as measured with quasi-CW input pulses.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1417663-photonic-band-gap-gyrotron-amplifier-picosecond-pulses','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1417663-photonic-band-gap-gyrotron-amplifier-picosecond-pulses"><span><span class="hlt">Photonic</span>-band-gap gyrotron amplifier with picosecond pulses</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Nanni, Emilio A.; Jawla, Sudheer; Lewis, Samantha M.; ...</p> <p>2017-12-05</p> <p>Here, we report the amplification of 250 GHz pulses as short as 260 ps without observation of pulse broadening using a <span class="hlt">photonic</span>-band-gap circuit gyrotron traveling-wave-amplifier. The gyrotron amplifier operates with a device <span class="hlt">gain</span> of 38 dB and an instantaneous bandwidth of 8 GHz. The operational bandwidth of the amplifier can be tuned over 16 GHz by adjusting the operating voltage of the electron beam and the magnetic field. The amplifier uses a 30 cm long <span class="hlt">photonic</span>-band-gap interaction circuit to confine the desired TE 03-like operating mode while suppressing lower order modes which can result in undesired oscillations. The circuit gainmore » is >55 dB for a beam voltage of 23 kV and a current of 700 mA. These results demonstrate the wide bandwidths and a high <span class="hlt">gain</span> achievable with gyrotron amplifiers. The amplification of picosecond pulses of variable lengths, 260–800 ps, shows good agreement with the theory using the coupled dispersion relation and the <span class="hlt">gain</span>-spectrum of the amplifier as measured with quasi-CW input pulses.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1356553-fermi-large-area-telescope-detection-two-very-high-energy-gt-gev-ray-photons-from-blazar-pks','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1356553-fermi-large-area-telescope-detection-two-very-high-energy-gt-gev-ray-photons-from-blazar-pks"><span>Fermi Large Area Telescope <span class="hlt">detection</span> of two very-high-energy ( E > 100 GeV) γ-ray <span class="hlt">photons</span> from the z = 1.1 blazar PKS 0426–380</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Tanaka, Y. T.; Cheung, C. C.; Inoue, Y.; ...</p> <p>2013-10-18</p> <p>Here, we report the Fermi Large Area Telescope (LAT) <span class="hlt">detection</span> of two very-high-energy (VHE, E > 100 GeV) γ-ray <span class="hlt">photons</span> from the directional vicinity of the distant (redshift, z = 1.1) blazar PKS 0426–380. The null hypothesis that both the 134 and 122 GeV <span class="hlt">photons</span> originate from unrelated sources can be rejected at the 5.5σ confidence level. We therefore claim that at least one of the two VHE <span class="hlt">photons</span> is securely associated with PKS 0426–380, making it the most distant VHE emitter known to date. The results are in agreement with recent Fermi-LAT constraints on the extragalactic background light (EBL)more » intensity, which imply a z sime 1 horizon for sime 100 GeV <span class="hlt">photons</span>. The LAT <span class="hlt">detection</span> of the two VHE γ-rays coincided roughly with flaring states of the source, although we did not find an exact correspondence between the VHE <span class="hlt">photon</span> arrival times and the flux maxima at lower γ-ray energies. Modeling the γ-ray continuum of PKS 0426–380 with daily bins revealed a significant spectral hardening around the time of the first VHE event <span class="hlt">detection</span> (LAT <span class="hlt">photon</span> index Γ sime 1.4) but on the other hand no pronounced spectral changes near the <span class="hlt">detection</span> time of the second one. This combination implies a rather complex variability pattern of the source in γ-rays during the flaring epochs. An additional flat component is possibly present above several tens of GeV in the EBL-corrected Fermi-LAT spectrum accumulated over the ~8 month high state.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3408906','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3408906"><span><span class="hlt">Photonic</span> crystal enhanced fluorescence using a quartz substrate to reduce limits of <span class="hlt">detection</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Pokhriyal, Anusha; Lu, Meng; Chaudhery, Vikram; Huang, Cheng-Sheng; Schulz, Stephen; Cunningham, Brian T.</p> <p>2010-01-01</p> <p>A <span class="hlt">Photonic</span> Crystal (PC) surface fabricated upon a quartz substrate using nanoimprint lithography has been demonstrated to enhance light emission from fluorescent molecules in close proximity to the PC surface. Quartz was selected for its low autofluorescence characteristics compared to polymer-based PCs, improving the <span class="hlt">detection</span> sensitivity and signal-to-noise ratio (SNR) of PC Enhanced Fluorescence (PCEF). Nanoimprint lithography enables economical fabrication of the subwavelength PCEF surface structure over entire 1x3 in2 quartz slides. The demonstrated PCEF surface supports a transverse magnetic (TM) resonant mode at a wavelength of λ = 632.8 nm and an incident angle of θ = 11°, which amplifies the electric field magnitude experienced by surface-bound fluorophores. Meanwhile, another TM mode at a wavelength of λ = 690 nm and incident angle of θ = 0° efficiently directs the fluorescent emission toward the <span class="hlt">detection</span> optics. An enhancement factor as high as 7500 × was achieved for the <span class="hlt">detection</span> of LD-700 dye spin-coated upon the PC, compared to <span class="hlt">detecting</span> the same material on an unpatterned glass surface. The <span class="hlt">detection</span> of spotted Alexa-647 labeled polypeptide on the PC exhibits a 330 × SNR improvement. Using dose-response characterization of deposited fluorophore-tagged protein spots, the PCEF surface demonstrated a 140 × lower limit of <span class="hlt">detection</span> compared to a conventional glass substrate. PMID:21164826</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017OptCo.388...68Q','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017OptCo.388...68Q"><span>A nonlinear merging method of analog and <span class="hlt">photon</span> signals for CO2 <span class="hlt">detection</span> in lower altitudes using differential absorption lidar</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Qi, Zhong; Zhang, Teng; Han, Ge; Li, Dongcang; Ma, Xin; Gong, Wei</p> <p>2017-04-01</p> <p>The current acquisition system of a lidar <span class="hlt">detects</span> return signals in two modes (i.e., analog and <span class="hlt">photon</span> counting); resulting in the lower (below 1500 m) and upper (higher than 1100 m) atmospheric parameters need analog and <span class="hlt">photon</span> counting signal to retrieve, respectively. Hence, a lidar cannot obtain a continuous column of the concentrations of atmospheric components. For carbon cycle studies, the range-resolved concentration of atmospheric CO2 in the lower troposphere (below 1500 m) is one of the most significant parameters that should be determined. This study proposes a novel gluing method that merges the CO2 signal <span class="hlt">detected</span> by ground-based DIAL in the lower troposphere. Through simulation experiments, the best uniform approximation polynomial theorem is utilized to determine the transformation coefficient to correlate signals from the different modes perfectly. The experimental results (both simulation experiments and actual measurement of signals) show that the proposed method is suitable and feasible for merging data in the region below 1500 m. Hence, the <span class="hlt">photon</span>-counting signals whose SNRs are higher than those of the analog signals can be used to retrieve atmospheric parameters at an increased near range, facilitating atmospheric soundings using ground-based lidar in various fields.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000JBO.....5..173R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000JBO.....5..173R"><span><span class="hlt">Photon</span> migration through fetal head in utero using continuous wave, near infrared spectroscopy: clinical and experimental model studies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ramanujam, Nirmala; Vishnoi, Gargi; Hielscher, Andreas H.; Rode, Martha; Forouzan, Iraj; Chance, Britton</p> <p>2000-04-01</p> <p>Near infrared (NIR) measurements were made from the maternal abdomen (clinical studies) and laboratory tissue phantoms (experimental studies) to <span class="hlt">gain</span> insight into <span class="hlt">photon</span> migration through the fetal head in utero. Specifically, a continuous wave spectrometer was modified and employed to make NIR measurements at 760 and 850 nm, at a large (10 cm) and small (2.5/4 cm) source-detector separation, simultaneously, on the maternal abdomen, directly above the fetal head. A total of 19 patients were evaluated, whose average gestational age and fetal head depth, were 37 weeks +/- 3 and 2.25 cm +/- 0.7, respectively. At the large source-detector separation, the <span class="hlt">photons</span> are expected to migrate through both the underlying maternal and fetal tissues before being <span class="hlt">detected</span> at the surface, while at the short source-detector separation, the <span class="hlt">photons</span> are expected to migrate primarily through the superficial maternal tissues before being <span class="hlt">detected</span>. Second, similar NIR measurements were made on laboratory tissue phantoms, with variable optical properties and physical geometries. The variable optical properties were obtained using different concentrations of India ink and Intralipid in water, while the variable physical geometries were realized by employing glass containers of different shapes and sizes. Third, the NIR measurements, which were made on the laboratory tissue phantoms, were compared to the NIR measurements made on the maternal abdomen to determine which tissue phantom best simulates the <span class="hlt">photon</span> migration path through the fetal head in utero. The results of the comparison were used to provide insight into the optical properties and physical geometry of the maternal and fetal tissues in the <span class="hlt">photon</span> migration path.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20020080604','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20020080604"><span>Development of High Quantum Efficiency UV/Blue Photocathode Epitaxial Semiconductor Heterostructures for Scintillation and Cherenkov Radiation <span class="hlt">Detection</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Leopold, Daniel J.</p> <p>2002-01-01</p> <p>The primary goal of this research project was to further extend the use of advanced heteroepitaxial-semiconductor crystal growth techniques such as molecular beam epitaxy (MBE) and to demonstrate significant <span class="hlt">gains</span> in UV/blue <span class="hlt">photonic</span> <span class="hlt">detection</span> by designing and fabricating atomically-tailored heteroepitaxial GaAlN/GaInN photocathode device structures. This NASA Explorer technology research program has focused on the development of photocathodes for Cherenkov and scintillation radiation <span class="hlt">detection</span>. Support from the program allowed us to enhance our MBE system to include a nitrogen plasma source and a magnetic bearing turbomolecular pump for delivery and removal of high purity atomic nitrogen during GaAlN/GaInN film growth. Under this program we have also designed, built and incorporated a cesium activation stage. In addition, a connected UHV chamber with photocathode transfer/positioner components as well as a hybrid phototube stage was designed and built to make in-situ quantum efficiency measurements without ever having to remove the photocathodes from UHV conditions. Thus we have constructed a system with the capability to couple atomically-tailored MBE-grown photocathode heterostructures with real high <span class="hlt">gain</span> readout devices for single <span class="hlt">photon</span> <span class="hlt">detection</span> evaluation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JSemi..39f1001W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JSemi..39f1001W"><span>Emerging technologies in Si active <span class="hlt">photonics</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Xiaoxin; Liu, Jifeng</p> <p>2018-06-01</p> <p>Silicon <span class="hlt">photonics</span> for synergistic electronic–<span class="hlt">photonic</span> integration has achieved remarkable progress in the past two decades. Active <span class="hlt">photonic</span> devices, including lasers, modulators, and photodetectors, are the key challenges for Si <span class="hlt">photonics</span> to meet the requirement of high bandwidth and low power consumption in <span class="hlt">photonic</span> datalinks. Here we review recent efforts and progress in high-performance active <span class="hlt">photonic</span> devices on Si, focusing on emerging technologies beyond conventional foundry-ready Si <span class="hlt">photonics</span> devices. For emerging laser sources, we will discuss recent progress towards efficient monolithic Ge lasers, mid-infrared GeSn lasers, and high-performance InAs quantum dot lasers on Si for data center applications in the near future. We will then review novel modulator materials and devices beyond the free carrier plasma dispersion effect in Si, including GeSi and graphene electro-absorption modulators and plasmonic-organic electro-optical modulators, to achieve ultralow power and high speed modulation. Finally, we discuss emerging photodetectors beyond epitaxial Ge p–i–n photodiodes, including GeSn mid-infrared photodetectors, all-Si plasmonic Schottky infrared photodetectors, and Si quanta image sensors for non-avalanche, low noise single <span class="hlt">photon</span> <span class="hlt">detection</span> and <span class="hlt">photon</span> counting. These emerging technologies, though still under development, could make a significant impact on the future of large-scale electronicSilicon <span class="hlt">photonics</span> for synergistic electronic-<span class="hlt">photonic</span> integration has achieved remarkable progress in the past two decades. Active <span class="hlt">photonic</span> devices, including lasers, modulators, and photodetectors, are the key challenges for Si <span class="hlt">photonics</span> to meet the requirement of high bandwidth and low power consumption in <span class="hlt">photonic</span> datalinks. Here we review recent efforts and progress in high-performance active <span class="hlt">photonic</span> devices on Si, focusing on emerging technologies beyond conventional foundry-ready Si <span class="hlt">photonics</span> devices. For emerging laser sources, we will discuss recent</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27447506','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27447506"><span>Quantum Logic with Cavity <span class="hlt">Photons</span> From Single Atoms.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Holleczek, Annemarie; Barter, Oliver; Rubenok, Allison; Dilley, Jerome; Nisbet-Jones, Peter B R; Langfahl-Klabes, Gunnar; Marshall, Graham D; Sparrow, Chris; O'Brien, Jeremy L; Poulios, Konstantinos; Kuhn, Axel; Matthews, Jonathan C F</p> <p>2016-07-08</p> <p>We demonstrate quantum logic using narrow linewidth <span class="hlt">photons</span> that are produced with an a priori nonprobabilistic scheme from a single ^{87}Rb atom strongly coupled to a high-finesse cavity. We use a controlled-not gate integrated into a <span class="hlt">photonic</span> chip to entangle these <span class="hlt">photons</span>, and we observe nonclassical correlations between <span class="hlt">photon</span> <span class="hlt">detection</span> events separated by periods exceeding the travel time across the chip by 3 orders of magnitude. This enables quantum technology that will use the properties of both narrow-band single <span class="hlt">photon</span> sources and integrated quantum <span class="hlt">photonics</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPIE.9705E..0OC','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPIE.9705E..0OC"><span>Silicon chip integrated <span class="hlt">photonic</span> sensors for biological and chemical sensing</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chakravarty, Swapnajit; Zou, Yi; Yan, Hai; Tang, Naimei; Chen, Ray T.</p> <p>2016-03-01</p> <p>We experimentally demonstrate applications of <span class="hlt">photonic</span> crystal waveguide based devices for on-chip optical absorption spectroscopy for the <span class="hlt">detection</span> of chemical warfare simulant, triethylphosphate as well as applications with <span class="hlt">photonic</span> crystal microcavity devices in the <span class="hlt">detection</span> of biomarkers for pancreatic cancer in patient serum and cadmium metal ions in heavy metal pollution sensing. At mid-infrared wavelengths, we experimentally demonstrate the higher sensitivity of <span class="hlt">photonic</span> crystal based structures compared to other nanophotonic devices such as strip and slot waveguides with <span class="hlt">detection</span> down to 10ppm triethylphosphate. We also <span class="hlt">detected</span> 5ppb (parts per billion) of cadmium metal ions in water at near-infrared wavelengths using established techniques for the <span class="hlt">detection</span> of specific probe-target biomarker conjugation chemistries.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19790056046&hterms=birth+order&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dbirth%2Border','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19790056046&hterms=birth+order&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dbirth%2Border"><span>Optical communication with two-<span class="hlt">photon</span> coherent states. II - Photoemissive <span class="hlt">detection</span> and structured receiver performance</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Shapiro, J. H.; Yuen, H. P.; Machado Mata, J. A.</p> <p>1979-01-01</p> <p>In a previous paper (1978), the authors developed a method of analyzing the performance of two-<span class="hlt">photon</span> coherent state (TCS) systems for free-space optical communications. General theorems permitting application of classical point process results to <span class="hlt">detection</span> and estimation of signals in arbitrary quantum states were derived. The present paper examines the general problem of photoemissive <span class="hlt">detection</span> statistics. On the basis of the photocounting theory of Kelley and Kleiner (1964) it is shown that for arbitrary pure state illumination, the resulting photocurrent is in general a self-exciting point process. The photocount statistics for first-order coherent fields reduce to those of a special class of Markov birth processes, which the authors term single-mode birth processes. These general results are applied to the structure of TCS radiation, and it is shown that the use of TCS radiation with direct or heterodyne <span class="hlt">detection</span> results in minimal performance increments over comparable coherent-state systems. However, significant performance advantages are offered by use of TCS radiation with homodyne <span class="hlt">detection</span>. The abstract quantum descriptions of homodyne and heterodyne <span class="hlt">detection</span> are derived and a synthesis procedure for obtaining quantum measurements described by arbitrary TCS is given.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PhRvL.120t3604D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PhRvL.120t3604D"><span>General Model of <span class="hlt">Photon</span>-Pair <span class="hlt">Detection</span> with an Image Sensor</span></a></p> <p><a target="_blank" 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 <span class="hlt">photon</span> pairs illuminating it. Experiments using an effective single-<span class="hlt">photon</span> 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" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3673107','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3673107"><span><span class="hlt">Photonic</span> Crystal Sensors Based on Porous Silicon</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Pacholski, Claudia</p> <p>2013-01-01</p> <p>Porous silicon has been established as an excellent sensing platform for the optical <span class="hlt">detection</span> of hazardous chemicals and biomolecular interactions such as DNA hybridization, antigen/antibody binding, and enzymatic reactions. Its porous nature provides a high surface area within a small volume, which can be easily controlled by changing the pore sizes. As the porosity and consequently the refractive index of an etched porous silicon layer depends on the electrochemial etching conditions <span class="hlt">photonic</span> crystals composed of multilayered porous silicon films with well-resolved and narrow optical reflectivity features can easily be obtained. The prominent optical response of the <span class="hlt">photonic</span> crystal decreases the <span class="hlt">detection</span> limit and therefore increases the sensitivity of porous silicon sensors in comparison to sensors utilizing Fabry-Pérot based optical transduction. Development of porous silicon <span class="hlt">photonic</span> crystal sensors which allow for the <span class="hlt">detection</span> of analytes by the naked eye using a simple color change or the fabrication of stacked porous silicon <span class="hlt">photonic</span> crystals showing two distinct optical features which can be utilized for the discrimination of analytes emphasize its high application potential. PMID:23571671</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvP...8b4022W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvP...8b4022W"><span>Graphene-Based Josephson-Junction Single-<span class="hlt">Photon</span> Detector</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Walsh, Evan D.; Efetov, Dmitri K.; Lee, Gil-Ho; Heuck, Mikkel; Crossno, Jesse; Ohki, Thomas A.; Kim, Philip; Englund, Dirk; Fong, Kin Chung</p> <p>2017-08-01</p> <p>We propose to use graphene-based Josephson junctions (GJJs) to <span class="hlt">detect</span> single <span class="hlt">photons</span> 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 <span class="hlt">photon</span> <span class="hlt">detection</span> required for research areas including quantum information processing and radio astronomy. As an example, we present our device concepts for GJJ single-<span class="hlt">photon</span> 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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPIE.9739E..0HR','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPIE.9739E..0HR"><span>A burst-mode <span class="hlt">photon</span> counting receiver with automatic channel estimation and bit rate <span class="hlt">detection</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rao, Hemonth G.; DeVoe, Catherine E.; Fletcher, Andrew S.; Gaschits, Igor D.; Hakimi, Farhad; Hamilton, Scott A.; Hardy, Nicholas D.; Ingwersen, John G.; Kaminsky, Richard D.; Moores, John D.; Scheinbart, Marvin S.; Yarnall, Timothy M.</p> <p>2016-04-01</p> <p>We demonstrate a multi-rate burst-mode <span class="hlt">photon</span>-counting receiver for undersea communication at data rates up to 10.416 Mb/s over a 30-foot water channel. To the best of our knowledge, this is the first demonstration of burst-mode <span class="hlt">photon</span>-counting communication. With added attenuation, the maximum link loss is 97.1 dB at λ=517 nm. In clear ocean water, this equates to link distances up to 148 meters. For λ=470 nm, the achievable link distance in clear ocean water is 450 meters. The receiver incorporates soft-decision forward error correction (FEC) based on a product code of an inner LDPC code and an outer BCH code. The FEC supports multiple code rates to achieve error-free performance. We have selected a burst-mode receiver architecture to provide robust performance with respect to unpredictable channel obstructions. The receiver is capable of on-the-fly data rate <span class="hlt">detection</span> and adapts to changing levels of signal and background light. The receiver updates its phase alignment and channel estimates every 1.6 ms, allowing for rapid changes in water quality as well as motion between transmitter and receiver. We demonstrate on-the-fly rate <span class="hlt">detection</span>, channel BER within 0.2 dB of theory across all data rates, and error-free performance within 1.82 dB of soft-decision capacity across all tested code rates. All signal processing is done in FPGAs and runs continuously in real time.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19740039065&hterms=signal+amplification&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dsignal%2Bamplification','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19740039065&hterms=signal+amplification&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dsignal%2Bamplification"><span>Four <span class="hlt">photon</span> parametric amplification. [in unbiased Josephson junction</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Parrish, P. T.; Feldman, M. J.; Ohta, H.; Chiao, R. Y.</p> <p>1974-01-01</p> <p>An analysis is presented describing four-<span class="hlt">photon</span> parametric amplification in an unbiased Josephson junction. Central to the theory is the model of the Josephson effect as a nonlinear inductance. Linear, small signal analysis is applied to the two-fluid model of the Josephson junction. The <span class="hlt">gain</span>, <span class="hlt">gain</span>-bandwidth product, high frequency limit, and effective noise temperature are calculated for a cavity reflection amplifier. The analysis is extended to multiple (series-connected) junctions and subharmonic pumping.</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" onclick="trackOutboundLink('https://www.osti.gov/biblio/22413032-photonic-crystals-improving-light-absorption-organic-solar-cells','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22413032-photonic-crystals-improving-light-absorption-organic-solar-cells"><span><span class="hlt">Photonic</span> crystals for improving light absorption in organic solar cells</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Duché, D., E-mail: david.duche@im2np.fr; Le Rouzo, J.; Masclaux, C.</p> <p>2015-02-07</p> <p>We theoretically and experimentally study the structuration of organic solar cells in the shape of <span class="hlt">photonic</span> crystal slabs. By taking advantage of the optical properties of <span class="hlt">photonic</span> crystals slabs, we show the possibility to couple Bloch modes with very low group velocities in the active layer of the cells. These Bloch modes, also called slow Bloch modes (SBMs), allow increasing the lifetime of <span class="hlt">photons</span> within the active layer. Finally, we present experimental demonstration performed by using nanoimprint to directly pattern the standard poly-3-hexylthiophène:[6,6]-phenyl-C61-butiryc acid methyl ester organic semiconductor blend in thin film form in the shape of a <span class="hlt">photonic</span> crystalmore » able to couple SBMs. In agreement with the model, optical characterizations will demonstrate significant <span class="hlt">photonic</span> absorption <span class="hlt">gains</span>.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018SPIE10491E..12S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018SPIE10491E..12S"><span>On-chip <span class="hlt">photonic</span> particle sensor</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Singh, Robin; Ma, Danhao; Agarwal, Anu; Anthony, Brian</p> <p>2018-02-01</p> <p>We propose an on-chip <span class="hlt">photonic</span> particle sensor design that can perform particle sizing and counting for various environmental applications. The sensor is based on micro <span class="hlt">photonic</span> ring resonators that are able to <span class="hlt">detect</span> the presence of the free space particles through the interaction with their evanescent electric field tail. The sensor can characterize a wide range of the particle size ranging from a few nano meters to micron ( 1 micron). The <span class="hlt">photonic</span> platform offers high sensitivity, compactness, fast response of the device. Further, FDTD simulations are performed to analyze different particle-light interactions. Such a compact and portable platform, packaged with integrated <span class="hlt">photonic</span> circuit provides a useful sensing modality in space shuttle and environmental applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvD..96i6008E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvD..96i6008E"><span>Prospects for <span class="hlt">detecting</span> a net <span class="hlt">photon</span> circular polarization produced by decaying dark matter</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Elagin, Andrey; Kumar, Jason; Sandick, Pearl; Teng, Fei</p> <p>2017-11-01</p> <p>If dark matter interactions with Standard Model particles are C P violating, then dark matter annihilation/decay can produce <span class="hlt">photons</span> with a net circular polarization. We consider the prospects for experimentally <span class="hlt">detecting</span> evidence for such a circular polarization. We identify optimal models for dark matter interactions with the Standard Model, from the point of view of <span class="hlt">detectability</span> of the net polarization, for the case of either symmetric or asymmetric dark matter. We find that, for symmetric dark matter, evidence for net polarization could be found by a search of the Galactic center by an instrument sensitive to circular polarization with an efficiency-weighted exposure of at least 50 ,000 cm2 yr , provided the systematic detector uncertainties are constrained at the 1% level. Better sensitivity can be obtained in the case of asymmetric dark matter. We discuss the prospects for achieving the needed level of performance using possible detector technologies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22596843-fault-tolerant-filtering-fault-detection-quantum-systems-driven-fields-single-photon-states','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22596843-fault-tolerant-filtering-fault-detection-quantum-systems-driven-fields-single-photon-states"><span>Fault tolerant filtering and fault <span class="hlt">detection</span> for quantum systems driven by fields in single <span class="hlt">photon</span> states</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Gao, Qing, E-mail: qing.gao.chance@gmail.com; Dong, Daoyi, E-mail: daoyidong@gmail.com; Petersen, Ian R., E-mail: i.r.petersen@gmai.com</p> <p></p> <p>The purpose of this paper is to solve the fault tolerant filtering and fault <span class="hlt">detection</span> problem for a class of open quantum systems driven by a continuous-mode bosonic input field in single <span class="hlt">photon</span> states when the systems are subject to stochastic faults. Optimal estimates of both the system observables and the fault process are simultaneously calculated and characterized by a set of coupled recursive quantum stochastic differential equations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013NatCo...4E2104T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013NatCo...4E2104T"><span>Realistic loophole-free Bell test with atom-<span class="hlt">photon</span> entanglement</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Teo, C.; Araújo, M.; Quintino, M. T.; Minář, J.; Cavalcanti, D.; Scarani, V.; Terra Cunha, M.; França Santos, M.</p> <p>2013-07-01</p> <p>The establishment of nonlocal correlations, guaranteed through the violation of a Bell inequality, is not only important from a fundamental point of view but constitutes the basis for device-independent quantum information technologies. Although several nonlocality tests have been conducted so far, all of them suffered from either locality or <span class="hlt">detection</span> loopholes. Among the proposals for overcoming these problems are the use of atom-<span class="hlt">photon</span> entanglement and hybrid <span class="hlt">photonic</span> measurements (for example, photodetection and homodyning). Recent studies have suggested that the use of atom-<span class="hlt">photon</span> entanglement can lead to Bell inequality violations with moderate transmission and <span class="hlt">detection</span> efficiencies. Here we combine these ideas and propose an experimental setup realizing a simple atom-<span class="hlt">photon</span> entangled state that can be used to obtain nonlocality when considering realistic experimental parameters including <span class="hlt">detection</span> efficiencies and losses due to required propagation distances.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1164669','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/1164669"><span><span class="hlt">Photonic</span> crystal surface-emitting lasers enabled by an accidental Dirac point</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Chua, Song Liang; Lu, Ling; Soljacic, Marin</p> <p>2014-12-02</p> <p>A <span class="hlt">photonic</span>-crystal surface-emitting laser (PCSEL) includes a <span class="hlt">gain</span> medium electromagnetically coupled to a <span class="hlt">photonic</span> crystal whose energy band structure exhibits a Dirac cone of linear dispersion at the center of the <span class="hlt">photonic</span> crystal's Brillouin zone. This Dirac cone's vertex is called a Dirac point; because it is at the Brillouin zone center, it is called an accidental Dirac point. Tuning the <span class="hlt">photonic</span> crystal's band structure (e.g., by changing the <span class="hlt">photonic</span> crystal's dimensions or refractive index) to exhibit an accidental Dirac point increases the <span class="hlt">photonic</span> crystal's mode spacing by orders of magnitudes and reduces or eliminates the <span class="hlt">photonic</span> crystal's distributed in-plane feedback. Thus, the <span class="hlt">photonic</span> crystal can act as a resonator that supports single-mode output from the PCSEL over a larger area than is possible with conventional PCSELs, which have quadratic band edge dispersion. Because output power generally scales with output area, this increase in output area results in higher possible output powers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1991PhLB..268..437B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1991PhLB..268..437B"><span>Prompt <span class="hlt">photon</span> pair production in association with top-antitop pairs. An important background to intermediate mass Higgs <span class="hlt">detection</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ballestrero, Alessandro; Maina, Ezio</p> <p>1991-10-01</p> <p>The reaction pp→ t t¯γγ is studied for 80⩽ Mγγ⩽140 GeV, as a possible background to the <span class="hlt">detection</span> of an intermedia te mass standard model Higgs in the rare ℓ νγγ final state. If the top is not too heavy the prompt <span class="hlt">photon</span> production, integrated over a window of 6 GeV in Mγγ around the Higgs mass, can be larger than the production of <span class="hlt">photon</span> pairs from Higgs decay. Standard isolation cuts can effectively dispose of this background for mt⩾150 GeV. For mt∼100 GeV approximately the same nu mber of background and signal events pass the cuts.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017NaPho..11..247Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017NaPho..11..247Z"><span>Single-<span class="hlt">photon</span> imager based on a superconducting nanowire delay line</span></a></p> <p><a target="_blank" 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><span class="hlt">Detecting</span> spatial and temporal information of individual <span class="hlt">photons</span> is critical to applications in spectroscopy, communication, biological imaging, astronomical observation and quantum-information processing. Here we demonstrate a scalable single-<span class="hlt">photon</span> imager using a single continuous superconducting nanowire that is not only a single-<span class="hlt">photon</span> detector but also functions as an efficient microwave delay line. In this context, <span class="hlt">photon-detection</span> pulses are guided in the nanowire and enable the readout of the position and time of <span class="hlt">photon</span>-absorption events from the arrival times of the <span class="hlt">detection</span> 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 <span class="hlt">photon</span> imaging in space and time.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011ApPhL..99i1112D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011ApPhL..99i1112D"><span>Magneto-<span class="hlt">photonic</span> crystal optical sensors with sensitive covers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dissanayake, Neluka; Levy, Miguel; Chakravarty, A.; Heiden, P. A.; Chen, N.; Fratello, V. J.</p> <p>2011-08-01</p> <p>We report on a magneto-<span class="hlt">photonic</span> crystal on-chip optical sensor for specific analyte <span class="hlt">detection</span> with polypyrrole and gold nano particles as modified <span class="hlt">photonic</span> crystal waveguide cover layers. The reaction of the active sensor material with various analytes modifies the electronic structure of the sensor layer causing changes in its refractive index and a strong transduction signal. Magneto-<span class="hlt">photonic</span> crystal enhanced polarization rotation sensitive to the nature of the cover layer <span class="hlt">detects</span> the index modification upon analyte adsorption. A high degree of selectivity and sensitivity are observed for aqueous ammonia and methanol with polypyrrole and for thiolated-gold- with gold-nanoparticles covers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1413458-automated-microfluidic-assay-photonic-crystal-enhanced-detection-analysis-antiviral-antibody-cancer-biomarker-serum','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1413458-automated-microfluidic-assay-photonic-crystal-enhanced-detection-analysis-antiviral-antibody-cancer-biomarker-serum"><span>An Automated Microfluidic Assay for <span class="hlt">Photonic</span> Crystal Enhanced <span class="hlt">Detection</span> and Analysis of an Antiviral Antibody Cancer Biomarker in Serum</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Race, Caitlin M.; Kwon, Lydia E.; Foreman, Myles T.; ...</p> <p>2017-11-24</p> <p>Here, we report on the implementation of an automated platform for <span class="hlt">detecting</span> the presence of an antibody biomarker for human papillomavirus-associated oropharyngeal cancer from a single droplet of serum, in which a nanostructured <span class="hlt">photonic</span> crystal surface is used to amplify the output of a fluorescence-linked immunosorbent assay. The platform is comprised of a microfluidic cartridge with integrated <span class="hlt">photonic</span> crystal chips that interfaces with an assay instrument that automates the introduction of reagents, wash steps, and surface drying. Upon assay completion, the cartridge interfaces with a custom laser-scanning instrument that couples light into the <span class="hlt">photonic</span> crystal at the optimal resonance conditionmore » for fluorescence enhancement. The instrument is used to measure the fluorescence intensity values of microarray spots corresponding to the biomarkers of interest, in addition to several experimental controls that verify correct functioning of the assay protocol. In this work, we report both dose-response characterization of the system using anti-E7 antibody introduced at known concentrations into serum and characterization of a set of clinical samples from which results were compared with a conventional enzyme-linked immunosorbent assay (ELISA) performed in microplate format. Finally, the demonstrated capability represents a simple, rapid, automated, and high-sensitivity method for multiplexed <span class="hlt">detection</span> of protein biomarkers from a low-volume test sample.