Time stamping of single optical photons with 10 ns resolution

DOE PAGES

Chakaberia, Irakli; Cotlet, Mircea; Fisher-Levine, Merlin; ...

2017-05-08

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 detection, and the further addition of sensitivity to single optical photons with the capability of timestamping them further broadens the field of potential applications. Here, photon counting is already widely used in X-ray imaging, where the high energy of the photons makes their detection easier.

Probing the SEB Sensitive Depth of a Power MOSFET Using a Two-Photon Absorption Laser Method

NASA Technical Reports Server (NTRS)

Lauenstein, Jean-Marie; Liu, Sandra; Titus, Jeffrey L.; McMorrow, Dale; Casey, Megan C.; Buchner, Stephen P.; Warner, Jeffrey; Phan, Anthony M.; Topper, Alyson D.; Kim, Hak S.;

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

Graphene-Based Josephson-Junction Single-Photon Detector

NASA Astrophysics Data System (ADS)

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

2017-08-01

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

Effect of MMF stub on the sensitivity of a photonic crystal fiber interferometer sensor at 1550 nm

NASA Astrophysics Data System (ADS)

Dhara, P.; Singh, Vinod K.

2015-01-01

A simple photonic crystal fiber (PCF) based Mach-Zehnder interferometric sensor is reported for sensing the refractive index and level of liquid. The sensing head is formed by all-fiber in-line single mode-multi mode-photonic crystal-single mode fiber structure using the fusion splicing method. The interferometric pattern, observed in the PCF interferometer using monochromatic source and temperature sensing arrangement, is novel and reported for the first time to the best of our knowledge. The refractive index sensitivity of the interferometric device is increased by using multimode fiber. The output intensity at the end of lead-out single mode fiber decreases with increase in refractive index of surrounding. The index sensitivities of the interferometric devices are 440.32 μw/RIU, 267.48 μw/RIU and 195.36 μw/RIU with sensing length 2.10 cm, 5.50 cm and 7.20 cm respectively. A 7.20 cm longed PCF sensor exhibits liquid level sensitivities -1.032 μw/cm, -1.197 μw/cm, and -1.489 μw/cm for three different liquid respectively.

Development of a single-photon-counting camera with use of a triple-stacked micro-channel plate.

PubMed

Yasuda, Naruomi; Suzuki, Hitoshi; Katafuchi, Tetsuro

2016-01-01

At the quantum-mechanical level, all substances (not merely electromagnetic waves such as light and X-rays) exhibit wave–particle duality. Whereas students of radiation science can easily understand the wave nature of electromagnetic waves, the particle (photon) nature may elude them. Therefore, to assist students in understanding the wave–particle duality of electromagnetic waves, we have developed a photon-counting camera that captures single photons in two-dimensional images. As an image intensifier, this camera has a triple-stacked micro-channel plate (MCP) with an amplification factor of 10(6). The ultra-low light of a single photon entering the camera is first converted to an electron through the photoelectric effect on the photocathode. The electron is intensified by the triple-stacked MCP and then converted to a visible light distribution, which is measured by a high-sensitivity complementary metal oxide semiconductor image sensor. Because it detects individual photons, the photon-counting camera is expected to provide students with a complete understanding of the particle nature of electromagnetic waves. Moreover, it measures ultra-weak light that cannot be detected by ordinary low-sensitivity cameras. Therefore, it is suitable for experimental research on scintillator luminescence, biophoton detection, and similar topics.

Behavioural and physiological limits to vision in mammals

PubMed Central

Field, Greg D.

2017-01-01

Human vision is exquisitely sensitive—a dark-adapted observer is capable of reliably detecting the absorption of a few quanta of light. Such sensitivity requires that the sensory receptors of the retina, rod photoreceptors, generate a reliable signal when single photons are absorbed. In addition, the retina must be able to extract this information and relay it to higher visual centres under conditions where very few rods signal single-photon responses while the majority generate only noise. Critical to signal transmission are mechanistic optimizations within rods and their dedicated retinal circuits that enhance the discriminability of single-photon responses by mitigating photoreceptor and synaptic noise. We describe behavioural experiments over the past century that have led to the appreciation of high sensitivity near absolute visual threshold. We further consider mechanisms within rod photoreceptors and dedicated rod circuits that act to extract single-photon responses from cellular noise. We highlight how these studies have shaped our understanding of brain function and point out several unresolved questions in the processing of light near the visual threshold. This article is part of the themed issue ‘Vision in dim light’. PMID:28193817

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.

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.

Evaluation of a fast single-photon avalanche photodiode for measurement of early transmitted photons through diffusive media.

PubMed

Mu, Ying; Valim, Niksa; Niedre, Mark

2013-06-15

We tested the performance of a fast single-photon avalanche photodiode (SPAD) in measurement of early transmitted photons through diffusive media. In combination with a femtosecond titanium:sapphire laser, the overall instrument temporal response time was 59 ps. Using two experimental models, we showed that the SPAD allowed measurement of photon-density sensitivity functions that were approximately 65% narrower than the ungated continuous wave case at very early times. This exceeds the performance that we have previously achieved with photomultiplier-tube-based systems and approaches the theoretical maximum predicted by time-resolved Monte Carlo simulations.

Hybrid photodetector for single-molecule spectroscopy and microscopy

PubMed Central

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

2011-01-01

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

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

NASA Technical Reports Server (NTRS)

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

Direct two-photon excitation of Sm3+, Eu3+, Tb3+, Tb.DOTA-, and Tb.propargylDO3A in solution

NASA Astrophysics Data System (ADS)

Sørensen, Thomas Just; Blackburn, Octavia A.; Tropiano, Manuel; Faulkner, Stephen

2012-07-01

We have observed direct two-photon excitation of samarium, europium and terbium ions in solution upon near IR excitation using a tuneable pulsed light source, and have also studied two-photon processes in a pair of related terbium complexes, namely [Tb.DOTA]- and Tb.propargylDO3A. Direct two-photon excitation of lanthanides is observed in simple systems in the absence of sensitizing chromophores. Where even simple chromophores such as a triple bond are present in the complex, then single and two-photon excitation of chromophore excited states competes with direct two-photon excitation of the ions and is the dominant pathway for sensitizing formation of the lanthanide excited state.

Processing of single-photon responses in the mammalian On and Off retinal pathways at the sensitivity limit of vision

PubMed Central

2017-01-01

Visually guided behaviour at its sensitivity limit relies on single-photon responses originating in a small number of rod photoreceptors. For decades, researchers have debated the neural mechanisms and noise sources that underlie this striking sensitivity. To address this question, we need to understand the constraints arising from the retinal output signals provided by distinct retinal ganglion cell types. It has recently been shown in the primate retina that On and Off parasol ganglion cells, the cell types likely to underlie light detection at the absolute visual threshold, differ fundamentally not only in response polarity, but also in the way they handle single-photon responses originating in rods. The On pathway provides the brain with a thresholded, low-noise readout and the Off pathway with a noisy, linear readout. We outline the mechanistic basis of these different coding strategies and analyse their implications for detecting the weakest light signals. We show that high-fidelity, nonlinear signal processing in the On pathway comes with costs: more single-photon responses are lost and their propagation is delayed compared with the Off pathway. On the other hand, the responses of On ganglion cells allow better intensity discrimination compared with the Off ganglion cell responses near visual threshold. This article is part of the themed issue ‘Vision in dim light’. PMID:28193818

Processing of single-photon responses in the mammalian On and Off retinal pathways at the sensitivity limit of vision.

PubMed

Takeshita, Daisuke; Smeds, Lina; Ala-Laurila, Petri

2017-04-05

Visually guided behaviour at its sensitivity limit relies on single-photon responses originating in a small number of rod photoreceptors. For decades, researchers have debated the neural mechanisms and noise sources that underlie this striking sensitivity. To address this question, we need to understand the constraints arising from the retinal output signals provided by distinct retinal ganglion cell types. It has recently been shown in the primate retina that On and Off parasol ganglion cells, the cell types likely to underlie light detection at the absolute visual threshold, differ fundamentally not only in response polarity, but also in the way they handle single-photon responses originating in rods. The On pathway provides the brain with a thresholded, low-noise readout and the Off pathway with a noisy, linear readout. We outline the mechanistic basis of these different coding strategies and analyse their implications for detecting the weakest light signals. We show that high-fidelity, nonlinear signal processing in the On pathway comes with costs: more single-photon responses are lost and their propagation is delayed compared with the Off pathway. On the other hand, the responses of On ganglion cells allow better intensity discrimination compared with the Off ganglion cell responses near visual threshold.This article is part of the themed issue 'Vision in dim light'. © 2017 The Authors.

Study on ultra-fast single photon counting spectrometer based on PCI

NASA Astrophysics Data System (ADS)

Zhang, Xi-feng

2010-10-01

The time-correlated single photon counting spectrometer developed uses PCI bus technology. We developed the ultrafast data acquisition card based on PCI, replace multi-channel analyzer primary. The system theory and design of the spectrometer are presented in detail, and the process of operation is introduced with the integration of the system. Many standard samples have been measured and the data have been analyzed and contrasted. Experimental results show that the spectrometer, s sensitive is single photon counting, and fluorescence life-span and time resolution is picosecond level. And the instrument could measure time-resolved spectroscopy.

Brain single-photon emission CT physics principles.

PubMed

Accorsi, R

2008-08-01

The basic principles of scintigraphy are reviewed and extended to 3D imaging. Single-photon emission computed tomography (SPECT) is a sensitive and specific 3D technique to monitor in vivo functional processes in both clinical and preclinical studies. SPECT/CT systems are becoming increasingly common and can provide accurately registered anatomic information as well. In general, SPECT is affected by low photon-collection efficiency, but in brain imaging, not all of the large FOV of clinical gamma cameras is needed: The use of fan- and cone-beam collimation trades off the unused FOV for increased sensitivity and resolution. The design of dedicated cameras aims at increased angular coverage and resolution by minimizing the distance from the patient. The corrections needed for quantitative imaging are challenging but can take advantage of the relative spatial uniformity of attenuation and scatter. Preclinical systems can provide submillimeter resolution in small animal brain imaging with workable sensitivity.

Fast two-photon imaging of subcellular voltage dynamics in neuronal tissue with genetically encoded indicators.

PubMed

Chamberland, Simon; Yang, Helen H; Pan, Michael M; Evans, Stephen W; Guan, Sihui; Chavarha, Mariya; Yang, Ying; Salesse, Charleen; Wu, Haodi; Wu, Joseph C; Clandinin, Thomas R; Toth, Katalin; Lin, Michael Z; St-Pierre, François

2017-07-27

Monitoring voltage dynamics in defined neurons deep in the brain is critical for unraveling the function of neuronal circuits but is challenging due to the limited performance of existing tools. In particular, while genetically encoded voltage indicators have shown promise for optical detection of voltage transients, many indicators exhibit low sensitivity when imaged under two-photon illumination. Previous studies thus fell short of visualizing voltage dynamics in individual neurons in single trials. Here, we report ASAP2s, a novel voltage indicator with improved sensitivity. By imaging ASAP2s using random-access multi-photon microscopy, we demonstrate robust single-trial detection of action potentials in organotypic slice cultures. We also show that ASAP2s enables two-photon imaging of graded potentials in organotypic slice cultures and in Drosophila . These results demonstrate that the combination of ASAP2s and fast two-photon imaging methods enables detection of neural electrical activity with subcellular spatial resolution and millisecond-timescale precision.