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/1413458-automated-microfluidic-assay-photonic-crystal-enhanced-detection-analysis-antiviral-antibody-cancer-biomarker-serum','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1413458-automated-microfluidic-assay-photonic-crystal-enhanced-detection-analysis-antiviral-antibody-cancer-biomarker-serum"><span>An Automated Microfluidic Assay for <span class="hlt">Photonic</span> Crystal Enhanced <span class="hlt">Detection</span> and Analysis of an Antiviral Antibody Cancer Biomarker in Serum</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Race, Caitlin M.; Kwon, Lydia E.; Foreman, Myles T.</p> <p></p> <p>Here, we report on the implementation of an automated platform for <span class="hlt">detecting</span> the presence of an antibody biomarker for human papillomavirus-associated oropharyngeal cancer from a single droplet of serum, in which a nanostructured <span class="hlt">photonic</span> crystal surface is used to amplify the output of a fluorescence-linked immunosorbent assay. The platform is comprised of a microfluidic cartridge with integrated <span class="hlt">photonic</span> crystal chips that interfaces with an assay instrument that automates the introduction of reagents, wash steps, and surface drying. Upon assay completion, the cartridge interfaces with a custom laser-scanning instrument that couples light into the <span class="hlt">photonic</span> crystal at the optimal resonance conditionmore » for fluorescence enhancement. The instrument is used to measure the fluorescence intensity values of microarray spots corresponding to the biomarkers of interest, in addition to several experimental controls that verify correct functioning of the assay protocol. In this work, we report both dose-response characterization of the system using anti-E7 antibody introduced at known concentrations into serum and characterization of a set of clinical samples from which results were compared with a conventional enzyme-linked immunosorbent assay (ELISA) performed in microplate format. Finally, the demonstrated capability represents a simple, rapid, automated, and high-sensitivity method for multiplexed <span class="hlt">detection</span> of protein biomarkers from a low-volume test sample.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26480367','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26480367"><span>Resolution-improved in situ DNA hybridization <span class="hlt">detection</span> based on microwave <span class="hlt">photonic</span> interrogation.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cao, Yuan; Guo, Tuan; Wang, Xudong; Sun, Dandan; Ran, Yang; Feng, Xinhuan; Guan, Bai-ou</p> <p>2015-10-19</p> <p>In situ bio-sensing system based on microwave <span class="hlt">photonics</span> filter (MPF) interrogation method with improved resolution is proposed and experimentally demonstrated. A microfiber Bragg grating (mFBG) is used as sensing probe for DNA hybridization <span class="hlt">detection</span>. Different from the traditional wavelength monitoring technique, we use the frequency interrogation scheme for resolution-improved bio-sensing <span class="hlt">detection</span>. Experimental results show that the frequency shift of MPF notch presents a linear response to the surrounding refractive index (SRI) change over the range of 1.33 to 1.38, with a SRI resolution up to 2.6 × 10(-5) RIU, which has been increased for almost two orders of magnitude compared with the traditional fundamental mode monitoring technique (~3.6 × 10(-3) RIU). Due to the high Q value (about 27), the whole process of DNA hybridization can be in situ monitored. The proposed MPF-based bio-sensing system provides a new interrogation method over the frequency domain with improved sensing resolution and rapid interrogation rate for biochemical and environmental measurement.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3674960','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3674960"><span>Promising New <span class="hlt">Photon</span> <span class="hlt">Detection</span> Concepts for High-Resolution Clinical and Preclinical PET</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Levin, Craig S.</p> <p>2013-01-01</p> <p>The ability of PET to visualize and quantify regions of low concentration of PET tracer representing subtle cellular and molecular signatures of disease depends on relatively complex biochemical, biologic, and physiologic factors that are challenging to control, as well as on instrumentation performance parameters that are, in principle, still possible to improve on. Thus, advances to the latter can somewhat offset barriers of the former. PET system performance parameters such as spatial resolution, contrast resolution, and <span class="hlt">photon</span> sensitivity contribute significantly to PET’s ability to visualize and quantify lower concentrations of signal in the presence of background. In this report we present some technology innovations under investigation toward improving these PET system performance parameters. We focus particularly on a promising advance known as 3-dimensional position-sensitive detectors, which are detectors capable of distinguishing and measuring the position, energy, and arrival time of individual interactions of multi-interaction <span class="hlt">photon</span> events in 3 dimensions. If successful, these new strategies enable enhancements such as the <span class="hlt">detection</span> of fewer diseased cells in tissue or the ability to characterize lower-abundance molecular targets within cells. Translating these advanced capabilities to the clinic might allow expansion of PET’s roles in disease management, perhaps to earlier stages of disease. In preclinical research, such enhancements enable more sensitive and accurate studies of disease biology in living subjects. PMID:22302960</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5216112','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5216112"><span>Pushing the limits of CMOS optical parametric amplifiers with USRN:Si7N3 above the two-<span class="hlt">photon</span> absorption edge</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Ooi, K. J. A.; Ng, D. K. T.; Wang, T.; Chee, A. K. L.; Ng, S. K.; Wang, Q.; Ang, L. K.; Agarwal, A. M.; Kimerling, L. C.; Tan, D. T. H.</p> <p>2017-01-01</p> <p>CMOS platforms operating at the telecommunications wavelength either reside within the highly dissipative two-<span class="hlt">photon</span> regime in silicon-based optical devices, or possess small nonlinearities. Bandgap engineering of non-stoichiometric silicon nitride using state-of-the-art fabrication techniques has led to our development of USRN (ultra-silicon-rich nitride) in the form of Si7N3, that possesses a high Kerr nonlinearity (2.8 × 10−13 cm2 W−1), an order of magnitude larger than that in stoichiometric silicon nitride. Here we experimentally demonstrate high-<span class="hlt">gain</span> optical parametric amplification using USRN, which is compositionally tailored such that the 1,550 nm wavelength resides above the two-<span class="hlt">photon</span> absorption edge, while still possessing large nonlinearities. Optical parametric <span class="hlt">gain</span> of 42.5 dB, as well as cascaded four-wave mixing with <span class="hlt">gain</span> down to the third idler is observed and attributed to the high <span class="hlt">photon</span> efficiency achieved through operating above the two-<span class="hlt">photon</span> absorption edge, representing one of the largest optical parametric <span class="hlt">gains</span> to date on a CMOS platform. PMID:28051064</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015NatSR...513253N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015NatSR...513253N"><span>Single-<span class="hlt">photon</span> decision maker</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Naruse, Makoto; Berthel, Martin; Drezet, Aurélien; Huant, Serge; Aono, Masashi; Hori, Hirokazu; Kim, Song-Ju</p> <p>2015-08-01</p> <p>Decision making is critical in our daily lives and for society in general and is finding evermore practical applications in information and communication technologies. Herein, we demonstrate experimentally that single <span class="hlt">photons</span> can be used to make decisions in uncertain, dynamically changing environments. Using a nitrogen-vacancy in a nanodiamond as a single-<span class="hlt">photon</span> source, we demonstrate the decision-making capability by solving the multi-armed bandit problem. This capability is directly and immediately associated with single-<span class="hlt">photon</span> <span class="hlt">detection</span> in the proposed architecture, leading to adequate and adaptive autonomous decision making. This study makes it possible to create systems that benefit from the quantum nature of light to perform practical and vital intelligent functions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017OptCo.384...93A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017OptCo.384...93A"><span>Infiltrated <span class="hlt">photonic</span> crystal cavity as a highly sensitive platform for glucose concentration <span class="hlt">detection</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Arafa, Safia; Bouchemat, Mohamed; Bouchemat, Touraya; Benmerkhi, Ahlem; Hocini, Abdesselam</p> <p>2017-02-01</p> <p>A Bio-sensing platform based on an infiltrated <span class="hlt">photonic</span> crystal ring shaped holes cavity-coupled waveguide system is proposed for glucose concentration <span class="hlt">detection</span>. Considering silicon-on-insulator (SOI) technology, it has been demonstrated that the ring shaped holes configuration provides an excellent optical confinement within the cavity region, which further enhances the light-matter interactions at the precise location of the analyte medium. Thus, the sensitivity and the quality factor (Q) can be significantly improved. The transmission characteristics of light in the biosensor under different refractive indices that correspond to the change in the analyte glucose concentration are analyzed by performing finite-difference time-domain (FDTD) simulations. Accordingly, an improved sensitivity of 462 nm/RIU and a Q factor as high as 1.11х105 have been achieved, resulting in a <span class="hlt">detection</span> limit of 3.03х10-6 RIU. Such combination of attributes makes the designed structure a promising element for performing label-free biosensing in medical diagnosis and environmental monitoring.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SPIE10225E..0QL','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SPIE10225E..0QL"><span>An automated <span class="hlt">detection</span> for axonal boutons in vivo two-<span class="hlt">photon</span> imaging of mouse</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, Weifu; Zhang, Dandan; Xie, Qiwei; Chen, Xi; Han, Hua</p> <p>2017-02-01</p> <p>Activity-dependent changes in the synaptic connections of the brain are tightly related to learning and memory. Previous studies have shown that essentially all new synaptic contacts were made by adding new partners to existing synaptic elements. To further explore synaptic dynamics in specific pathways, concurrent imaging of pre and postsynaptic structures in identified connections is required. Consequently, considerable attention has been paid for the automated <span class="hlt">detection</span> of axonal boutons. Different from most previous methods proposed in vitro data, this paper considers a more practical case in vivo neuron images which can provide real time information and direct observation of the dynamics of a disease process in mouse. Additionally, we present an automated approach for <span class="hlt">detecting</span> axonal boutons by starting with deconvolving the original images, then thresholding the enhanced images, and reserving the regions fulfilling a series of criteria. Experimental result in vivo two-<span class="hlt">photon</span> imaging of mouse demonstrates the effectiveness of our proposed method.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018AAS...23115216P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018AAS...23115216P"><span>Charge <span class="hlt">Gain</span>, Voltage <span class="hlt">Gain</span>, and Node Capacitance of the SAPHIRA Detector Pixel by Pixel</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pastrana, Izabella M.; Hall, Donald N. B.; Baker, Ian M.; Jacobson, Shane M.; Goebel, Sean B.</p> <p>2018-01-01</p> <p>The University of Hawai`i Institute for Astronomy has partnered with Leonardo (formerly Selex) in the development of HgCdTe linear mode avalanche photodiode (L-APD) SAPHIRA detectors. The SAPHIRA (Selex Avalanche Photodiode High-speed Infra-Red Array) is ideally suited for <span class="hlt">photon</span>-starved astronomical observations, particularly near infrared (NIR) adaptive optics (AO) wave-front sensing. I have measured the stability, and linearity with current, of a 1.7-um (10% spectral bandpass) infrared light emitting diode (IR LED) used to illuminate the SAPHIRA and have then utilized this source to determine the charge <span class="hlt">gain</span> (in e-/ADU), voltage <span class="hlt">gain</span> (in uV/ADU), and node capacitance (in fF) for each pixel of the 320x256@24um SAPHIRA. These have previously only been averages over some sub-array. Determined from the ratio of the temporal averaged signal level to variance under constant 1.7-um LED illumination, I present the charge <span class="hlt">gain</span> pixel-by-pixel in a 64x64 sub-array at the center of the active area of the SAPHIRA (analyzed separately as four 32x32 sub-arrays) to be about 1.6 e-/ADU (σ=0.5 e-/ADU). Additionally, the standard technique of varying the pixel reset voltage (PRV) in 10 mV increments and recording output frames for the same 64x64 subarray found the voltage <span class="hlt">gain</span> per pixel to be about 11.7 uV/ADU (σ=0.2 uV/ADU). Finally, node capacitance was found to be approximately 23 fF (σ=6 fF) utilizing the aforementioned charge and voltage <span class="hlt">gain</span> measurements. I further discuss the linearity measurements of the 1.7-um LED used in the charge <span class="hlt">gain</span> characterization procedure.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22525105-heating-up-galaxy-hidden-photons','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22525105-heating-up-galaxy-hidden-photons"><span>Heating up the Galaxy with hidden <span class="hlt">photons</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Dubovsky, Sergei; Hernández-Chifflet, Guzmán, E-mail: dubovsky@nyu.edu, E-mail: ghc236@nyu.edu</p> <p>2015-12-01</p> <p>We elaborate on the dynamics of ionized interstellar medium in the presence of hidden <span class="hlt">photon</span> dark matter. Our main focus is the ultra-light regime, where the hidden <span class="hlt">photon</span> mass is smaller than the plasma frequency in the Milky Way. We point out that as a result of the Galactic plasma shielding direct <span class="hlt">detection</span> of ultra-light <span class="hlt">photons</span> in this mass range is especially challenging. However, we demonstrate that ultra-light hidden <span class="hlt">photon</span> dark matter provides a powerful heating source for the ionized interstellar medium. This results in a strong bound on the kinetic mixing between hidden and regular <span class="hlt">photons</span> all the waymore » down to the hidden <span class="hlt">photon</span> masses of order 10{sup −20} eV.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22458418-heating-up-galaxy-hidden-photons','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22458418-heating-up-galaxy-hidden-photons"><span>Heating up the Galaxy with hidden <span class="hlt">photons</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Dubovsky, Sergei; Hernández-Chifflet, Guzmán; Instituto de Física, Facultad de Ingeniería, Universidad de la República,Montevideo, 11300</p> <p>2015-12-29</p> <p>We elaborate on the dynamics of ionized interstellar medium in the presence of hidden <span class="hlt">photon</span> dark matter. Our main focus is the ultra-light regime, where the hidden <span class="hlt">photon</span> mass is smaller than the plasma frequency in the Milky Way. We point out that as a result of the Galactic plasma shielding direct <span class="hlt">detection</span> of ultra-light <span class="hlt">photons</span> in this mass range is especially challenging. However, we demonstrate that ultra-light hidden <span class="hlt">photon</span> dark matter provides a powerful heating source for the ionized interstellar medium. This results in a strong bound on the kinetic mixing between hidden and regular <span class="hlt">photons</span> all the waymore » down to the hidden <span class="hlt">photon</span> masses of order 10{sup −20} eV.« 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_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" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvP...8d4012L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvP...8d4012L"><span>Quantum Biometrics with Retinal <span class="hlt">Photon</span> Counting</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Loulakis, M.; Blatsios, G.; Vrettou, C. S.; Kominis, I. K.</p> <p>2017-10-01</p> <p>It is known that the eye's scotopic photodetectors, rhodopsin molecules, and their associated phototransduction mechanism leading to light perception, are efficient single-<span class="hlt">photon</span> counters. We here use the <span class="hlt">photon</span>-counting principles of human rod vision to propose a secure quantum biometric identification based on the quantum-statistical properties of retinal <span class="hlt">photon</span> <span class="hlt">detection</span>. The <span class="hlt">photon</span> path along the human eye until its <span class="hlt">detection</span> by rod cells is modeled as a filter having a specific transmission coefficient. Precisely determining its value from the photodetection statistics registered by the conscious observer is a quantum parameter estimation problem that leads to a quantum secure identification method. The probabilities for false-positive and false-negative identification of this biometric technique can readily approach 10-10 and 10-4, respectively. The security of the biometric method can be further quantified by the physics of quantum measurements. An impostor must be able to perform quantum thermometry and quantum magnetometry with energy resolution better than 10-9ℏ , in order to foil the device by noninvasively monitoring the biometric activity of a user.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006SPIE.6265E..23A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006SPIE.6265E..23A"><span><span class="hlt">Photon</span> sieve telescope</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Andersen, Geoff; Tullson, Drew</p> <p>2006-06-01</p> <p>In designing next-generation, ultra-large (>20m) apertures for space, many current concepts involve compactable, curved membrane reflectors. Here we present the idea of using a flat diffractive element that requires no out-of-plane deformation and so is much simpler to deploy. The primary is a <span class="hlt">photon</span> sieve - a diffractive element consisting of a large number of precisely positioned holes distributed according to an underlying Fresnel Zone Plate (FZP) geometry. The advantage of the <span class="hlt">photon</span> sieve over the FZP is that all the regions are connected, so the membrane substrate under simple tension can avoid buckling. Also, the hole distribution can be varied to generate any conic or apodization for specialized telescope requirements such as exo-solar planet <span class="hlt">detection</span>. We have designed and tested numerous <span class="hlt">photon</span> sieves as telescope primaries. Some of these have over 10 million holes in a 0.1 m diameter aperture and all of them give diffraction limited imaging. While <span class="hlt">photon</span> sieves are diffractive elements and thus suffer from dispersion, we will present two successful solutions to this problem.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4229433','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4229433"><span>Optofluidic lasers with a single molecular layer of <span class="hlt">gain</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Chen, Qiushu; Ritt, Michael; Sivaramakrishnan, Sivaraj; Sun, Yuze; Fan, Xudong</p> <p>2014-01-01</p> <p>We achieve optofluidic lasers with a single molecular layer of <span class="hlt">gain</span>, in which green fluorescent protein, dye-labeled bovine serum albumin, and dye-labeled DNA are respectively used as the <span class="hlt">gain</span> medium and attached to the surface of a ring resonator via surface immobilization biochemical methods. It is estimated that the surface density of the <span class="hlt">gain</span> molecules is on the order of 1012/cm2, sufficient for lasing under pulsed optical excitation. It is further shown that the optofluidic laser can be tuned by energy transfer mechanisms through biomolecular interactions. This work not only opens a door to novel <span class="hlt">photonic</span> devices that can be controlled at the level of a single molecular layer, but also provides a promising sensing platform to analyze biochemical processes at the solid-liquid interface. PMID:25312306</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1999SPIE.3764..234N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999SPIE.3764..234N"><span><span class="hlt">Photon</span>-counting intensified random-access charge injection device</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Norton, Timothy J.; Morrissey, Patrick F.; Haas, Patrick; Payne, Leslie J.; Carbone, Joseph; Kimble, Randy A.</p> <p>1999-11-01</p> <p>At NASA GSFC we are developing a high resolution solar-blind <span class="hlt">photon</span> counting detector system for UV space based astronomy. The detector comprises a high <span class="hlt">gain</span> MCP intensifier fiber- optically coupled to a charge injection device (CID). The detector system utilizes an FPGA based centroiding system to locate the center of <span class="hlt">photon</span> events from the intensifier to high accuracy. The <span class="hlt">photon</span> event addresses are passed via a PCI interface with a GPS derived time stamp inserted per frame to an integrating memory. Here we present imaging performance data which show resolution of MCP tube pore structure at an MCP pore diameter of 8 micrometer. This data validates the ICID concept for intensified <span class="hlt">photon</span> counting readout. We also discuss correction techniques used in the removal of fixed pattern noise effects inherent in the centroiding algorithms used and present data which shows the local dynamic range of the device. Progress towards development of a true random access CID (RACID 810) is also discussed and astronomical data taken with the ICID detector system demonstrating the <span class="hlt">photon</span> event time-tagging mode of the system is also presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015OptLT..73...44Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015OptLT..73...44Y"><span>The design of rapid turbidity measurement system based on single <span class="hlt">photon</span> <span class="hlt">detection</span> techniques</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yang, Yixin; Wang, Huanqin; Cao, Yangyang; Gui, Huaqiao; Liu, Jianguo; Lu, Liang; Cao, Huibin; Yu, Tongzhu; You, Hui</p> <p>2015-10-01</p> <p>A new rapid turbidity measurement system has been developed to measure the turbidity of drinking water. To determinate the turbidity quantitatively, the total intensity of scattering light has been measured and quantified as number of <span class="hlt">photons</span> by adopting the single <span class="hlt">photon</span> <span class="hlt">detection</span> techniques (SPDT) which has the advantage of high sensitivity. On the basis of SPDT, the measurement system has been built and series of experiments have been carried out. Combining then the 90° Mie scattering theory with the principle of SPDT, a turbidity measurement model has been proposed to explain the experimental results. The experimental results show that a turbidity, which is as low as 0.1 NTU (Nephelometric Turbidity Units), can be measured steadily within 100 ms. It also shows a good linearity and stability over the range of 0.1-400 NTU and the precision can be controlled within 5% full scale. In order to improve its precision and stability, some key parameters, including the sampling time and incident light intensity, have been discussed. It has been proved that, to guarantee an excellent system performance, a good compromise between the measurement speed and the low power consumption should be considered adequately depending on the practical applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012JOpt...14b0201B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012JOpt...14b0201B"><span>EDITORIAL: Special issue on green <span class="hlt">photonics</span> Special issue on green <span class="hlt">photonics</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Boardman, Allan; Brongersma, Mark; Polman, Albert</p> <p>2012-02-01</p> <p>Photovoltaic (PV) cells can provide virtually unlimited amounts of energy by effectively converting sunlight into clean electrical power. Over the years, significant research and development efforts have been devoted to improving the structural and charge transport properties of the materials used in PV cells. Despite these efforts, the current energy conversion efficiencies of commercial solar cells are still substantially lower than the ultimate limits set by thermodynamics. Economic arguments in addition to the scarcity of some semiconductors and materials used in transparent conductive oxides are also driving us to use less and less material in a cell. For these reasons, it is clear that new approaches need to be found. One possible solution that is more-or-less orthogonal to previous approaches is aimed at managing the <span class="hlt">photons</span> rather than the electrons or atoms in a cell. This type of <span class="hlt">photon</span> management is termed Green <span class="hlt">Photonics</span>. Nano- and micro-<span class="hlt">photonic</span> trapping techniques are currently <span class="hlt">gaining</span> significant attention. The use of engineered plasmonic and high refractive index structures shows tremendous potential for enhancing the light absorption per unit volume in semiconductors. Unfortunately, the design space in terms of the nanostructure sizes, shapes, and array structures is too large to allow for optimization of PV cells using brute force simulations. For this reason, new intuitive models and rapid optimization techniques for advanced light trapping technologies need to be developed. At the same time we need to come up with new, inexpensive, and scalable nanostructure fabrication and optical characterization techniques in order to realize the dream of inexpensive, high power conversion efficiency cells that make economic sense. This special issue discusses some of the exciting new approaches to light trapping that leverage the most recent advances in the field of nanophotonics. It also provides some insights into why giving the green light to green</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014APS..DMP.D1121G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014APS..DMP.D1121G"><span><span class="hlt">Photonic</span> Molecule Lasers Revisited</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gagnon, Denis; Dumont, Joey; Déziel, Jean-Luc; Dubé, Louis J.</p> <p>2014-05-01</p> <p><span class="hlt">Photonic</span> molecules (PMs) formed by coupling two or more optical resonators are ideal candidates for the fabrication of integrated microlasers, <span class="hlt">photonic</span> molecule lasers. Whereas most calculations on PM lasers have been based on cold-cavity (passive) modes, i.e. quasi-bound states, a recently formulated steady-state ab initio laser theory (SALT) offers the possibility to take into account the spectral properties of the underlying <span class="hlt">gain</span> transition, its position and linewidth, as well as incorporating an arbitrary pump profile. We will combine two theoretical approaches to characterize the lasing properties of PM lasers: for two-dimensional systems, the generalized Lorenz-Mie theory will obtain the resonant modes of the coupled molecules in an active medium described by SALT. Not only is then the theoretical description more complete, the use of an active medium provides additional parameters to control, engineer and harness the lasing properties of PM lasers for ultra-low threshold and directional single-mode emission. We will extend our recent study and present new results for a number of promising geometries. The authors acknowledge financial support from NSERC (Canada) and the CERC in <span class="hlt">Photonic</span> Innovations of Y. Messaddeq.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3231581','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3231581"><span><span class="hlt">Photonic</span> Biosensor Assays to <span class="hlt">Detect</span> and Distinguish Subspecies of Francisella tularensis</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Cooper, Kristie L.; Bandara, Aloka B.; Wang, Yunmiao; Wang, Anbo; Inzana, Thomas J.</p> <p>2011-01-01</p> <p>The application of <span class="hlt">photonic</span> biosensor assays to diagnose the category-A select agent Francisella tularensis was investigated. Both interferometric and long period fiber grating sensing structures were successfully demonstrated; both these sensors are capable of <span class="hlt">detecting</span> the optical changes induced by either immunological binding or DNA hybridization. <span class="hlt">Detection</span> was made possible by the attachment of DNA probes or immunoglobulins (IgG) directly to the fiber surface via layer-by-layer electrostatic self-assembly. An optical fiber biosensor was tested using a standard transmission mode long period fiber grating of length 15 mm and period 260 μm, and coated with the IgG fraction of antiserum to F. tularensis. The IgG was deposited onto the optical fiber surface in a nanostructured film, and the resulting refractive index change was measured using spectroscopic ellipsometry. The presence of F. tularensis was <span class="hlt">detected</span> from the decrease of peak wavelength caused by binding of specific antigen. <span class="hlt">Detection</span> and differentiation of F. tularensis subspecies tularensis (type A strain TI0902) and subspecies holarctica (type B strain LVS) was further accomplished using a single-mode multi-cavity fiber Fabry-Perot interferometric sensor. These sensors were prepared by depositing seven polymer bilayers onto the fiber tip followed by attaching one of two DNA probes: (a) a 101-bp probe from the yhhW gene unique to type-A strains, or (b) a 117-bp probe of the lpnA gene, common to both type-A and type-B strains. The yhhW probe was reactive with the type-A, but not the type-B strain. Probe lpnA was reactive with both type-A and type-B strains. Nanogram quantities of the target DNA could be <span class="hlt">detected</span>, highlighting the sensitivity of this method for DNA <span class="hlt">detection</span> without the use of PCR. The DNA probe reacted with 100% homologous target DNA, but did not react with sequences containing 2-bp mismatches, indicating the high specificity of the assay. These assays will fill an important void that</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AIPC.1793p0007P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AIPC.1793p0007P"><span>Radiometric Short-Term Fourier Transform analysis of <span class="hlt">photonic</span> Doppler velocimetry recordings and <span class="hlt">detectivity</span> limit</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Prudhomme, G.; Berthe, L.; Bénier, J.; Bozier, O.; Mercier, P.</p> <p>2017-01-01</p> <p><span class="hlt">Photonic</span> Doppler Velocimetry is a plug-and-play and versatile diagnostic used in dynamic physic experiments to measure velocities. When signals are analyzed using a Short-Time Fourier Transform, multiple velocities can be distinguished: for example, the velocities of moving particle-cloud appear on spectrograms. In order to estimate the back-scattering fluxes of target, we propose an original approach "PDV Radiometric analysis" resulting in an expression of time-velocity spectrograms coded in power units. Experiments involving micron-sized particles raise the issue of <span class="hlt">detection</span> limit; particle-size limit is very difficult to evaluate. From the quantification of noise sources, we derive an estimation of the spectrogram noise leading to a <span class="hlt">detectivity</span> limit, which may be compared to the fraction of the incoming power which has been back-scattered by the particle and then collected by the probe. This fraction increases with their size. At last, some results from laser-shock accelerated particles using two different PDV systems are compared: it shows the improvement of <span class="hlt">detectivity</span> with respect to the Effective Number of Bits (ENOB) of the digitizer.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JInst..12P1021R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JInst..12P1021R"><span>Enhanced <span class="hlt">photon</span> traps for Hyper-Kamiokande</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rott, Carsten; In, Seongjin; Retière, Fabrice; Gumplinger, Peter</p> <p>2017-11-01</p> <p>Hyper-Kamiokande, the next generation large water Cherenkov detector in Japan, is planning to use approximately 80,000 20-inch photomultiplier tubes (PMTs). They are one of the major cost factors of the experiment. We propose a novel enhanced <span class="hlt">photon</span> trap design based on a smaller and more economical PMT in combination with wavelength shifters, dichroic mirrors, and broadband mirrors. GEANT4 is utilized to obtain <span class="hlt">photon</span> collection efficiencies and timing resolution of the <span class="hlt">photon</span> traps. We compare the performance of different trap configurations and sizes. Our simulations indicate an enhanced <span class="hlt">photon</span> trap with a 12-inch PMT can match a 20-inch PMT's collection efficiency, however at a cost of reduced timing resolution. The <span class="hlt">photon</span> trap might be suitable as <span class="hlt">detection</span> module for the outer detector with large photo coverage area.</p> </li> <li> <p><a target="_blank" 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 <span class="hlt">photon</span> counter for discrimination of single-rail optical qubits</span></a></p> <p><a target="_blank" 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 <span class="hlt">detection</span> strategy composed of a displacement operation and a <span class="hlt">photon</span> 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 <span class="hlt">photon</span> states corresponding to the {\\hat{σ }}x eigenstates in the single-rail encoding of <span class="hlt">photonic</span> qubits. We experimentally characterize the <span class="hlt">detection</span> strategy in vacuum-single <span class="hlt">photon</span> 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 <span class="hlt">detection</span>. Our proof-of-principle experiment shows that the proposed scheme can achieve a discrimination error surpassing homodyne <span class="hlt">detection</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1362162','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1362162"><span>Time stamping of single optical <span class="hlt">photons</span> with 10 ns resolution</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Chakaberia, Irakli; Cotlet, Mircea; Fisher-Levine, Merlin</p> <p></p> <p>High spatial and temporal resolution are key features for many modern applications, e.g. mass spectrometry, probing the structure of materials via neutron scattering, studying molecular structure, etc. Fast imaging also provides the capability of coincidence <span class="hlt">detection</span>, and the further addition of sensitivity to single optical <span class="hlt">photons</span> with the capability of timestamping them further broadens the field of potential applications. Here, <span class="hlt">photon</span> counting is already widely used in X-ray imaging, where the high energy of the <span class="hlt">photons</span> makes their <span class="hlt">detection</span> easier.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1362162-time-stamping-single-optical-photons-ns-resolution','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1362162-time-stamping-single-optical-photons-ns-resolution"><span>Time stamping of single optical <span class="hlt">photons</span> with 10 ns resolution</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Chakaberia, Irakli; Cotlet, Mircea; Fisher-Levine, Merlin; ...</p> <p>2017-05-08</p> <p>High spatial and temporal resolution are key features for many modern applications, e.g. mass spectrometry, probing the structure of materials via neutron scattering, studying molecular structure, etc. Fast imaging also provides the capability of coincidence <span class="hlt">detection</span>, and the further addition of sensitivity to single optical <span class="hlt">photons</span> with the capability of timestamping them further broadens the field of potential applications. Here, <span class="hlt">photon</span> counting is already widely used in X-ray imaging, where the high energy of the <span class="hlt">photons</span> makes their <span class="hlt">detection</span> easier.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/875143','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/875143"><span>Semiconductor radiation detector with internal <span class="hlt">gain</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Iwanczyk, Jan; Patt, Bradley E.; Vilkelis, Gintas</p> <p></p> <p>An avalanche drift photodetector (ADP) incorporates extremely low capacitance of a silicon drift photodetector (SDP) and internal <span class="hlt">gain</span> that mitigates the surface leakage current noise of an avalanche photodetector (APD). The ADP can be coupled with scintillators such as CsI(Tl), NaI(Tl), LSO or others to form large volume scintillation type gamma ray detectors for gamma ray spectroscopy, <span class="hlt">photon</span> counting, gamma ray counting, etc. Arrays of the ADPs can be used to replace the photomultiplier tubes (PMTs) used in conjunction with scintillation crystals in conventional gamma cameras for nuclear medical imaging.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005PhDT........52E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005PhDT........52E"><span>Peptide backbone orientation and dynamics in spider dragline silk and two-<span class="hlt">photon</span> excitation in nuclear magnetic and quadrupole resonance</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Eles, Philip Thomas</p> <p>2005-07-01</p> <p>In the first part of the dissertation, spider dragline silk is studied by solid state NMR techniques. The dependence of NMR frequency on molecular orientation is exploited using the DECODER experiment to determine the orientation of the protein backbone within the silk fibre. Practical experimental considerations require that the silk fibres be wound about a cylindrical axis perpendicular to the external magnetic field, complicating the reconstruction of the underlying orientation distribution and necess-itating the development of numerical techniques for this purpose. A two-component model of silk incorporating static b-sheets and polyglycine II helices adequately fits the NMR data and suggests that the b-sheets are well aligned along the silk axis (20 FWHM) while the helices are poorly aligned (68 FWHM). The effects of fibre strain, draw rate and hydration on orientation are measured. Measurements of the time-scale for peptide backbone motion indicate that when wet, a strain-dependent frac-tion of the poorly aligned component becomes mobile. This suggests a mechanism for the supercontraction of silk involving latent entropic springs that undergo a local strain-dependent phase transition, driving supercontraction. In the second part of this dissertation a novel method is developed for exciting NMR and nuclear quadrupole resonance (NQR) by rf irradiation at multiple frequencies that sum to (or differ by) the resonance frequency. This is fundamentally different than traditional NMR experiments where irradiation is applied on-resonance. With excitation outside the <span class="hlt">detection</span> bandwidth, two-<span class="hlt">photon</span> excitation allows for <span class="hlt">detection</span> of free induction signals during excitation, completely eliminating receiver dead-time. A theoretical approach to describing two-<span class="hlt">photon</span> excitation is developed based on average Hamiltonian theory. An intuition for two-<span class="hlt">photon</span> excitation is <span class="hlt">gained</span> by analogy to the coherent absorption of multiple <span class="hlt">photons</span> requiring conservation of total energy and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018ApPhB.124....8W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018ApPhB.124....8W"><span><span class="hlt">Detection</span> of carbon monoxide (CO) in sooting hydrocarbon flames using femtosecond two-<span class="hlt">photon</span> laser-induced fluorescence (fs-TPLIF)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Yejun; Kulatilaka, Waruna D.</p> <p>2018-01-01</p> <p>Ultrashort-pulse, femtosecond (fs)-duration, two-<span class="hlt">photon</span> laser-induced fluorescence (fs-TPLIF) measurements of carbon monoxide (CO) are reported in rich, sooting hydrocarbon flames. CO-TPLIF <span class="hlt">detection</span> using conventional nanosecond or picosecond lasers are often plagued by photochemical interferences, specifically under fuel-rich flames conditions. In the current study, we investigate the commonly used CO two-<span class="hlt">photon</span> excitation scheme of the B1Σ+ ← X1Σ+ electronic transition, using approximately 100-fs-duration excitation pulses. Fluorescence emission was observed in the Ångström band originating from directly populated B1Σ+ upper state, as well as, in the third positive band from collisionally populated b3Σ+ upper state. The current work was focused on the Ångström band emission. Interference from nascent C2 emissions originating from hot soot particles in the flame could be reduced to a negligible level using a narrower <span class="hlt">detection</span> gate width. In contrast, avoiding interferences from laser-generated C2 Swan-band emissions required specific narrowband spectral filtering in sooting flame conditions. The observed less than quadratic laser pulse energy dependence of the TPLIF signal suggests the presence of strong three-<span class="hlt">photon</span> ionization and stimulated emission processes. In a range of CH4/air and C2H4/air premixed flames investigated, the measured CO fluorescence signals agree well with the calculated equilibrium CO number densities. Reduced-interference CO-TPLIF imaging in premixed C2H4/O2/N2 jet flames is also reported.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015SPIE.9490E..0EE','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015SPIE.9490E..0EE"><span>Multiplex <span class="hlt">detection</span> of pathogen biomarkers in human blood, serum, and saliva using silicon <span class="hlt">photonic</span> microring resonators</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Estrada, I. A.; Burlingame, R. W.; Wang, A. P.; Chawla, K.; Grove, T.; Wang, J.; Southern, S. O.; Iqbal, M.; Gunn, L. C.; Gleeson, M. A.</p> <p>2015-05-01</p> <p>Genalyte has developed a multiplex silicon <span class="hlt">photonic</span> chip diagnostics platform (MaverickTM) for rapid <span class="hlt">detection</span> of up to 32 biological analytes from a drop of sample in just 10 to 20 minutes. The chips are manufactured with waveguides adjacent to ring resonators, and probed with a continuously variable wavelength laser. A shift in the resonant wavelength as mass binds above the ring resonators is measured and is directly proportional to the amount of bound macromolecules. We present here the ability to multiplex the <span class="hlt">detection</span> of hemorrhagic fever antigens in whole blood, serum, and saliva in a 16 minute assay. Our proof of concept testing of a multiplex antigencapture chip has the ability to <span class="hlt">detect</span> Zaire Ebola (ZEBOV) recombinant soluble glycoprotein (rsGP), Marburg virus (MARV) Angola recombinant glycoprotein (rGP) and dengue nonstructural protein I (NS1). In parallel, <span class="hlt">detection</span> of 2 malaria antigens has proven successful, but has yet to be incorporated into multiplex with the others. Each assay performs with sensitivity ranging from 1.6 ng/ml to 39 ng/ml depending on the antigen <span class="hlt">detected</span>, and with minimal cross-reactivity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010PhRvA..82e3814S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010PhRvA..82e3814S"><span>Cloning entangled <span class="hlt">photons</span> to scales one can see</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sekatski, Pavel; Sanguinetti, Bruno; Pomarico, Enrico; Gisin, Nicolas; Simon, Christoph</p> <p>2010-11-01</p> <p>By amplifying <span class="hlt">photonic</span> qubits it is possible to produce states that contain enough <span class="hlt">photons</span> to be seen with the human eye, potentially bringing quantum effects to macroscopic scales [P. Sekatski, N. Brunner, C. Branciard, N. Gisin, and C. Simon, Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.103.113601 103, 113601 (2009)]. In this paper we theoretically study quantum states obtained by amplifying one side of an entangled <span class="hlt">photon</span> pair with different types of optical cloning machines for <span class="hlt">photonic</span> qubits. We propose a <span class="hlt">detection</span> scheme that involves lossy threshold detectors (such as the human eye) on the amplified side and conventional <span class="hlt">photon</span> detectors on the other side. We show that correlations obtained with such coarse-grained measurements prove the entanglement of the initial <span class="hlt">photon</span> pair and do not prove the entanglement of the amplified state. We emphasize the importance of the <span class="hlt">detection</span> loophole in Bell violation experiments by giving a simple preparation technique for separable states that violate a Bell inequality without closing this loophole. Finally, we analyze the genuine entanglement of the amplified states and its robustness to losses before, during, and after amplification.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009NIMPA.604..584P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009NIMPA.604..584P"><span><span class="hlt">Detection</span> efficiency calculation for <span class="hlt">photons</span>, electrons and positrons in a well detector. Part I: Analytical model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pommé, S.</p> <p>2009-06-01</p> <p>An analytical model is presented to calculate the total <span class="hlt">detection</span> efficiency of a well-type radiation detector for <span class="hlt">photons</span>, electrons and positrons emitted from a radioactive source at an arbitrary position inside the well. The model is well suited to treat a typical set-up with a point source or cylindrical source and vial inside a NaI well detector, with or without lead shield surrounding it. It allows for fast absolute or relative total efficiency calibrations for a wide variety of geometrical configurations and also provides accurate input for the calculation of coincidence summing effects. Depending on its accuracy, it may even be applied in 4π-γ counting, a primary standardisation method for activity. Besides an accurate account of <span class="hlt">photon</span> interactions, precautions are taken to simulate the special case of 511 keV annihilation quanta and to include realistic approximations for the range of (conversion) electrons and β -- and β +-particles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3535416','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3535416"><span>High-speed and high-efficiency travelling wave single-<span class="hlt">photon</span> detectors embedded in nanophotonic circuits</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Pernice, W.H.P.; Schuck, C.; Minaeva, O.; Li, M.; Goltsman, G.N.; Sergienko, A.V.; Tang, H.X.</p> <p>2012-01-01</p> <p>Ultrafast, high-efficiency single-<span class="hlt">photon</span> detectors are among the most sought-after elements in modern quantum optics and quantum communication. However, imperfect modal matching and finite <span class="hlt">photon</span> absorption rates have usually limited their maximum attainable <span class="hlt">detection</span> efficiency. Here we demonstrate superconducting nanowire detectors atop nanophotonic waveguides, which enable a drastic increase of the absorption length for incoming <span class="hlt">photons</span>. This allows us to achieve high on-chip single-<span class="hlt">photon</span> <span class="hlt">detection</span> 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 <span class="hlt">detection</span> efficiency. The detectors are fully embedded in scalable silicon <span class="hlt">photonic</span> circuits and provide ultrashort timing jitter of 18 ps. Exploiting this high temporal resolution, we demonstrate ballistic <span class="hlt">photon</span> transport in silicon ring resonators. Our direct implementation of a high-performance single-<span class="hlt">photon</span> detector on chip overcomes a major barrier in integrated quantum <span class="hlt">photonics</span>. PMID:23271658</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" onclick="trackOutboundLink('https://www.osti.gov/biblio/22413152-gigahertz-gated-ingaas-inp-single-photon-detector-detection-efficiency-exceeding','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22413152-gigahertz-gated-ingaas-inp-single-photon-detector-detection-efficiency-exceeding"><span>Gigahertz-gated InGaAs/InP single-<span class="hlt">photon</span> detector with <span class="hlt">detection</span> efficiency exceeding 55% at 1550 nm</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Comandar, L. C.; Engineering Department, Cambridge University, 9 J J Thomson Ave, Cambridge CB3 0FA; Fröhlich, B.</p> <p></p> <p>We report on a gated single-<span class="hlt">photon</span> detector based on InGaAs/InP avalanche photodiodes (APDs) with a single-<span class="hlt">photon</span> <span class="hlt">detection</span> 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% <span class="hlt">detection</span> 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</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20010082969&hterms=Social+media&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DSocial%2Bmedia','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20010082969&hterms=Social+media&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DSocial%2Bmedia"><span><span class="hlt">Detection</span> of Objects Hidden in Highly Scattering Media Using Time-Gated Imaging Methods</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Galland, Pierre A.; Wang, L.; Liang, X.; Ho, P. P.; Alfano, R. R.</p> <p>2000-01-01</p> <p>Non-intrusive and non-invasive optical imaging techniques has generated great interest among researchers for their potential applications to biological study, device characterization, surface defect <span class="hlt">detection</span>, and jet fuel dynamics. Non-linear optical parametric amplification gate (NLOPG) has been used to <span class="hlt">detect</span> back-scattered images of objects hidden in diluted Intralipid solutions. To directly <span class="hlt">detect</span> objects hidden in highly scattering media, the diffusive component of light needs to be sorted out from early arrived ballistic and snake <span class="hlt">photons</span>. In an optical imaging system, images are collected in transmission or back-scattered geometry. The early arrival <span class="hlt">photons</span> in the transmission approach, always carry the direct information of the hidden object embedded in the turbid medium. In the back-scattered approach, the result is not so forth coming. In the presence of a scattering host, the first arrival <span class="hlt">photons</span> in back-scattered approach will be directly <span class="hlt">photons</span> from the host material. In the presentation, NLOPG was applied to acquire time resolved back-scattered images under the phase matching condition. A time-gated amplified signal was obtained through this NLOPG process. The system's <span class="hlt">gain</span> was approximately 100 times. The time-gate was achieved through phase matching condition where only coherent <span class="hlt">photons</span> retain their phase. As a result, the diffusive <span class="hlt">photons</span>, which were the primary contributor to the background, were removed. With a large dynamic range and high resolution, time-gated early light imaging has the potential for improving rocket/aircraft design by determining jets shape and particle sizes. Refinements to these techniques may enable drop size measurements in the highly scattering, optically dense region of multi-element rocket injectors. These types of measurements should greatly enhance the design of stable, and higher performing rocket engines.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/publication/?seqNo115=232738','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/publication/?seqNo115=232738"><span>Use of Glycerol as an Optical Clearing Agent for Enhancing <span class="hlt">Photonic</span> Transference and <span class="hlt">Detection</span> of Salmonella typhimurium through Porcine Skin</span></a></p> <p><a target="_blank" href="https://www.ars.usda.gov/research/publications/find-a-publication/">USDA-ARS?s Scientific Manuscript database</a></p> <p></p> <p></p> <p>The objective of this study was to evaluate glycerol (GLY) and GLY + dimethyl sulfoxide (DMSO) to increase <span class="hlt">photonic</span> <span class="hlt">detection</span> of transformed Salmonella typhimurium (S. typh-lux) through porcine skin. Skin was placed on 96-well plates containing S. typh-lux, imaged (5 min) using a CCD camera, and the...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/publication/?seqNo115=232114','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/publication/?seqNo115=232114"><span>Use of Glycerol as an Optical Clearing Agent for Enhancing <span class="hlt">Photonic</span> Transference and <span class="hlt">Detection</span> of Salmonella typhimurium Through Porcine Skin</span></a></p> <p><a target="_blank" href="https://www.ars.usda.gov/research/publications/find-a-publication/">USDA-ARS?s Scientific Manuscript database</a></p> <p></p> <p></p> <p>The objective of this study was to evaluate glycerol (GLY) and GLY + dimethyl sulfoxide (DMSO) to increase <span class="hlt">photonic</span> <span class="hlt">detection</span> of transformed Salmonella typhimurium (S. typh-lux) through porcine skin. Skin was placed on 96-well plates containing S. typh-lux, imaged (5 min) using a CCD camera, and the...</p> </li> <li> <p><a target="_blank" 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 <span class="hlt">Photon</span> Counters as Light Detectors for Cosmic Rays</span></a></p> <p><a target="_blank" 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 <span class="hlt">detection</span>. A photomultiplier tube (PMT) was used in conjunction to <span class="hlt">detect</span> 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 <span class="hlt">photon</span> counters (MPPCs) as readout detectors. Under this configuration, a high <span class="hlt">gain</span> 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 <span class="hlt">detecting</span> weak light signals, and can be used in place of the PMT for certain counting applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018RScI...89d3707S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018RScI...89d3707S"><span>Design and characterization of a dead-time regime enhanced early <span class="hlt">photon</span> projection imaging system</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sinha, L.; Fogarty, M.; Zhou, W.; Giudice, A.; Brankov, J. G.; Tichauer, K. M.</p> <p>2018-04-01</p> <p>Scattering of visible and near-infrared light in biological tissue reduces spatial resolution for imaging of tissues thicker than 100 μm. In this study, an optical projection imaging system is presented and characterized that exploits the dead-time characteristics typical of <span class="hlt">photon</span> counting modules based on single <span class="hlt">photon</span> avalanche diodes (SPADs). With this system, it is possible to attenuate the <span class="hlt">detection</span> of more scattered late-arriving <span class="hlt">photons</span>, such that <span class="hlt">detection</span> of less scattered early-arriving <span class="hlt">photons</span> can be enhanced with increased light intensity, without being impeded by the maximum count rate of the SPADs. The system has the potential to provide transmittance-based anatomical information or fluorescence-based functional information (with slight modification in the instrumentation) of biological samples with improved resolution in the mesoscopic domain (0.1-2 cm). The system design, calibration, stability, and performance were evaluated using simulation and experimental phantom studies. The proposed system allows for the <span class="hlt">detection</span> of very-rare early-<span class="hlt">photons</span> at a higher frequency and with a better signal-to-noise ratio. The experimental results demonstrated over a 3.4-fold improvement in the spatial resolution using early <span class="hlt">photon</span> <span class="hlt">detection</span> vs. conventional <span class="hlt">detection</span>, and a 1000-fold improvement in imaging time using enhanced early <span class="hlt">detection</span> vs. conventional early <span class="hlt">photon</span> <span class="hlt">detection</span> in a 4-mm thick phantom with a tissue-equivalent absorption coefficient of μa = 0.05 mm-1 and a reduced scattering coefficient of μs' = 5 mm-1.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018SPIE10504E..0DD','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018SPIE10504E..0DD"><span>Label-free in vitro prostate cancer cell <span class="hlt">detection</span> via <span class="hlt">photonic</span>-crystal biosensor</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>DeLuna, Frank; Ding, XiaoFei; Sagredo, Ismael; Bustamante, Gilbert; Sun, Lu-Zhe; Ye, Jing Yong</p> <p>2018-02-01</p> <p>Prostate-specific antigen (PSA) biomarker assays are the current clinical method for mass screening of prostate cancer. However, high false-positive rates are often reported due to PSA's low specificity, leading to an urgent need for the development of a more specific <span class="hlt">detection</span> system independent of PSA levels. In our previous research, we demonstrated the feasibility of using cellular refractive indices (RI) as a unique contrast parameter to accomplish label-free <span class="hlt">detection</span> of prostate cancer cells via variance testing, but were unable to determine if a specific cell was cancerous or noncancerous. In this paper, we report the use of our <span class="hlt">Photonic</span>-Crystal biosensor in a Total-Internal-Reflection (PC-TIR) configuration to construct a label-free imaging system, which allows for the <span class="hlt">detection</span> of individual prostate cancer cells utilizing cellular RI as the only contrast parameter. Noncancerous prostate (BPH-1) cells and prostate cancer (PC-3) cells were mixed at varied ratios and measured concurrently. Additionally, we isolated and induced PC-3 cells to undergo epithelial-mesenchymal transition (EMT) by exposing these cells to soluble factors such as TGF-β1. The biophysical characteristics of the cellular RI were quantified extensively in comparison to non-induced PC-3 cells as well as BPH-1 cells. EMT is a crucial mechanism for the invasion and metastasis of epithelial tumors characterized by the loss of cell-cell adhesion and increased cell mobility. Our study shows promising clinical potential in utilizing the PC-TIR biosensor imaging system to not only <span class="hlt">detect</span> prostate cancer cells, but also evaluate prostate cancer progression.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22299942','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22299942"><span>A new detector for mass spectrometry: direct <span class="hlt">detection</span> of low energy ions using a multi-pixel <span class="hlt">photon</span> counter.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wilman, Edward S; Gardiner, Sara H; Nomerotski, Andrei; Turchetta, Renato; Brouard, Mark; Vallance, Claire</p> <p>2012-01-01</p> <p>A new type of ion detector for mass spectrometry and general <span class="hlt">detection</span> of low energy ions is presented. The detector consists of a scintillator optically coupled to a single-<span class="hlt">photon</span> 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 <span class="hlt">detection</span> sensitivity on the ion kinetic energy is characterised.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29291596','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29291596"><span><span class="hlt">Photonic</span> crystals on copolymer film for label-free <span class="hlt">detection</span> of DNA hybridization.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Su, Han; Cheng, Xin R; Endo, Tatsuro; Kerman, Kagan</p> <p>2018-04-30</p> <p>The presence of a single-nucleotide polymorphism in Apolipoprotein E4 gene is implicated with the increased risk of developing Alzheimer's disease (AD). In this study, <span class="hlt">detection</span> of AD-related DNA oligonucleotide sequence associated with Apolipoprotein E4 gene sequence was achieved using localized-surface plasmon resonance (LSPR) on 2D-<span class="hlt">Photonic</span> crystal (2D-PC) and Au-coated 2D-PC surfaces. 2D-PC surfaces were fabricated on a flexible copolymer film using nano-imprint lithography (NIL). The film surface was then coated with a dual-functionalized polymer to react with surface immobilized DNA probe. DNA hybridization was <span class="hlt">detected</span> by monitoring the optical responses of either a Fresnel decrease in reflectance on 2D-PC surfaces or an increase in LSPR on Au-coated 2D-PC surfaces. The change in response due to DNA hybridization on the modified surfaces was also investigated using mismatched and non-complementary oligonucleotides sequences. The proof-of-concept results are promising towards the development of 2D-PC on copolymer film surfaces as miniaturized and wearable biosensors for various diagnostic and defense applications. Copyright © 2017 Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014SPIE.9289E..17G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014SPIE.9289E..17G"><span>Lighting the way: <span class="hlt">photonics</span> leaders II (PL2) optics and <span class="hlt">photonics</span> teacher professional development</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gilchrist, Pamela O.; Hilliard-Clark, Joyce; Bowles, Tuere; Carpenter, Eric</p> <p>2014-07-01</p> <p>A sample group of nineteen teachers completed the second phase of the <span class="hlt">Photonics</span> Leaders II Optics and <span class="hlt">Photonics</span> professional development program. Participants took a basic Physics content knowledge test that was designed by a Professor of Physics. The test was completed before the teachers participated in the program and at the end of the program to gather data for statistical inquiry. Statistical studies on pre-test and post-test data indicated significant <span class="hlt">gains</span> in physics content knowledge over time, and that instructors teaching at the middle school level or only teaching one subject area scored significantly lower during the pretest. Reports from previous participants are summarized to disseminate the percentage of teachers who have incorporated at least one workshop activity and the kind of activity performed. The concerns and limitations reported by previous participants are reviewed as well.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018QS%26T....3b5008P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018QS%26T....3b5008P"><span>Tunable optical coherence tomography in the infrared range using visible <span class="hlt">photons</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Paterova, Anna V.; Yang, Hongzhi; An, Chengwu; Kalashnikov, Dmitry A.; Krivitsky, Leonid A.</p> <p>2018-04-01</p> <p>Optical coherence tomography (OCT) is an appealing technique for bio-imaging, medicine, and material analysis. For many applications, OCT in mid- and far-infrared (IR) leads to significantly more accurate results. Reported mid-IR OCT systems require light sources and photodetectors which operate in mid-IR range. These devices are expensive and need cryogenic cooling. Here, we report a proof-of-concept demonstration of a wavelength tunable IR OCT technique with <span class="hlt">detection</span> of only visible range <span class="hlt">photons</span>. Our method is based on the nonlinear interference of frequency correlated <span class="hlt">photon</span> pairs. The nonlinear crystal, introduced in the Michelson-type interferometer, generates <span class="hlt">photon</span> pairs with one <span class="hlt">photon</span> in the visible and another in the IR range. The intensity of <span class="hlt">detected</span> visible <span class="hlt">photons</span> depends on the phase and loss of IR <span class="hlt">photons</span>, which interact with the sample under study. This enables us to characterize sample properties and perform imaging in the IR range by <span class="hlt">detecting</span> visible <span class="hlt">photons</span>. The technique possesses broad wavelength tunability and yields a fair axial and lateral resolution, which can be tailored to the specific application. The work contributes to the development of versatile 3D imaging and material characterization systems working in a broad range of IR wavelengths, which do not require the use of IR-range light sources and photodetectors.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015Nanos...7.7770C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015Nanos...7.7770C"><span>Interferometric nanoporous anodic alumina <span class="hlt">photonic</span> coatings for optical sensing</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chen, Yuting; Santos, Abel; Wang, Ye; Kumeria, Tushar; Wang, Changhai; Li, Junsheng; Losic, Dusan</p> <p>2015-04-01</p> <p>Herein, we present a systematic study on the development, optical optimization and sensing applicability of colored <span class="hlt">photonic</span> coatings based on nanoporous anodic alumina films grown on aluminum substrates. These optical nanostructures, so-called distributed Bragg reflectors (NAA-DBRs), are fabricated by galvanostatic pulse anodization process, in which the current density is altered in a periodic manner in order to engineer the effective medium of the resulting <span class="hlt">photonic</span> coatings. As-prepared NAA-DBR <span class="hlt">photonic</span> coatings present brilliant interference colors on the surface of aluminum, which can be tuned at will within the UV-visible spectrum by means of the anodization profile. A broad library of NAA-DBR colors is produced by means of different anodization profiles. Then, the effective medium of these NAA-DBR <span class="hlt">photonic</span> coatings is systematically assessed in terms of optical sensitivity, low limit of <span class="hlt">detection</span> and linearity by reflectometric interference spectroscopy (RIfS) in order to optimize their nanoporous structure toward optical sensors with enhanced sensing performance. Finally, we demonstrate the applicability of these <span class="hlt">photonic</span> nanostructures as optical platforms by selectively <span class="hlt">detecting</span> gold(iii) ions in aqueous solutions. The obtained results reveal that optimized NAA-DBR <span class="hlt">photonic</span> coatings can achieve an outstanding sensing performance for gold(iii) ions, with a sensitivity of 22.16 nm μM-1, a low limit of <span class="hlt">detection</span> of 0.156 μM (i.e. 30.7 ppb) and excellent linearity within the working range (0.9983).Herein, we present a systematic study on the development, optical optimization and sensing applicability of colored <span class="hlt">photonic</span> coatings based on nanoporous anodic alumina films grown on aluminum substrates. These optical nanostructures, so-called distributed Bragg reflectors (NAA-DBRs), are fabricated by galvanostatic pulse anodization process, in which the current density is altered in a periodic manner in order to engineer the effective medium of the resulting</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26367555','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26367555"><span>Operation bandwidth optimization of <span class="hlt">photonic</span> differentiators.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yan, Siqi; Zhang, Yong; Dong, Jianji; Zheng, Aoling; Liao, Shasha; Zhou, Hailong; Wu, Zhao; Xia, Jinsong; Zhang, Xinliang</p> <p>2015-07-27</p> <p>We theoretically investigate the operation bandwidth limitation of the <span class="hlt">photonic</span> differentiator including the upper limitation, which is restrained by the device operation bandwidth and the lower limitation, which is restrained by the energy efficiency (EE) and <span class="hlt">detecting</span> noise level. Taking the silicon <span class="hlt">photonic</span> crystal L3 nano-cavity (PCN) as an example, for the first time, we experimentally demonstrate that the lower limitation of the operation bandwidth does exist and differentiators with different bandwidths have significantly different acceptable pulse width range of input signals, which are consistent to the theoretical prediction. Furthermore, we put forward a novel <span class="hlt">photonic</span> differentiator scheme employing cascaded PCNs with different Q factors, which is likely to expand the operation bandwidth range of <span class="hlt">photonic</span> differentiator dramatically.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015NIMPB.350..116G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015NIMPB.350..116G"><span>Compact quasi-monoenergetic <span class="hlt">photon</span> sources from laser-plasma accelerators for nuclear <span class="hlt">detection</span> and characterization</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Geddes, Cameron G. R.; Rykovanov, Sergey; Matlis, Nicholas H.; Steinke, Sven; Vay, Jean-Luc; Esarey, Eric H.; Ludewigt, Bernhard; Nakamura, Kei; Quiter, Brian J.; Schroeder, Carl B.; Toth, Csaba; Leemans, Wim P.</p> <p>2015-05-01</p> <p>Near-monoenergetic <span class="hlt">photon</span> sources at MeV energies offer improved sensitivity at greatly reduced dose for active interrogation, and new capabilities in treaty verification, nondestructive assay of spent nuclear fuel and emergency response. Thomson (also referred to as Compton) scattering sources are an established method to produce appropriate <span class="hlt">photon</span> beams. Applications are however restricted by the size of the required high-energy electron linac, scattering (<span class="hlt">photon</span> production) system, and shielding for disposal of the high energy electron beam. Laser-plasma accelerators (LPAs) produce GeV electron beams in centimeters, using the plasma wave driven by the radiation pressure of an intense laser. Recent LPA experiments are presented which have greatly improved beam quality and efficiency, rendering them appropriate for compact high-quality <span class="hlt">photon</span> sources based on Thomson scattering. Designs for MeV <span class="hlt">photon</span> sources utilizing the unique properties of LPAs are presented. It is shown that control of the scattering laser, including plasma guiding, can increase <span class="hlt">photon</span> production efficiency. This reduces scattering laser size and/or electron beam current requirements to scale compatible with the LPA. Lastly, the plasma structure can decelerate the electron beam after <span class="hlt">photon</span> production, reducing the size of shielding required for beam disposal. Together, these techniques provide a path to a compact <span class="hlt">photon</span> source system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27150702','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27150702"><span>Label-free optical <span class="hlt">detection</span> of C-reactive protein by nanoimprint lithography-based 2D-<span class="hlt">photonic</span> crystal film.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Endo, Tatsuro; Kajita, Hiroshi; Kawaguchi, Yukio; Kosaka, Terumasa; Himi, Toshiyuki</p> <p>2016-06-01</p> <p>The development of high-sensitive, and cost-effective novel biosensors have been strongly desired for future medical diagnostics. To develop novel biosensor, the authors focused on the specific optical characteristics of <span class="hlt">photonic</span> crystal. In this study, a label-free optical biosensor, polymer-based two-dimensional <span class="hlt">photonic</span> crystal (2D-PhC) film fabricated using nanoimprint lithography (NIL), was developed for <span class="hlt">detection</span> of C-reactive protein (CRP) in human serum. The nano-hole array constructed NIL-based 2D-PhC (hole diameter: 230 nm, distance: 230, depth: 200 nm) was fabricated on a cyclo-olefin polymer (COP) film (100 µm) using thermal NIL and required surface modifications to reduce nonspecific adsorption of target proteins. Antigen-antibody reactions on the NIL-based 2D-PhC caused changes to the surrounding refractive index, which was monitored as reflection spectrum changes in the visible region. By using surface modified 2D-PhC, the calculated <span class="hlt">detection</span> limit for CRP was 12.24 pg/mL at an extremely short reaction time (5 min) without the need for additional labeling procedures and secondary antibody. Furthermore, using the dual-functional random copolymer, CRP could be <span class="hlt">detected</span> in a pooled blood serum diluted 100× with dramatic reduction of nonspecific adsorption. From these results, the NIL-based 2D-PhC film has great potential for development of an on-site, high-sensitivity, cost-effective, label-free biosensor for medical diagnostics applications. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JASMS..28.1987A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JASMS..28.1987A"><span><span class="hlt">Gain</span> Switching for a <span class="hlt">Detection</span> System to Accommodate a Newly Developed MALDI-Based Quantification Method</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ahn, Sung Hee; Hyeon, Taeghwan; Kim, Myung Soo; Moon, Jeong Hee</p> <p>2017-09-01</p> <p>In matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF), matrix-derived ions are routinely deflected away to avoid problems with ion <span class="hlt">detection</span>. This, however, limits the use of a quantification method that utilizes the analyte-to-matrix ion abundance ratio. In this work, we will show that it is possible to measure this ratio by a minor instrumental modification of a simple form of MALDI-TOF. This involves detector <span class="hlt">gain</span> switching. [Figure not available: see fulltext.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22418369','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22418369"><span><span class="hlt">Detectivity</span> enhancement in quantum well infrared photodetectors utilizing a <span class="hlt">photonic</span> crystal slab resonator.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kalchmair, S; Gansch, R; Ahn, S I; Andrews, A M; Detz, H; Zederbauer, T; Mujagić, E; Reininger, P; Lasser, G; Schrenk, W; Strasser, G</p> <p>2012-02-27</p> <p>We characterize the performance of a quantum well infrared photodetector (QWIP), which is fabricated as a <span class="hlt">photonic</span> crystal slab (PCS) resonator. The strongest resonance of the PCS is designed to coincide with the absorption peak frequency at 7.6 µm of the QWIP. To accurately characterize the detector performance, it is illuminated by using single mode mid-infrared lasers. The strong resonant absorption enhancement yields a <span class="hlt">detectivity</span> increase of up to 20 times. This enhancement is a combined effect of increased responsivity and noise current reduction. With increasing temperature, we observe a red shift of the PCS-QWIP resonance peak of -0.055 cm(-1)/K. We attribute this effect to a refractive index change and present a model based on the revised plane wave method.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012SPIE.8233E..0QT','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012SPIE.8233E..0QT"><span><span class="hlt">Detection</span> of amino acid neurotransmitters by surface enhanced Raman scattering and hollow core <span class="hlt">photonic</span> crystal fiber</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tiwari, Vidhu S.; Khetani, Altaf; Monfared, Ali Momenpour T.; Smith, Brett; Anis, Hanan; Trudeau, Vance L.</p> <p>2012-03-01</p> <p>The present work explores the feasibility of using surface enhanced Raman scattering (SERS) for <span class="hlt">detecting</span> the neurotransmitters such as glutamate (GLU) and gamma-amino butyric acid (GABA). These amino acid neurotransmitters that respectively mediate fast excitatory and inhibitory neurotransmission in the brain, are important for neuroendocrine control, and upsets in their synthesis are also linked to epilepsy. Our SERS-based <span class="hlt">detection</span> scheme enabled the <span class="hlt">detection</span> of low amounts of GLU (10-7 M) and GABA (10-4 M). It may complement existing techniques for characterizing such kinds of neurotransmitters that include high-performance liquid chromatography (HPLC) or mass spectrography (MS). This is mainly because SERS has other advantages such as ease of sample preparation, molecular specificity and sensitivity, thus making it potentially applicable to characterization of experimental brain extracts or clinical diagnostic samples of cerebrospinal fluid and saliva. Using hollow core <span class="hlt">photonic</span> crystal fiber (HC-PCF) further enhanced the Raman signal relative to that in a standard cuvette providing sensitive <span class="hlt">detection</span> of GLU and GABA in micro-litre volume of aqueous solutions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17217242','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17217242"><span>[Antipsychotic-induced weight <span class="hlt">gain</span>--pharmacogenetic studies].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Olajossy-Hilkesberger, Luiza; Godlewska, Beata; Marmurowska-Michałowskal, Halina; Olajossy, Marcin; Landowski, Jerzy</p> <p>2006-01-01</p> <p>Drug-naive patients with schizophrenia often present metabolic abnormalities and obesity. Weight <span class="hlt">gain</span> may be the side effect of treatment with many antipsychotic drugs. Genetic effects, besides many other factors, are known to influence obesity in patients with schizophrenia treated with antipsychotics. Numerous studies of several genes' polymorphisms have been performed. -759C/T polymorphism of 5HT2C gene attracted most attention. In 5 independent studies of this polymorphism the association between T allele with the lower AP-induced weight <span class="hlt">gain</span> was <span class="hlt">detected</span>. No associations could be <span class="hlt">detected</span> between weight <span class="hlt">gain</span> and other polymorphisms of serotonergic system genes as well as histaminergic system genes. Studies of adrenergic and dopaminergic system have neither produced any unambiguous results. Analysis of the newest candidate genes (SAP-25, leptin gene) confirmed the role of genetic factors in AP-induced weight <span class="hlt">gain</span>. It is worth emphasising, that the studies have been conducted in relatively small and heterogenic groups and that various treatment strategies were used.