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

PubMed Central

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

2017-01-01

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

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.

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.

First Dark Matter Constraints from SuperCDMS Single-Charge Sensitive Detectors

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

Agnese, R.; et al.

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

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

NASA Astrophysics Data System (ADS)

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

2017-12-01

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

Protecting single-photon entanglement with practical entanglement source

NASA Astrophysics Data System (ADS)

Zhou, Lan; Ou-Yang, Yang; Wang, Lei; Sheng, Yu-Bo

2017-06-01

Single-photon entanglement (SPE) is important for quantum communication and quantum information processing. However, SPE is sensitive to photon loss. In this paper, we discuss a linear optical amplification protocol for protecting SPE. Different from the previous protocols, we exploit the practical spontaneous parametric down-conversion (SPDC) source to realize the amplification, for the ideal entanglement source is unavailable in current quantum technology. Moreover, we prove that the amplification using the entanglement generated from SPDC source as auxiliary is better than the amplification assisted with single photons. The reason is that the vacuum state from SPDC source will not affect the amplification, so that it can be eliminated automatically. This protocol may be useful in future long-distance quantum communications.

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

NASA Astrophysics Data System (ADS)

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

2018-02-01

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

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.

Fast time-domain measurements on telecom single photons

NASA Astrophysics Data System (ADS)

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

2017-09-01

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

Silicon on-chip bandpass filters for the multiplexing of high sensitivity photonic crystal microcavity biosensors

PubMed Central

Chakravarty, Swapnajit; Yang, Chun-Ju; Wang, Zheng; Tang, Naimei; Fan, Donglei; Chen, Ray T.

2015-01-01

A method for the dense integration of high sensitivity photonic crystal (PC) waveguide based biosensors is proposed and experimentally demonstrated on a silicon platform. By connecting an additional PC waveguide filter to a PC microcavity sensor in series, a transmission passband is created, containing the resonances of the PC microcavity for sensing purpose. With proper engineering of the passband, multiple high sensitivity PC microcavity sensors can be integrated into microarrays and be interrogated simultaneously between a single input and a single output port. The concept was demonstrated with a 2-channel L55 PC biosensor array containing PC waveguide filters. The experiment showed that the sensors on both channels can be monitored simultaneously from a single output spectrum. Less than 3 dB extra loss for the additional PC waveguide filter is observed. PMID:25829549

Towards sensitive, high-throughput, biomolecular assays based on fluorescence lifetime

NASA Astrophysics Data System (ADS)

Ioanna Skilitsi, Anastasia; Turko, Timothé; Cianfarani, Damien; Barre, Sophie; Uhring, Wilfried; Hassiepen, Ulrich; Léonard, Jérémie

2017-09-01

Time-resolved fluorescence detection for robust sensing of biomolecular interactions is developed by implementing time-correlated single photon counting in high-throughput conditions. Droplet microfluidics is used as a promising platform for the very fast handling of low-volume samples. We illustrate the potential of this very sensitive and cost-effective technology in the context of an enzymatic activity assay based on fluorescently-labeled biomolecules. Fluorescence lifetime detection by time-correlated single photon counting is shown to enable reliable discrimination between positive and negative control samples at a throughput as high as several hundred samples per second.

Silicon Photomultiplier Performance in High ELectric Field

NASA Astrophysics Data System (ADS)

Montoya, J.; Morad, J.

2016-12-01

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

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

Fast two-photon imaging of subcellular voltage dynamics in neuronal tissue with genetically encoded indicators

PubMed Central

Chamberland, Simon; Yang, Helen H; Pan, Michael M; Evans, Stephen W; Guan, Sihui; Chavarha, Mariya; Yang, Ying; Salesse, Charleen; Wu, Haodi; Wu, Joseph C; Clandinin, Thomas R; Toth, Katalin; Lin, Michael Z; St-Pierre, François

2017-01-01

Monitoring voltage dynamics in defined neurons deep in the brain is critical for unraveling the function of neuronal circuits but is challenging due to the limited performance of existing tools. In particular, while genetically encoded voltage indicators have shown promise for optical detection of voltage transients, many indicators exhibit low sensitivity when imaged under two-photon illumination. Previous studies thus fell short of visualizing voltage dynamics in individual neurons in single trials. Here, we report ASAP2s, a novel voltage indicator with improved sensitivity. By imaging ASAP2s using random-access multi-photon microscopy, we demonstrate robust single-trial detection of action potentials in organotypic slice cultures. We also show that ASAP2s enables two-photon imaging of graded potentials in organotypic slice cultures and in Drosophila. These results demonstrate that the combination of ASAP2s and fast two-photon imaging methods enables detection of neural electrical activity with subcellular spatial resolution and millisecond-timescale precision. DOI: http://dx.doi.org/10.7554/eLife.25690.001 PMID:28749338

Dead-time optimized time-correlated photon counting instrument with synchronized, independent timing channels

NASA Astrophysics Data System (ADS)

Wahl, Michael; Rahn, Hans-Jürgen; Gregor, Ingo; Erdmann, Rainer; Enderlein, Jörg

2007-03-01

Time-correlated single photon counting is a powerful method for sensitive time-resolved fluorescence measurements down to the single molecule level. The method is based on the precisely timed registration of single photons of a fluorescence signal. Historically, its primary goal was the determination of fluorescence lifetimes upon optical excitation by a short light pulse. This goal is still important today and therefore has a strong influence on instrument design. However, modifications and extensions of the early designs allow for the recovery of much more information from the detected photons and enable entirely new applications. Here, we present a new instrument that captures single photon events on multiple synchronized channels with picosecond resolution and over virtually unlimited time spans. This is achieved by means of crystal-locked time digitizers with high resolution and very short dead time. Subsequent event processing in programmable logic permits classical histogramming as well as time tagging of individual photons and their streaming to the host computer. Through the latter, any algorithms and methods for the analysis of fluorescence dynamics can be implemented either in real time or offline. Instrument test results from single molecule applications will be presented.

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

PubMed

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

2018-01-29

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

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

PubMed

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

2010-11-01

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

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

PubMed Central

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

2010-01-01

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

Silicon on-chip bandpass filters for the multiplexing of high sensitivity photonic crystal microcavity biosensors

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

Yan, Hai, E-mail: hai.yan@utexas.edu; Zou, Yi; Yang, Chun-Ju

A method for the dense integration of high sensitivity photonic crystal (PC) waveguide based biosensors is proposed and experimentally demonstrated on a silicon platform. By connecting an additional PC waveguide filter to a PC microcavity sensor in series, a transmission passband is created, containing the resonances of the PC microcavity for sensing purpose. With proper engineering of the passband, multiple high sensitivity PC microcavity sensors can be integrated into microarrays and be interrogated simultaneously between a single input and a single output port. The concept was demonstrated with a 2-channel L55 PC biosensor array containing PC waveguide filters. The experimentmore » showed that the sensors on both channels can be monitored simultaneously from a single output spectrum. Less than 3 dB extra loss for the additional PC waveguide filter is observed.« less

Palette of fluorinated voltage-sensitive hemicyanine dyes

PubMed Central

Yan, Ping; Acker, Corey D.; Zhou, Wen-Liang; Lee, Peter; Bollensdorff, Christian; Negrean, Adrian; Lotti, Jacopo; Sacconi, Leonardo; Antic, Srdjan D.; Kohl, Peter; Mansvelder, Huibert D.; Pavone, Francesco S.; Loew, Leslie M.

2012-01-01

Optical recording of membrane potential permits spatially resolved measurement of electrical activity in subcellular regions of single cells, which would be inaccessible to electrodes, and imaging of spatiotemporal patterns of action potential propagation in excitable tissues, such as the brain or heart. However, the available voltage-sensitive dyes (VSDs) are not always spectrally compatible with newly available optical technologies for sensing or manipulating the physiological state of a system. Here, we describe a series of 19 fluorinated VSDs based on the hemicyanine class of chromophores. Strategic placement of the fluorine atoms on the chromophores can result in either blue or red shifts in the absorbance and emission spectra. The range of one-photon excitation wavelengths afforded by these new VSDs spans 440–670 nm; the two-photon excitation range is 900–1,340 nm. The emission of each VSD is shifted by at least 100 nm to the red of its one-photon excitation spectrum. The set of VSDs, thus, affords an extended toolkit for optical recording to match a broad range of experimental requirements. We show the sensitivity to voltage and the photostability of the new VSDs in a series of experimental preparations ranging in scale from single dendritic spines to whole heart. Among the advances shown in these applications are simultaneous recording of voltage and calcium in single dendritic spines and optical electrophysiology recordings using two-photon excitation above 1,100 nm. PMID:23169660

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

NASA Astrophysics Data System (ADS)

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

2002-03-01

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

Demodulation of an optical fiber MEMS pressure sensor based on single bandpass microwave photonic filter.

PubMed

Wang, Yiping; Ni, Xiaoqi; Wang, Ming; Cui, Yifeng; Shi, Qingyun

2017-01-23

In this paper, a demodulation method for optic fiber micro-electromechanical systems (MEMS) extrinsic Fabry-Perot interferometer (EFPI) pressure sensor exploiting microwave photonics filter technique is firstly proposed and experimentally demonstrated. A single bandpass microwave photonic filter (MPF) which mainly consists of a spectrum-sliced light source, a pressurized optical fiber MEMS EFPI, a phase modulator (PM) and a length of dispersion compensating fiber (DCF) is demonstrated. The frequency response of the filter with respect to the pressure is studied. By detecting the resonance frequency shifts of the MPF, the pressure can be determined. The theoretical and experimental results show that the proposed EFPI pressure demodulation method has a higher resolution and higher speed than traditional methods based on optical spectrum analysis. The sensitivity of the sensor is measured to be as high as 86 MHz/MPa in the range of 0-4Mpa. Moreover, the sensitivity can be easily adjusted.

Single-photon counting multicolor multiphoton fluorescence microscope.