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1999SPIE.3878..253E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999SPIE.3878..253E"><span>Finite element modeling of micromachined MEMS <span class="hlt">photon</span> devices</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Evans, Boyd M., III; Schonberger, D. W.; Datskos, Panos G.</p> <p>1999-09-01</p> <p>The technology of microelectronics that has evolved over the past half century is one of great power and sophistication and can now be extended to many applications (MEMS and MOEMS) other than electronics. An interesting application of MEMS quantum devices is the <span class="hlt">detection</span> of electromagnetic radiation. The operation principle of MEMS quantum devices is based on the photoinduced stress in semiconductors, and the <span class="hlt">photon</span> <span class="hlt">detection</span> results from the measurement of the photoinduced bending. These devices can be described as micromechanical <span class="hlt">photon</span> detectors. In this work, we have developed a technique for simulating electronic stresses using finite element analysis. We have used our technique to model the response of micromechanical <span class="hlt">photon</span> devices to external stimuli and compared these results with experimental data. Material properties, geometry, and bimaterial design play an important role in the performance of micromechanical <span class="hlt">photon</span> detectors. We have modeled these effects using finite element analysis and included the effects of bimaterial thickness coating, effective length of the device, width, and thickness.</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" onclick="trackOutboundLink('https://www.osti.gov/biblio/21180126-search-chameleon-particles-using-photon-regeneration-technique','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/21180126-search-chameleon-particles-using-photon-regeneration-technique"><span>Search for Chameleon Particles Using a <span class="hlt">Photon</span>-Regeneration Technique</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Chou, A. S.; Wester, W.; Baumbaugh, A.</p> <p>2009-01-23</p> <p>We report the first results from the GammeV search for chameleon particles, which may be created via <span class="hlt">photon-photon</span> interactions within a strong magnetic field. Chameleons are hypothesized scalar fields that could explain the dark energy problem. We implement a novel technique to create and trap the reflective particles within a jar and to <span class="hlt">detect</span> them later via their afterglow as they slowly convert back into <span class="hlt">photons</span>. These measurements provide the first experimental constraints on the couplings of chameleons to <span class="hlt">photons</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110015903','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110015903"><span>Single <span class="hlt">photon</span> <span class="hlt">detection</span> with self-quenching multiplication</span></a></p> <p><a target="_blank" 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 <span class="hlt">photon</span> 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" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA583059','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA583059"><span>Optically Pumped Atomic Rubidium Lasers: Two-<span class="hlt">Photon</span> and Exciplex Excitation Mechanisms</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2013-06-01</p> <p><span class="hlt">gain</span> is very high with <span class="hlt">photon</span> build-up times of 1−3.7 ns. Laser induced heating and subsequent condensation of alkali vapor in the heat pipe...encouragement during our time in classes, and recommendations while in the lab were invaluable. Finally, I want to thank the High Energy Laser Joint...intensity. The more non-traditional method is to use a single laser pulse to sketch out all needed energies. A <span class="hlt">photon</span> build-up time was determined from</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18999597','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18999597"><span>Joint temporal density measurements for two-<span class="hlt">photon</span> state characterization.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kuzucu, Onur; Wong, Franco N C; Kurimura, Sunao; Tovstonog, Sergey</p> <p>2008-10-10</p> <p>We demonstrate a technique for characterizing two-<span class="hlt">photon</span> quantum states based on joint temporal correlation measurements using time-resolved single-<span class="hlt">photon</span> <span class="hlt">detection</span> by femtosecond up-conversion. We measure for the first time the joint temporal density of a two-<span class="hlt">photon</span> entangled state, showing clearly the time anticorrelation of the coincident-frequency entangled <span class="hlt">photon</span> pair generated by ultrafast spontaneous parametric down-conversion under extended phase-matching conditions. The new technique enables us to manipulate the frequency entanglement by varying the down-conversion pump bandwidth to produce a nearly unentangled two-<span class="hlt">photon</span> state that is expected to yield a heralded single-<span class="hlt">photon</span> state with a purity of 0.88. The time-domain correlation technique complements existing frequency-domain measurement methods for a more complete characterization of <span class="hlt">photonic</span> entanglement.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19333355','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19333355"><span>Omnidirectional and multi-channel filtering by <span class="hlt">photonic</span> quantum wells with negative-index materials.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lin, Mi; Ouyang, Zhengbiao; Xu, Jun; Qiu, Gaoxin</p> <p>2009-03-30</p> <p>We propose a type of <span class="hlt">photonic</span> quantum well made of two different <span class="hlt">photonic</span> crystals with negative- and positive-index materials. It is demonstrated by transfer matrix method that, omnidirectional and multichannel filtering can be achieved. Resonance tunneling modes, or the multi-channel filtering modes, are found to exist when a passband of the well <span class="hlt">photonic</span> crystal is located inside the gap of the barrier <span class="hlt">photonic</span> crystals. And for each passband of the well <span class="hlt">photonic</span> crystal in the <span class="hlt">photonic</span> bandgap of the barrier <span class="hlt">photonic</span> crystal, the number of modes is the same as the number of periods in the well <span class="hlt">photonic</span> crystals. Moreover, the modes are insensitive to the incident angle from 0 to 85 degrees and the scaling of the barrier <span class="hlt">photonic</span> crystals at a certain range. Such structures are useful for all-direction receiving, sending, or linking-up of multi-channel signals in wireless-communication networks. And they can be applied in signal-<span class="hlt">detection</span> systems to enhance signal-<span class="hlt">detection</span> sensitivity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012SASS...31..177S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012SASS...31..177S"><span><span class="hlt">Photon</span> Counting - One More Time</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stanton, Richard H.</p> <p>2012-05-01</p> <p><span class="hlt">Photon</span> counting has been around for more than 60 years, and has been available to amateurs for most of that time. In most cases single <span class="hlt">photons</span> are <span class="hlt">detected</span> using photomultiplier tubes, "old technology" that became available after the Second World War. But over the last couple of decades the perfection of CCD devices has given amateurs the ability to perform accurate photometry with modest telescopes. Is there any reason to still count <span class="hlt">photons</span>? This paper discusses some of the strengths of current <span class="hlt">photon</span> counting technology, particularly relating to the search for fast optical transients. Technology advances in counters and photomultiplier modules are briefly mentioned. Illustrative data are presented including FFT analysis of bright star photometry and a technique for finding optical pulses in a large file of noisy data. This latter technique is shown to enable the discovery of a possible optical flare on the polar variable AM Her.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1997SPIE.2980..552Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1997SPIE.2980..552Z"><span>Single-molecule <span class="hlt">detection</span> by two-<span class="hlt">photon</span> excitation of fluorescence</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zander, Christoph; Brand, Leif; Eggeling, C.; Drexhage, Karl-Heinz; Seidel, Claus A. M.</p> <p>1997-05-01</p> <p>Using a mode-locked titanium: sapphire laser at 700 nm for two-<span class="hlt">photon</span> excitation we studied fluorescence bursts from individual coumarin 120 molecules in water and triacetin. Fluorescence lifetimes and multichannel scaler traces have been measured simultaneously. Due to the fact that scattered excitation light as well as Raman scattered <span class="hlt">photons</span> can be suppressed by a short-pass filter a very low background level was achieved. To identify the fluorophore by its characteristic fluorescence lifetime the time-resolved fluorescence signals were analyzed by a maximum likelihood estimator. The obtained average fluorescence lifetimes (tau) av equals 4.8 +/- 1.2 ns for coumarin 120 in water and (tau) av equals 3.3 +/- 0.6 for coumarin 120 in triacetin are in good agreement with results obtained from separate measurements at higher concentrations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SuScT..30kLT01G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SuScT..30kLT01G"><span>A miniaturized 4 K platform for superconducting infrared <span class="hlt">photon</span> counting detectors</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>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.</p> <p>2017-11-01</p> <p>We report on a miniaturized platform for superconducting infrared <span class="hlt">photon</span> counting detectors. We have implemented a fibre-coupled superconducting nanowire single <span class="hlt">photon</span> 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 <span class="hlt">detection</span> efficiency at 1310 nm wavelength at a dark count rate of 1 kHz. We have carried out compelling application demonstrations in single <span class="hlt">photon</span> depth metrology and singlet oxygen luminescence <span class="hlt">detection</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018AAS...23211904D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018AAS...23211904D"><span>Re-visiting the Amplifier <span class="hlt">Gains</span> of the HST/ACS Wide Field Channel CCDs</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Desjardins, Tyler D.; Grogin, Norman A.; ACS Team</p> <p>2018-06-01</p> <p>For the first time since HST Servicing Mission 4 (SM4) in May 2009, we present an analysis of the amplifier <span class="hlt">gains</span> of the Advanced Camera for Surveys (ACS) Wide Field Channel (WFC) CCDs. Using a series of in-flight flat-field exposures taken in November 2017 with a tungsten calibration lamp, we utilize the <span class="hlt">photon</span> transfer method to estimate the <span class="hlt">gains</span> of the WFC1 and WFC2 CCD amplifiers. We find evidence that the <span class="hlt">gains</span> of the four readout amplifiers have changed by a small, but statistically significant, 1–2% since SM4. We further present a study of historical ACS/WFC observations of the globular cluster NGC 104 (47 Tuc) in an attempt to estimate the time dependence of the <span class="hlt">gains</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011SPIE.8330E..0DC','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011SPIE.8330E..0DC"><span>Switchable multiwavelength erbium-doped <span class="hlt">photonic</span> crystal fiber ring laser based on a length of polarization-maintaining <span class="hlt">photonic</span> crystal fiber</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cheng, Jianqun; Ruan, Shuangchen</p> <p>2011-11-01</p> <p>A switchable multi-wavelength Erbium-doped <span class="hlt">photonic</span> crystal fiber (ED-PCF) ring laser based on a length of polarization-maintaining <span class="hlt">photonic</span> crystal fiber(PM-PCF) is presented and demonstrated experimentally. A segment of ED-PCF is used as linear <span class="hlt">gain</span> medium in the resonant cavity. Due to the polarization hole burning (PHB) caused by the PM-PCF and a polarization controller (PC), the laser can operate in stable dual- or triple- wavelength modes at room temperature. The optical signal-to-noise ratio (OSNR) of the laser without any wavelength-selective components is greater than 30 dB. The amplitude variations of lasing peaks in ten minutes are less than 0.26dB for two different operating modes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012SPIE.8330E..0DC','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012SPIE.8330E..0DC"><span>Switchable multiwavelength erbium-doped <span class="hlt">photonic</span> crystal fiber ring laser based on a length of polarization-maintaining <span class="hlt">photonic</span> crystal fiber</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cheng, Jianqun; Ruan, Shuangchen</p> <p>2012-03-01</p> <p>A switchable multi-wavelength Erbium-doped <span class="hlt">photonic</span> crystal fiber (ED-PCF) ring laser based on a length of polarization-maintaining <span class="hlt">photonic</span> crystal fiber(PM-PCF) is presented and demonstrated experimentally. A segment of ED-PCF is used as linear <span class="hlt">gain</span> medium in the resonant cavity. Due to the polarization hole burning (PHB) caused by the PM-PCF and a polarization controller (PC), the laser can operate in stable dual- or triple- wavelength modes at room temperature. The optical signal-to-noise ratio (OSNR) of the laser without any wavelength-selective components is greater than 30 dB. The amplitude variations of lasing peaks in ten minutes are less than 0.26dB for two different operating modes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28934853','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28934853"><span>Responsive <span class="hlt">Photonic</span> Crystal Carbohydrate Hydrogel Sensor Materials for Selective and Sensitive Lectin Protein <span class="hlt">Detection</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cai, Zhongyu; Sasmal, Aniruddha; Liu, Xinyu; Asher, Sanford A</p> <p>2017-10-27</p> <p>Lectin proteins, such as the highly toxic lectin protein, ricin, and the immunochemically important lectin, jacalin, play significant roles in many biological functions. It is highly desirable to develop a simple but efficient method to selectively <span class="hlt">detect</span> lectin proteins. Here we report the development of carbohydrate containing responsive hydrogel sensing materials for the selective <span class="hlt">detection</span> of lectin proteins. The copolymerization of a vinyl linked carbohydrate monomer with acrylamide and acrylic acid forms a carbohydrate hydrogel that shows specific "multivalent" binding to lectin proteins. The resulting carbohydrate hydrogels are attached to 2-D <span class="hlt">photonic</span> crystals (PCs) that brightly diffract visible light. This diffraction provides an optical readout that sensitively monitors the hydrogel volume. We utilize lactose, galactose, and mannose containing hydrogels to fabricate a series of 2-D PC sensors that show strong selective binding to the lectin proteins ricin, jacalin, and concanavalin A (Con A). This binding causes a carbohydrate hydrogel shrinkage which significantly shifts the diffraction wavelength. The resulting 2-D PC sensors can selectively <span class="hlt">detect</span> the lectin proteins ricin, jacalin, and Con A. These unoptimized 2-D PC hydrogel sensors show a limit of <span class="hlt">detection</span> (LoD) of 7.5 × 10 -8 M for ricin, a LoD of 2.3 × 10 -7 M for jacalin, and a LoD of 3.8 × 10 -8 M for Con A, respectively. This sensor fabrication approach may enable numerous sensors for the selective <span class="hlt">detection</span> of numerous lectin proteins.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018SuScT..31g4001H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018SuScT..31g4001H"><span>High speed superconducting nanowire single-<span class="hlt">photon</span> detector with nine interleaved nanowires</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Huang, Jia; Zhang, Weijun; You, Lixing; Zhang, Chengjun; Lv, Chaolin; Wang, Yong; Liu, Xiaoyu; Li, Hao; Wang, Zhen</p> <p>2018-07-01</p> <p>Count rate (CR) is one of the key parameters of superconducting nanowire single-<span class="hlt">photon</span> 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 <span class="hlt">photons</span>. A feasible approach to decrease the kinetic inductance and consequently increase the <span class="hlt">detection</span> 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 <span class="hlt">detection</span> efficiency (SDE) and 200 Hz dark count rate at the low-<span class="hlt">photon</span>-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 <span class="hlt">photon</span> flux of 1.26 × 1010 <span class="hlt">photons</span> s‑1 with an SDE of ∼7.4%, and a CR of 200 MHz with an SDE of over 50%. Furthermore, a <span class="hlt">photon</span> number resolvability of up to nine <span class="hlt">photons</span> was also demonstrated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26886983','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26886983"><span>On the <span class="hlt">Detectability</span> of Acoustic Waves Induced Following Irradiation by a Radiotherapy Linear Accelerator.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hickling, Susannah; Leger, Pierre; El Naqa, Issam</p> <p>2016-02-11</p> <p>Irradiating an object with a megavoltage <span class="hlt">photon</span> beam generated by a clinical radiotherapy linear accelerator (linac) induces acoustic waves through the photoacoustic effect. The <span class="hlt">detection</span> and characterization of such acoustic waves has potential applications in radiation therapy dosimetry. The purpose of this work was to <span class="hlt">gain</span> insight into the properties of such acoustic waves by simulating and experimentally <span class="hlt">detecting</span> them in a well-defined system consisting of a metal block suspended in a water tank. A novel simulation workflow was developed by combining radiotherapy Monte Carlo and acoustic wave transport simulation techniques. Different set-up parameters such as <span class="hlt">photon</span> beam energy, metal block depth, metal block width, and metal block material were varied, and the simulated and experimental acoustic waveforms showed the same relative amplitude trends and frequency variations for such setup changes. The simulation platform developed in this work can easily be extended to other irradiation situations, and will be an invaluable tool for developing a radiotherapy dosimetry system based on the <span class="hlt">detection</span> of the acoustic waves induced following linear accelerator irradiation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JInst...8P7012K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JInst...8P7012K"><span>Readout of the UFFO Slewing Mirror Telescope to <span class="hlt">detect</span> UV/optical <span class="hlt">photons</span> from Gamma-Ray Bursts</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kim, J. E.; Lim, H.; Nam, J. W.; Brandt, S.; Budtz-Jørgensen, C.; Castro-Tirado, A. J.; Chen, P.; Choi, H. S.; Grossan, B.; Huang, M. A.; Jeong, S.; Jung, A.; Kim, M. B.; Kim, S.-W.; Lee, J.; Linder, E. V.; Liu, T.-C.; Na, G. W.; Panasyuk, M. I.; Park, I. H.; Ripa, J.; Reglero, V.; Smoot, G. F.; Svertilov, S.; Vedenkin, N.; Yashin, I.</p> <p>2013-07-01</p> <p>The Slewing Mirror Telescope (SMT) was proposed for rapid response to prompt UV/optical <span class="hlt">photons</span> from Gamma-Ray Bursts (GRBs). The SMT is a key component of the Ultra-Fast Flash Observatory (UFFO)-pathfinder, which will be launched aboard the Lomonosov spacecraft at the end of 2013. The SMT utilizes a motorized mirror that slews rapidly forward to its target within a second after triggering by an X-ray coded mask camera, which makes unnecessary a reorientation of the entire spacecraft. Subsequent measurement of the UV/optical is accomplished by a 10 cm aperture Ritchey-Chrètien telescope and the focal plane detector of Intensified Charge-Coupled Device (ICCD). The ICCD is sensitive to UV/optical <span class="hlt">photons</span> of 200-650 nm in wavelength by using a UV-enhanced S20 photocathode and amplifies photoelectrons at a <span class="hlt">gain</span> of 104-106 in double Micro-Channel Plates. These <span class="hlt">photons</span> are read out by a Kodak KAI-0340 interline CCD sensor and a CCD Signal Processor with 10-bit Analog-to-Digital Converter. Various control clocks for CCD readout are implemented using a Field Programmable Gate Array (FPGA). The SMT readout is in charge of not only data acquisition, storage and transfer, but also control of the slewing mirror, the ICCD high voltage adjustments, power distribution, and system monitoring by interfacing to the UFFO-pathfinder. These functions are realized in the FPGA to minimize power consumption and to enhance processing time. The SMT readout electronics are designed and built to meet the spacecraft's constraints of power consumption, mass, and volume. The entire system is integrated with the SMT optics, as is the UFFO-pathfinder. The system has been tested and satisfies the conditions of launch and those of operation in space: those associated with shock and vibration and those associated with thermal and vacuum, respectively. In this paper, we present the SMT readout electronics: the design, construction, and performance, as well as the results of space environment test.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PhRvL.120w0502W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PhRvL.120w0502W"><span>Toward Scalable Boson Sampling with <span class="hlt">Photon</span> Loss</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Hui; Li, Wei; Jiang, Xiao; He, Y.-M.; Li, Y.-H.; Ding, X.; Chen, M.-C.; Qin, J.; Peng, C.-Z.; Schneider, C.; Kamp, M.; Zhang, W.-J.; Li, H.; You, L.-X.; Wang, Z.; Dowling, J. P.; Höfling, S.; Lu, Chao-Yang; Pan, Jian-Wei</p> <p>2018-06-01</p> <p>Boson sampling is a well-defined task that is strongly believed to be intractable for classical computers, but can be efficiently solved by a specific quantum simulator. However, an outstanding problem for large-scale experimental boson sampling is the scalability. Here we report an experiment on boson sampling with <span class="hlt">photon</span> loss, and demonstrate that boson sampling with a few <span class="hlt">photons</span> lost can increase the sampling rate. Our experiment uses a quantum-dot-micropillar single-<span class="hlt">photon</span> source demultiplexed into up to seven input ports of a 16 ×16 mode ultralow-loss <span class="hlt">photonic</span> circuit, and we <span class="hlt">detect</span> three-, four- and fivefold coincidence counts. We implement and validate lossy boson sampling with one and two <span class="hlt">photons</span> lost, and obtain sampling rates of 187, 13.6, and 0.78 kHz for five-, six-, and seven-<span class="hlt">photon</span> boson sampling with two <span class="hlt">photons</span> lost, which is 9.4, 13.9, and 18.0 times faster than the standard boson sampling, respectively. Our experiment shows an approach to significantly enhance the sampling rate of multiphoton boson sampling.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29932715','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29932715"><span>Toward Scalable Boson Sampling with <span class="hlt">Photon</span> Loss.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Hui; Li, Wei; Jiang, Xiao; He, Y-M; Li, Y-H; Ding, X; Chen, M-C; Qin, J; Peng, C-Z; Schneider, C; Kamp, M; Zhang, W-J; Li, H; You, L-X; Wang, Z; Dowling, J P; Höfling, S; Lu, Chao-Yang; Pan, Jian-Wei</p> <p>2018-06-08</p> <p>Boson sampling is a well-defined task that is strongly believed to be intractable for classical computers, but can be efficiently solved by a specific quantum simulator. However, an outstanding problem for large-scale experimental boson sampling is the scalability. Here we report an experiment on boson sampling with <span class="hlt">photon</span> loss, and demonstrate that boson sampling with a few <span class="hlt">photons</span> lost can increase the sampling rate. Our experiment uses a quantum-dot-micropillar single-<span class="hlt">photon</span> source demultiplexed into up to seven input ports of a 16×16 mode ultralow-loss <span class="hlt">photonic</span> circuit, and we <span class="hlt">detect</span> three-, four- and fivefold coincidence counts. We implement and validate lossy boson sampling with one and two <span class="hlt">photons</span> lost, and obtain sampling rates of 187, 13.6, and 0.78 kHz for five-, six-, and seven-<span class="hlt">photon</span> boson sampling with two <span class="hlt">photons</span> lost, which is 9.4, 13.9, and 18.0 times faster than the standard boson sampling, respectively. Our experiment shows an approach to significantly enhance the sampling rate of multiphoton boson sampling.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5440726','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5440726"><span>Mid-infrared coincidence measurements on twin <span class="hlt">photons</span> at room temperature</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Mancinelli, M.; Trenti, A.; Piccione, S.; Fontana, G.; Dam, J. S.; Tidemand-Lichtenberg, P.; Pedersen, C.; Pavesi, L.</p> <p>2017-01-01</p> <p>Quantum measurements using single-<span class="hlt">photon</span> 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 <span class="hlt">detection</span> of correlated single <span class="hlt">photons</span>. In the visible and near infrared wavelength ranges suitable single-<span class="hlt">photon</span> detectors do exist. However, low detector quantum efficiency or excessive noise has hampered their mid-infrared (MIR) counterpart. Fast and highly efficient single-<span class="hlt">photon</span> 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 <span class="hlt">photons</span> 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 <span class="hlt">detected</span> with low-noise silicon avalanche photodiodes without the need for cryogenic cooling. PMID:28504244</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19506621','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19506621"><span><span class="hlt">Detecting</span> <span class="hlt">photons</span> in the dark region of Laguerre-Gauss beams.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Klimov, Vasily; Bloch, Daniel; Ducloy, Martial; Rios Leite, Jose R</p> <p>2009-06-08</p> <p>We show that a <span class="hlt">photon</span> detector, sensitive to the magnetic field or to the gradient of electric field, can help to characterize the quantum properties of spatially-dependent optical fields. We discuss the excitation of an atom through magnetic dipole or electric quadrupole transitions with the <span class="hlt">photons</span> of a Bessel beam or a Laguerre-Gauss (LG) beams. These spiral beams are shown to be not true hollow beams, due to the presence of magnetic fields and gradients of electric fields on beam axis. This approach paves the way to an analysis at the quantum level of the propagating light beams having a complicated spatial structure.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5241694','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5241694"><span>Chemical bonding in aqueous hexacyano cobaltate from <span class="hlt">photon</span>- and electron-<span class="hlt">detection</span> perspectives</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Lalithambika, Sreeju Sreekantan Nair; Atak, Kaan; Seidel, Robert; Neubauer, Antje; Brandenburg, Tim; Xiao, Jie; Winter, Bernd; Aziz, Emad F.</p> <p>2017-01-01</p> <p>The electronic structure of the [Co(CN)6]3− complex dissolved in water is studied using X-ray spectroscopy techniques. By combining electron and <span class="hlt">photon</span> <span class="hlt">detection</span> methods from the solutions ionized or excited by soft X-rays we experimentally identify chemical bonding between the metal center and the CN ligand. Non-resonant photoelectron spectroscopy provides solute electron binding energies, and nitrogen 1 s and cobalt 2p resonant core-level photoelectron spectroscopy identifies overlap between metal and ligand orbitals. By probing resonances we are able to qualitatively determine the ligand versus metal character of the respective occupied and non-occupied orbitals, purely by experiment. For the same excitations we also <span class="hlt">detect</span> the emitted X-rays, yielding the complementary resonant inelastic X-ray scattering spectra. For a quantitative interpretation of the spectra, we perform theoretical electronic-structure calculations. The latter provide both orbital energies and orbital character which are found to be in good agreement with experimental energies and with experimentally inferred orbital mixing. We also report calculated X-ray absorption spectra, which in conjunction with our orbital-structure analysis, enables us to quantify various bonding interactions with a particular focus on the water-solvent – ligand interaction and the strength of π-backbonding between metal and ligand. PMID:28098216</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" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010SPIE.7746E..1PS','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010SPIE.7746E..1PS"><span><span class="hlt">Photonics</span>: how to get familiar with it</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Senderáková, Dagmar; Mesaros, Vladimir; Strba, Anton</p> <p>2010-12-01</p> <p>Year 2010 brought the 50th anniversary of laser. Our century seems to be called the <span class="hlt">photon</span>-century. Light in our lives plays both pervasive and primordial role. To describe the new role of today "interdisciplinary optics" a new term - <span class="hlt">photonics</span> appeared. The term was coined in 1967 by Pierre Aigrain, a French scientist, who defined <span class="hlt">photonics</span> as the science of the harnessing of light. <span class="hlt">Photonics</span> encompasses the generation of light, the <span class="hlt">detection</span> of light, the management of light through guidance, manipulation, and amplification, and most importantly, its utilisation for the benefit of mankind. Number of <span class="hlt">photonics</span> applications proves its importance. On one side, there is a demand for skilled people with <span class="hlt">photonics</span> training. On the other side, nearly everyone is affected by science in a way and it would be useful to have at least a basic understanding of scientific principles. However, it is not a brand-new idea, an effort to popularise new scientific achievements has still been present. The contribution is based on experience of popularising <span class="hlt">photonics</span> to high school students and attracting undergraduate University students for basis of optics via <span class="hlt">photonics</span>. The aim of it is to share and exchange experience.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013SPIE.8905E..1NC','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013SPIE.8905E..1NC"><span>Single <span class="hlt">photon</span> ranging system using two wavelengths laser and analysis of precision</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chen, Yunfei; He, Weiji; Miao, Zhuang; Gu, Guohua; Chen, Qian</p> <p>2013-09-01</p> <p>The laser ranging system based on time correlation single <span class="hlt">photon</span> counting technology and single <span class="hlt">photon</span> detector has the feature of high precision and low emergent energy etc. In this paper, we established a single <span class="hlt">photon</span> 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 <span class="hlt">photon</span> ranging system performance. The method is implemented by using two single-<span class="hlt">photon</span> 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 <span class="hlt">detection</span> time-of-flight. The <span class="hlt">detection</span> by two channels using two wavelengths will effectively improve the <span class="hlt">detection</span> precision and decrease the false alarm probability. Finally, an experimental single <span class="hlt">photon</span> 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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013ApJ...764..190A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013ApJ...764..190A"><span>Limits to the Fraction of High-energy <span class="hlt">Photon</span> Emitting Gamma-Ray Bursts</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Akerlof, Carl W.; Zheng, WeiKang</p> <p>2013-02-01</p> <p>After almost four years of operation, the two instruments on board the Fermi Gamma-ray Space Telescope have shown that the number of gamma-ray bursts (GRBs) with high-energy <span class="hlt">photon</span> emission above 100 MeV cannot exceed roughly 9% of the total number of all such events, at least at the present <span class="hlt">detection</span> limits. In a recent paper, we found that GRBs with <span class="hlt">photons</span> <span class="hlt">detected</span> in the Large Area Telescope have a surprisingly broad distribution with respect to the observed event <span class="hlt">photon</span> number. Extrapolation of our empirical fit to numbers of <span class="hlt">photons</span> below our previous <span class="hlt">detection</span> limit suggests that the overall rate of such low flux events could be estimated by standard image co-adding techniques. In this case, we have taken advantage of the excellent angular resolution of the Swift mission to provide accurate reference points for 79 GRB events which have eluded any previous correlations with high-energy <span class="hlt">photons</span>. We find a small but significant signal in the co-added field. Guided by the extrapolated power-law fit previously obtained for the number distribution of GRBs with higher fluxes, the data suggest that only a small fraction of GRBs are sources of high-energy <span class="hlt">photons</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2715267','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2715267"><span>Two-<span class="hlt">Photon</span> Imaging with Diffractive Optical Elements</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Watson, Brendon O.; Nikolenko, Volodymyr; Yuste, Rafael</p> <p>2009-01-01</p> <p>Two-<span class="hlt">photon</span> imaging has become a useful tool for optical monitoring of neural circuits, but it requires high laser power and serial scanning of each pixel in a sample. This results in slow imaging rates, limiting the measurements of fast signals such as neuronal activity. To improve the speed and signal-to-noise ratio of two-<span class="hlt">photon</span> imaging, we introduce a simple modification of a two-<span class="hlt">photon</span> microscope, using a diffractive optical element (DOE) which splits the laser beam into several beamlets that can simultaneously scan the sample. We demonstrate the advantages of DOE scanning by enhancing the speed and sensitivity of two-<span class="hlt">photon</span> calcium imaging of action potentials in neurons from neocortical brain slices. DOE scanning can easily improve the <span class="hlt">detection</span> of time-varying signals in two-<span class="hlt">photon</span> and other non-linear microscopic techniques. PMID:19636390</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25575021','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25575021"><span>Nanoantenna enhancement for telecom-wavelength superconducting single <span class="hlt">photon</span> detectors.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Heath, Robert M; Tanner, Michael G; Drysdale, Timothy D; Miki, Shigehito; Giannini, Vincenzo; Maier, Stefan A; Hadfield, Robert H</p> <p>2015-02-11</p> <p>Superconducting nanowire single <span class="hlt">photon</span> detectors are rapidly emerging as a key infrared <span class="hlt">photon</span>-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 <span class="hlt">detection</span> 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 <span class="hlt">detection</span> at longer wavelengths.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015amos.confE..94S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015amos.confE..94S"><span>High Speed Large Format <span class="hlt">Photon</span> Counting Microchannel Plate Imaging Sensors</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Siegmund, O.; Ertley, C.; Vallerga, J.; Craven, C.; Popecki, M.; O'Mahony, A.; Minot, M.</p> <p></p> <p>The development of a new class of microchannel plate technology, using atomic layer deposition (ALD) techniques applied to a borosilicate microcapillary array is enabling the implementation of larger, more stable detectors for Astronomy and remote sensing. Sealed tubes with MCPs with SuperGenII, bialkali, GaAs and GaN photocathodes have been developed to cover a wide range of optical/UV sensing applications. Formats of 18mm and 25mm circular, and 50mm (Planacon) and 20cm square have been constructed for uses from night time remote reconnaissance and biological single-molecule fluorescence lifetime imaging microscopy, to large area focal plane imagers for Astronomy, neutron <span class="hlt">detection</span> and ring imaging Cherenkov <span class="hlt">detection</span>. The large focal plane areas were previously unattainable, but the new developments in construction of ALD microchannel plates allow implementation of formats of 20cm or more. Continuing developments in ALD microchannel plates offer improved overall sealed tube lifetime and <span class="hlt">gain</span> stability, and furthermore show reduced levels of radiation induced background. High time resolution astronomical and remote sensing applications can be addressed with microchannel plate based imaging, <span class="hlt">photon</span> time tagging detector sealed tube schemes. <span class="hlt">Photon</span> counting imaging readouts for these devices vary from cross strip (XS), cross delay line (XDL), to stripline anodes, and pad arrays depending on the intended application. The XS and XDL readouts have been implemented in formats from 22mm, and 50mm to 20cm. Both use MCP charge signals <span class="hlt">detected</span> on two orthogonal layers of conductive fingers to encode event X-Y positions. XDL readout uses signal propagation delay to encode positions while XS readout uses charge cloud centroiding. Spatial resolution readout of XS detectors can be better than 20 microns FWHM, with good image linearity while using low <span class="hlt">gain</span> (<10^6), allowing high local counting rates and longer overall tube lifetime. XS tubes with electronics can encode event</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013PhDT........18J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013PhDT........18J"><span>Hybrid Silicon <span class="hlt">Photonic</span> Integration using Quantum Well Intermixing</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jain, Siddharth R.