PubMed

Buehler, Christof; Kim, Ki H; Greuter, Urs; Schlumpf, Nick; So, Peter T C

2005-01-01

We present a multicolor multiphoton fluorescence microscope with single-photon counting sensitivity. The system integrates a standard multiphoton fluorescence microscope, an optical grating spectrograph operating in the UV-Vis wavelength region, and a 16-anode photomultiplier tube (PMT). The major technical innovation is in the development of a multichannel photon counting card (mC-PhCC) for direct signal collection from multi-anode PMTs. The electronic design of the mC-PhCC employs a high-throughput, fully-parallel, single-photon counting scheme along with a high-speed electrical or fiber-optical link interface to the data acquisition computer. There is no electronic crosstalk among the detection channels of the mC-PhCC. The collected signal remains linear up to an incident photon rate of 10(8) counts per second. The high-speed data interface offers ample bandwidth for real-time readout: 2 MByte lambda-stacks composed of 16 spectral channels, 256 x 256 pixel image with 12-bit dynamic range can be transferred at 30 frames per second. The modular design of the mC-PhCC can be readily extended to accommodate PMTs of more anodes. Data acquisition from a 64-anode PMT has been verified. As a demonstration of system performance, spectrally resolved images of fluorescent latex spheres and ex-vivo human skin are reported. The multicolor multiphoton microscope is suitable for highly sensitive, real-time, spectrally-resolved three-dimensional imaging in biomedical applications.

Modal and polarization qubits in Ti:LiNbO3 photonic circuits for a universal quantum logic gate.

PubMed

Saleh, Mohammed F; Di Giuseppe, Giovanni; Saleh, Bahaa E A; Teich, Malvin Carl

2010-09-13

Lithium niobate photonic circuits have the salutary property of permitting the generation, transmission, and processing of photons to be accommodated on a single chip. Compact photonic circuits such as these, with multiple components integrated on a single chip, are crucial for efficiently implementing quantum information processing schemes.We present a set of basic transformations that are useful for manipulating modal qubits in Ti:LiNbO(3) photonic quantum circuits. These include the mode analyzer, a device that separates the even and odd components of a state into two separate spatial paths; the mode rotator, which rotates the state by an angle in mode space; and modal Pauli spin operators that effect related operations. We also describe the design of a deterministic, two-qubit, single-photon, CNOT gate, a key element in certain sets of universal quantum logic gates. It is implemented as a Ti:LiNbO(3) photonic quantum circuit in which the polarization and mode number of a single photon serve as the control and target qubits, respectively. It is shown that the effects of dispersion in the CNOT circuit can be mitigated by augmenting it with an additional path. The performance of all of these components are confirmed by numerical simulations. The implementation of these transformations relies on selective and controllable power coupling among single- and two-mode waveguides, as well as the polarization sensitivity of the Pockels coefficients in LiNbO(3).

Two-color single-photon emission from InAs quantum dots: toward logic information management using quantum light.

PubMed

Rivas, David; Muñoz-Matutano, Guillermo; Canet-Ferrer, Josep; García-Calzada, Raúl; Trevisi, Giovanna; Seravalli, Luca; Frigeri, Paola; Martínez-Pastor, Juan P

2014-02-12

In this work, we propose the use of the Hanbury-Brown and Twiss interferometric technique and a switchable two-color excitation method for evaluating the exciton and noncorrelated electron-hole dynamics associated with single photon emission from indium arsenide (InAs) self-assembled quantum dots (QDs). Using a microstate master equation model we demonstrate that our single QDs are described by nonlinear exciton dynamics. The simultaneous detection of two-color, single photon emission from InAs QDs using these nonlinear dynamics was used to design a NOT AND logic transference function. This computational functionality combines the advantages of working with light/photons as input/output device parameters (all-optical system) and that of a nanodevice (QD size of ∼ 20 nm) while also providing high optical sensitivity (ultralow optical power operational requirements). These system features represent an important and interesting step toward the development of new prototypes for the incoming quantum information technologies.

Old and new news about single-photon sensitivity in human vision

NASA Astrophysics Data System (ADS)

Nelson, Philip

It is sometimes said that ``our eyes can see single photons,'' when in fact the faintest flash of light that can reliably be reported by human subjects is closer to 100 photons. Nevertheless, there is a sense in which the familiar claim is true. Experiments conducted long after the seminal work of Hecht, Shlaer, and Pirenne in two distinct realms, those of human psychophysics and single-cell physiology, now admit a more precisem conclusion to be drawn about our visual apparatus. Finding a single framework that accommodates both kinds of result is a nontrivial challenge, and one that sets severe quantitative constraints on any model of dim-light visual processing. I will present one such model and compare it to a recent experiment. Partially supported by the NSF under Grants EF-0928048 and DMR-0832802.

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

DOE PAGES

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

2017-09-26

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

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

NASA Astrophysics Data System (ADS)

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

2017-09-01

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

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

PubMed

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

2017-09-29

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

Negative Avalanche Feedback Detectors for Photon-Counting Optical Communications

NASA Technical Reports Server (NTRS)

Farr, William H.

2009-01-01

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

High sensitivity fluorescent single particle and single molecule detection apparatus and method

DOEpatents

Mathies, Richard A.; Peck, Konan; Stryer, Lubert

1990-01-01

Apparatus is described for ultrasensitive detection of single fluorescent particles down to the single fluorescent molecule limit in a fluid or on a substrate comprising means for illuminating a predetermined volume of the fluid or area of the substrate whereby to emit light including background light from the fluid and burst of photons from particles residing in the area. The photon burst is detected in real time to generate output representative signal. The signal is received and the burst of energy from the fluorescent particles is distinguished from the background energy to provide an indication of the number, location or concentration of the particles or molecules.

The electrophotonic silicon biosensor

NASA Astrophysics Data System (ADS)

Juan-Colás, José; Parkin, Alison; Dunn, Katherine E.; Scullion, Mark G.; Krauss, Thomas F.; Johnson, Steven D.

2016-09-01

The emergence of personalized and stratified medicine requires label-free, low-cost diagnostic technology capable of monitoring multiple disease biomarkers in parallel. Silicon photonic biosensors combine high-sensitivity analysis with scalable, low-cost manufacturing, but they tend to measure only a single biomarker and provide no information about their (bio)chemical activity. Here we introduce an electrochemical silicon photonic sensor capable of highly sensitive and multiparameter profiling of biomarkers. Our electrophotonic technology consists of microring resonators optimally n-doped to support high Q resonances alongside electrochemical processes in situ. The inclusion of electrochemical control enables site-selective immobilization of different biomolecules on individual microrings within a sensor array. The combination of photonic and electrochemical characterization also provides additional quantitative information and unique insight into chemical reactivity that is unavailable with photonic detection alone. By exploiting both the photonic and the electrical properties of silicon, the sensor opens new modalities for sensing on the microscale.

Performance optimization of detector electronics for millimeter laser ranging

NASA Technical Reports Server (NTRS)

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

1993-01-01

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

Image transfer by cascaded stack of photonic crystal and air layers.

PubMed

Shen, C; Michielsen, K; De Raedt, H

2006-01-23

We demonstrate image transfer by a cascaded stack consisting of two and three triangular-lattice photonic crystal slabs separated by air. The quality of the image transfered by the stack is sensitive to the air/photonic crystal interface termination and the frequency. Depending on the frequency and the surface termination, the image can be transfered by the stack with very little deterioration of the resolution, that is the resolution of the final image is approximately the same as the resolution of the image formed behind one single photonic crystal slab.

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

NASA Astrophysics Data System (ADS)

Zimmermann, Olaf; Tamma, Vincenzo

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

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

NASA Astrophysics Data System (ADS)

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

2018-02-01

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

Flexible single-crystal silicon nanomembrane photonic crystal cavity.

PubMed

Xu, Xiaochuan; Subbaraman, Harish; Chakravarty, Swapnajit; Hosseini, Amir; Covey, John; Yu, Yalin; Kwong, David; Zhang, Yang; Lai, Wei-Cheng; Zou, Yi; Lu, Nanshu; Chen, Ray T

2014-12-23

Flexible inorganic electronic devices promise numerous applications, especially in fields that could not be covered satisfactorily by conventional rigid devices. Benefits on a similar scale are also foreseeable for silicon photonic components. However, the difficulty in transferring intricate silicon photonic devices has deterred widespread development. In this paper, we demonstrate a flexible single-crystal silicon nanomembrane photonic crystal microcavity through a bonding and substrate removal approach. The transferred cavity shows a quality factor of 2.2×10(4) and could be bent to a curvature of 5 mm radius without deteriorating the performance compared to its counterparts on rigid substrates. A thorough characterization of the device reveals that the resonant wavelength is a linear function of the bending-induced strain. The device also shows a curvature-independent sensitivity to the ambient index variation.

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

NASA Technical Reports Server (NTRS)

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

2018-01-01

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

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.

Two-photon targeted recording of GFP-expressing neurons for light responses and live cell imaging in the mouse retina

PubMed Central

Wei, Wei; Elstrott, Justin; Feller, Marla B.

2015-01-01

Cell type-specific GFP expression in the retina has been achieved in an expanding repertoire of transgenic mouse lines, which are valuable tools for dissecting the retinal circuitry. However, measuring light responses from GFP-labeled cells is challenging because single-photon excitation of GFP easily bleaches the photoreceptors. To circumvent this problem, we used two-photon excitation at 920 nm to target GFP-expressing cells, followed by electrophysiological recording of light responses using conventional infrared optics. This protocol offers fast and sensitive detection of GFP while preserving the light sensitivity of the retina, and can be used to obtain the light responses as well as the detailed morphology of a GFP-expressing cell. Targeting of a GFP-expressing neuron takes less than 3 minutes, and the retina preparation remains light sensitive and suitable for recording for at least 8 hours. This protocol can also be applied to study retinal neurons labeled with other two-photon-excitable fluorophores. PMID:20595962

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.

Detecting Axion Dark Matter with Superconducting Qubits

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

Dixit, Akash; Chou, Aaron; Schuster, David

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

Phospholipase C mediated Suppression of Dark Noise Enables Single Photon Detection in Drosophila Photoreceptors

PubMed Central

Katz, Ben; Minke, Baruch

2012-01-01

Drosophila photoreceptor cells use the ubiquitous G-protein-mediated phospholipase C (PLC) cascade to achieve ultimate single photon sensitivity. This is manifested in the single photon 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 photon detection. 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 photons. 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 photon 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

Temperature insensitive curvature sensor based on cascading photonic crystal fiber

NASA Astrophysics Data System (ADS)

Fu, Guangwei; Li, Yunpu; Fu, Xinghu; Jin, Wa; Bi, Weihong

2018-03-01

A temperature insensitive curvature sensor is proposed based on cascading photonic crystal fiber. Using the arc fusion splicing method, this sensor is fabricated by cascading together a single-mode fiber (SMF), a three layers air holes structure of photonic crystal fiber (3PCF), a five layers air holes structure of photonic crystal fiber (5PCF) and a SMF in turn. So the structure SMF-3PCF-5PCF-SMF can be obtained with a total length of 20 mm. During the process of fabrication, the splicing machine parameters and the length of each optical fiber are adjusted to obtain a high sensitivity curvature sensor. The experimental results show that the curvature sensitivity is -8.40 nm/m-1 in the curvature variation range of 0-1.09 m-1, which also show good linearity. In the range of 30-90 °C, the temperature sensitivity is only about 3.24 pm/°C, indicating that the sensor is not sensitive to temperature. The sensor not only has the advantages of easy fabricating, simple structure, high sensitivity but also can solve the problem of temperature measurement cross sensitivity, so it can be used for different areas including aerospace, large-scale bridge, architectural structure health monitoring and so on.