</p> <p></p> <p>With the push for faster data transfer across all domains of telecommunication, optical interconnects are transitioning into shorter range applications such as in data centers and personal computing. Silicon <span class="hlt">photonics</span>, with its economic advantages of leveraging well-established silicon manufacturing facilities, is considered the most promising approach to further scale down the cost and size of optical interconnects for chip-to-chip communication. Intrinsic properties of silicon however limit its ability to generate and modulate light, both of which are key to realizing on-chip optical data transfer. The hybrid silicon approach directly addresses this problem by using molecularly bonded III-V epitaxial layers on silicon for optical <span class="hlt">gain</span> and absorption. This technology includes direct transfer of III-V wafer to a pre-patterned silicon-on-insulator wafer. Several discrete devices for light generation, modulation, amplification and <span class="hlt">detection</span> have already been demonstrated on this platform. As in the case of electronics, multiple <span class="hlt">photonic</span> elements can be integrated on a single chip to improve performance and functionality. However, scalable <span class="hlt">photonic</span> integration requires the ability to control the bandgap for individual devices along with design changes to simplify fabrication. In the research presented here, quantum well intermixing is used as a technique to define multiple bandgaps for integration on the hybrid silicon platform. Implantation enhanced disordering is used to generate four bandgaps spread over 120+ nm. By combining these selectively intermixed III-V layers with pre-defined gratings and waveguides on silicon, we fabricate distributed feedback, distributed Bragg reflector, Fabry-Perot and mode-locked lasers along with photodetectors, electro-absorption modulators and other test structures, all on a single chip. We demonstrate a broadband laser source with continuous-wave operational lasers over a 200 nm bandwidth. Some of these lasers are integrated with</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA564598','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA564598"><span>Electrically Driven <span class="hlt">Photonic</span> Crystal Nanocavity Devices</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2012-01-01</p> <p>material, here gallium arsenide and indium arsenide self- assembled quantum dots (QDs). QDs are preferred for the <span class="hlt">gain</span> medium because they can have...blue points ) and 150 K (green points ). The black lines are linear fits to the above threshold output power of the lasers, which are used to find the...SHAMBAT et al.: ELECTRICALLY DRIVEN <span class="hlt">PHOTONIC</span> CRYSTAL NANOCAVITY DEVICES 1707 Fig. 13. (a) Tilted SEM picture of a fabricated triple cavity device. The in</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27708380','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27708380"><span>Two-<span class="hlt">photon</span> interference of temporally separated <span class="hlt">photons</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kim, Heonoh; Lee, Sang Min; Moon, Han Seb</p> <p>2016-10-06</p> <p>We present experimental demonstrations of two-<span class="hlt">photon</span> interference involving temporally separated <span class="hlt">photons</span> within two types of interferometers: a Mach-Zehnder interferometer and a polarization-based Michelson interferometer. The two-<span class="hlt">photon</span> states are probabilistically prepared in a symmetrically superposed state within the two interferometer arms by introducing a large time delay between two input <span class="hlt">photons</span>; this state is composed of two temporally separated <span class="hlt">photons</span>, which are in two different or the same spatial modes. We then observe two-<span class="hlt">photon</span> interference fringes involving both the Hong-Ou-Mandel interference effect and the interference of path-entangled two-<span class="hlt">photon</span> states simultaneously in a single interferometric setup. The observed two-<span class="hlt">photon</span> interference fringes provide simultaneous observation of the interferometric properties of the single-<span class="hlt">photon</span> and two-<span class="hlt">photon</span> wavepackets. The observations can also facilitate a more comprehensive understanding of the origins of the interference phenomena arising from spatially bunched/anti-bunched two-<span class="hlt">photon</span> states comprised of two temporally separated <span class="hlt">photons</span> within the interferometer arms.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5052585','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5052585"><span>Two-<span class="hlt">photon</span> interference of temporally separated <span class="hlt">photons</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Kim, Heonoh; Lee, Sang Min; Moon, Han Seb</p> <p>2016-01-01</p> <p>We present experimental demonstrations of two-<span class="hlt">photon</span> interference involving temporally separated <span class="hlt">photons</span> within two types of interferometers: a Mach-Zehnder interferometer and a polarization-based Michelson interferometer. The two-<span class="hlt">photon</span> states are probabilistically prepared in a symmetrically superposed state within the two interferometer arms by introducing a large time delay between two input <span class="hlt">photons</span>; this state is composed of two temporally separated <span class="hlt">photons</span>, which are in two different or the same spatial modes. We then observe two-<span class="hlt">photon</span> interference fringes involving both the Hong-Ou-Mandel interference effect and the interference of path-entangled two-<span class="hlt">photon</span> states simultaneously in a single interferometric setup. The observed two-<span class="hlt">photon</span> interference fringes provide simultaneous observation of the interferometric properties of the single-<span class="hlt">photon</span> and two-<span class="hlt">photon</span> wavepackets. The observations can also facilitate a more comprehensive understanding of the origins of the interference phenomena arising from spatially bunched/anti-bunched two-<span class="hlt">photon</span> states comprised of two temporally separated <span class="hlt">photons</span> within the interferometer arms. PMID:27708380</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24322098','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24322098"><span>Hybrid single quantum well InP/Si nanobeam lasers for silicon <span class="hlt">photonics</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Fegadolli, William S; Kim, Se-Heon; Postigo, Pablo Aitor; Scherer, Axel</p> <p>2013-11-15</p> <p>We report on a hybrid InP/Si <span class="hlt">photonic</span> crystal nanobeam laser emitting at 1578 nm with a low threshold power of ~14.7 μW. Laser <span class="hlt">gain</span> is provided from a single InAsP quantum well embedded in a 155 nm InP layer bonded on a standard silicon-on-insulator wafer. This miniaturized nanolaser, with an extremely small modal volume of 0.375(λ/n)(3), is a promising and efficient light source for silicon <span class="hlt">photonics</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19960025059','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19960025059"><span>Quantum Probability Cancellation Due to a Single-<span class="hlt">Photon</span> State</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ou, Z. Y.</p> <p>1996-01-01</p> <p>When an N-<span class="hlt">photon</span> state enters a lossless symmetric beamsplitter from one input port, the <span class="hlt">photon</span> distribution for the two output ports has the form of Bernouli Binormial, with highest probability at equal partition (N/2 at one outport and N/2 at the other). However, injection of a single <span class="hlt">photon</span> state at the other input port can dramatically change the <span class="hlt">photon</span> distribution at the outputs, resulting in zero probability at equal partition. Such a strong deviation from classical particle theory stems from quantum probability amplitude cancellation. The effect persists even if the N-<span class="hlt">photon</span> state is replaced by an arbitrary state of light. A special case is the coherent state which corresponds to homodyne <span class="hlt">detection</span> of a single <span class="hlt">photon</span> state and can lead to the measurement of the wave function of a single <span class="hlt">photon</span> state.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/14361','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/14361"><span>Finite Element Modeling of Micromachined MEMS <span class="hlt">Photon</span> Devices</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Datskos, P.G.; Evans, B.M.; Schonberger, D.</p> <p>1999-09-20</p> <p>The technology of microelectronics that has evolved over the past half century is one of great power and sophistication and can now be extended to many applications (MEMS and MOEMS) other than electronics. An interesting application of MEMS quantum devices is the <span class="hlt">detection</span> of electromagnetic radiation. The operation principle of MEMS quantum devices is based on the photoinduced stress in semiconductors, and the <span class="hlt">photon</span> <span class="hlt">detection</span> results from the measurement of the photoinduced bending. These devices can be described as micromechanical <span class="hlt">photon</span> detectors. In this work, we have developed a technique for simulating electronic stresses using finite element analysis. We havemore » used our technique to model the response of micromechanical <span class="hlt">photon</span> devices to external stimuli and compared these results with experimental data. Material properties, geometry, and bimaterial design play an important role in the performance of micromechanical <span class="hlt">photon</span> detectors. We have modeled these effects using finite element analysis and included the effects of bimaterial thickness coating, effective length of the device, width, and thickness.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22608315-data-analysis-photon-beam-position-pls-ii','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22608315-data-analysis-photon-beam-position-pls-ii"><span>Data analysis of <span class="hlt">photon</span> beam position at PLS-II</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Ko, J.; Shin, S., E-mail: tlssh@postech.ac.kr; Huang, Jung-Yun</p> <p></p> <p>In the third generation light source, <span class="hlt">photon</span> beam position stability is critical issue on user experiment. Generally <span class="hlt">photon</span> beam position monitors have been developed for the <span class="hlt">detection</span> of the real <span class="hlt">photon</span> beam position and the position is controlled by feedback system in order to keep the reference <span class="hlt">photon</span> beam position. In the PLS-II, <span class="hlt">photon</span> beam position stability for front end of particular beam line, in which <span class="hlt">photon</span> beam position monitor is installed, has been obtained less than rms 1μm for user service period. Nevertheless, detail analysis for <span class="hlt">photon</span> beam position data in order to demonstrate the performance of <span class="hlt">photon</span> beammore » position monitor is necessary, since it can be suffers from various unknown noises. (for instance, a back ground contamination due to upstream or downstream dipole radiation, undulator gap dependence, etc.) In this paper, we will describe the start to end study for <span class="hlt">photon</span> beam position stability and the Singular Value Decomposition (SVD) analysis to demonstrate the reliability on <span class="hlt">photon</span> beam position data.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA586519','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA586519"><span>Research Studies on <span class="hlt">Photons</span> and Biphotons</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2013-10-01</p> <p>harmonic transmit through the crystal . Scattered <span class="hlt">photons</span> are <span class="hlt">detected</span> by a YAP:Ce scintillation detector with energy resolution of 30. We choose to phase...counts as a function of <span class="hlt">photon</span> energy is shown in Fig. 2a at full intensity (no filter before the diamond crystal ) and at the peak of the phase matching...are generated in the crystal or due to elastic scattering from the residual harmonic content in the incident beam. The absorption coefficients for Al</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5021450','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5021450"><span>Recent Advances in Biosensing With <span class="hlt">Photonic</span> Crystal Surfaces: A Review</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Cunningham, B.T.; Zhang, M.; Zhuo, Y.; Kwon, L.; Race, C.</p> <p>2016-01-01</p> <p><span class="hlt">Photonic</span> crystal surfaces that are designed to function as wavelength-selective optical resonators have become a widely adopted platform for label-free biosensing, and for enhancement of the output of <span class="hlt">photon</span>-emitting tags used throughout life science research and in vitro diagnostics. While some applications, such as analysis of drug-protein interactions, require extremely high resolution and the ability to accurately correct for measurement artifacts, others require sensitivity that is high enough for <span class="hlt">detection</span> of disease biomarkers in serum with concentrations less than 1 pg/ml. As the analysis of cells becomes increasingly important for studying the behavior of stem cells, cancer cells, and biofilms under a variety of conditions, approaches that enable high resolution imaging of live cells without cytotoxic stains or photobleachable fluorescent dyes are providing new tools to biologists who seek to observe individual cells over extended time periods. This paper will review several recent advances in <span class="hlt">photonic</span> crystal biosensor <span class="hlt">detection</span> instrumentation and device structures that are being applied towards direct <span class="hlt">detection</span> of small molecules in the context of high throughput drug screening, <span class="hlt">photonic</span> crystal fluorescence enhancement as utilized for high sensitivity multiplexed cancer biomarker <span class="hlt">detection</span>, and label-free high resolution imaging of cells and individual nanoparticles as a new tool for life science research and single-molecule diagnostics. PMID:27642265</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JInst..12C2055S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JInst..12C2055S"><span>Double <span class="hlt">Photon</span> Emission Coincidence Imaging using GAGG-SiPM pixel detectors</span></a></p> <p><a target="_blank" 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 <span class="hlt">photon</span> emission computed tomography(SPECT) is a useful medical imaging modality using single <span class="hlt">photon</span> <span class="hlt">detection</span> 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 <span class="hlt">Photon</span> Emission CT / DPECT) using a coincidence <span class="hlt">detection</span> 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 <span class="hlt">photons</span> of 171 keV and 245 keV with a short delay of approximately 85 ns. The coincidence <span class="hlt">detection</span> of two gamma-rays theoretically determines the position in a single point compared with a line in single <span class="hlt">photon</span> <span class="hlt">detection</span> 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 <span class="hlt">detected</span> 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 <span class="hlt">detected</span> and used for making back-projection image. The basic principle of DPECT is characterized including the <span class="hlt">detection</span> efficiency and timing resolution.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19997259','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19997259"><span>Electrically controllable <span class="hlt">photonic</span> molecule laser.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Fasching, G; Deutsch, Ch; Benz, A; Andrews, A M; Klang, P; Zobl, R; Schrenk, W; Strasser, G; Ragulis, P; Tamosiūnas, V; Unterrainer, K</p> <p>2009-10-26</p> <p>We have studied the coherent intercavity coupling of the evanescent fields of two microdisk terahertz quantum-cascade lasers. The electrically controllable optical coupling of the single-mode operating lasers has been observed for cavity spacings up to 30 mum. The strongest coupled <span class="hlt">photonic</span> molecule with 2 mum intercavity spacing allows to conditionally switch the optical emission by the electrical modulation of only one microdisk. The lasing threshold characteristics demonstrate the linear dependence of the <span class="hlt">gain</span> of a quantum-cascade laser on the applied electric field.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017APS..MARY31009W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017APS..MARY31009W"><span>Critical Current Statistics of a Graphene-Based Josephson Junction Infrared Single <span class="hlt">Photon</span> Detector</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>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</p> <p></p> <p>Graphene is a promising material for single <span class="hlt">photon</span> <span class="hlt">detection</span> due to its broadband absorption and exceptionally low specific heat. We present a <span class="hlt">photon</span> detector using a graphene sheet as the weak link in a Josephson junction (JJ) to form a threshold detector for single infrared <span class="hlt">photons</span>. 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 <span class="hlt">photon</span> <span class="hlt">detection</span> 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 <span class="hlt">photon</span> flux.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014APS..DNP.GB140B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014APS..DNP.GB140B"><span>Experimental Setup and Commissioning of a Test Facility for <span class="hlt">Gain</span> Evaluation of Microchannel-Plate Photomultipliers in High Magnetic Field at Jefferson Lab</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bringley, Eric; Cao, Tongtong; Ilieva, Yordonka; Nadel-Turonski, Pawel; Park, Kijun; Zorn, Carl</p> <p>2014-09-01</p> <p>At the Thomas Jefferson National Accelerator Facility (JLab) a research and development project for a Detector of Internally-Reflected Cherenkov light for the upcoming Electron Ion Collider is underway. One goal is the development of a compact readout camera that can operate in high magnetic fields. Small-size <span class="hlt">photon</span> sensors, such as Microchannel-Plate Photomultipliers (MCP-PMT), are key components of the readout. Here we present our work to set up and commission a dedicated test facility at JLab where MCP-PMT <span class="hlt">gain</span> is evaluated in magnetic fields of up to 5 T, and to develop a test procedure and analysis software to determine the <span class="hlt">gain</span>. We operate the setup in a single-<span class="hlt">photon</span> mode, where a light-emitting diode delivers <span class="hlt">photons</span> to the sensor's photocathode. The PMT spectrum is measured with a flash Analog-to-Digital converter (fADC). We model the spectrum as a sum of an exponential background and a convolution of Poisson and Gaussian distributions of the pedestal and multiple photoelectron peaks, respectively. We determine the PMT's <span class="hlt">gain</span> from the position of the single-photoelectron peak obtained by fitting the fADC spectrum to the model. Our <span class="hlt">gain</span> uncertainty is <10%. The facility is now established and will have a long-lasting value for sensor tests and beyond-nuclear-physics applications.</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" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007NIMPB.261..326J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007NIMPB.261..326J"><span>High-energy <span class="hlt">photon</span> interrogation for nonproliferation applications</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jones, J. L.; Blackburn, B. W.; Watson, S. M.; Norman, D. R.; Hunt, A. W.</p> <p>2007-08-01</p> <p>There is an immediate need for technologies that can successfully address homeland security challenges related to the inspection of commercial rail, air and maritime-cargo container inspections for nuclear and radiological devices. The pulsed photonuclear assessment (PPA) technology, developed through collaboration between Idaho National Laboratory (INL), Los Alamos National Laboratory (LANL) and the Idaho Accelerator Center (IAC) has demonstrated the ability to <span class="hlt">detect</span> shielded/unshielded nuclear material primarily through the analysis of delayed neutrons and gamma-rays produced via photonuclear reactions. Because of current food irradiation limitations, however, most active <span class="hlt">photon</span> (i.e. bremsstrahlung) interrogation studies have been performed with electron beam energies at or below 10 MeV. While this energy limit currently applies to cargo inspections, the World Health Organization has indicated that higher energy electron beam operations could be considered for future operations. Clinical applications using <span class="hlt">photon</span> energies well in excess of 10 MeV are already well established. Notwithstanding the current limitation of 10 MeV, there is a definite advantage in using higher <span class="hlt">photon</span> energies for cargo inspections. At higher energies, several phenomena contribute to increased sensitivity in regards to <span class="hlt">detecting</span> shielded nuclear material. Two of the most important are: (1) increased ability for source <span class="hlt">photons</span> to penetrate shielding; and (2) enhanced signature production via increased (γ,n) and (γ,f) cross-sections in materials such as 235U and 239Pu directly leading to faster inspection throughput. Experimental assessments have been conducted for various electron beam energies from 8 to 25 MeV. Increases of up to three orders of magnitude in delayed signatures have been measured over these energy ranges. Through the continued investigation into PPA-based inspection applications using <span class="hlt">photon</span> energies greater than 10 MeV, higher <span class="hlt">detection</span> sensitivities with potentially</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/20717808-discharge-pumped-cw-gas-lasers-utilizing-dressed-atom-gain-media','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/20717808-discharge-pumped-cw-gas-lasers-utilizing-dressed-atom-gain-media"><span>Discharge-pumped cw gas lasers utilizing 'dressed-atom' <span class="hlt">gain</span> media</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Sorokin, P.P.; Glownia, J.H.; Hodgson, R.T.</p> <p></p> <p>The possibility of realizing an efficient gaseous laser-beam-generating medium that utilizes {lambda}-type coherently phased (i.e., 'dressed') atoms for the active laser species, but that does not inherently require the use of external laser beams for pumping, is explored. Specifically, it is investigated if multiphoton stimulated hyper-Raman scattering (SHRS) processes driven by fluorescence radiation generated in a continuous electrical discharge present within the vapor-containing cell could produce continuous-wave (cw) optical <span class="hlt">gain</span> at the {lambda}-atom resonance frequencies {omega}{sub o} and {omega}{sub o}{sup '}. It is deduced that such <span class="hlt">gain</span> could result from n-<span class="hlt">photon</span> (n{>=}4) SHRS processes only if absorption of fluorescence pumpmore » light occurs in the first three transitions of the n-<span class="hlt">photon</span> sequence representing the process unit step. Estimates of the amount of optical <span class="hlt">gain</span> that could be produced in such a system indicate that it should be sufficient to allow multiwatt cw laser operation to occur on one set of {lambda} transitions connecting levels in a 'double-{lambda}' structure, with the pump light being discharge-produced fluorescence centered about the transitions of the other {lambda} pair. However, to initiate operation of such a device would require injection into the laser optical cavity of intense 'starter' laser pulses at both lasing frequencies. What should be an optimal experimental configuration for determining feasibility of the proposed laser device is described. In the suggested configuration, Cs-atom 6S{sub 1/2}-6P{sub 1/2} transitions form the double-{lambda} structure.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20040111394&hterms=ultrafast&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dultrafast','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20040111394&hterms=ultrafast&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dultrafast"><span>Two-<span class="hlt">Photon</span> Flow Cytometry</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Zhog, Cheng Frank; Ye, Jing Yong; Norris, Theodore B.; Myc, Andrzej; Cao, Zhengyl; Bielinska, Anna; Thomas, Thommey; Baker, James R., Jr.</p> <p>2004-01-01</p> <p>Flow cytometry is a powerful technique for obtaining quantitative information from fluorescence in cells. Quantitation is achieved by assuring a high degree of uniformity in the optical excitation and <span class="hlt">detection</span>, generally by using a highly controlled flow such as is obtained via hydrodynamic focusing. In this work, we demonstrate a two-beam, two- channel <span class="hlt">detection</span> and two-<span class="hlt">photon</span> excitation flow cytometry (T(sup 3)FC) system that enables multi-dye analysis to be performed very simply, with greatly relaxed requirements on the fluid flow. Two-<span class="hlt">photon</span> excitation using a femtosecond near-infrared (NIR) laser has the advantages that it enables simultaneous excitation of multiple dyes and achieves very high signal-to-noise ratio through simplified filtering and fluorescence background reduction. By matching the excitation volume to the size of a cell, single-cell <span class="hlt">detection</span> is ensured. Labeling of cells by targeted nanoparticles with multiple fluorophores enables normalization of the fluorescence signal and thus ratiometric measurements under nonuniform excitation. Quantitative size measurements can also be done even under conditions of nonuniform flow via a two-beam layout. This innovative <span class="hlt">detection</span> scheme not only considerably simplifies the fluid flow system and the excitation and collection optics, it opens the way to quantitative cytometry in simple and compact microfluidics systems, or in vivo. Real-time <span class="hlt">detection</span> of fluorescent microbeads in the vasculature of mouse ear demonstrates the ability to do flow cytometry in vivo. The conditions required to perform quantitative in vivo cytometry on labeled cells will be presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008PhDT.......162K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008PhDT.......162K"><span>Fiber based <span class="hlt">photonic</span>-crystal acoustic sensor</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kilic, Onur</p> <p></p> <p><span class="hlt">Photonic</span>-crystal slabs are two-dimensional <span class="hlt">photonic</span> crystals etched into a dielectric layer such as silicon. Standard micro fabrication techniques can be employed to manufacture these structures, which makes it feasible to produce them in large areas, usually an important criterion for practical applications. An appealing feature of these structures is that they can be employed as free-space optical devices such as broadband reflectors. The small thickness of the slab (usually in the vicinity of half a micron) also makes it deflectable. These combined optical and mechanical properties make it possible to employ <span class="hlt">photonic</span>-crystal slabs in a range of practical applications, including displacement sensors, which in turn can be used for example to <span class="hlt">detect</span> acoustic waves. An additional benefit of employing a <span class="hlt">photonic</span>-crystal slab is that it is possible to tailor its optical and mechanical properties by adjusting the geometrical parameters of the structure such as hole radius or shape, pitch, and the slab thickness. By altering the hole radius and pitch, it is possible to make broadband reflectors or sharp transmission filters out of these structures. Adjusting the thickness also affects its deformability, making it possible to make broadband mirrors compliant to acoustic waves. Altering the hole shape, for example by introducing an asymmetry, extends the functionalities of <span class="hlt">photonic</span>-crystal slabs even further. Breaking the symmetry by introducing asymmetric holes enables polarization-sensitive devices such as retarders, polarization beam splitters, and <span class="hlt">photonic</span> crystals with additional non-degenerate resonances useful for increased sensitivity in sensors. All these practical advantages of <span class="hlt">photonic</span>-crystal slabs makes them suitable as key components in micromachined sensor applications. We report one such example of an application of <span class="hlt">photonic</span>-crystal slabs in the form of a micromachined acoustic sensor. It consists of a Fabry-Perot interferometer made of a <span class="hlt">photonic</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvA..96f3832L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvA..96f3832L"><span>Single-<span class="hlt">photon</span> superradiant beating from a Doppler-broadened ladder-type atomic ensemble</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lee, Yoon-Seok; Lee, Sang Min; Kim, Heonoh; Moon, Han Seb</p> <p>2017-12-01</p> <p>We report on heralded-single-<span class="hlt">photon</span> superradiant beating in the spontaneous four-wave mixing process of Doppler-broadened ladder-type 87Rb atoms. When Doppler-broadened atoms contribute to two-<span class="hlt">photon</span> coherence, the <span class="hlt">detection</span> probability amplitudes of the heralded single <span class="hlt">photons</span> are coherently superposed despite inhomogeneous broadened atomic media. Single-<span class="hlt">photon</span> superradiant beating is observed, which constitutes evidence for the coherent superposition of two-<span class="hlt">photon</span> amplitudes from different velocity classes in the Doppler-broadened atomic ensemble. We present a theoretical model in which the single-<span class="hlt">photon</span> superradiant beating originates from the interference between wavelength-separated two-<span class="hlt">photon</span> amplitudes via the reabsorption filtering effect.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22714227','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22714227"><span>Enhanced chemiluminescent <span class="hlt">detection</span> scheme for trace vapor sensing in pneumatically-tuned hollow core <span class="hlt">photonic</span> bandgap fibers.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Stolyarov, Alexander M; Gumennik, Alexander; McDaniel, William; Shapira, Ofer; Schell, Brent; Sorin, Fabien; Kuriki, Ken; Benoit, Gilles; Rose, Aimee; Joannopoulos, John D; Fink, Yoel</p> <p>2012-05-21</p> <p>We demonstrate an in-fiber gas phase chemical <span class="hlt">detection</span> architecture in which a chemiluminescent (CL) reaction is spatially and spectrally matched to the core modes of hollow <span class="hlt">photonic</span> bandgap (PBG) fibers in order to enhance <span class="hlt">detection</span> efficiency. A peroxide-sensitive CL material is annularly shaped and centered within the fiber's hollow core, thereby increasing the overlap between the emission intensity and the intensity distribution of the low-loss fiber modes. This configuration improves the sensitivity by 0.9 dB/cm compared to coating the material directly on the inner fiber surface, where coupling to both higher loss core modes and cladding modes is enhanced. By integrating the former configuration with a custom-built optofluidic system designed for concomitant controlled vapor delivery and emission measurement, we achieve a limit-of-<span class="hlt">detection</span> of 100 parts per billion (ppb) for hydrogen peroxide vapor. The PBG fibers are produced by a new fabrication method whereby external gas pressure is used as a control knob to actively tune the transmission bandgaps through the entire visible range during the thermal drawing process.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20150008322&hterms=photon&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dphoton','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20150008322&hterms=photon&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dphoton"><span>Negative Avalanche Feedback Detectors for <span class="hlt">Photon</span>-Counting Optical Communications</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Farr, William H.</p> <p>2009-01-01</p> <p>Negative Avalanche Feedback <span class="hlt">photon</span> 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 <span class="hlt">photon</span> counting without requiring any external reset circuitry and may even be operated at room temperature. We have now characterized the <span class="hlt">detection</span> efficiency, dark count rate, after-pulsing, and single <span class="hlt">photon</span> jitter for three variants of this new detector class, as well as operated these uniquely simple to use devices in actual <span class="hlt">photon</span> starved free space optical communications links.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28335436','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28335436"><span><span class="hlt">Photonic</span> Low Cost Micro-Sensor for in-Line Wear Particle <span class="hlt">Detection</span> in Flowing Lube Oils.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mabe, Jon; Zubia, Joseba; Gorritxategi, Eneko</p> <p>2017-03-14</p> <p>The presence of microscopic particles in suspension in industrial fluids is often an early warning of latent or imminent failures in the equipment or processes where they are being used. This manuscript describes work undertaken to integrate different <span class="hlt">photonic</span> principles with a micro- mechanical fluidic structure and an embedded processor to develop a fully autonomous wear debris sensor for in-line monitoring of industrial fluids. Lens-less microscopy, stroboscopic illumination, a CMOS imager and embedded machine vision technologies have been merged to develop a sensor solution that is able to <span class="hlt">detect</span> and quantify the number and size of micrometric particles suspended in a continuous flow of a fluid. A laboratory test-bench has been arranged for setting up the configuration of the optical components targeting a static oil sample and then a sensor prototype has been developed for migrating the measurement principles to real conditions in terms of operating pressure and flow rate of the oil. Imaging performance is quantified using micro calibrated samples, as well as by measuring real used lubricated oils. Sampling a large fluid volume with a decent 2D spatial resolution, this <span class="hlt">photonic</span> micro sensor offers a powerful tool at very low cost and compacted size for in-line wear debris monitoring.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5375872','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5375872"><span><span class="hlt">Photonic</span> Low Cost Micro-Sensor for in-Line Wear Particle <span class="hlt">Detection</span> in Flowing Lube Oils</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Mabe, Jon; Zubia, Joseba; Gorritxategi, Eneko</p> <p>2017-01-01</p> <p>The presence of microscopic particles in suspension in industrial fluids is often an early warning of latent or imminent failures in the equipment or processes where they are being used. This manuscript describes work undertaken to integrate different <span class="hlt">photonic</span> principles with a micro- mechanical fluidic structure and an embedded processor to develop a fully autonomous wear debris sensor for in-line monitoring of industrial fluids. Lens-less microscopy, stroboscopic illumination, a CMOS imager and embedded machine vision technologies have been merged to develop a sensor solution that is able to <span class="hlt">detect</span> and quantify the number and size of micrometric particles suspended in a continuous flow of a fluid. A laboratory test-bench has been arranged for setting up the configuration of the optical components targeting a static oil sample and then a sensor prototype has been developed for migrating the measurement principles to real conditions in terms of operating pressure and flow rate of the oil. Imaging performance is quantified using micro calibrated samples, as well as by measuring real used lubricated oils. Sampling a large fluid volume with a decent 2D spatial resolution, this <span class="hlt">photonic</span> micro sensor offers a powerful tool at very low cost and compacted size for in-line wear debris monitoring. PMID:28335436</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27386511','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27386511"><span>Optical π phase shift created with a single-<span class="hlt">photon</span> pulse.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tiarks, Daniel; Schmidt, Steffen; Rempe, Gerhard; Dürr, Stephan</p> <p>2016-04-01</p> <p>A deterministic <span class="hlt">photon-photon</span> quantum logic gate is a long-standing goal. Building such a gate becomes possible if a light pulse containing only one <span class="hlt">photon</span> imprints a phase shift of π onto another light field. We experimentally demonstrate the generation of such a π phase shift with a single-<span class="hlt">photon</span> pulse. A first light pulse containing less than one <span class="hlt">photon</span> on average is stored in an atomic gas. Rydberg blockade combined with electromagnetically induced transparency creates a phase shift for a second light pulse, which propagates through the medium. We measure the π phase shift of the second pulse when we postselect the data upon the <span class="hlt">detection</span> of a retrieved <span class="hlt">photon</span> from the first pulse. This demonstrates a crucial step toward a <span class="hlt">photon-photon</span> gate and offers a variety of applications in the field of quantum information processing.