Inexpensive electronics and software for photon statistics and correlation spectroscopy.

PubMed

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

2014-07-01

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

Inexpensive electronics and software for photon statistics and correlation spectroscopy

PubMed Central

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

2016-01-01

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

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

NASA Astrophysics Data System (ADS)

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

2016-09-01

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

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

PubMed Central

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

2014-01-01

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

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

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

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

Exciton dynamics of C60-based single-photon emitters explored by Hanbury Brown-Twiss scanning tunnelling microscopy.

PubMed

Merino, P; Große, C; Rosławska, A; Kuhnke, K; Kern, K

2015-09-29

Exciton creation and annihilation by charges are crucial processes for technologies relying on charge-exciton-photon conversion. Improvement of organic light sources or dye-sensitized solar cells requires methods to address exciton dynamics at the molecular scale. Near-field techniques have been instrumental for this purpose; however, characterizing exciton recombination with molecular resolution remained a challenge. Here, we study exciton dynamics by using scanning tunnelling microscopy to inject current with sub-molecular precision and Hanbury Brown-Twiss interferometry to measure photon correlations in the far-field electroluminescence. Controlled injection allows us to generate excitons in solid C60 and let them interact with charges during their lifetime. We demonstrate electrically driven single-photon emission from localized structural defects and determine exciton lifetimes in the picosecond range. Monitoring lifetime shortening and luminescence saturation for increasing carrier injection rates provides access to charge-exciton annihilation dynamics. Our approach introduces a unique way to study single quasi-particle dynamics on the ultimate molecular scale.

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

NASA Astrophysics Data System (ADS)

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

2013-09-01

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

Truxene-cored π-expanded triarylborane dyes as single- and two-photon fluorescent probes for fluoride.

PubMed

Yuan, Mao-Sen; Wang, Qi; Wang, Wenji; Wang, Dong-En; Wang, Junru; Wang, Jinyi

2014-03-21

Fluoride anion (F(-)) significantly affects chemical, biological, and environmental processes. Fluoride recognition and detection have received increasing attention. Convenient, effective, and sensitive fluorescent probes for F(-) should urgently be designed and synthesized. In this study, we describe a strategy for constructing two triarylborane-based fluoride fluorescent probes: 2,7,12-tri(2-(5-(dimesitylboryl)thiophen-2-yl)ethynyl)-5,5',10,10',15,15'-hexaethyltruxene (C3B3) with π-3A (acceptor) configuration and 2,7-di(N,N-diphenylamino)-12-(5-(dimesitylboryl)thiophen-2-yl)-5,5',10,10',15,15'-hexaethyltruxene (N2SB) with 2D (donor)-π-A configuration. The loss of color of the tetrahydrofuran solution of these probes from greenish yellow suggests that they can conveniently monitor F(-) at a low concentration (10 μM) free of apparatus. The different structural features of these probes varied their fluorescent responses to F(-). The single-photon fluorescence intensity of C3B3 declined to 90% upon the addition of 4.5 equivalents of F(-) to its tetrahydrofuran solution. However, the single-photon fluorescence intensity of N2SB was enhanced six-fold upon addition of 2.5 equivalents of the F(-). Under the experimental conditions, the detection limits of the two probes for F(-) can reach 12-13 μM (C3B3) and 3-5 μM (N2SB). The ability of the two probes in detecting F(-) in their toluene solutions in the two-photon mode was also investigated. The sensitive two-photon fluorescence responses of both probes make them excellent two-photon fluorescence probes.

Aqueye+: a new ultrafast single photon counter for optical high time resolution astrophysics

NASA Astrophysics Data System (ADS)

Zampieri, L.; Naletto, G.; Barbieri, C.; Verroi, E.; Barbieri, M.; Ceribella, G.; D'Alessandro, M.; Farisato, G.; Di Paola, A.; Zoccarato, P.

2015-05-01

Aqueye+ is a new ultrafast optical single photon counter, based on single photon avalanche photodiodes (SPAD) and a 4- fold split-pupil concept. It is a completely revisited version of its predecessor, Aqueye, successfully mounted at the 182 cm Copernicus telescope in Asiago. Here we will present the new technological features implemented on Aqueye+, namely a state of the art timing system, a dedicated and optimized optical train, a high sensitivity and high frame rate field camera and remote control, which will give Aqueye plus much superior performances with respect to its predecessor, unparalleled by any other existing fast photometer. The instrument will host also an optical vorticity module to achieve high performance astronomical coronography and a real time acquisition of atmospheric seeing unit. The present paper describes the instrument and its first performances.

InGaAs/InP SPAD photon-counting module with auto-calibrated gate-width generation and remote control

NASA Astrophysics Data System (ADS)

Tosi, Alberto; Ruggeri, Alessandro; Bahgat Shehata, Andrea; Della Frera, Adriano; Scarcella, Carmelo; Tisa, Simone; Giudice, Andrea

2013-01-01

We present a photon-counting module based on InGaAs/InP SPAD (Single-Photon Avalanche Diode) for detecting single photons up to 1.7 μm. The module exploits a novel architecture for generating and calibrating the gate width, along with other functions (such as module supervision, counting and processing of detected photons, etc.). The gate width, i.e. the time interval when the SPAD is ON, is user-programmable in the range from 500 ps to 1.5 μs, by means of two different delay generation methods implemented with an FPGA (Field-Programmable Gate Array). In order to compensate chip-to-chip delay variation, an auto-calibration circuit picks out a combination of delays in order to match at best the selected gate width. The InGaAs/InP module accepts asynchronous and aperiodic signals and introduces very low timing jitter. Moreover the photon counting module provides other new features like a microprocessor for system supervision, a touch-screen for local user interface, and an Ethernet link for smart remote control. Thanks to the fullyprogrammable and configurable architecture, the overall instrument provides high system flexibility and can easily match all requirements set by many different applications requiring single photon-level sensitivity in the near infrared with very low photon timing jitter.

When quantum optics meets topology

NASA Astrophysics Data System (ADS)

Amo, Alberto

2018-02-01

Routing photons at the micrometer scale remains one of the greatest challenges of integrated quantum optics. The main difficulty is the scattering losses at bends and splitters in the photonic circuit. Current approaches imply elaborate designs, quite sensitive to fabrication details (1). Inspired by the physics underlying the one-way transport of electrons in topological insulators, on page 666 of this issue, Barik et al. (2) report a topological photonic crystal in which single photons are emitted and routed through bends with negligible loss. The marriage between quantum optics and topology promises new opportunities for compact quantum optics gating and manipulation.

A Novel Quantum Solution to Privacy-Preserving Nearest Neighbor Query in Location-Based Services

NASA Astrophysics Data System (ADS)

Luo, Zhen-yu; Shi, Run-hua; Xu, Min; Zhang, Shun

2018-04-01

We present a cheating-sensitive quantum protocol for Privacy-Preserving Nearest Neighbor Query based on Oblivious Quantum Key Distribution and Quantum Encryption. Compared with the classical related protocols, our proposed protocol has higher security, because the security of our protocol is based on basic physical principles of quantum mechanics, instead of difficulty assumptions. Especially, our protocol takes single photons as quantum resources and only needs to perform single-photon projective measurement. Therefore, it is feasible to implement this protocol with the present technologies.

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.

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

NASA Technical Reports Server (NTRS)

Zhao, Kai; Lo, YuHwa; Farr, William

2010-01-01

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

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

NASA Astrophysics Data System (ADS)

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

2018-01-01

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

Ion photon emission microscope

DOEpatents

Doyle, Barney L.

2003-04-22

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

Experimental demonstration of photon upconversion via cooperative energy pooling

DOE PAGES

Weingarten, Daniel H.; LaCount, Michael D.; van de Lagemaat, Jao; ...

2017-03-15

Photon upconversion is a fundamental interaction of light and matter that has applications in fields ranging from bioimaging to microfabrication. However, all photon upconversion methods demonstrated thus far involve challenging aspects, including requirements of high excitation intensities, degradation in ambient air, requirements of exotic materials or phases, or involvement of inherent energy loss processes. Here we experimentally demonstrate a mechanism of photon upconversion in a thin film, binary mixture of organic chromophores that provides a pathway to overcoming the aforementioned disadvantages. This singlet-based process, called Cooperative Energy Pooling (CEP), utilizes a sensitizer-acceptor design in which multiple photoexcited sensitizers resonantly andmore » simultaneously transfer their energies to a higher-energy state on a single acceptor. Data from this proof-of-concept implementation is fit by a proposed model of the CEP process. As a result, design guidelines are presented to facilitate further research and development of more optimized CEP systems.« less

Experimental demonstration of photon upconversion via cooperative energy pooling

PubMed Central

Weingarten, Daniel H.; LaCount, Michael D.; van de Lagemaat, Jao; Rumbles, Garry; Lusk, Mark T.; Shaheen, Sean E.

2017-01-01

Photon upconversion is a fundamental interaction of light and matter that has applications in fields ranging from bioimaging to microfabrication. However, all photon upconversion methods demonstrated thus far involve challenging aspects, including requirements of high excitation intensities, degradation in ambient air, requirements of exotic materials or phases, or involvement of inherent energy loss processes. Here we experimentally demonstrate a mechanism of photon upconversion in a thin film, binary mixture of organic chromophores that provides a pathway to overcoming the aforementioned disadvantages. This singlet-based process, called Cooperative Energy Pooling (CEP), utilizes a sensitizer-acceptor design in which multiple photoexcited sensitizers resonantly and simultaneously transfer their energies to a higher-energy state on a single acceptor. Data from this proof-of-concept implementation is fit by a proposed model of the CEP process. Design guidelines are presented to facilitate further research and development of more optimized CEP systems. PMID:28294129

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

NASA Astrophysics Data System (ADS)

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

2012-02-01

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

Experimental demonstration of photon upconversion via cooperative energy pooling

NASA Astrophysics Data System (ADS)

Weingarten, Daniel H.; Lacount, Michael D.; van de Lagemaat, Jao; Rumbles, Garry; Lusk, Mark T.; Shaheen, Sean E.

2017-03-01

Photon upconversion is a fundamental interaction of light and matter that has applications in fields ranging from bioimaging to microfabrication. However, all photon upconversion methods demonstrated thus far involve challenging aspects, including requirements of high excitation intensities, degradation in ambient air, requirements of exotic materials or phases, or involvement of inherent energy loss processes. Here we experimentally demonstrate a mechanism of photon upconversion in a thin film, binary mixture of organic chromophores that provides a pathway to overcoming the aforementioned disadvantages. This singlet-based process, called Cooperative Energy Pooling (CEP), utilizes a sensitizer-acceptor design in which multiple photoexcited sensitizers resonantly and simultaneously transfer their energies to a higher-energy state on a single acceptor. Data from this proof-of-concept implementation is fit by a proposed model of the CEP process. Design guidelines are presented to facilitate further research and development of more optimized CEP systems.

High Sensitivity SPECT for Small Animals and Plants

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

Mitchell, Gregory S.

Imaging systems using single gamma-ray emitting radioisotopes typically implement collimators in order to form the images. However, a tradeoff in sensitivity is inherent in the use of collimators, and modern preclinical single-photon emission computed tomography (SPECT) systems detect a very small fraction of emitted gamma-rays (<0.3%). We have built a collimator-less system, which can reach sensitivity of 40% for 99mTc imaging, while still producing images of sufficient spatial resolution for certain applications in thin objects such as mice, small plants, and well plates used for in vitro experiments.

Quantum entanglement of high angular momenta.

PubMed

Fickler, Robert; Lapkiewicz, Radek; Plick, William N; Krenn, Mario; Schaeff, Christoph; Ramelow, Sven; Zeilinger, Anton

2012-11-02

Single photons with helical phase structures may carry a quantized amount of orbital angular momentum (OAM), and their entanglement is important for quantum information science and fundamental tests of quantum theory. Because there is no theoretical upper limit on how many quanta of OAM a single photon can carry, it is possible to create entanglement between two particles with an arbitrarily high difference in quantum number. By transferring polarization entanglement to OAM with an interferometric scheme, we generate and verify entanglement between two photons differing by 600 in quantum number. The only restrictive factors toward higher numbers are current technical limitations. We also experimentally demonstrate that the entanglement of very high OAM can improve the sensitivity of angular resolution in remote sensing.

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

NASA Astrophysics Data System (ADS)

Yoshida, Eiji; Tashima, Hideaki; Yamaya, Taiga

2014-11-01

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

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

NASA Astrophysics Data System (ADS)

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

2018-05-01

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

Two-photon imaging of spatially extended neuronal network dynamics with high temporal resolution.

PubMed

Lillis, Kyle P; Eng, Alfred; White, John A; Mertz, Jerome

2008-07-30

We describe a simple two-photon fluorescence imaging strategy, called targeted path scanning (TPS), to monitor the dynamics of spatially extended neuronal networks with high spatiotemporal resolution. Our strategy combines the advantages of mirror-based scanning, minimized dead time, ease of implementation, and compatibility with high-resolution low-magnification objectives. To demonstrate the performance of TPS, we monitor the calcium dynamics distributed across an entire juvenile rat hippocampus (>1.5mm), at scan rates of 100 Hz, with single cell resolution and single action potential sensitivity. Our strategy for fast, efficient two-photon microscopy over spatially extended regions provides a particularly attractive solution for monitoring neuronal population activity in thick tissue, without sacrificing the signal-to-noise ratio or high spatial resolution associated with standard two-photon microscopy. Finally, we provide the code to make our technique generally available.

Transverse single-spin asymmetries for direct photon and neutral pion production in midrapidity at PHENIX

NASA Astrophysics Data System (ADS)

Lewis, Nicole; Phenix Collaboration

2017-09-01

Large transverse single spin asymmetries for hadron production in proton-proton collisions were some of the first indicators of significant nonperturbative spin-momentum correlations in the proton. They have been found to persist up to collision energies of 510 GeV, yet their origin remains poorly understood. Measurements of different final-state particles in a wide variety of collision systems over a range of kinematics can help to identify and separate contributions from the proton versus hadronization, and from different parton flavors. Depending on the rapidity pion production can provide access to both initial- and final-state effects for a mix of parton flavors, while direct photons depend only on initial-state effects and are particularly sensitive to gluon dynamics in RHIC kinematics. The status of transverse single spin measurements for neutral pions and direct photons performed for p+p, p+Al, and p+Au collisions at PHENIX will be presented.

In-line microfluidic refractometer based on C-shaped fiber assisted photonic crystal fiber Sagnac interferometer.

PubMed

Wu, Chuang; Tse, Ming-Leung Vincent; Liu, Zhengyong; Guan, Bai-Ou; Lu, Chao; Tam, Hwa-Yaw

2013-09-01

We propose and demonstrate a highly sensitive in-line photonic crystal fiber (PCF) microfluidic refractometer. Ultrathin C-shaped fibers are spliced in-between the PCF and standard single-mode fibers. The C-shaped fibers provide openings for liquid to flow in and out of the PCF. Based on a Sagnac interferometer, the refractive index (RI) response of the device is investigated theoretically and experimentally. A high sensitivity of 6621 nm/RIU for liquid RI from 1.330 to 1.333 is achieved in the experiment, which agrees well with the theoretical analysis.

Photonic crystal fiber Fabry-Perot interferometers with high-reflectance internal mirrors

NASA Astrophysics Data System (ADS)

Fan, Rong; Hou, Yuanbin; Sun, Wei

2015-06-01

We demonstrated an in-line micro fiber-optic Fabry-Perot interferometer with an air cavity which was created by multi-step fusion splicing a muti-mode photonic crystal fiber (MPCF) to a standard single mode fiber (SMF). The fringe visibility of the interference pattern was up to 20 dB by reshaping the air cavity. Experimental results showed that such a device could be used as a highly sensitive strain sensor with the sensitivity of 4.5 pm/μɛ. Moreover, it offered some other outstanding advantages, such as the extremely compact structure, easy fabrication, low cost, and high accuracy.

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

NASA Astrophysics Data System (ADS)

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

2017-08-01

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

Temperature-insensitive refractive index sensing by use of micro Fabry-Pérot cavity based on simplified hollow-core photonic crystal fiber.

PubMed

Wang, Ying; Wang, D N; Liao, C R; Hu, Tianyi; Guo, Jiangtao; Wei, Huifeng

2013-02-01

A temperature-insensitive micro Fabry-Pérot (FP) cavity based on simplified hollow-core (SHC) photonic crystal fiber (PCF) is demonstrated. Such a device is fabricated by splicing a section of SHC PCF with single mode fibers at both cleaved ends. An extremely low temperature sensitivity of ~0.273 pm/°C is obtained between room temperature and 900°C. By drilling vertical micro-channels using a femtosecond laser, the micro FP cavity can be filled with liquids and functions as a sensitive refractometer and the refractive index sensitivity obtained is ~851.3 nm/RIU (refractive index unit), which indicates an ultra low temperature cross-sensitivity of ~3.2×10(-7) RIU/°C.

Temperature-independent curvature sensor based on tapered photonic crystal fiber interferometer

NASA Astrophysics Data System (ADS)

Ni, Kai; Li, Tao; Hu, Limin; Qian, Wenwen; Zhang, Quanyao; Jin, Shangzhong

2012-11-01

A temperature-independent highly-sensitive curvature sensor by using a tapered-photonic crystal fiber (PCF)-based Mach-Zehnder interferometer (MZI) is proposed and experimentally demonstrated. It is fabricated by sandwiching a tapered-PCF between two standard single mode fibers (SMFs) with the air holes of the PCF in the fusion splicing region being fully collapsed. The tapering of PCF is found to enhance the sensitivity significantly. Large curvature sensitivities of 2.81 dB/m-1 and 8.35 dB/m-1 are achieved in the measurement ranges of 0.36-0.87 m-1 and 0.87-1.34 m-1, respectively, with the resolution of 0.0012 m-1 being guaranteed. The proposed sensor also shows negligible temperature sensitivity less than 0.006 dB/°C.

Torsion sensing setup based on a Mach-Zehnder interferometer with photonics crystal fiber

NASA Astrophysics Data System (ADS)

Pacheco-Chacon, Eliana I.; Gallegos-Arellano, E.; Sierra-Hernandez, Juan M.; Rojas-Laguna, Roberto; Estudillo-Ayala, Julian M.; Hernandez, Emmanuel; Jauregui-Vazquez, D.; Hernandez-Garcia, J. C.

2017-02-01

A torsion experimental sensing setup based on a Mach-Zehnder interferometer (MZI) with photonics crystal fiber is presented. The MZI was fabricated by fusion splicing a piece of photonic crystal fiber (PCF) between two segments of a single-mode fiber (SMF). Here, a spectral MZI fringe shifting is induced by applying torsion over the SMF-PCF-SMF. As a result a torsion sensitivity of 35.79 pm/ and a high visibility of 10 dB were achieved. Finally, it is shown that the sensing arrangement is compact and robust.

Airborne UV photon-counting radiometer

NASA Astrophysics Data System (ADS)

Bauer, Marc C.; Wilcher, George; Banks, Calvin R.; Wood, Ronald L.

2000-11-01

The radiometric measurements group at the Arnold Engineering Development Center (AEDC) has developed new solar-blind radiometers for the SENSOR TALON flight test. These radiometers will be flown in an instrument pod by the 46th Test Wing at Eglin AFB. The radiometers are required to fit into a single quadrant of a 22-in.-diam sphere turret of the instrument pod. Because of minimal space requirements and photon-counting sensitivity needs, the radiometric measurements group used image intensifiers instead of the standard photomultiplier tubes (PMTs). The new design concept improved the photon-counting sensitivity, dynamic range, and uniformity of the field of view as compared to standard PMTs. A custom data acquisition system was required to miniaturize the electronics and generate a pulse code-modulated (PCM) data stream to the standard tape recording system.

The TORCH detector R&D: Status and perspectives

NASA Astrophysics Data System (ADS)

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

2017-12-01

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

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

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

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

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

Nano-displacement sensor based on photonic crystal fiber modal interferometer.

PubMed

Dash, Jitendra Narayan; Jha, Rajan; Villatoro, Joel; Dass, Sumit

2015-02-15

A stable nano-displacement sensor based on large mode area photonic crystal fiber (PCF) modal interferometer is presented. The compact setup requires simple splicing of a small piece of PCF with a single mode fiber (SMF). The excitation and recombination of modes is carried out in a single splice. The use of a reflecting target creates an extra cavity that discretizes the interference pattern of the mode interferometer, boosting the displacement resolution to nanometer level. The proposed modal interferometric based displacement sensor is highly stable and shows sensitivity of 32  pm/nm.

Transmission properties of one-dimensional ternary plasma photonic crystals

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

Shiveshwari, Laxmi; Awasthi, S. K.

2015-09-15

Omnidirectional photonic band gaps (PBGs) are found in one-dimensional ternary plasma photonic crystals (PPC) composed of single negative metamaterials. The band characteristics and transmission properties are investigated through the transfer matrix method. We show that the proposed structure can trap light in three-dimensional space due to the elimination of Brewster's angle transmission resonance allowing the existence of complete PBG. The results are discussed in terms of incident angle, layer thickness, dielectric constant of the dielectric material, and number of unit cells (N) for TE and TM polarizations. It is seen that PBG characteristics is apparent even in an N ≥ 2 system,more » which is weakly sensitive to the incident angle and completely insensitive to the polarization. Finite PPC could be used for multichannel transmission filter without introducing any defect in the geometry. We show that the locations of the multichannel transmission peaks are in the allowed band of the infinite structure. The structure can work as a single or multichannel filter by varying the number of unit cells. Binary PPC can also work as a polarization sensitive tunable filter.« less

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

NASA Astrophysics Data System (ADS)

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

2018-01-01

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

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.