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PhRvB..97b0302D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PhRvB..97b0302D"><span>Understanding <span class="hlt">photon</span> sideband statistics and correlation for determining phonon coherence</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ding, Ding; Yin, Xiaobo; Li, Baowen</p> <p>2018-01-01</p> <p>Generating and <span class="hlt">detecting</span> coherent high-frequency heat-carrying phonons have been topics of great interest in recent years. Although there have been successful attempts in generating and observing coherent phonons, rigorous techniques to characterize and <span class="hlt">detect</span> phonon coherence in a crystalline material have been lagging compared to what has been achieved for <span class="hlt">photons</span>. One main challenge is a lack of detailed understanding of how <span class="hlt">detection</span> signals for phonons can be related to coherence. The quantum theory of photoelectric <span class="hlt">detection</span> has greatly advanced the ability to characterize <span class="hlt">photon</span> coherence in the past century, and a similar theory for phonon <span class="hlt">detection</span> is necessary. Here, we reexamine the optical sideband fluorescence technique that has been used to <span class="hlt">detect</span> high-frequency phonons in materials with optically active defects. We propose a quantum theory of phonon <span class="hlt">detection</span> using the sideband technique and found that there are distinct differences in sideband counting statistics between thermal and coherent phonons. We further propose a second-order correlation function unique to sideband signals that allows for a rigorous distinction between thermal and coherent phonons. Our theory is relevant to a correlation measurement with nontrivial response functions at the quantum level and can potentially bridge the gap of experimentally determining phonon coherence to be on par with that of <span class="hlt">photons</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28789326','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28789326"><span>Optimal design of similariton fiber lasers without <span class="hlt">gain</span>-bandwidth limitation.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Li, Xingliang; Zhang, Shumin; Yang, Zhenjun</p> <p>2017-07-24</p> <p>We have numerically investigated broadband high-energy similariton fiber lasers, demonstrated that the self-similar evolution of pulses can locate in a segment of <span class="hlt">photonic</span> crystal fiber without <span class="hlt">gain</span>-bandwidth limitation. The effects of various parameters, including the cavity length, the spectral filter bandwidth, the pump power, the length of the <span class="hlt">photonic</span> crystal fiber and the output coupling ratio have also been studied in detail. Using the optimal parameters, a single pulse with spectral width of 186.6 nm, pulse energy of 23.8 nJ, dechirped pulse duration of 22.5 fs and dechirped pulse peak power of 1.26 MW was obtained. We believe that this detailed analysis of the behaviour of pulses in the similariton regime may have major implications in the development of broadband high-energy fiber lasers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhDT........15C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhDT........15C"><span>A Microwave <span class="hlt">Photonic</span> Interference Canceller: Architectures, Systems, and Integration</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chang, Matthew P.</p> <p></p> <p>This thesis is a comprehensive portfolio of work on a Microwave <span class="hlt">Photonic</span> Self-Interference Canceller (MPC), a specialized optical system designed to eliminate interference from radio-frequency (RF) receivers. The novelty and value of the microwave <span class="hlt">photonic</span> system lies in its ability to operate over bandwidths and frequencies that are orders of magnitude larger than what is possible using existing RF technology. The work begins, in 2012, with a discrete fiber-optic microwave <span class="hlt">photonic</span> canceller, which prior work had demonstrated as a proof-of-concept, and culminates, in 2017, with the first ever monolithically integrated microwave <span class="hlt">photonic</span> canceller. With an eye towards practical implementation, the thesis establishes novelty through three major project thrusts. (Fig. 1): (1) Extensive RF and system analysis to develop a full understanding of how, and through what mechanisms, MPCs affect an RF receiver. The first investigations of how a microwave <span class="hlt">photonic</span> canceller performs in an actual wireless environment and a digital radio are also presented. (2) New architectures to improve the performance and functionality of MPCs, based on the analysis performed in Thrust 1. A novel balanced microwave <span class="hlt">photonic</span> canceller architecture is developed and experimentally demonstrated. The balanced architecture shows significant improvements in link <span class="hlt">gain</span>, noise figure, and dynamic range. Its main advantage is its ability to suppress common-mode noise and reduce noise figure by increasing the optical power. (3) Monolithic integration of the microwave <span class="hlt">photonic</span> canceller into a <span class="hlt">photonic</span> integrated circuit. This thrust presents the progression of integrating individual discrete devices into their semiconductor equivalent, as well as a full functional and RF analysis of the first ever integrated microwave <span class="hlt">photonic</span> canceller.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1172749','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/1172749"><span><span class="hlt">Photon</span> detector configured to employ the Gunn effect and method of use</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Cich, Michael J</p> <p>2015-03-17</p> <p>Embodiments disclosed herein relate to <span class="hlt">photon</span> detectors configured to employ the Gunn effect for <span class="hlt">detecting</span> high-energy <span class="hlt">photons</span> (e.g., x-rays and gamma rays) and methods of use. In an embodiment, a <span class="hlt">photon</span> detector for <span class="hlt">detecting</span> high-energy <span class="hlt">photons</span> is disclosed. The <span class="hlt">photon</span> detector includes a p-i-n semiconductor diode having a p-type semiconductor region, an n-type semiconductor region, and a compensated i-region disposed between the p-type semiconductor region and the n-type semiconductor region. The compensated i-region and has a width of about 100 .mu.m to about 400 .mu.m and is configured to exhibit the Gunn effect when the p-i-n semiconductor diode is forward biased a sufficient amount. The compensated i-region is doped to include a free carrier concentration of less than about 10.sup.10 cm.sup.-3.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29160936','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29160936"><span>Liquid <span class="hlt">Photonic</span> Crystals for Mesopore <span class="hlt">Detection</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhu, Biting; Fu, Qianqian; Chen, Ke; Ge, Jianping</p> <p>2018-01-02</p> <p>Nitrogen adsorption-desorption for mesopore characterization requires the using of expensive instrumentation, time-consuming processes, and the consumption of liquid nitrogen. Herein, a new method is developed to measure the pore parameters through mixing a mesoporous substance with a supersaturated SiO 2 colloidal solution at different temperatures, and subsequent rapid measurement of reflection changes of the precipitated liquid <span class="hlt">photonic</span> crystals. The pore volumes and diameters of mesoporous silica were measured according to the positive correlation between unit mass reflection change (Δλ/m) and pore volume (V), and the negative correlation between average absorption temperature (T) and pore diameter (D). This new approach may provide an alternative method for fast, convenient and economical characterization of mesoporous materials. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1997ApJ...483..370D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1997ApJ...483..370D"><span>A Method Based on Wavelet Transforms for Source <span class="hlt">Detection</span> in <span class="hlt">Photon</span>-counting Detector Images. II. Application to ROSAT PSPC Images</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Damiani, F.; Maggio, A.; Micela, G.; Sciortino, S.</p> <p>1997-07-01</p> <p>We apply to the specific case of images taken with the ROSAT PSPC detector our wavelet-based X-ray source <span class="hlt">detection</span> algorithm presented in a companion paper. Such images are characterized by the presence of detector ``ribs,'' strongly varying point-spread function, and vignetting, so that their analysis provides a challenge for any <span class="hlt">detection</span> algorithm. First, we apply the algorithm to simulated images of a flat background, as seen with the PSPC, in order to calibrate the number of spurious <span class="hlt">detections</span> as a function of significance threshold and to ascertain that the spatial distribution of spurious <span class="hlt">detections</span> is uniform, i.e., unaffected by the ribs; this goal was achieved using the exposure map in the <span class="hlt">detection</span> procedure. Then, we analyze simulations of PSPC images with a realistic number of point sources; the results are used to determine the efficiency of source <span class="hlt">detection</span> and the accuracy of output quantities such as source count rate, size, and position, upon a comparison with input source data. It turns out that sources with 10 <span class="hlt">photons</span> or less may be confidently <span class="hlt">detected</span> near the image center in medium-length (~104 s), background-limited PSPC exposures. The positions of sources <span class="hlt">detected</span> near the image center (off-axis angles < 15') are accurate to within a few arcseconds. Output count rates and sizes are in agreement with the input quantities, within a factor of 2 in 90% of the cases. The errors on position, count rate, and size increase with off-axis angle and for <span class="hlt">detections</span> of lower significance. We have also checked that the upper limits computed with our method are consistent with the count rates of undetected input sources. Finally, we have tested the algorithm by applying it on various actual PSPC images, among the most challenging for automated <span class="hlt">detection</span> procedures (crowded fields, extended sources, and nonuniform diffuse emission). The performance of our method in these images is satisfactory and outperforms those of other current X-ray <span class="hlt">detection</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1995SPIE.2525..538H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1995SPIE.2525..538H"><span>National <span class="hlt">photonics</span> skills standards for technicians</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hull, Darrell M.</p> <p>1995-10-01</p> <p><span class="hlt">Photonics</span> is defined as the generation, manipulation, transport, <span class="hlt">detection</span>, and use of light information and energy whose quantum unit is the <span class="hlt">photon</span>. The range of applications of phonics extends from energy generation to <span class="hlt">detection</span> to communication and information processing. <span class="hlt">Photonics</span> is at the heart of today's communication systems, from the laser that generates the digital information transported along a fiber- optic cable to the detector that decodes the information. Whether the transmitted information is a phone call from across the street or across the globe, <span class="hlt">photonics</span> brings it to you. Where your health is concerned, <span class="hlt">photonics</span> allows physicians to do minimally invasive surgery using fiber-optic endoscopes and lasers. Researches using spectroscopy and microscopy are pushing the frontiers of biotechnology in activities as widespread as diagnosing disease and probing the mysteries of the genetic code. Advanced sensing and imaging techniques monitor the environment, gathering data on crops and forests, analyzing the ocean's currents and contents, and probing the atmosphere of pollutants. Transportation needs are being impacted by <span class="hlt">photonic</span> sensors and laser rangefinders that will soon monitor and control the traffic on our nation's highways. In our factories, <span class="hlt">photonics</span> provides machine vision systems that give a level of quality control human inspectors could never achieve. In manufacturing, lasers are replacing a variety of cutting, welding, and marking techniques, while imaging systems teamed with neural networks are producing intelligent robots. In short, <span class="hlt">photonics</span> is paving our way into the new millennium. The skill standard is intended to define the knowledge and capabilities - the skills - that workers in the phonics industry need. Phonics will be one of the primary battlefields of the world economic conflict, and it is imperative that U.S. <span class="hlt">photonics</span> technicians be skilled enough to allow the United States to remain competitive in a global marketplace. The</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2844933','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2844933"><span>Two <span class="hlt">Photon</span> Polymerization of Microneedles for Transdermal Drug Delivery</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Gittard, Shaun D.; Ovsianikov, Aleksandr; Chichkov, Boris N.; Doraiswamy, Anand; Narayan, Roger J.</p> <p>2010-01-01</p> <p>Importance of the field Microneedles are small-scale devices that are finding use for transdermal delivery of protein-based pharmacologic agents and nucleic acid-based pharmacologic agents; however, microneedles prepared using conventional microelectronics-based technologies have several shortcomings, which have limited translation of these devices into widespread clinical use. Areas covered in this review Two <span class="hlt">photon</span> polymerization is a laser-based rapid prototyping technique that has been recently used for direct fabrication of hollow microneedles with a wide variety of geometries. In addition, an indirect rapid prototyping method that involves two <span class="hlt">photon</span> polymerization and polydimethyl siloxane micromolding has been used for fabrication of solid microneedles with exceptional mechanical properties. What the reader will <span class="hlt">gain</span> In this review, the use of two <span class="hlt">photon</span> polymerization for fabricating in-plane and out-of-plane hollow microneedle arrays is described. The use of two <span class="hlt">photon</span> polymerization-micromolding for fabrication of solid microneedles is also reviewed. In addition, fabrication of microneedles with antimicrobial properties is discussed; antimicrobial microneedles may reduce the risk of infection associated with formation of channels through the stratum corneum. Take home message It is anticipated that the use of two <span class="hlt">photon</span> polymerization as well as two <span class="hlt">photon</span> polymerization-micromolding for fabrication of microneedles and other microstructured drug delivery devices will increase over the coming years. PMID:20205601</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27982617','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27982617"><span>Ultrafast Coherent Dynamics of a <span class="hlt">Photonic</span> Crystal All-Optical Switch.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Colman, Pierre; Lunnemann, Per; Yu, Yi; Mørk, Jesper</p> <p>2016-12-02</p> <p>We present pump-probe measurements of an all-optical <span class="hlt">photonic</span> crystal switch based on a nanocavity, resolving fast coherent temporal dynamics. The measurements demonstrate the importance of coherent effects typically neglected when considering nanocavity dynamics. In particular, we report the observation of an idler pulse and more than 10 dB parametric <span class="hlt">gain</span>. The measurements are in good agreement with a theoretical model that ascribes the observation to oscillations of the free-carrier population in the nanocavity. The effect opens perspectives for the realization of new all-optical <span class="hlt">photonic</span> crystal switches with unprecedented switching contrast.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009JNano...3a1608M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009JNano...3a1608M"><span>Integrated <span class="hlt">photonics</span> using colloidal quantum dots</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Menon, Vinod M.; Husaini, Saima; Okoye, Nicky; Valappil, Nikesh V.</p> <p>2009-11-01</p> <p>Integrated <span class="hlt">photonic</span> devices were realized using colloidal quantum dot composites such as flexible microcavity laser, microdisk emitters and integrated active-passive waveguides. The microcavity laser structure was realized using spin coating and consisted of an all-polymer distributed Bragg reflector with a poly-vinyl carbazole cavity layer embedded with InGaP/ZnS colloidal quantum dots. These microcavities can be peeled off the substrate yielding a flexible structure that can conform to any shape and whose emission spectra can be mechanically tuned. Planar <span class="hlt">photonic</span> devices consisting of vertically coupled microring resonators, microdisk emitters, active-passive integrated waveguide structures and coupled active microdisk resonators were realized using soft lithography, photo-lithography, and electron beam lithography, respectively. The <span class="hlt">gain</span> medium in all these devices was a composite consisting of quantum dots embedded in SU8 matrix. Finally, the effect of the host matrix on the optical properties of the quantum dots using results of steady-state and time-resolved luminescence measurements was determined. In addition to their specific functionalities, these novel device demonstrations and their development present a low-cost alternative to the traditional <span class="hlt">photonic</span> device fabrication techniques.</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" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29185471','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29185471"><span>Capsize of polarization in dilute <span class="hlt">photonic</span> crystals.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gevorkian, Zhyrair; Hakhoumian, Arsen; Gasparian, Vladimir; Cuevas, Emilio</p> <p>2017-11-29</p> <p>We investigate, experimentally and theoretically, polarization rotation effects in dilute <span class="hlt">photonic</span> crystals with transverse permittivity inhomogeneity perpendicular to the traveling direction of waves. A capsize, namely a drastic change of polarization to the perpendicular direction is observed in a one-dimensional <span class="hlt">photonic</span> crystal in the frequency range 10 ÷ 140 GHz. To <span class="hlt">gain</span> more insights into the rotational mechanism, we have developed a theoretical model of dilute <span class="hlt">photonic</span> crystal, based on Maxwell's equations with a spatially dependent two dimensional inhomogeneous dielectric permittivity. We show that the polarization's rotation can be explained by an optical splitting parameter appearing naturally in Maxwell's equations for magnetic or electric fields components. This parameter is an optical analogous of Rashba like spin-orbit interaction parameter present in quantum waves, introduces a correction to the band structure of the two-dimensional Bloch states, creates the dynamical phase shift between the waves propagating in the orthogonal directions and finally leads to capsizing of the initial polarization. Excellent agreement between theory and experiment is found.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/21528845-distillation-mixed-state-continuous-variable-entanglement-photon-subtraction','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/21528845-distillation-mixed-state-continuous-variable-entanglement-photon-subtraction"><span>Distillation of mixed-state continuous-variable entanglement by <span class="hlt">photon</span> subtraction</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Zhang Shengli; Loock, Peter van</p> <p>2010-12-15</p> <p>We present a detailed theoretical analysis for the distillation of one copy of a mixed two-mode continuous-variable entangled state using beam splitters and coherent <span class="hlt">photon-detection</span> techniques, including conventional on-off detectors and <span class="hlt">photon</span>-number-resolving detectors. The initial Gaussian mixed-entangled states are generated by transmitting a two-mode squeezed state through a lossy bosonic channel, corresponding to the primary source of errors in current approaches to optical quantum communication. We provide explicit formulas to calculate the entanglement in terms of logarithmic negativity before and after distillation, including losses in the channel and the <span class="hlt">photon</span> <span class="hlt">detection</span>, and show that one-copy distillation is still possible evenmore » for losses near the typical fiber channel attenuation length. A lower bound for the transmission coefficient of the <span class="hlt">photon</span>-subtraction beam splitter is derived, representing the minimal value that still allows to enhance the entanglement.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28280432','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28280432"><span><span class="hlt">Photons</span>, <span class="hlt">photon</span> jets, and dark <span class="hlt">photons</span> at 750 GeV and beyond.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dasgupta, Basudeb; Kopp, Joachim; Schwaller, Pedro</p> <p>2016-01-01</p> <p>In new physics searches involving <span class="hlt">photons</span> at the LHC, one challenge is to distinguish scenarios with isolated <span class="hlt">photons</span> from models leading to "<span class="hlt">photon</span> jets". For instance, in the context of the 750 GeV diphoton excess, it was pointed out that a true diphoton resonance [Formula: see text] can be mimicked by a process of the form [Formula: see text], where S is a new scalar with a mass of 750 GeV and a is a light pseudoscalar decaying to two collinear <span class="hlt">photons</span>. <span class="hlt">Photon</span> jets can be distinguished from isolated <span class="hlt">photons</span> by exploiting the fact that a large fraction of <span class="hlt">photons</span> convert to an [Formula: see text] pair inside the inner detector. In this note, we quantify this discrimination power, and we study how the sensitivity of future searches differs for <span class="hlt">photon</span> jets compared to isolated <span class="hlt">photons</span>. We also investigate how our results depend on the lifetime of the particle(s) decaying to the <span class="hlt">photon</span> jet. Finally, we discuss the extension to [Formula: see text], where there are no <span class="hlt">photons</span> at all but the dark <span class="hlt">photon</span> [Formula: see text] decays to [Formula: see text] pairs. Our results will be useful in future studies of the putative 750 GeV signal, but also more generally in any new physics search involving hard <span class="hlt">photons</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017NIMPA.870..110J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017NIMPA.870..110J"><span>Enhanced UV light <span class="hlt">detection</span> using a p-terphenyl wavelength shifter</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Joosten, S.; Kaczanowicz, E.; Ungaro, M.; Rehfuss, M.; Johnston, K.; Meziani, Z.-E.</p> <p>2017-10-01</p> <p>UV-glass photomultiplier tubes (PMTs) have poor <span class="hlt">photon</span> <span class="hlt">detection</span> efficiency for wavelengths below 300 nm due to the opaqueness of the window material. Costly quartz PMTs could be used to enhance the efficiency below 300 nm. A less expensive solution that dramatically improves this efficiency is the application of a thin film of a p-terphenyl (PT) wavelength shifter on UV-glass PMTs. This improvement was quantified for Photonis XP4500B PMTs for wavelengths between 200 nm and 400 nm. The <span class="hlt">gain</span> factor ranges up to 5 . 4 ± 0 . 5 at a wavelength of 215 nm, with a material load of 110 ± 10 μg /cm2 (894 nm). The wavelength shifter was found to be fully transparent for wavelengths greater than 300 nm. The resulting <span class="hlt">gain</span> in <span class="hlt">detection</span> efficiency, when used in a typical C̆erenkov counter, was estimated to be of the order of 40%. Consistent coating quality was assured by a rapid <span class="hlt">gain</span> testing procedure using narrow-band UV LEDs. Based on these results, 200 Photonis XP4500B PMTs were treated with PT for the upgraded low-threshold C̆erenkov counter (LTCC) to be used in the CEBAF Large Acceptance Spectrometer upgraded detector (CLAS12) at the Thomas Jefferson National Accelerator Facility.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017APS..APRJ13006M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017APS..APRJ13006M"><span>Resonance Search for a Heavy <span class="hlt">Photon</span> in the 2015 Engineering Run Data of the Heavy <span class="hlt">Photon</span> Search Experiment</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Moreno, Omar; Heavy Photon Search Collaboration</p> <p>2017-01-01</p> <p>The Heavy <span class="hlt">Photon</span> Search (HPS) experiment at Jefferson Lab is searching for a new U(1) vector boson (``heavy <span class="hlt">photon</span>'',``dark <span class="hlt">photon</span>'' or A') in the mass range of 20-500 MeV/c2. An A' in this mass range is theoretically favorable and may also mediate dark matter interactions. The A' couples to the ordinary <span class="hlt">photon</span> through kinetic mixing, which induces their coupling to electric charge. Since heavy <span class="hlt">photons</span> couple to electrons, they can be produced through a process analogous to bremsstrahlung, subsequently decaying to an e+e- , which can be observed as a narrow resonance above the dominant QED trident background. For suitably small couplings, heavy <span class="hlt">photons</span> travel <span class="hlt">detectable</span> distances before decaying, providing a second signature. Using the CEBAF electron beam at Jefferson Lab incident on a thin tungsten target, along with a compact, large acceptance forward spectrometer consisting of a silicon vertex tracker and lead tungstate electromagnetic calorimeter, HPS is accessing unexplored regions in the mass-coupling phase space. The HPS engineering run took place in spring of 2015 using a 1.056 GeV, 50 nA beam and collected 1165 nb-1 (7.29 mC) of data. This talk will present the results of a resonance search for a heavy <span class="hlt">photon</span> using the engineering run data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/21550010-quantum-teleportation-spin-orbit-variables-photon-pairs','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/21550010-quantum-teleportation-spin-orbit-variables-photon-pairs"><span>Quantum teleportation in the spin-orbit variables of <span class="hlt">photon</span> pairs</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Khoury, A. Z.; Milman, P.; Laboratoire Materiaux et Phenomenes Quantiques, CNRS UMR 7162, Universite Paris Diderot, F-75013, Paris</p> <p>2011-06-15</p> <p>We propose a polarization to orbital angular momentum teleportation scheme using entangled <span class="hlt">photon</span> pairs generated by spontaneous parametric down-conversion. By making a joint <span class="hlt">detection</span> of the polarization and angular momentum parity of a single <span class="hlt">photon</span>, we are able to <span class="hlt">detect</span> all the Bell states and perform, in principle, perfect teleportation from a discrete to a continuous system using minimal resources. The proposed protocol implementation demands experimental resources that are currently available in quantum optics laboratories.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvA..95f1805S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvA..95f1805S"><span>Setting a disordered password on a <span class="hlt">photonic</span> memory</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Su, Shih-Wei; Gou, Shih-Chuan; Chew, Lock Yue; Chang, Yu-Yen; Yu, Ite A.; Kalachev, Alexey; Liao, Wen-Te</p> <p>2017-06-01</p> <p>An all-optical method of setting a disordered password on different schemes of <span class="hlt">photonic</span> memory is theoretically studied. While <span class="hlt">photons</span> are regarded as ideal information carriers, it is imperative to implement such data protection on all-optical storage. However, we wish to address the intrinsic risk of data breaches in existing schemes of <span class="hlt">photonic</span> memory. We theoretically demonstrate a protocol using spatially disordered laser fields to encrypt data stored on an optical memory, namely, encrypted <span class="hlt">photonic</span> memory. To address the broadband storage, we also investigate a scheme of disordered echo memory with a high fidelity approaching unity. The proposed method increases the difficulty for the eavesdropper to retrieve the stored <span class="hlt">photon</span> without the preset password even when the randomized and stored <span class="hlt">photon</span> state is nearly perfectly cloned. Our results pave ways to significantly reduce the exposure of memories, required for long-distance communication, to eavesdropping and therefore restrict the optimal attack on communication protocols. The present scheme also increases the sensitivity of <span class="hlt">detecting</span> any eavesdropper and so raises the security level of <span class="hlt">photonic</span> information technology.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA503452','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA503452"><span>Feasibility of Dual Optics/Ultrasound Imaging and Contrast Media for the <span class="hlt">Detection</span> and Characterization of Prostate Cancer</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2009-03-01</p> <p>acousto - optic effect will be used to only modulate light (at the ultrasound frequency) which propagates through a small ultrasound focal zone. This...DOD Idea Development Award is concerned with the development of a novel acousto - optic <span class="hlt">detection</span> idea based on quadrature measurements with a <span class="hlt">gain</span>...perform acousto - optic molecular imaging of prostate cancer with incoherent <span class="hlt">photons</span> using endogenous contrast, e.g. hypoxia, and with fluorescent probes and microbubbles for increased specificity and signal enhancement.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018SPIE10500E..02Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018SPIE10500E..02Y"><span><span class="hlt">Photon</span> spectroscopy by picoseconds differential Geiger-mode Si photomultiplier</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yamamoto, Masanobu; Hernandez, Keegan; Robinson, J. Paul</p> <p>2018-02-01</p> <p>The pixel array silicon photomultiplier (SiPM) is known as an excellent <span class="hlt">photon</span> sensor with picoseconds avalanche process with the capacity for millions amplification of photoelectrons. In addition, a higher quantum efficiency(QE), small size, low bias voltage, light durability are attractive features for biological applications. The primary disadvantage is the limited dynamic range due to the 50ns recharge process and a high dark count which is an additional hurdle. We have developed a wide dynamic Si <span class="hlt">photon</span> <span class="hlt">detection</span> system applying ultra-fast differentiation signal processing, temperature control by thermoelectric device and Giga <span class="hlt">photon</span> counter with 9 decimal digits dynamic range. The tested performance is six orders of magnitude with 600ps pulse width and sub-fW sensitivity. Combined with 405nm laser illumination and motored monochromator, Laser Induced Fluorescence <span class="hlt">Photon</span> Spectrometry (LIPS) has been developed with a scan range from 200 900nm at maximum of 500nm/sec and 1nm FWHM. Based on the Planck equation E=hν, this <span class="hlt">photon</span> counting spectrum provides a fundamental advance in spectral analysis by digital processing. Advantages include its ultimate sensitivity, theoretical linearity, as well as quantitative and logarithmic analysis without use of arbitrary units. Laser excitation is also useful for evaluation of photobleaching or oxidation in materials by higher energy illumination. Traditional typical photocurrent <span class="hlt">detection</span> limit is about 1pW which includes millions of <span class="hlt">photons</span>, however using our system it is possible to evaluate the <span class="hlt">photon</span> spectrum and determine background noise and auto fluorescence(AFL) in optics in any cytometry or imaging system component. In addition, the <span class="hlt">photon</span>-stream digital signal opens up a new approach for picosecond time-domain analysis. <span class="hlt">Photon</span> spectroscopy is a powerful method for analysis of fluorescence and optical properties in biology.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvA..96e3846C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvA..96e3846C"><span>State preparation and detector effects in quantum measurements of rotation with circular polarization-entangled <span class="hlt">photons</span> and <span class="hlt">photon</span> counting</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cen, Longzhu; Zhang, Zijing; Zhang, Jiandong; Li, Shuo; Sun, Yifei; Yan, Linyu; Zhao, Yuan; Wang, Feng</p> <p>2017-11-01</p> <p>Circular polarization-entangled <span class="hlt">photons</span> can be used to obtain an enhancement of the precision in a rotation measurement. In this paper, the method of entanglement transformation is used to produce NOON states in circular polarization from a readily generated linear polarization-entangled <span class="hlt">photon</span> source. <span class="hlt">Detection</span> of N -fold coincidences serves as the postselection and N -fold superoscillating fringes are obtained simultaneously. A parity strategy and conditional probabilistic statistics contribute to a better fringe, saturating the angle sensitivity to the Heisenberg limit. The impact of imperfect state preparation and <span class="hlt">detection</span> is discussed both separately and jointly. For the separated case, the influence of each system imperfection is pronounced. For the joint case, the feasibility region for surpassing the standard quantum limit is given. Our work pushes the state preparation of circular polarization-entangled <span class="hlt">photons</span> to the same level as that in the case of linear polarization. It is also confirmed that entanglement can be transformed into different frames for specific applications, serving as a useful scheme for using entangled sources.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3758924','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3758924"><span>Tiny Grains Give Huge <span class="hlt">Gains</span>: Nanocrystal–Based Signal Amplification for Biomolecule <span class="hlt">Detection</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Tong, Sheng; Ren, Binbin; Zheng, Zhilan; Shen, Han; Bao, Gang</p> <p>2013-01-01</p> <p>Nanocrystals, despite their tiny sizes, contain thousands to millions of atoms. Here we show that the large number of atoms packed in each metallic nanocrystal can provide a huge <span class="hlt">gain</span> in signal amplification for biomolecule <span class="hlt">detection</span>. We have devised a highly sensitive, linear amplification scheme by integrating the dissolution of bound nanocrystals and metal-induced stoichiometric chromogenesis, and demonstrated that signal amplification is fully defined by the size and atom density of nanocrystals, which can be optimized through well-controlled nanocrystal synthesis. Further, the rich library of chromogenic reactions allows implementation of this scheme in various assay formats, as demonstrated by the iron oxide nanoparticle linked immunosorbent assay (ILISA) and blotting assay developed in this study. Our results indicate that, owing to the inherent simplicity, high sensitivity and repeatability, the nanocrystal based amplification scheme can significantly improve biomolecule quantification in both laboratory research and clinical diagnostics. This novel method adds a new dimension to current nanoparticle-based bioassays. PMID:23659350</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20052243','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20052243"><span>Three-color Sagnac source of polarization-entangled <span class="hlt">photon</span> pairs.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hentschel, Michael; Hübel, Hannes; Poppe, Andreas; Zeilinger, Anton</p> <p>2009-12-07</p> <p>We demonstrate a compact and stable source of polarization-entangled pairs of <span class="hlt">photons</span>, one at 810 nm wavelength for high <span class="hlt">detection</span> efficiency and the other at 1550 nm for long-distance fiber communication networks. Due to a novel Sagnac-based design of the interferometer no active stabilization is needed. Using only one 30 mm ppKTP bulk crystal the source produces <span class="hlt">photons</span> with a spectral brightness of 1.13 x 10(6) pairs/s/mW/THz with an entanglement fidelity of 98.2%. Both <span class="hlt">photons</span> are single-mode fiber coupled and ready to be used in quantum key distribution (QKD) or transmission of <span class="hlt">photonic</span> quantum states over large distances.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26214251','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26214251"><span>Deterministic <span class="hlt">photon</span>-emitter coupling in chiral <span class="hlt">photonic</span> circuits.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Söllner, Immo; Mahmoodian, Sahand; Hansen, Sofie Lindskov; Midolo, Leonardo; Javadi, Alisa; Kiršanskė, Gabija; Pregnolato, Tommaso; El-Ella, Haitham; Lee, Eun Hye; Song, Jin Dong; Stobbe, Søren; Lodahl, Peter</p> <p>2015-09-01</p> <p>Engineering <span class="hlt">photon</span> emission and scattering is central to modern <span class="hlt">photonics</span> applications ranging from light harvesting to quantum-information processing. To this end, nanophotonic waveguides are well suited as they confine <span class="hlt">photons</span> to a one-dimensional geometry and thereby increase the light-matter interaction. In a regular waveguide, a quantum emitter interacts equally with <span class="hlt">photons</span> in either of the two propagation directions. This symmetry is violated in nanophotonic structures in which non-transversal local electric-field components imply that <span class="hlt">photon</span> emission and scattering may become directional. Here we show that the helicity of the optical transition of a quantum emitter determines the direction of single-<span class="hlt">photon</span> emission in a specially engineered <span class="hlt">photonic</span>-crystal waveguide. We observe single-<span class="hlt">photon</span> emission into the waveguide with a directionality that exceeds 90% under conditions in which practically all the emitted <span class="hlt">photons</span> are coupled to the waveguide. The chiral light-matter interaction enables deterministic and highly directional <span class="hlt">photon</span> emission for experimentally achievable on-chip non-reciprocal <span class="hlt">photonic</span> elements. These may serve as key building blocks for single-<span class="hlt">photon</span> optical diodes, transistors and deterministic quantum gates. Furthermore, chiral <span class="hlt">photonic</span> circuits allow the dissipative preparation of entangled states of multiple emitters for experimentally achievable parameters, may lead to novel topological <span class="hlt">photon</span> states and could be applied for directional steering of light.