Characterization of MOSFET dosimeters for low-dose measurements in maxillofacial anthropomorphic phantoms.

PubMed

Koivisto, Juha H; Wolff, Jan E; Kiljunen, Timo; Schulze, Dirk; Kortesniemi, Mika

2015-07-08

The aims of this study were to characterize reinforced metal-oxide-semiconductor field-effect transistor (MOSFET) dosimeters to assess the measurement uncertainty, single exposure low-dose limit with acceptable accuracy, and the number of exposures required to attain the corresponding limit of the thermoluminescent dosimeters (TLD). The second aim was to characterize MOSFET dosimeter sensitivities for two dental photon energy ranges, dose dependency, dose rate dependency, and accumulated dose dependency. A further aim was to compare the performance of MOSFETs with those of TLDs in an anthropomorphic phantom head using a dentomaxillofacial CBCT device. The uncertainty was assessed by exposing 20 MOSFETs and a Barracuda MPD reference dosimeter. The MOSFET dosimeter sensitivities were evaluated for two photon energy ranges (50-90 kVp) using a constant dose and polymethylmethacrylate backscatter material. MOSFET and TLD comparative point-dose measurements were performed on an anthropomorphic phantom that was exposed with a clinical CBCT protocol. The MOSFET single exposure low dose limit (25% uncertainty, k = 2) was 1.69 mGy. An averaging of eight MOSFET exposures was required to attain the corresponding TLD (0.3 mGy) low-dose limit. The sensitivity was 3.09 ± 0.13 mV/mGy independently of the photon energy used. The MOSFET dosimeters did not present dose or dose rate sensitivity but, however, presented a 1% decrease of sensitivity per 1000 mV for accumulated threshold voltages between 8300 mV and 17500 mV. The point doses in an anthropomorphic phantom ranged for MOSFETs between 0.24 mGy and 2.29 mGy and for TLDs between 0.25 and 2.09 mGy, respectively. The mean difference was -8%. The MOSFET dosimeters presented statistically insignificant energy dependency. By averaging multiple exposures, the MOSFET dosimeters can achieve a TLD-comparable low-dose limit and constitute a feasible method for diagnostic dosimetry using anthropomorphic phantoms. However, for single in vivo measurements (<1.7 mGy) the sensitivity is too low.

Time stamping of single optical photons with 10 ns resolution

NASA Astrophysics Data System (ADS)

Chakaberia, Irakli; Cotlet, Mircea; Fisher-Levine, Merlin; Hodges, Diedra R.; Nguyen, Jayke; Nomerotski, Andrei

2017-05-01

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.1-5 Fast imaging also provides the capability of coincidence detection, and the further addition of sensitivity to single optical photons with the capability of timestamping them further broadens the field of potential applications. Photon counting is already widely used in X-ray imaging,6 where the high energy of the photons makes their detection easier. TimepixCam is a novel optical imager,7 which achieves high spatial resolution using an array of 256×256 55 μm × 55μm pixels which have individually controlled functionality. It is based on a thin-entrance-window silicon sensor, bump-bonded to a Timepix ASIC.8 TimepixCam provides high quantum efficiency in the optical wavelength range (400-1000 nm). We perform the timestamping of single photons with a time resolution of 20 ns, by coupling TimepixCam to a fast image-intensifier with a P47 phosphor screen. The fast emission time of the P479 allows us to preserve good time resolution while maintaining the capability to focus the optical output of the intensifier onto the 256×256 pixel Timepix sensor area. We demonstrate the capability of the (TimepixCam + image intensifier) setup to provide high-resolution single-photon timestamping, with an effective frame rate of 50 MHz.

Low-temperature sensitivity periodically tapered photonic crystal-fiber-based refractometer.

PubMed

Wang, Pengfei; Bo, Lin; Guan, Chunying; Semenova, Yuliya; Wu, Qiang; Brambilla, Gilberto; Farrell, Gerald

2013-10-01

In this Letter, an all-fiber refractometer with a simple configuration of periodical tapers on a photonic crystal fiber (PCF) is proposed and investigated experimentally. The proposed fiber refractive index (RI) sensor consists of a PCF sandwiched between two standard single-mode fibers, with tapers periodically fabricated along the PCF using a CO(2) laser beam focused by a ZnSe cylindrical lens. The proposed fiber sensor can be used for RI sensing by measuring the wavelength shift of the multimode interference dip over the transmission spectrum. An average sensitivity of 222 nm/RIU has been experimentally achieved over a RI range from 1.33 to 1.38. The proposed refractometer is also significantly less sensitive to temperature, and an experimental demonstration of this reduced sensitivity is presented. The proposed RI sensor benefits from simplicity and low-cost and achieves a competitive sensitivity compared with other existing fiber-optic sensors.

Geiger-mode APD camera system for single-photon 3D LADAR imaging

NASA Astrophysics Data System (ADS)

Entwistle, Mark; Itzler, Mark A.; Chen, Jim; Owens, Mark; Patel, Ketan; Jiang, Xudong; Slomkowski, Krystyna; Rangwala, Sabbir

2012-06-01

The unparalleled sensitivity of 3D LADAR imaging sensors based on single photon detection provides substantial benefits for imaging at long stand-off distances and minimizing laser pulse energy requirements. To obtain 3D LADAR images with single photon sensitivity, we have demonstrated focal plane arrays (FPAs) based on InGaAsP Geiger-mode avalanche photodiodes (GmAPDs) optimized for use at either 1.06 μm or 1.55 μm. These state-of-the-art FPAs exhibit excellent pixel-level performance and the capability for 100% pixel yield on a 32 x 32 format. To realize the full potential of these FPAs, we have recently developed an integrated camera system providing turnkey operation based on FPGA control. This system implementation enables the extremely high frame-rate capability of the GmAPD FPA, and frame rates in excess of 250 kHz (for 0.4 μs range gates) can be accommodated using an industry-standard CameraLink interface in full configuration. Real-time data streaming for continuous acquisition of 2 μs range gate point cloud data with 13-bit time-stamp resolution at 186 kHz frame rates has been established using multiple solid-state storage drives. Range gate durations spanning 4 ns to 10 μs provide broad operational flexibility. The camera also provides real-time signal processing in the form of multi-frame gray-scale contrast images and single-frame time-stamp histograms, and automated bias control has been implemented to maintain a constant photon detection efficiency in the presence of ambient temperature changes. A comprehensive graphical user interface has been developed to provide complete camera control using a simple serial command set, and this command set supports highly flexible end-user customization.

Design and performance of single photon APD focal plane arrays for 3-D LADAR imaging

NASA Astrophysics Data System (ADS)

Itzler, Mark A.; Entwistle, Mark; Owens, Mark; Patel, Ketan; Jiang, Xudong; Slomkowski, Krystyna; Rangwala, Sabbir; Zalud, Peter F.; Senko, Tom; Tower, John; Ferraro, Joseph

2010-08-01

×We describe the design, fabrication, and performance of focal plane arrays (FPAs) for use in 3-D LADAR imaging applications requiring single photon sensitivity. These 32 × 32 FPAs provide high-efficiency single photon sensitivity for three-dimensional LADAR imaging applications at 1064 nm. Our GmAPD arrays are designed using a planarpassivated avalanche photodiode device platform with buried p-n junctions that has demonstrated excellent performance uniformity, operational stability, and long-term reliability. The core of the FPA is a chip stack formed by hybridizing the GmAPD photodiode array to a custom CMOS read-out integrated circuit (ROIC) and attaching a precision-aligned GaP microlens array (MLA) to the back-illuminated detector array. Each ROIC pixel includes an active quenching circuit governing Geiger-mode operation of the corresponding avalanche photodiode pixel as well as a pseudo-random counter to capture per-pixel time-of-flight timestamps in each frame. The FPA has been designed to operate at frame rates as high as 186 kHz for 2 μs range gates. Effective single photon detection efficiencies as high as 40% (including all optical transmission and MLA losses) are achieved for dark count rates below 20 kHz. For these planar-geometry diffused-junction GmAPDs, isolation trenches are used to reduce crosstalk due to hot carrier luminescence effects during avalanche events, and we present details of the crosstalk performance for different operating conditions. Direct measurement of temporal probability distribution functions due to cumulative timing uncertainties of the GmAPDs and ROIC circuitry has demonstrated a FWHM timing jitter as low as 265 ps (standard deviation is ~100 ps).

Ultra-high sensitivity Fabry-Perot interferometer gas refractive index fiber sensor based on photonic crystal fiber and Vernier effect.

PubMed

Quan, Mingran; Tian, Jiajun; Yao, Yong

2015-11-01

An ultra-high sensitivity open-cavity Fabry-Perot interferometer (FPI) gas refractive index (RI) sensor based on the photonic crystal fiber (PCF) and Vernier effect is proposed and demonstrated. The sensor is prepared by splicing a section of PCF to a section of fiber tube fused with a section of single mode fiber. The air holes running along the cladding of the PCF enable the gas to enter or leave the cavity freely. The reflection beam from the last end face of the PCF is used to generate the Vernier effect, which significantly improves the sensitivity of the sensor. Experimental results show that the proposed sensor can provide an ultra-high RI sensitivity of 30899 nm/RIU. This sensor has potential applications in fields such as gas concentration analyzing and humidity monitoring.

Temperature sensor based on an isopropanol-sealed photonic crystal fiber in-line interferometer with enhanced refractive index sensitivity.

PubMed

Qiu, Sun-jie; Chen, Ye; Xu, Fei; Lu, Yan-qing

2012-03-01

We fabricate a simple, compact, and stable temperature sensor based on a liquid-sealed photonic crystal fiber (PCF) in-line nonpolarimetric modal interferometer. Different from other reported PCF devices, it does not need expensive polarimetric devices, and the liquid is sealed in one fiber. The device consists of a stub of isopropanol-filled PCF spliced between standard single-mode fibers. The temperature sensitivity (-166 pm/°C) increases over an order of magnitude compared with those of the previous sensors based on air-sealed PCF interferometers built via fusion splicing with the same mechanism. In addition, the refractive index sensitivity also increases. Higher temperature sensitivity can be realized by infiltrating some liquid having a higher thermo-optic coefficient into the microholes of the PCF. © 2012 Optical Society of America

λ/26 silver nanodots fabricated by direct laser writing through highly sensitive two-photon photoreduction

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

Cao, Yaoyu; Gu, Min, E-mail: mgu@swin.edu.au

We demonstrated an approach to break the diffraction limit and realise deep-subwavelength two-photon direct laser writing by employing a highly sensitive photoreduction process. The photoreduction photosensitivity increased by at least 4 times while the wavelength of the fabrication laser beam was tuned from 800 nm to 580 nm. The increase of the photosensitivity resulted in improved resolution for the silver dot fabrication. By developing the photoreduction material with adding electron donors, the photosensitivity further increased and enabled the realisation of a single silver dot at 22 nm which is λ/26 for the wavelength of the fabrication laser beam.

Temperature-independent refractometer based on a tapered photonic crystal fiber interferometer

NASA Astrophysics Data System (ADS)

Ni, Kai; Chan, Chi Chiu; Dong, Xinyong; Poh, C. L.; Li, Tao

2013-03-01

A temperature-independent refractometer by using a tapered photonic crystal fiber (PCF) based Mach-Zehnder interferometer (MZI) is proposed and experimentally demonstrated. It is fabricated by sandwiching a tapered PCF of 29 mm long between two standard single mode fibers (SMFs) with the fully collapsed air holes of the PCF in the fusion splicing region. It has been found that tapering the PCF greatly enhances the sensitivity of the refractometer. A maximum sensitivity of 1529 nm/RIU (refractive index unit) is achieved within the range from 1.3355 to 1.413. The refractometer is nearly temperature-insensitive due to the ultra low temperature dependence of the used.

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

High-speed multi-exposure laser speckle contrast imaging with a single-photon counting camera

PubMed Central

Dragojević, Tanja; Bronzi, Danilo; Varma, Hari M.; Valdes, Claudia P.; Castellvi, Clara; Villa, Federica; Tosi, Alberto; Justicia, Carles; Zappa, Franco; Durduran, Turgut

2015-01-01

Laser speckle contrast imaging (LSCI) has emerged as a valuable tool for cerebral blood flow (CBF) imaging. We present a multi-exposure laser speckle imaging (MESI) method which uses a high-frame rate acquisition with a negligible inter-frame dead time to mimic multiple exposures in a single-shot acquisition series. Our approach takes advantage of the noise-free readout and high-sensitivity of a complementary metal-oxide-semiconductor (CMOS) single-photon avalanche diode (SPAD) array to provide real-time speckle contrast measurement with high temporal resolution and accuracy. To demonstrate its feasibility, we provide comparisons between in vivo measurements with both the standard and the new approach performed on a mouse brain, in identical conditions. PMID:26309751

Chemical silicon surface modification and bioreceptor attachment to develop competitive integrated photonic biosensors.

PubMed

Escorihuela, Jorge; Bañuls, María José; García Castelló, Javier; Toccafondo, Veronica; García-Rupérez, Jaime; Puchades, Rosa; Maquieira, Ángel

2012-12-01

Methodology for the functionalization of silicon-based materials employed for the development of photonic label-free nanobiosensors is reported. The studied functionalization based on organosilane chemistry allowed the direct attachment of biomolecules in a single step, maintaining their bioavailability. Using this immobilization approach in probe microarrays, successful specific detection of bacterial DNA is achieved, reaching hybridization sensitivities of 10 pM. The utility of the immobilization approach for the functionalization of label-free nanobiosensors based on photonic crystals and ring resonators was demonstrated using bovine serum albumin (BSA)/anti-BSA as a model system.

Highly birefringent suspended-core photonic microcells for refractive-index sensing

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

Wang, Chao; The Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen 518057; Jin, Wa

2014-08-11

An in-line photonic microcell with a highly birefringent suspended microfiber core is fabricated by locally heating and pressurizing selected air-holes of an endless single mode photonic crystal fiber. The microfiber core has rhombus-like cross-sectional geometry and could achieve a high birefringence of up to 10{sup −2}. The microfiber core is fixed at the center of the microcell by thin struts attached to an outer jacket tube, which protects and isolates the microfiber from environmental contaminations. Highly sensitive and robust refractive index sensors based on such microcells are experimentally demonstrated.

Calibration and characterization of the IceCube photomultiplier tube

NASA Astrophysics Data System (ADS)

Abbasi, R.; Abdou, Y.; Abu-Zayyad, T.; Adams, J.; Aguilar, J. A.; Ahlers, M.; Andeen, K.; Auffenberg, J.; Bai, X.; Baker, M.; Barwick, S. W.; Bay, R.; Bazo Alba, J. L.; Beattie, K.; Beatty, J. J.; Bechet, S.; Becker, J. K.; Becker, K.-H.; Benabderrahmane, M. L.; Berdermann, J.; Berghaus, P.; Berley, D.; Bernardini, E.; Bertrand, D.; Besson, D. Z.; Bissok, M.; Blaufuss, E.; Boersma, D. J.; Bohm, C.; Botner, O.; Bradley, L.; Braun, J.; Buitink, S.; Carson, M.; Chirkin, D.; Christy, B.; Clem, J.; Cohen, S.; Colnard, C.; Cowen, D. F.; D'Agostino, M. V.; Danninger, M.; de Clercq, C.; Demirörs, L.; Depaepe, O.; Descamps, F.; Desiati, P.; de Vries-Uiterweerd, G.; Deyoung, T.; Díaz-Vélez, J. C.; Dreyer, J.; Dumm, J. P.; Duvoort, M. R.; Ehrlich, R.; Eisch, J.; Ellsworth, R. W.; Engdegård, O.; Euler, S.; Evenson, P. A.; Fadiran, O.; Fazely, A. R.; Feusels, T.; Filimonov, K.; Finley, C.; Foerster, M. M.; Fox, B. D.; Franckowiak, A.; Franke, R.; Gaisser, T. K.; Gallagher, J.; Ganugapati, R.; Geisler, M.; Gerhardt, L.; Gladstone, L.; Goldschmidt, A.; Goodman, J. A.; Grant, D.; Griesel, T.; Groß, A.; Grullon, S.; Gunasingha, R. M.; Gurtner, M.; Ha, C.; Hallgren, A.; Halzen, F.; Han, K.; Hanson, K.; Hasegawa, Y.; Haugen, J.; Helbing, K.; Herquet, P.; Hickford, S.; Hill, G. C.; Hoffman, K. D.; Homeier, A.; Hoshina, K.; Hubert, D.; Huelsnitz, W.; Hülß, J.-P.; Hulth, P. O.; Hultqvist, K.; Hussain, S.; Imlay, R. L.; Inaba, M.; Ishihara, A.; Jacobsen, J.; Japaridze, G. S.; Johansson, H.; Joseph, J. M.; Kampert, K.-H.; Kappes, A.; Karg, T.; Karle, A.; Kelley, J. L.; Kemming, N.; Kenny, P.; Kiryluk, J.; Kislat, F.; Kitamura, N.; Klein, S. R.; Knops, S.; Kohnen, G.; Kolanoski, H.; Köpke, L.; Koskinen, D. J.; Kowalski, M.; Kowarik, T.; Krasberg, M.; Krings, T.; Kroll, G.; Kuehn, K.; Kuwabara, T.; Labare, M.; Lafebre, S.; Laihem, K.; Landsman, H.; Lauer, R.; Laundrie, A.; Lehmann, R.; Lennarz, D.; Lünemann, J.; Madsen, J.; Majumdar, P.; Maruyama, R.; Mase, K.; Matis, H. S.; Matusik, M.; Meagher, K.; Merck, M.; Mészáros, P.; Meures, T.; Middell, E.; Milke, N.; Miyamoto, H.; Montaruli, T.; Morse, R.; Movit, S. M.; Nahnhauer, R.; Nam, J. W.; Naumann, U.; Nießen, P.; Nygren, D. R.; Odrowski, S.; Olivas, A.; Olivo, M.; Ono, M.; Panknin, S.; Paul, L.; Pérez de Los Heros, C.; Petrovic, J.; Piegsa, A.; Pieloth, D.; Pohl, A. C.; Porrata, R.; Posselt, J.; Price, P. B.; Prikockis, M.; Przybylski, G. T.; Rawlins, K.; Redl, P.; Resconi, E.; Rhode, W.; Ribordy, M.; Rizzo, A.; Robl, P.; Rodrigues, J. P.; Roth, P.; Rothmaier, F.; Rott, C.; Roucelle, C.; Rutledge, D.; Ruzybayev, B.; Ryckbosch, D.; Sander, H.-G.; Sandstrom, P.; Sarkar, S.; Schatto, K.; Schlenstedt, S.; Schmidt, T.; Schneider, D.; Schukraft, A.; Schultes, A.; Schulz, O.; Schunck, M.; Seckel, D.; Semburg, B.; Seo, S. H.; Sestayo, Y.; Seunarine, S.; Silvestri, A.; Slipak, A.; Spiczak, G. M.; Spiering, C.; Stamatikos, M.; Stanev, T.; Stephens, G.; Stezelberger, T.; Stokstad, R. G.; Stoyanov, S.; Strahler, E. A.; Straszheim, T.; Sullivan, G. W.; Swillens, Q.; Taboada, I.; Tamburro, A.; Tarasova, O.; Tepe, A.; Ter-Antonyan, S.; Terranova, C.; Tilav, S.; Toale, P. A.; Tosi, D.; Turčan, D.; van Eijndhoven, N.; Vandenbroucke, J.; van Overloop, A.; van Santen, J.; Voigt, B.; Wahl, D.; Walck, C.; Waldenmaier, T.; Wallraff, M.; Walter, M.; Wendt, C.; Westerhoff, S.; Whitehorn, N.; Wiebe, K.; Wiebusch, C. H.; Wikström, G.; Williams, D. R.; Wischnewski, R.; Wissing, H.; Woschnagg, K.; Xu, C.; Xu, X. W.; Yodh, G.; Yoshida, S.; Zarzhitsky, P.; IceCube Collaboration

2010-06-01

Over 5000 PMTs are being deployed at the South Pole to compose the IceCube neutrino observatory. Many are placed deep in the ice to detect Cherenkov light emitted by the products of high-energy neutrino interactions, and others are frozen into tanks on the surface to detect particles from atmospheric cosmic ray showers. IceCube is using the 10-in. diameter R7081-02 made by Hamamatsu Photonics. This paper describes the laboratory characterization and calibration of these PMTs before deployment. PMTs were illuminated with pulses ranging from single photons to saturation level. Parameterizations are given for the single photoelectron charge spectrum and the saturation behavior. Time resolution, late pulses and afterpulses are characterized. Because the PMTs are relatively large, the cathode sensitivity uniformity was measured. The absolute photon detection efficiency was calibrated using Rayleigh-scattered photons from a nitrogen laser. Measured characteristics are discussed in the context of their relevance to IceCube event reconstruction and simulation efforts.

Linear Optical Quantum Metrology with Single Photons: Exploiting Spontaneously Generated Entanglement to Beat the Shot-Noise Limit

NASA Astrophysics Data System (ADS)

Motes, Keith R.; Olson, Jonathan P.; Rabeaux, Evan J.; Dowling, Jonathan P.; Olson, S. Jay; Rohde, Peter P.