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015NatNa..10..775S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015NatNa..10..775S"><span>Deterministic <span class="hlt">photon</span>-emitter coupling in chiral <span class="hlt">photonic</span> circuits</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Söllner, Immo; Mahmoodian, Sahand; Hansen, Sofie Lindskov; Midolo, Leonardo; Javadi, Alisa; Kiršanskė, Gabija; Pregnolato, Tommaso; El-Ella, Haitham; Lee, Eun Hye; Song, Jin Dong; Stobbe, Søren; Lodahl, Peter</p> <p>2015-09-01</p> <p>Engineering <span class="hlt">photon</span> emission and scattering is central to modern <span class="hlt">photonics</span> applications ranging from light harvesting to quantum-information processing. To this end, nanophotonic waveguides are well suited as they confine <span class="hlt">photons</span> to a one-dimensional geometry and thereby increase the light-matter interaction. In a regular waveguide, a quantum emitter interacts equally with <span class="hlt">photons</span> in either of the two propagation directions. This symmetry is violated in nanophotonic structures in which non-transversal local electric-field components imply that <span class="hlt">photon</span> emission and scattering may become directional. Here we show that the helicity of the optical transition of a quantum emitter determines the direction of single-<span class="hlt">photon</span> emission in a specially engineered <span class="hlt">photonic</span>-crystal waveguide. We observe single-<span class="hlt">photon</span> emission into the waveguide with a directionality that exceeds 90% under conditions in which practically all the emitted <span class="hlt">photons</span> are coupled to the waveguide. The chiral light-matter interaction enables deterministic and highly directional <span class="hlt">photon</span> emission for experimentally achievable on-chip non-reciprocal <span class="hlt">photonic</span> elements. These may serve as key building blocks for single-<span class="hlt">photon</span> optical diodes, transistors and deterministic quantum gates. Furthermore, chiral <span class="hlt">photonic</span> circuits allow the dissipative preparation of entangled states of multiple emitters for experimentally achievable parameters, may lead to novel topological <span class="hlt">photon</span> states and could be applied for directional steering of light.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4526863','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4526863"><span>Rational Design of <span class="hlt">Photonic</span> Dust from Nanoporous Anodic Alumina Films: A Versatile <span class="hlt">Photonic</span> Nanotool for Visual Sensing</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Chen, Yuting; Santos, Abel; Wang, Ye; Kumeria, Tushar; Ho, Daena; Li, Junsheng; Wang, Changhai; Losic, Dusan</p> <p>2015-01-01</p> <p>Herein, we present a systematic study on the development, optimisation and applicability of interferometrically coloured distributed Bragg reflectors based on nanoporous anodic alumina (NAA-DBRs) in the form of films and nanoporous microparticles as visual/colorimetric analytical tools. Firstly, we synthesise a complete palette of NAA-DBRs by galvanostatic pulse anodisation approach, in which the current density is altered in a periodic fashion in order to engineer the effective medium of the resulting <span class="hlt">photonic</span> films in depth. NAA-DBR <span class="hlt">photonic</span> films feature vivid colours that can be tuned across the UV-visible-NIR spectrum by structural engineering. Secondly, the effective medium of the resulting <span class="hlt">photonic</span> films is assessed systematically by visual analysis and reflectometric interference spectroscopy (RIfS) in order to establish the most optimal nanoporous platforms to develop visual/colorimetric tools. Then, we demonstrate the applicability of NAA-DBR <span class="hlt">photonic</span> films as a chemically selective sensing platform for visual <span class="hlt">detection</span> of mercury(II) ions. Finally, we generate a new nanomaterial, so-called <span class="hlt">photonic</span> dust, by breaking down NAA-DBRs films into nanoporous microparticles. The resulting microparticles (μP-NAA-DBRs) display vivid colours and are sensitive towards changes in their effective medium, opening new opportunities for developing advanced <span class="hlt">photonic</span> nanotools for a broad range of applications. PMID:26245759</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015NatSR...512893C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015NatSR...512893C"><span>Rational Design of <span class="hlt">Photonic</span> Dust from Nanoporous Anodic Alumina Films: A Versatile <span class="hlt">Photonic</span> Nanotool for Visual Sensing</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chen, Yuting; Santos, Abel; Wang, Ye; Kumeria, Tushar; Ho, Daena; Li, Junsheng; Wang, Changhai; Losic, Dusan</p> <p>2015-08-01</p> <p>Herein, we present a systematic study on the development, optimisation and applicability of interferometrically coloured distributed Bragg reflectors based on nanoporous anodic alumina (NAA-DBRs) in the form of films and nanoporous microparticles as visual/colorimetric analytical tools. Firstly, we synthesise a complete palette of NAA-DBRs by galvanostatic pulse anodisation approach, in which the current density is altered in a periodic fashion in order to engineer the effective medium of the resulting <span class="hlt">photonic</span> films in depth. NAA-DBR <span class="hlt">photonic</span> films feature vivid colours that can be tuned across the UV-visible-NIR spectrum by structural engineering. Secondly, the effective medium of the resulting <span class="hlt">photonic</span> films is assessed systematically by visual analysis and reflectometric interference spectroscopy (RIfS) in order to establish the most optimal nanoporous platforms to develop visual/colorimetric tools. Then, we demonstrate the applicability of NAA-DBR <span class="hlt">photonic</span> films as a chemically selective sensing platform for visual <span class="hlt">detection</span> of mercury(II) ions. Finally, we generate a new nanomaterial, so-called <span class="hlt">photonic</span> dust, by breaking down NAA-DBRs films into nanoporous microparticles. The resulting microparticles (μP-NAA-DBRs) display vivid colours and are sensitive towards changes in their effective medium, opening new opportunities for developing advanced <span class="hlt">photonic</span> nanotools for a broad range of applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JInst..13P1024H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JInst..13P1024H"><span>Characterization of Sphinx1 ASIC X-ray detector using <span class="hlt">photon</span> counting and charge integration</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Habib, A.; Arques, M.; Moro, J.-L.; Accensi, M.; Stanchina, S.; Dupont, B.; Rohr, P.; Sicard, G.; Tchagaspanian, M.; Verger, L.</p> <p>2018-01-01</p> <p>Sphinx1 is a novel pixel architecture adapted for X-ray imaging, it <span class="hlt">detects</span> radiation by <span class="hlt">photon</span> counting and charge integration. In <span class="hlt">photon</span> counting mode, each <span class="hlt">photon</span> is compensated by one or more counter-charges typically consisting of 100 electrons (e-) each. The number of counter-charges required gives a measure of the incoming <span class="hlt">photon</span> energy, thus allowing spectrometric <span class="hlt">detection</span>. Pixels can also <span class="hlt">detect</span> radiation by integrating the charges deposited by all incoming <span class="hlt">photons</span> during one image frame and converting this analog value into a digital response with a 100 electrons least significant bit (LSB), based on the counter-charge concept. A proof of concept test chip measuring 5 mm × 5 mm, with 200 μm × 200 μm pixels has been produced and characterized. This paper provides details on the architecture and the counter-charge design; it also describes the two modes of operation: <span class="hlt">photon</span> counting and charge integration. The first performance measurements for this test chip are presented. Noise was found to be ~80 e-rms in <span class="hlt">photon</span> counting mode with a power consumption of only 0.9 μW/pixel for the static analog part and 0.3 μW/pixel for the static digital part.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002SPIE.4821..455M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002SPIE.4821..455M"><span>Single <span class="hlt">photon</span> source with individualized single <span class="hlt">photon</span> certifications</span></a></p> <p><a target="_blank" 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-<span class="hlt">photon</span> sources cannot be made to produce single <span class="hlt">photons</span> with high probability, while simultaneously suppressing the probability of yielding two or more <span class="hlt">photons</span>. Because of this, single <span class="hlt">photon</span> sources cannot really produce single <span class="hlt">photons</span> on demand. We describe a multiplexed system that allows the probabilities of producing one and more <span class="hlt">photons</span> to be adjusted independently, enabling a much better approximation of a source of single <span class="hlt">photons</span> on demand. The scheme uses a heralded <span class="hlt">photon</span> 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 <span class="hlt">photon</span> than is possible with a conventional arrangement. This scheme allows <span class="hlt">photons</span> to be produced along with a quantitative 'certification' that they are single <span class="hlt">photons</span>. Some of the single-<span class="hlt">photon</span> 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 <span class="hlt">photons</span>, 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" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008PhRvA..77a2324S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008PhRvA..77a2324S"><span>Experimental sub-Rayleigh resolution by an unseeded high-<span class="hlt">gain</span> optical parametric amplifier for quantum lithography</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sciarrino, Fabio; Vitelli, Chiara; de Martini, Francesco; Glasser, Ryan; Cable, Hugo; Dowling, Jonathan P.</p> <p>2008-01-01</p> <p>Quantum lithography proposes to adopt entangled quantum states in order to increase resolution in interferometry. In the present paper we experimentally demonstrate that the output of a high-<span class="hlt">gain</span> optical parametric amplifier can be intense yet exhibits quantum features, namely, sub-Rayleigh fringes, as proposed by [Agarwal , Phys. Rev. Lett. 86, 1389 (2001)]. We investigate multiphoton states generated by a high-<span class="hlt">gain</span> optical parametric amplifier operating with a quantum vacuum input for <span class="hlt">gain</span> values up to 2.5. The visibility has then been increased by means of three-<span class="hlt">photon</span> absorption. The present paper opens interesting perspectives for the implementation of such an advanced interferometrical setup.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4864373','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4864373"><span>Broadband <span class="hlt">photon-photon</span> interactions mediated by cold atoms in a <span class="hlt">photonic</span> crystal fiber</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Litinskaya, Marina; Tignone, Edoardo; Pupillo, Guido</p> <p>2016-01-01</p> <p>We demonstrate theoretically that <span class="hlt">photon-photon</span> attraction can be engineered in the continuum of scattering states for pairs of <span class="hlt">photons</span> propagating in a hollow-core <span class="hlt">photonic</span> crystal fiber filled with cold atoms. The atoms are regularly spaced in an optical lattice configuration and the <span class="hlt">photons</span> are resonantly tuned to an internal atomic transition. We show that the hard-core repulsion resulting from saturation of the atomic transitions induces bunching in the <span class="hlt">photonic</span> component of the collective atom-<span class="hlt">photon</span> modes (polaritons). Bunching is obtained in a frequency range as large as tens of GHz, and can be controlled by the inter-atomic separation. We provide a fully analytical explanation for this phenomenon by proving that correlations result from a mismatch of the quantization volumes for atomic excitations and <span class="hlt">photons</span> in the continuum. Even stronger correlations can be observed for in-gap two-polariton bound states. Our theoretical results use parameters relevant for current experiments and suggest a simple and feasible way to induce interactions between <span class="hlt">photons</span>. PMID:27170160</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" onclick="trackOutboundLink('http://hdl.handle.net/2060/19950007552','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19950007552"><span>Nonlocal effects on the polarization state of a <span class="hlt">photon</span>, induced by distant absorbers</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ryff, Luis Carlos B.</p> <p>1994-01-01</p> <p>A variant of a Franson's two-<span class="hlt">photon</span> correlation experiment is discussed, in which the linear polarization state of one of the <span class="hlt">photons</span> depends on the path followed in the interferometer. It is shown that although the path difference is greater than the coherence length, the <span class="hlt">photon</span> can be found in a polarization state represented by the superposition of the polarization states associated to the paths when there is coincident <span class="hlt">detection</span>. Since the <span class="hlt">photons</span>, produced via parametric down-conversion, are fairly well localized in space and time, the situation in which one of the <span class="hlt">photons</span> is <span class="hlt">detected</span> before the other can reach the interferometer raises an intriguing point: it seems that in some cases the second <span class="hlt">photon</span> would have to be described by two wave packets simultaneously. Unlike previous experiments, in which nonlocal effects were induced by means of polarizers of phase shifters, in the proposed experiment nonlocal effects can be induced by means of variable absorbers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26996608','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26996608"><span>Thermally Driven <span class="hlt">Photonic</span> Actuator Based on Silica Opal <span class="hlt">Photonic</span> Crystal with Liquid Crystal Elastomer.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Xing, Huihui; Li, Jun; Shi, Yang; Guo, Jinbao; Wei, Jie</p> <p>2016-04-13</p> <p>We have developed a novel thermoresponsive <span class="hlt">photonic</span> actuator based on three-dimensional SiO2 opal <span class="hlt">photonic</span> crystals (PCs) together with liquid crystal elastomers (LCEs). In the process of fabrication of such a <span class="hlt">photonic</span> actuator, the LCE precursor is infiltrated into the SiO2 opal PC followed by UV light-induced photopolymerization, thereby forming the SiO2 opal PC/LCE composite film with a bilayer structure. We find that this bilayer composite film simultaneously exhibits actuation behavior as well as the <span class="hlt">photonic</span> band gap (PBG) response to external temperature variation. When the SiO2 opal PC/LCE composite film is heated, it exhibits a considerable bending deformation, and its PBG shifts to a shorter wavelength at the same time. In addition, this actuation is quite fast, reversible, and highly repeatable. The thermoresponsive behavior of the SiO2 opal PC/LCE composite films mainly derives from the thermal-driven change of nematic order of the LCE layer which leads to the asymmetric shrinkage/expansion of the bilayer structure. These results will be of interest in designing optical actuator systems for environment-temperature <span class="hlt">detection</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018NIMPA.895..158A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018NIMPA.895..158A"><span>Studies of uniformity of 50 μm low-<span class="hlt">gain</span> avalanche detectors at the Fermilab test beam</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Apresyan, A.; Xie, S.; Pena, C.; Arcidiacono, R.; Cartiglia, N.; Carulla, M.; Derylo, G.; Ferrero, M.; Flores, D.; Freeman, P.; Galloway, Z.; Ghassemi, A.; Al Ghoul, H.; Gray, L.; Hidalgo, S.; Kamada, S.; Los, S.; Mandurrino, M.; Merlos, A.; Minafra, N.; Pellegrini, G.; Quirion, D.; Ronzhin, A.; Royon, C.; Sadrozinski, H.; Seiden, A.; Sola, V.; Spiropulu, M.; Staiano, A.; Uplegger, L.; Yamamoto, K.; Yamamura, K.</p> <p>2018-07-01</p> <p>In this paper we report measurements of the uniformity of time resolution, signal amplitude, and charged particle <span class="hlt">detection</span> efficiency across the sensor surface of low-<span class="hlt">gain</span> avalanche detectors (LGAD). Comparisons of the performance of sensors with different doping concentrations and different active thicknesses are presented, as well as their temperature dependence and radiation tolerance up to 6 × 1014 n/cm2. Results were obtained at the Fermilab test beam facility using 120 GeV proton beams, and a high precision pixel tracking detector. LGAD sensors manufactured by the Centro Nacional de Microelectrónica (CNM) and Hamamatsu <span class="hlt">Photonics</span> (HPK) were studied. The uniformity of the sensor response in pulse height before irradiation was found to have a 2% spread. The signal <span class="hlt">detection</span> efficiency and timing resolution in the sensitive areas before irradiation were found to be 100% and 30-40 ps, respectively. A "no-response" area between pads was measured to be about 130 μm for CNM and 170 μm for HPK sensors. After a neutron fluence of 6 × 1014 n/cm2 the CNM sensor exhibits a large <span class="hlt">gain</span> variation of up to a factor of 2.5 when comparing metalized and non-metalized sensor areas. An irradiated CNM sensor achieved a time resolution of 30 ps for the metalized area and 40 ps for the non-metalized area, while a HPK sensor irradiated to the same fluence achieved a 30 ps time resolution.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26480155','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26480155"><span>Tunable <span class="hlt">photonic</span> nanojet formed by generalized Luneburg lens.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mao, Xiurun; Yang, Yang; Dai, Haitao; Luo, Dan; Yao, Baoli; Yan, Shaohui</p> <p>2015-10-05</p> <p>Nanojet has been emerging as an interesting topic in variety <span class="hlt">photonics</span> applications. In this paper, inspired by the properties of generalized Luneburg lens (GLLs), a two-dimensional <span class="hlt">photonic</span> nanojet system has been developed, which focal distance can be tuned by engineering the refractive index profile of GLLs. Simulation and analysis results show that the maximum light intensity, transverse and longitudinal dimensions of the <span class="hlt">photonic</span> nanojet are dependent on the focal distance of the GLLs, thereby, by simply varying the focal distance, it is possible to obtain localized <span class="hlt">photon</span> fluxes with different power characteristics and spatial dimensions. This can be of interest for many promising applications, such as high-resolution optical <span class="hlt">detection</span>, optical manipulation, technology of direct-write nano-patterning and nano-lithography.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3665960','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3665960"><span>Waveguide integrated low noise NbTiN nanowire single-<span class="hlt">photon</span> detectors with milli-Hz dark count rate</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Schuck, Carsten; Pernice, Wolfram H. P.; Tang, Hong X.</p> <p>2013-01-01</p> <p>Superconducting nanowire single-<span class="hlt">photon</span> detectors are an ideal match for integrated quantum <span class="hlt">photonic</span> circuits due to their high <span class="hlt">detection</span> efficiency for telecom wavelength <span class="hlt">photons</span>. Quantum optical technology also requires single-<span class="hlt">photon</span> <span class="hlt">detection</span> with low dark count rate and high timing accuracy. Here we present very low noise superconducting nanowire single-<span class="hlt">photon</span> 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 <span class="hlt">detection</span> 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 <span class="hlt">detection</span> 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</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhRvB..94x5307H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhRvB..94x5307H"><span>Spin-based single-<span class="hlt">photon</span> transistor, dynamic random access memory, diodes, and routers in semiconductors</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hu, C. Y.</p> <p>2016-12-01</p> <p>The realization of quantum computers and quantum Internet requires not only quantum gates and quantum memories, but also transistors at single-<span class="hlt">photon</span> levels to control the flow of information encoded on single <span class="hlt">photons</span>. Single-<span class="hlt">photon</span> transistor (SPT) is an optical transistor in the quantum limit, which uses a single <span class="hlt">photon</span> to open or block a <span class="hlt">photonic</span> channel. In sharp contrast to all previous SPT proposals which are based on single-<span class="hlt">photon</span> nonlinearities, here I present a design for a high-<span class="hlt">gain</span> and high-speed (up to THz) SPT based on a linear optical effect: giant circular birefringence induced by a single spin in a double-sided optical microcavity. A gate <span class="hlt">photon</span> sets the spin state via projective measurement and controls the light propagation in the optical channel. This spin-cavity transistor can be directly configured as diodes, routers, DRAM units, switches, modulators, etc. Due to the duality as quantum gate and transistor, the spin-cavity unit provides a solid-state platform ideal for future Internet: a mixture of all-optical Internet with quantum Internet.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26481996','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26481996"><span>Sensitive and rapid <span class="hlt">detection</span> of endogenous hydrogen sulfide distributing in different mouse viscera via a two-<span class="hlt">photon</span> fluorescent probe.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chen, Qian; Yang, Jinfeng; Li, Yinhui; Zheng, Jing; Yang, Ronghua</p> <p>2015-10-08</p> <p>Development of efficient methods for <span class="hlt">detection</span> of endogenous H2S in living cells and tissues is of considerable significance for better understanding the biological and pathological functions of H2S. Two-<span class="hlt">photon</span> (TP) fluorescent probes are favorable as powerful molecular tools for studying physiological process due to its non-invasiveness, high spatiotemporal resolution and deep-tissues imaging. Up to date, several TP probes for intracellular H2S imaging have been designed, but real-time imaging of endogenous H2S-related biological processes in tissues is hampered due to low sensitivity, long response time and interference from other biothiols. To address this issue, we herein report a novel two-<span class="hlt">photon</span> fluorescent probe (TPP-H2S) for highly sensitive and fast monitoring and imaging H2S levels in living cells and tissues. In the presence of H2S, it exhibits obviously improved sensitivity (LOD: 0.12 μM) and fast response time (about 2 min) compared with the reported two-<span class="hlt">photon</span> H2S probes. With two-<span class="hlt">photon</span> excitation, TPP-H2S displays high signal-to-noise ratio and sensitivity even no interference in cell growth media. As further application, TPP-H2S is applied for fast imaging of H2S in living cells and different fresh tissues by two-<span class="hlt">photon</span> confocal microscope. Most importantly we first measured the endogenous H2S level in different viscera by vivisection and found that the distribution of endogenous H2S mostly in brain, liver and lung. The excellent sensing properties of TPP-H2S make it a practically useful tool for further studying biological roles of H2S. Copyright © 2015 Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005SPIE.5705...14L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005SPIE.5705...14L"><span>Analysis of nanoparticles using <span class="hlt">photonic</span> nanojet</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, Xu; Chen, Zhigang; Siegel, Michael P.; Taflove, Allen; Backman, Vadim</p> <p>2005-04-01</p> <p>A <span class="hlt">photonic</span> nanojet is a local field enhancement generated in the vicinity of a properly chosen microsphere or microcylinder illuminated by a collimated light beam. These <span class="hlt">photonic</span> nanojets have waists smaller than the diffraction limit and propagate over several optical wavelengths without significant diffraction. We investigate the properties of <span class="hlt">photonic</span> nanojets using rigorous solutions of Maxwell"s equations. A remarkable property we have found is that they can significantly enhance the backscattering of light by nanometer-scale particles (as small as ~1 nm) located within the jets. The enhancement factor for the backscattering intensity can be as high as five to six orders of magnitude. As a result, the observed intensity of the backscattered light from the dielectric microsphere can be substantially altered due to the presence of a nanoparticle within the light jet. Furthermore, the intensity and angular distribution of the backscattered signal is extremely sensitive to the size of the nanoparticle, which may enable differentiating particles with accuracy up to 1 nm. These properties of <span class="hlt">photonic</span> nanojets make them an ideal tool for <span class="hlt">detecting</span>, differentiating and sorting nanoparticles, which is of immense necessity for the field of nano-biotechnology. For example, they could yield potential novel ultramicroscopy techniques using visible light for <span class="hlt">detecting</span> proteins, viral particles, and even single molecules; and monitoring molecular synthesis and aggregation processes of importance in many areas of biology, chemistry, material sciences, and tissue engineering.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19905612','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19905612"><span>Experimental test of fidelity limits in six-<span class="hlt">photon</span> interferometry and of rotational invariance properties of the <span class="hlt">photonic</span> six-qubit entanglement singlet state.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rådmark, Magnus; Zukowski, Marek; Bourennane, Mohamed</p> <p>2009-10-09</p> <p>Quantum multiphoton interferometry has now reached the six-<span class="hlt">photon</span> stage. Thus far, the observed fidelities of entangled states never reached 2/3. We report a high fidelity (estimated at 88%) experiment in which six-qubit singlet correlations were observed. With such a high fidelity we are able to demonstrate the central property of these "singlet" correlations, their "rotational invariance," by performing a full set of measurements in three complementary polarization bases. The patterns are almost indistinguishable. The data reveal genuine six-<span class="hlt">photon</span> entanglement. We also study several five-<span class="hlt">photon</span> states, which result upon <span class="hlt">detection</span> of one of the <span class="hlt">photons</span>. Multiphoton singlet states survive some types of depolarization and are thus important in quantum communication schemes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26196640','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26196640"><span>Spin Pumping in Electrodynamically Coupled Magnon-<span class="hlt">Photon</span> Systems.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bai, Lihui; Harder, M; Chen, Y P; Fan, X; Xiao, J Q; Hu, C-M</p> <p>2015-06-05</p> <p>We use electrical <span class="hlt">detection</span>, in combination with microwave transmission, to investigate both resonant and nonresonant magnon-<span class="hlt">photon</span> coupling at room temperature. Spin pumping in a dynamically coupled magnon-<span class="hlt">photon</span> system is found to be distinctly different from previous experiments. Characteristic coupling features such as modes anticrossing, linewidth evolution, peculiar line shape, and resonance broadening are systematically measured and consistently analyzed by a theoretical model set on the foundation of classical electrodynamic coupling. Our experimental and theoretical approach paves the way for pursuing microwave coherent manipulation of pure spin current via the combination of spin pumping and magnon-<span class="hlt">photon</span> coupling.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015APS..DNP.EA037B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015APS..DNP.EA037B"><span><span class="hlt">Gain</span> Evaluation of Micro-Channel-Plate Photomultipliers in the Upgraded High-B Test Facility at Jefferson Lab</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Barber, Corinne; DIRC at EIC Collaboration</p> <p>2015-10-01</p> <p>The High-B test facility at Thomas Jefferson National Accelerator Facility allows researchers to evaluate the <span class="hlt">gain</span> of compact <span class="hlt">photon</span> sensors, such as Micro-Channel-Plate Photomultipliers (MCP-PMTs), in magnetic fields up to 5 T. These ongoing studies support the development of a Detector of Internally Reflected Cherenkov light (DIRC) to be used in an Electron Ion Collider (EIC). Here, we present our summer 2015 activities to upgrade and improve the facility, and we show results for MCP-PMT <span class="hlt">gain</span> changes in high B-fields. To monitor the light stability delivered to the MCP-PMTs being tested, we implemented a Silicon Photomultiplier (SiPM) in the setup and calibrated the ADC reading this sensor. A 405-nm Light-Emitting Diode (LED) housed in an optical tube compatible with neutral density filters was also installed. The filters provide an alternative way of reducing the light output of the LED to operate the MCP-PMTs in a single-<span class="hlt">photon</span> mode. We calibrated a set of filters by means of a photodiode and measured the <span class="hlt">photon</span> flux at multiple positions relative to the LED. This information helped us to design 3D-printed holders unique to each MCP-PMT so that the photocathode receives the greatest amount of light. The improvements to the setup allow for more precise PMT <span class="hlt">gain</span> evaluation. This team includes 7 collaborators/co-authors besides myself: Yordanka Ilieva, Kijun Park, Greg Kalicy, Carl Zorn, Pawel Nadel-Turonski, Tongtong Cao, and Lee.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PhyS...93f5101W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PhyS...93f5101W"><span><span class="hlt">Gain</span> assisted coherent control of microwave pulse in a one dimensional array of artificial atoms</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Waqas, Mohsin; Ayaz, M. Q.; Waseem, M.; Qamar, Sajid; Qamar, Shahid</p> <p>2018-06-01</p> <p>We study the coherent propagation of a microwave pulse through a one-dimensional array of artificial atoms. The scheme is based upon <span class="hlt">gain</span> assisted propagation of the pulse using two-<span class="hlt">photon</span> Raman transition in a three-level superconducting artificial atoms (SAAs) coupled to a microwave transmission line. Our results show that the group velocity can be significantly reduced by increasing the Rabi frequency of the pump fields which in turn can lead to an efficient storage of the pulse inside a 1D array of SAAs. Further, the intensity of the transmitted pulse increases with the number of artificial atoms owing to the <span class="hlt">gain</span> associated with the two-<span class="hlt">photon</span> Raman transition. Our results also show that the window width decreases for both scattering and negligible scattering cases with the increase in the number of SAAs. The fidelity of the system also remains high even after the passage of the pulse through a large number of SAAs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015SPIE.9492E..0NS','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015SPIE.9492E..0NS"><span>Gun muzzle flash <span class="hlt">detection</span> using a single <span class="hlt">photon</span> avalanche diode array in 0.18µm CMOS technology</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Savuskan, Vitali; Jakobson, Claudio; Merhav, Tomer; Shoham, Avi; Brouk, Igor; Nemirovsky, Yael</p> <p>2015-05-01</p> <p>In this study, a CMOS Single <span class="hlt">Photon</span> Avalanche Diode (SPAD) 2D array is used to record and sample muzzle flash events in the visible spectrum, from representative weapons. SPADs <span class="hlt">detect</span> the emission peaks of alkali salts, potassium or sodium, with spectral emission lines around 769nm and 589nm, respectively. The alkali salts are included in the gunpowder to suppress secondary flashes ignited during the muzzle flash event. The SPADs possess two crucial properties for muzzle flash imaging: (i) very high <span class="hlt">photon</span> <span class="hlt">detection</span> sensitivity, (ii) a unique ability to convert the optical signal to a digital signal at the source pixel, thus practically eliminating readout noise. The sole noise sources are the ones prior to the readout circuitry (optical signal distribution, avalanche initiation distribution and nonphotonic generation). This enables high sampling frequencies in the kilohertz range without significant SNR degradation, in contrast to regular CMOS image sensors. This research will demonstrate the SPAD's ability to accurately sample and reconstruct the temporal behavior of the muzzle flash in the visible wavelength, in the presence of sunlight. The reconstructed signal is clearly distinguishable from background clutter, through exploitation of flash temporal characteristics and signal processing, which will be reported. The frame rate of ~16 KHz was chosen as an optimum between SNR degradation and temporal profile recognition accuracy. In contrast to a single SPAD, the 2D array allows for multiple events to be processed simultaneously. Moreover, a significant field of view is covered, enabling comprehensive surveillance and imaging.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1998AstL...24..134N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1998AstL...24..134N"><span>Blazar 3C 66A: Another extragalactic source of ultra-high-energy gamma-ray <span class="hlt">photons</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Neshpor, Yu. I.; Stepanyan, A. A.; Kalekin, O. P.; Fomin, V. P.; Chalenko, N. N.; Shitov, V. G.</p> <p>1998-03-01</p> <p>he observations of the object 3C 66A which were carried out with the GT-48 gamma-ray telescope at the Crimean Astrophysical Observatory in November-December 1996 revealed a flux of ultra-high-energy (>10^12 eV) gamma-ray <span class="hlt">photons</span> from this blazar. According to preliminary estimates, the <span class="hlt">photon</span> flux is (31) 10^11 <span class="hlt">photons</span> cm^-2 s^-1. The blazar 3C 66A is the third extragalactic object from which a flux of ultra- high-energy gamma-ray <span class="hlt">photons</span> was <span class="hlt">detected</span>. Fluxes of gamma-ray <span class="hlt">photons</span> were previously <span class="hlt">detected</span> from the galaxies Mk 421 and Mk 501 at the Whipple observatory. This result provides further evidence that active processes proceed in blazars which are accompanied by the generation of cosmic rays responsible for the emission of gamma-ray <span class="hlt">photons</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018NJPh...20b3008D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018NJPh...20b3008D"><span>Sensing coherent phonons with two-<span class="hlt">photon</span> interference</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ding, Ding; Yin, Xiaobo; Li, Baowen</p> <p>2018-02-01</p> <p><span class="hlt">Detecting</span> coherent phonons pose different challenges compared to coherent <span class="hlt">photons</span> due to the much stronger interaction between phonons and matter. This is especially true for high frequency heat carrying phonons, which are intrinsic lattice vibrations experiencing many decoherence events with the environment, and are thus generally assumed to be incoherent. Two <span class="hlt">photon</span> interference techniques, especially coherent population trapping (CPT) and electromagnetically induced transparency (EIT), have led to extremely sensitive <span class="hlt">detection</span>, spectroscopy and metrology. Here, we propose the use of two <span class="hlt">photon</span> interference in a three-level system to sense coherent phonons. Unlike prior works which have treated phonon coupling as damping, we account for coherent phonon coupling using a full quantum-mechanical treatment. We observe strong asymmetry in absorption spectrum in CPT and negative dispersion in EIT susceptibility in the presence of coherent phonon coupling which cannot be accounted for if only pure phonon damping is considered. Our proposal has application in sensing heat carrying coherent phonons effects and understanding coherent bosonic multi-pathway interference effects in three coupled oscillator systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015ApPhL.107i1101B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ApPhL.107i1101B"><span>Angle-resolved photoemission spectroscopy with 9-eV <span class="hlt">photon</span>-energy pulses generated in a gas-filled hollow-core <span class="hlt">photonic</span> crystal fiber</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bromberger, H.; Ermolov, A.; Belli, F.; Liu, H.; Calegari, F.; Chávez-Cervantes, M.; Li, M. T.; Lin, C. T.; Abdolvand, A.; Russell, P. St. J.; Cavalleri, A.; Travers, J. C.; Gierz, I.</p> <p>2015-08-01</p> <p>A recently developed source of ultraviolet radiation, based on optical soliton propagation in a gas-filled hollow-core <span class="hlt">photonic</span> crystal fiber, is applied here to angle-resolved photoemission spectroscopy (ARPES). Near-infrared femtosecond pulses of only few μJ energy generate vacuum ultraviolet radiation between 5.5 and 9 eV inside the gas-filled fiber. These pulses are used to measure the band structure of the topological insulator Bi2Se3 with a signal to noise ratio comparable to that obtained with high order harmonics from a gas jet. The two-order-of-magnitude <span class="hlt">gain</span> in efficiency promises time-resolved ARPES measurements at repetition rates of hundreds of kHz or even MHz, with <span class="hlt">photon</span> energies that cover the first Brillouin zone of most materials.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22099095-scintillator-high-gain-avalanche-rushing-photoconductor-active-matrix-flat-panel-imager-zero-spatial-frequency-ray-imaging-properties-solid-state-sharp-sensor-structure','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22099095-scintillator-high-gain-avalanche-rushing-photoconductor-active-matrix-flat-panel-imager-zero-spatial-frequency-ray-imaging-properties-solid-state-sharp-sensor-structure"><span>Scintillator high-<span class="hlt">gain</span> avalanche rushing photoconductor active-matrix flat panel imager: Zero-spatial frequency x-ray imaging properties of the solid-state SHARP sensor structure</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Wronski, M.; Zhao, W.; Tanioka, K.</p> <p></p> <p>Purpose: The authors are investigating the feasibility of a new type of solid-state x-ray imaging sensor with programmable avalanche <span class="hlt">gain</span>: scintillator high-<span class="hlt">gain</span> avalanche rushing photoconductor active matrix flat panel imager (SHARP-AMFPI). The purpose of the present work is to investigate the inherent x-ray <span class="hlt">detection</span> properties of SHARP and demonstrate its wide dynamic range through programmable <span class="hlt">gain</span>. Methods: A distributed resistive layer (DRL) was developed to maintain stable avalanche <span class="hlt">gain</span> operation in a solid-state HARP. The signal and noise properties of the HARP-DRL for optical <span class="hlt">photon</span> <span class="hlt">detection</span> were investigated as a function of avalanche <span class="hlt">gain</span> both theoretically and experimentally, and themore » results were compared with HARP tube (with electron beam readout) used in previous investigations of zero spatial frequency performance of SHARP. For this new investigation, a solid-state SHARP x-ray image sensor was formed by direct optical coupling of the HARP-DRL with a structured cesium iodide (CsI) scintillator. The x-ray sensitivity of this sensor was measured as a function of avalanche <span class="hlt">gain</span> and the results were compared with the sensitivity of HARP-DRL measured optically. The dynamic range of HARP-DRL with variable avalanche <span class="hlt">gain</span> was investigated for the entire exposure range encountered in radiography/fluoroscopy (R/F) applications. Results: The signal from HARP-DRL as a function of electric field showed stable avalanche <span class="hlt">gain</span>, and the noise associated with the avalanche process agrees well with theory and previous measurements from a HARP tube. This result indicates that when coupled with CsI for x-ray <span class="hlt">detection</span>, the additional noise associated with avalanche <span class="hlt">gain</span> in HARP-DRL is negligible. The x-ray sensitivity measurements using the SHARP sensor produced identical avalanche <span class="hlt">gain</span> dependence on electric field as the optical measurements with HARP-DRL. Adjusting the avalanche multiplication <span class="hlt">gain</span> in HARP-DRL enabled a very wide dynamic range which</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29260151','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29260151"><span>Chem/bio sensing with non-classical light and integrated <span class="hlt">photonics</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Haas, J; Schwartz, M; Rengstl, U; Jetter, M; Michler, P; Mizaikoff, B</p> <p>2018-01-29</p> <p>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 <span class="hlt">detection</span> schemes. This is further facilliated by the progress in fabrication, miniaturization and integration of visible and infrared quantum <span class="hlt">photonics</span>. Especially, the combination of efficient single-<span class="hlt">photon</span> sources together with waveguiding/sensing structures, serving as active optical transducer, as well as advanced detector materials is promising integrated quantum <span class="hlt">photonic</span> 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 <span class="hlt">photonic</span> sensing platforms based on N00N states are discussed along with appropriate recognition chemistries, facilitating the <span class="hlt">detection</span> 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-<span class="hlt">photon</span> sources.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3609020','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3609020"><span>Observing fermionic statistics with <span class="hlt">photons</span> in arbitrary processes</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Matthews, Jonathan C. F.; Poulios, Konstantinos; Meinecke, Jasmin D. A.; Politi, Alberto; Peruzzo, Alberto; Ismail, Nur; Wörhoff, Kerstin; Thompson, Mark G.; O'Brien, Jeremy L.</p> <p>2013-01-01</p> <p>Quantum mechanics defines two classes of particles-bosons and fermions-whose exchange statistics fundamentally dictate quantum dynamics. Here we develop a scheme that uses entanglement to directly observe the correlated <span class="hlt">detection</span> statistics of any number of fermions in any physical process. This approach relies on sending each of the entangled particles through identical copies of the process and by controlling a single phase parameter in the entangled state, the correlated <span class="hlt">detection</span> statistics can be continuously tuned between bosonic and fermionic statistics. We implement this scheme via two entangled <span class="hlt">photons</span> shared across the polarisation modes of a single <span class="hlt">photonic</span> chip to directly mimic the fermion, boson and intermediate behaviour of two-particles undergoing a continuous time quantum walk. The ability to simulate fermions with <span class="hlt">photons</span> is likely to have applications for verifying boson scattering and for observing particle correlations in analogue simulation using any physical platform that can prepare the entangled state prescribed here. PMID:23531788</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24522637','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24522637"><span>A sensitive two-<span class="hlt">photon</span> probe to selectively <span class="hlt">detect</span> monoamine oxidase B activity in Parkinson's disease models.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Li, Lin; Zhang, Cheng-Wu; Chen, Grace Y J; Zhu, Biwei; Chai, Chou; Xu, Qing-Hua; Tan, Eng-King; Zhu, Qing; Lim, Kah-Leong; Yao, Shao Q</p> <p>2014-01-01</p> <p>The unusually high MAO-B activity consistently observed in Parkinson's disease (PD) patients has been proposed as a biomarker; however, this has not been realized due to the lack of probes suitable for MAO-B-specific <span class="hlt">detection</span> in live cells/tissues. Here we report the first two-<span class="hlt">photon</span>, small molecule fluorogenic probe (U1) that enables highly sensitive/specific and real-time imaging of endogenous MAO-B activities across biological samples. We also used U1 to confirm the reported inverse relationship between parkin and MAO-B in PD models. With no apparent toxicity, U1 may be used to monitor MAO-B activities in small animals during disease development. In clinical samples, we find elevated MAO-B activities only in B lymphocytes (not in fibroblasts), hinting that MAO-B activity in peripheral blood cells might be an accessible biomarker for rapid <span class="hlt">detection</span> of PD. Our results provide important starting points for using small molecule imaging techniques to explore MAO-B at the organism level.</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" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012ApPhB.108..683Q','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012ApPhB.108..683Q"><span>The influence of atmospheric turbulence on partially coherent two-<span class="hlt">photon</span> entangled field</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Qiu, Y.; She, W.</p> <p>2012-09-01</p> <p>The propagation of a two-<span class="hlt">photon</span> field from down-conversion of a partially coherent Gaussian Schell-model (GSM) pump beam in free space has been reported. However, the propagation of this two-<span class="hlt">photon</span> field through a turbulent atmosphere has not been investigated yet. In this paper, an analytical expression of the coincidence count rate of the two-<span class="hlt">photon</span> entangled field is derived. Unlike what has been reported, the field is from a parameter down-conversion of a partially coherent dark hollow pump beam and propagates through a turbulent atmosphere. The effects of the propagation parameters on the coincidence count rate are evaluated and illustrated. The results show that the pump beam parameters and atmospheric turbulence can evidently affect the <span class="hlt">detection</span> probability of the <span class="hlt">photon</span> pair at two different positions. It is found that the <span class="hlt">detection</span> probability of the two-<span class="hlt">photon</span> field is higher, and thus less susceptible to turbulence, if the field is produced by a lower mode of partially coherent pump beam.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JPSJ...87b4001Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JPSJ...87b4001Z"><span>Nonclassicality of <span class="hlt">Photon</span>-Added Displaced Thermal State via Quantum Phase-Space Distributions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Ran; Meng, Xiang-Guo; Du, Chuan-Xun; Wang, Ji-Suo</p> <p>2018-02-01</p> <p>We introduce a new kind of nonclassical mixed state generated by adding arbitrary <span class="hlt">photons</span> to a displaced thermal state, i.e., the <span class="hlt">photon</span>-added displaced thermal state (PADTS), and obtain the normalization factor, which is simply related to two-variable Hermite polynomials. We also discuss the nonclassicality of the PADTS by considering quantum phase-space distributions. The results indicate that the value of the <span class="hlt">photon</span> count statistics is maximum when the number of <span class="hlt">detected</span> <span class="hlt">photons</span> is equal to the number of added <span class="hlt">photons</span>, and that the <span class="hlt">photon</span>-added operation has a similar modulation effect with increasing displacement. Moreover, the negative volume of the Wigner function for the PADTS takes a maximal value for a specific <span class="hlt">photon</span>-added number.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JKPS...63.2012J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JKPS...63.2012J"><span><span class="hlt">Detection</span> mechanism and characteristics of ZnO-based N2O sensors operating with <span class="hlt">photons</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jeong, T. S.; Yu, J. H.; Mo, H. S.; Kim, T. S.; Youn, C. J.; Hong, K. J.</p> <p>2013-11-01</p> <p>N2O sensors made with ZnO-based ZnCdO films were grown on Pyrex substrates by using the RF co-sputtering method. The structure of the N2O sensor was electrode/sensor/glass/illuminant. The mechanism of the photo-assisted oxidation and reduction process on the surface of the N2O sensors was investigated using light from a UV lamp and violet light emitting diode (LED). For <span class="hlt">photon</span> exposure wavelengths of 365 and 405 nm, the sensitivity of the ZnO-based ZnCdO sensors was measured. From these measurements, the values of the sensitivity of the sensors with x = 0, 0.01, and 0.05 were found to be S = 1.44, 1.39, and 1.33 under LED light with a wavelength of 405 nm, respectively. These sensitivities were compared to those of SnO2 and WO3 materials measured at operating temperatures of 300-600 °C. Also, under exposure with UV light, the response times were observed to be 130 to 270 sec. These response times were slightly slower than that for the traditional method of thermal heating. However, they indicate that the described <span class="hlt">photon</span> exposure method for N2O <span class="hlt">detection</span> can replace the conventional heating mode. Consequently, we demonstrated that portable N2O sensors for room-temperature operation could be fabricated without thermal heating.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JInst..13P1012T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JInst..13P1012T"><span>Energy discrimination for positron emission tomography using the time information of the first <span class="hlt">detected</span> <span class="hlt">photons</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Therrien, A. C.; Lemaire, W.; Lecoq, P.; Fontaine, R.; Pratte, J.-F.</p> <p>2018-01-01</p> <p>The advantages of Time-of-Flight positron emission tomography (TOF-PET) have pushed the development of detectors with better time resolution. In particular, Silicon Photomultipliers (SiPM) have evolved tremendously in the past decade and arrays with a fully digital readout are the next logical step (dSiPM). New multi-timestamp methods use the precise time information of multiple <span class="hlt">photons</span> to estimate the time of a PET event with greater accuracy, resulting in excellent time resolution. We propose a method which uses the same timestamps as the time estimator to perform energy discrimination, thus using data obtained within 5 ns of the beginning of the event. Having collected all the necessary information, the dSiPM could then be disabled for the remaining scintillation while dedicated electronics process the collected data. This would reduce afterpulsing as the SPAD would be turned off for several hundred nanoseconds, emptying the majority of traps. The proposed method uses a strategy based on subtraction and minimal electronics to reject energy below a selected threshold. This method achieves an error rate of less than 3% for photopeak discrimination (threshold at 400 keV) for dark count rates up to 100 cps/μm2, time-to-digital converter resolution up to 50 ps and a <span class="hlt">photon</span> <span class="hlt">detection</span> efficiency ranging from 10 to 70%.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21164870','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21164870"><span>Ultrafast nonlinear optofluidics in selectively liquid-filled <span class="hlt">photonic</span> crystal fibers.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Vieweg, M; Gissibl, T; Pricking, S; Kuhlmey, B T; Wu, D C; Eggleton, B J; Giessen, H</p> <p>2010-11-22</p> <p>Selective filling of <span class="hlt">photonic</span> crystal fibers with different media enables a plethora of possibilities in linear and nonlinear optics. Using two-<span class="hlt">photon</span> direct-laser writing we demonstrate full flexibility of individual closing of holes and subsequent filling of <span class="hlt">photonic</span> crystal fibers with highly nonlinear liquids. We experimentally demonstrate solitonic supercontinuum generation over 600 nm bandwidth using a compact femtosecond oscillator as pump source. Encapsulating our fibers at the ends we realize a compact ultrafast nonlinear optofluidic device. Our work is fundamentally important to the field of nonlinear optics as it provides a new platform for investigations of spatio-temporal nonlinear effects and underpins new applications in sensing and communications. Selective filling of different linear and nonlinear liquids, metals, gases, <span class="hlt">gain</span> media, and liquid crystals into <span class="hlt">photonic</span> crystal fibers will be the basis of new reconfigurable and versatile optical fiber devices with unprecedented performance. Control over both temporal and spatial dispersion as well as linear and nonlinear coupling will lead to the generation of spatial-temporal solitons, so-called optical bullets.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26193575','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26193575"><span>Integrated quantum <span class="hlt">photonic</span> sensor based on Hong-Ou-Mandel interference.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Basiri-Esfahani, Sahar; Myers, Casey R; Armin, Ardalan; Combes, Joshua; Milburn, Gerard J</p> <p>2015-06-15</p> <p><span class="hlt">Photonic</span>-crystal-based integrated optical systems have been used for a broad range of sensing applications with great success. This has been motivated by several advantages such as high sensitivity, miniaturization, remote sensing, selectivity and stability. Many <span class="hlt">photonic</span> crystal sensors have been proposed with various fabrication designs that result in improved optical properties. In parallel, integrated optical systems are being pursued as a platform for <span class="hlt">photonic</span> quantum information processing using linear optics and Fock states. Here we propose a novel integrated Fock state optical sensor architecture that can be used for force, refractive index and possibly local temperature <span class="hlt">detection</span>. In this scheme, two coupled cavities behave as an "effective beam splitter". The sensor works based on fourth order interference (the Hong-Ou-Mandel effect) and requires a sequence of single <span class="hlt">photon</span> pulses and consequently has low pulse power. Changes in the parameter to be measured induce variations in the effective beam splitter reflectivity and result in changes to the visibility of interference. We demonstrate this generic scheme in coupled L3 <span class="hlt">photonic</span> crystal cavities as an example and find that this system, which only relies on <span class="hlt">photon</span> coincidence <span class="hlt">detection</span> and does not need any spectral resolution, can estimate forces as small as 10(-7) Newtons and can measure one part per million change in refractive index using a very low input power of 10(-10)W. Thus linear optical quantum <span class="hlt">photonic</span> architectures can achieve comparable sensor performance to semiclassical devices.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1356592-minimal-spanning-tree-algorithm-ray-source-detection-sparse-photon-images-cluster-parameters-selection-strategies','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1356592-minimal-spanning-tree-algorithm-ray-source-detection-sparse-photon-images-cluster-parameters-selection-strategies"><span>Minimal spanning tree algorithm for γ-ray source <span class="hlt">detection</span> in sparse <span class="hlt">photon</span> images: cluster parameters and selection strategies</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Campana, R.; Bernieri, E.; Massaro, E.; ...</p> <p>2013-05-22</p> <p>We present that the minimal spanning tree (MST) algorithm is a graph-theoretical cluster-finding method. We previously applied it to γ-ray bidimensional images, showing that it is quite sensitive in finding faint sources. Possible sources are associated with the regions where the <span class="hlt">photon</span> arrival directions clusterize. MST selects clusters starting from a particular “tree” connecting all the point of the image and performing a cut based on the angular distance between <span class="hlt">photons</span>, with a number of events higher than a given threshold. In this paper, we show how a further filtering, based on some parameters linked to the cluster properties, canmore » be applied to reduce spurious <span class="hlt">detections</span>. We find that the most efficient parameter for this secondary selection is the magnitudeM of a cluster, defined as the product of its number of events by its clustering degree. We test the sensitivity of the method by means of simulated and real Fermi-Large Area Telescope (LAT) fields. Our results show that √M is strongly correlated with other statistical significance parameters, derived from a wavelet based algorithm and maximum likelihood (ML) analysis, and that it can be used as a good estimator of statistical significance of MST <span class="hlt">detections</span>. Finally, we apply the method to a 2-year LAT image at energies higher than 3 GeV, and we show the presence of new clusters, likely associated with BL Lac objects.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010SPIE.7838E..04L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010SPIE.7838E..04L"><span>Fast <span class="hlt">detection</span> of narcotics by single <span class="hlt">photon</span> ionization mass spectrometry and laser ion mobility spectrometry</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Laudien, Robert; Schultze, Rainer; Wieser, Jochen</p> <p>2010-10-01</p> <p>In this contribution two analytical devices for the fast <span class="hlt">detection</span> of security-relevant substances like narcotics and explosives are presented. One system is based on an ion trap mass spectrometer (ITMS) with single <span class="hlt">photon</span> ionization (SPI). This soft ionization technique, unlike electron impact ionization (EI), reduces unwanted fragment ions in the mass spectra allowing the clear determination of characteristic (usually molecular) ions. Their enrichment in the ion trap and identification by tandem MS investigations (MS/MS) enables the <span class="hlt">detection</span> of the target substances in complex matrices at low concentrations without time-consuming sample preparation. For SPI an electron beam pumped excimer light source of own fabrication (E-Lux) is used. The SPI-ITMS system was characterized by the analytical study of different drugs like cannabis, heroin, cocaine, amphetamines, and some precursors. Additionally, it was successfully tested on-site in a closed illegal drug laboratory, where low quantities of MDMA could be directly <span class="hlt">detected</span> in samples from floors, walls and lab equipments. The second analytical system is based on an ion mobility (IM) spectrometer with resonant multiphoton ionization (REMPI). With the frequency quadrupled Nd:YAG laser (266 nm), used for ionization, a selective and sensitive <span class="hlt">detection</span> of aromatic compounds is possible. By application of suited aromatic dopants, in addition, also non-aromatic polar compounds are accessible by ion molecule reactions like proton transfer or complex formation. Selected drug precursors could be successfully <span class="hlt">detected</span> with this device as well, qualifying it to a lower-priced alternative or useful supplement of the SPI-ITMS system for security analysis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPIE.9858E..0MV','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPIE.9858E..0MV"><span>Recent advances in superconducting nanowire single <span class="hlt">photon</span> detectors for single-<span class="hlt">photon</span> imaging</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>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.</p> <p>2016-05-01</p> <p>We demonstrate a 64-pixel free-space-coupled array of superconducting nanowire single <span class="hlt">photon</span> detectors optimized for high <span class="hlt">detection</span> 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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AAS...22910601V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AAS...22910601V"><span>A new imaging technique for <span class="hlt">detecting</span> interstellar communications</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vallerga, John; Welsh, Barry; Kotze, Marissa; Siegmund, Oswald</p> <p>2017-01-01</p> <p>We report on a unique <span class="hlt">detection</span> methodology using the Berkeley Visible Image Tube (BVIT) mounted on the 10m Southern African Large Telescope (SALT) to search for laser pulses originating in communications from advanced extraterrestrial (ET) civilizations residing on nearby Earth-like planets located within their habitability zones. The <span class="hlt">detection</span> technique assumes that ET communicates through high powered pulsed lasers with pulse durations on the order of 5 nanoseconds, the signals thereby being brighter than that of the host star within this very short period of time. Our technique turns down the <span class="hlt">gain</span> of the optically sensitive <span class="hlt">photon</span> counting microchannel plate detector such that ~30 <span class="hlt">photons</span> are required in a 5ns window to generate an imaged event. Picking a priori targets with planets in the habitable zone substantially reduces the false alarm rate. Interplanetary communication by optical masers was first postulated by Schwartz and Townes in 1961. Under the assumption that ET has access to a 10 m class telescope operated as a transmitter then we could <span class="hlt">detect</span> lasers with a similar power to that of the Livermore Laboratory laser (~1.8Mj per pulse), to a distance of ~ 1000 pc. In this talk we present the results of 2400 seconds of BVIT observations on the SALT of the star Wolf 1061, which is known to harbor an Earth-sized exoplanet located in the habitability zone. At this distance (4.3 pc), BVIT on SALT could <span class="hlt">detect</span> a 48 joule per pulse laser, now commercially available as tabletop devices.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JAP...123k3104H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JAP...123k3104H"><span>Electrical <span class="hlt">gain</span> in interband cascade infrared photodetectors</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Huang, Wenxiang; Li, Lu; Lei, Lin; Massengale, Jeremy A.; Yang, Rui Q.; Mishima, Tetsuya D.; Santos, Michael B.</p> <p>2018-03-01</p> <p>In order to achieve improved understanding and <span class="hlt">gain</span> insights into the device operation of interband cascade infrared photodetectors (ICIPs) and ultimately to optimize the design, we present a comparative study of five long-wavelength (LW) ICIPs based on a type-II InAs/GaSb superlattice. This study shows how the device responsivity is affected by the individual absorber thicknesses and the number of cascade stages, through the impact of light attenuation. Additionally, this study further validates that the electrical <span class="hlt">gain</span> universally exists in non-current-matched ICIPs. With multiple cascade stages to suppress noise, these LW ICIPs achieved superior device performance at high temperatures, in terms of Johnson-noise limited <span class="hlt">detectivities</span>, compared to commercial MCT detectors. Furthermore, a theory is developed to quantitatively describe the electrical <span class="hlt">gain</span> in ICIPs and our calculations are in good agreement with the experimental results. Based on the theory, the optimal number of stages for maximizing the device <span class="hlt">detectivity</span> D* is identified with inclusion of the electrical <span class="hlt">gain</span>. Our calculation shows that this optimal number of stages is relatively large in the presence of the <span class="hlt">gain</span> and the maximized D* has a relatively weak dependence on the absorber thickness when it is sufficiently thin.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20100010895','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20100010895"><span>WGM-Based <span class="hlt">Photonic</span> Local Oscillators and Modulators</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Matsko, Andrey; Maleki, Lute; Iltchenko, Vladimir; Savchenkov, Anatoliy</p> <p>2007-01-01</p> <p><span class="hlt">Photonic</span> local oscillators and modulators that include whispering-gallery mode (WGM) optical resonators have been proposed as power-efficient devices for generating and <span class="hlt">detecting</span> radiation at frequencies of the order of a terahertz. These devices are intended especially to satisfy anticipated needs for receivers capable of <span class="hlt">detecting</span> lowpower, narrow-band terahertz signals to be used for sensing substances of interest in scientific and military applications. At present, available terahertz-signal detectors are power-inefficient and do not afford the spectral and amplitude resolution needed for <span class="hlt">detecting</span> such signals. The proposed devices would not be designed according to the conventional approach of direct <span class="hlt">detection</span> of terahertz radiation. Instead, terahertz radiation would first be up-converted into the optical domain, wherein signals could be processed efficiently by <span class="hlt">photonic</span> means and <span class="hlt">detected</span> by optical photodetectors, which are more efficient than are photodetectors used in conventional direct <span class="hlt">detection</span> of terahertz radiation. The <span class="hlt">photonic</span> devices used to effect the up-conversion would include a tunable optical local oscillator and a novel electro-optical modulator. A local oscillator according to the proposal would be a WGM-based modelocked laser operating at a desired pulserepetition rate of the order of a terahertz. The oscillator would include a terahertz optical filter based on a WGM microresonator, a fiber-optic delay line, an optical amplifier (which could be either a semiconductor optical amplifier or an erbium-doped optical fiberamplifier), and a WGM Ka-band modulator. The terahertz repetition rate would be obtained through harmonic mode locking: for example, by modulating the light at a frequency of 33 GHz and locking each 33d optical mode, one would create a 1.089-THz pulse train. The high resonance quality factors (Q values) of WGM optical resonators should make it possible to decrease signal-generation threshold power levels significantly below</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26488887','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26488887"><span>Construction of Nanowire Heterojunctions: <span class="hlt">Photonic</span> Function-Oriented Nanoarchitectonics.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Li, Yong Jun; Yan, Yongli; Zhao, Yong Sheng; Yao, Jiannian</p> <p>2016-02-10</p> <p>Nanophotonics has received broad research interest because it may provide an alternative opportunity to overcome the fundamental limitations of electronic circuits. So far, diverse <span class="hlt">photonic</span> functions, such as light generation, modulation, and <span class="hlt">detection</span>, have been realized based on various nano-materials. The exact structural features of these material systems, including geometric characteristics, surface morphology, and material composition, play a key role in determining the <span class="hlt">photonic</span> functions. Therefore, rational designs and constructions of materials on both morphological and componential levels, namely nanoarchitectonics, are indispensable for any <span class="hlt">photonic</span> device with specific functionalities. Recently, a series of nanowire heterojunctions (NWHJs), which are usually made from two or more kinds of material compositions, were constructed for novel <span class="hlt">photonic</span> applications based on various interactions between different materials at the junctions, for instance, energy transfer, exciton-plasmon coupling, or <span class="hlt">photon</span>-plasmon coupling. A summary of these works is necessary to get a more comprehensive understanding of the relationship between <span class="hlt">photonic</span> functions and architectonics of NWHJs, which will be instructive for designing novel <span class="hlt">photonic</span> devices towards integrated circuits. Here, <span class="hlt">photonic</span> function oriented nanoarchitectonics based on recent breakthroughs in nanophotonic devices are discussed, with emphasis on the design mechanisms, fabrication strategies, and excellent performances. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.</p> </li> <li> <p><a target="_blank" 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 <span class="hlt">detection</span> with an efficient and practical semiconductor single-<span class="hlt">photon</span> detector</span></a></p> <p><a target="_blank" 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 <span class="hlt">detection</span> 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-<span class="hlt">photon</span> 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" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018IJMPB..3250088G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018IJMPB..3250088G"><span>On-chip <span class="hlt">photonic</span> transistor based on the spike synchronization in circuit QED</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gül, Yusuf</p> <p>2018-03-01</p> <p>We consider the single <span class="hlt">photon</span> transistor in coupled cavity system of resonators interacting with multilevel superconducting artificial atom simultaneously. Effective single mode transformation is used for the diagonalization of the Hamiltonian and impedance matching in terms of the normal modes. Storage and transmission of the incident field are described by the interactions between the cavities controlling the atomic transitions of lowest lying states. Rabi splitting of vacuum-induced multiphoton transitions is considered in input/output relations by the quadrature operators in the absence of the input field. Second-order coherence functions are employed to investigate the <span class="hlt">photon</span> blockade and delocalization-localization transitions of cavity fields. Spontaneous virtual <span class="hlt">photon</span> conversion into real <span class="hlt">photons</span> is investigated in localized and oscillating regimes. Reflection and transmission of cavity output fields are investigated in the presence of the multilevel transitions. Accumulation and firing of the reflected and transmitted fields are used to investigate the synchronization of the bunching spike train of transmitted field and population imbalance of cavity fields. In the presence of single <span class="hlt">photon</span> gate field, <span class="hlt">gain</span> enhancement is explained for transmitted regime.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvB..96s5209M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvB..96s5209M"><span>Direct experimental observation of nonclassicality in ensembles of single-<span class="hlt">photon</span> emitters</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Moreva, E.; Traina, P.; Forneris, J.; Degiovanni, I. P.; Ditalia Tchernij, S.; Picollo, F.; Brida, G.; Olivero, P.; Genovese, M.</p> <p>2017-11-01</p> <p>In this work we experimentally demonstrate a recently proposed criterion addressed to <span class="hlt">detect</span> nonclassical behavior in the fluorescence emission of ensembles of single-<span class="hlt">photon</span> emitters. In particular, we apply the method to study clusters of nitrogen-vacancy centers in diamond characterized with single-<span class="hlt">photon</span>-sensitive confocal microscopy. Theoretical considerations on the behavior of the parameter at any arbitrary order in the presence of Poissonian noise are presented and, finally, the opportunity of <span class="hlt">detecting</span> manifold coincidences is discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28447975','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28447975"><span>Measurement of Quantum Interference in a Silicon Ring Resonator <span class="hlt">Photon</span> Source.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Steidle, Jeffrey A; Fanto, Michael L; Preble, Stefan F; Tison, Christopher C; Howland, Gregory A; Wang, Zihao; Alsing, Paul M</p> <p>2017-04-04</p> <p>Silicon <span class="hlt">photonic</span> chips have the potential to realize complex integrated quantum information processing circuits, including <span class="hlt">photon</span> sources, qubit manipulation, and integrated single-<span class="hlt">photon</span> detectors. Here, we present the key aspects of preparing and testing a silicon <span class="hlt">photonic</span> quantum chip with an integrated <span class="hlt">photon</span> source and two-<span class="hlt">photon</span> interferometer. The most important aspect of an integrated quantum circuit is minimizing loss so that all of the generated <span class="hlt">photons</span> are <span class="hlt">detected</span> with the highest possible fidelity. Here, we describe how to perform low-loss edge coupling by using an ultra-high numerical aperture fiber to closely match the mode of the silicon waveguides. By using an optimized fusion splicing recipe, the UHNA fiber is seamlessly interfaced with a standard single-mode fiber. This low-loss coupling allows the measurement of high-fidelity <span class="hlt">photon</span> production in an integrated silicon ring resonator and the subsequent two-<span class="hlt">photon</span> interference of the produced <span class="hlt">photons</span> in a closely integrated Mach-Zehnder interferometer. This paper describes the essential procedures for the preparation and characterization of high-performance and scalable silicon quantum <span class="hlt">photonic</span> circuits.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014IJTP...53.1601X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014IJTP...53.1601X"><span>Optical Parametric Amplification of Single <span class="hlt">Photon</span>: Statistical Properties and Quantum Interference</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xu, Xue-Xiang; Yuan, Hong-Chun</p> <p>2014-05-01</p> <p>By using phase space method, we theoretically investigate the quantum statistical properties and quantum interference of optical parametric amplification of single <span class="hlt">photon</span>. The statistical properties, such as the Wigner function (WF), average <span class="hlt">photon</span> number, <span class="hlt">photon</span> number distribution and parity, are derived analytically for the fields of the two output ports. The results indicate that the fields in the output ports are multiphoton states rather than single <span class="hlt">photon</span> state due to the amplification of the optical parametric amplifiers (OPA). In addition, the phase sensitivity is also examined by using the <span class="hlt">detection</span> scheme of parity measurement.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26792424','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26792424"><span>Quantum interference in heterogeneous superconducting-<span class="hlt">photonic</span> circuits on a silicon chip.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Schuck, C; Guo, X; Fan, L; Ma, X; Poot, M; Tang, H X</p> <p>2016-01-21</p> <p>Quantum information processing holds great promise for communicating and computing data efficiently. However, scaling current <span class="hlt">photonic</span> 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-<span class="hlt">photon</span> detectors. Here we develop a hybrid superconducting-<span class="hlt">photonic</span> 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 <span class="hlt">detecting</span> <span class="hlt">photon</span> pairs directly on the chip with waveguide-coupled single-<span class="hlt">photon</span> detectors. Using a directional coupler implemented with silicon nitride nanophotonic waveguides, we observe 97% interference visibility when measuring <span class="hlt">photon</span> statistics with two monolithically integrated superconducting single-<span class="hlt">photon</span> detectors. The <span class="hlt">photonic</span> circuit and detector fabrication processes are compatible with standard semiconductor thin-film technology, making it possible to implement more complex and larger scale quantum <span class="hlt">photonic</span> circuits on silicon chips.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4735806','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4735806"><span>Quantum interference in heterogeneous superconducting-<span class="hlt">photonic</span> circuits on a silicon chip</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Schuck, C.; Guo, X.; Fan, L.; Ma, X.; Poot, M.; Tang, H. X.</p> <p>2016-01-01</p> <p>Quantum information processing holds great promise for communicating and computing data efficiently. However, scaling current <span class="hlt">photonic</span> 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-<span class="hlt">photon</span> detectors. Here we develop a hybrid superconducting-<span class="hlt">photonic</span> 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 <span class="hlt">detecting</span> <span class="hlt">photon</span> pairs directly on the chip with waveguide-coupled single-<span class="hlt">photon</span> detectors. Using a directional coupler implemented with silicon nitride nanophotonic waveguides, we observe 97% interference visibility when measuring <span class="hlt">photon</span> statistics with two monolithically integrated superconducting single-<span class="hlt">photon</span> detectors. The <span class="hlt">photonic</span> circuit and detector fabrication processes are compatible with standard semiconductor thin-film technology, making it possible to implement more complex and larger scale quantum <span class="hlt">photonic</span> circuits on silicon chips. 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