2015-05-01

Quantum number-path entanglement is a resource for supersensitive quantum metrology and in particular provides for sub-shot-noise or even Heisenberg-limited sensitivity. However, such number-path entanglement has been thought to be resource intensive to create in the first place—typically requiring either very strong nonlinearities, or nondeterministic preparation schemes with feedforward, which are difficult to implement. Very recently, arising from the study of quantum random walks with multiphoton walkers, as well as the study of the computational complexity of passive linear optical interferometers fed with single-photon inputs, it has been shown that such passive linear optical devices generate a superexponentially large amount of number-path entanglement. A logical question to ask is whether this entanglement may be exploited for quantum metrology. We answer that question here in the affirmative by showing that a simple, passive, linear-optical interferometer—fed with only uncorrelated, single-photon inputs, coupled with simple, single-mode, disjoint photodetection—is capable of significantly beating the shot-noise limit. Our result implies a pathway forward to practical quantum metrology with readily available technology.

Linear optical quantum metrology with single photons: exploiting spontaneously generated entanglement to beat the shot-noise limit.

PubMed

Motes, Keith R; Olson, Jonathan P; Rabeaux, Evan J; Dowling, Jonathan P; Olson, S Jay; Rohde, Peter P

2015-05-01

Quantum number-path entanglement is a resource for supersensitive quantum metrology and in particular provides for sub-shot-noise or even Heisenberg-limited sensitivity. However, such number-path entanglement has been thought to be resource intensive to create in the first place--typically requiring either very strong nonlinearities, or nondeterministic preparation schemes with feedforward, which are difficult to implement. Very recently, arising from the study of quantum random walks with multiphoton walkers, as well as the study of the computational complexity of passive linear optical interferometers fed with single-photon inputs, it has been shown that such passive linear optical devices generate a superexponentially large amount of number-path entanglement. A logical question to ask is whether this entanglement may be exploited for quantum metrology. We answer that question here in the affirmative by showing that a simple, passive, linear-optical interferometer--fed with only uncorrelated, single-photon inputs, coupled with simple, single-mode, disjoint photodetection--is capable of significantly beating the shot-noise limit. Our result implies a pathway forward to practical quantum metrology with readily available technology.

Interference of Single Photons Emitted by Entangled Atoms in Free Space

NASA Astrophysics Data System (ADS)

Araneda, G.; Higginbottom, D. B.; Slodička, L.; Colombe, Y.; Blatt, R.

2018-05-01

The generation and manipulation of entanglement between isolated particles has precipitated rapid progress in quantum information processing. Entanglement is also known to play an essential role in the optical properties of atomic ensembles, but fundamental effects in the controlled emission and absorption from small, well-defined numbers of entangled emitters in free space have remained unobserved. Here we present the control of the emission rate of a single photon from a pair of distant, entangled atoms into a free-space optical mode. Changing the length of the optical path connecting the atoms modulates the single-photon emission rate in the selected mode with a visibility V =0.27 ±0.03 determined by the degree of entanglement shared between the atoms, corresponding directly to the concurrence Cρ=0.31 ±0.10 of the prepared state. This scheme, together with population measurements, provides a fully optical determination of the amount of entanglement. Furthermore, large sensitivity of the interference phase evolution points to applications of the presented scheme in high-precision gradient sensing.

Photonic crystal fiber long-period gratings for structural monitoring and chemical sensing

NASA Astrophysics Data System (ADS)

Tang, Jaw-Luen; Wang, Jian-Neng

2008-03-01

We present a simple, low-cost, temperature- and strain-insensitive long-period gratings (LPGs) written in photonic crystal fibers (PCFs) that can be used as sensitive chemical solution sensors or bend sensors for a variety of industrial applications, including civil engineering, aircraft, chemistry, food industry, and biosensing. Three different configurations of PCFs have been used for this study, including a polarization maintaining PCF, a large mode area PCF and an endlessly single mode PCF. These LPGs have been characterized for their sensitivity to temperature, strain, bending, and surrounding refractive index. Transmission spectra of the LPGs were found to exhibit negligible temperature and strain sensitivities, whereas possessing usable sensitivity to refractive index and bending. This type of PCF sensor could in principle be designed for optimum sensitivity to desired measurand(s), while minimizing or removing undesirable cross-sensitivities. The unique sensing features of PCFs are particularly suited for a wide variety of applications in smart structures, embedded materials, telecommunications and sensor systems.

Breast-Dedicated Radionuclide Imaging Systems.

PubMed

Hsu, David F C; Freese, David L; Levin, Craig S

2016-02-01

Breast-dedicated radionuclide imaging systems show promise for increasing clinical sensitivity for breast cancer while minimizing patient dose and cost. We present several breast-dedicated coincidence-photon and single-photon camera designs that have been described in the literature and examine their intrinsic performance, clinical relevance, and impact. Recent tracer development is mentioned, results from recent clinical tests are summarized, and potential areas for improvement are highlighted. © 2016 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

Identification of Intensity Ratio Break Points from Photon Arrival Trajectories in Ratiometric Single Molecule Spectroscopy

PubMed Central

Bingemann, Dieter; Allen, Rachel M.

2012-01-01

We describe a statistical method to analyze dual-channel photon arrival trajectories from single molecule spectroscopy model-free to identify break points in the intensity ratio. Photons are binned with a short bin size to calculate the logarithm of the intensity ratio for each bin. Stochastic photon counting noise leads to a near-normal distribution of this logarithm and the standard student t-test is used to find statistically significant changes in this quantity. In stochastic simulations we determine the significance threshold for the t-test’s p-value at a given level of confidence. We test the method’s sensitivity and accuracy indicating that the analysis reliably locates break points with significant changes in the intensity ratio with little or no error in realistic trajectories with large numbers of small change points, while still identifying a large fraction of the frequent break points with small intensity changes. Based on these results we present an approach to estimate confidence intervals for the identified break point locations and recommend a bin size to choose for the analysis. The method proves powerful and reliable in the analysis of simulated and actual data of single molecule reorientation in a glassy matrix. PMID:22837704

Characterization of Geiger mode avalanche photodiodes for fluorescence decay measurements

NASA Astrophysics Data System (ADS)

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

2002-05-01

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

Detecting infrared luminescence and non-chemical signaling of living cells: single cell mid-IR spectroscopy in cryogenic environments

NASA Astrophysics Data System (ADS)

Pereverzev, Sergey

2017-02-01

Many life-relevant interaction energies are in IR range, and it is reasonable to believe that some biochemical reactions inside cells can results in emission of IR photons. Cells can use this emission for non-chemical and non-electrical signaling. Detecting weak infrared radiation from live cells is complicated because of strong thermal radiation background and absorption of radiation by tissues. A microfluidic device with live cells inside a vacuum cryogenic environment should suppress this background, and thereby permit observation of live cell auto-luminescence or signaling in the IR regime. One can make IR-transparent windows not emitting in this range, so only the cell and a small amount of liquid around it will emit infrared radiation. Currently mid-IR spectroscopy of single cells requires the use of a synchrotron source to measure absorption or reflection spectra. Decreasing of thermal radiation background will allow absorption and reflection spectroscopy of cells without using synchrotron light. Moreover, cell auto-luminescence can be directly measured. The complete absence of thermal background radiation for cryogenically cooled samples allows the use IR photon-sensitive detectors and obtaining single molecule sensitivity in IR photo-luminescence measurements. Due to low photon energies, photo-luminescence measurements will be non-distractive for pressures samples. The technique described here is based upon US patent 9366574.

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

NASA Astrophysics Data System (ADS)

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

2016-08-01

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

Background-Free 3D Nanometric Localization and Sub-nm Asymmetry Detection of Single Plasmonic Nanoparticles by Four-Wave Mixing Interferometry with Optical Vortices

NASA Astrophysics Data System (ADS)

Zoriniants, George; Masia, Francesco; Giannakopoulou, Naya; Langbein, Wolfgang; Borri, Paola

2017-10-01

Single nanoparticle tracking using optical microscopy is a powerful technique with many applications in biology, chemistry, and material sciences. Despite significant advances, localizing objects with nanometric position precision in a scattering environment remains challenging. Applied methods to achieve contrast are dominantly fluorescence based, with fundamental limits in the emitted photon fluxes arising from the excited-state lifetime as well as photobleaching. Here, we show a new four-wave-mixing interferometry technique, whereby the position of a single nonfluorescing gold nanoparticle of 25-nm radius is determined with 16 nm precision in plane and 3 nm axially from rapid single-point measurements at 1-ms acquisition time by exploiting optical vortices. The precision in plane is consistent with the photon shot-noise, while axially it is limited by the nano-positioning sample stage, with an estimated photon shot-noise limit of 0.5 nm. The detection is background-free even inside biological cells. The technique is also uniquely sensitive to particle asymmetries of only 0.5% ellipticity, corresponding to a single atomic layer of gold, as well as particle orientation. This method opens new ways of unraveling single-particle trafficking within complex 3D architectures.

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

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

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

2016-07-27

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

Characterization of MOSFET dosimeters for low‐dose measurements in maxillofacial anthropomorphic phantoms

PubMed Central

Wolff, Jan E.; Kiljunen, Timo; Schulze, Dirk; Kortesniemi, Mika

2015-01-01

The aims of this study were to characterize reinforced metal‐oxide‐semiconductor field‐effect transistor (MOSFET) dosimeters to assess the measurement uncertainty, single exposure low‐dose limit with acceptable accuracy, and the number of exposures required to attain the corresponding limit of the thermoluminescent dosimeters (TLD). The second aim was to characterize MOSFET dosimeter sensitivities for two dental photon energy ranges, dose dependency, dose rate dependency, and accumulated dose dependency. A further aim was to compare the performance of MOSFETs with those of TLDs in an anthropomorphic phantom head using a dentomaxillofacial CBCT device. The uncertainty was assessed by exposing 20 MOSFETs and a Barracuda MPD reference dosimeter. The MOSFET dosimeter sensitivities were evaluated for two photon energy ranges (50–90 kVp) using a constant dose and polymethylmethacrylate backscatter material. MOSFET and TLD comparative point‐dose measurements were performed on an anthropomorphic phantom that was exposed with a clinical CBCT protocol. The MOSFET single exposure low dose limit (25% uncertainty, k=2) was 1.69 mGy. An averaging of eight MOSFET exposures was required to attain the corresponding TLD (0.3 mGy) low‐dose limit. The sensitivity was 3.09±0.13 mV/mGy independently of the photon energy used. The MOSFET dosimeters did not present dose or dose rate sensitivity but, however, presented a 1% decrease of sensitivity per 1000 mV for accumulated threshold voltages between 8300 mV and 17500 mV. The point doses in an anthropomorphic phantom ranged for MOSFETs between 0.24 mGy and 2.29 mGy and for TLDs between 0.25 and 2.09 mGy, respectively. The mean difference was −8%. The MOSFET dosimeters presented statistically insignificant energy dependency. By averaging multiple exposures, the MOSFET dosimeters can achieve a TLD‐comparable low‐dose limit and constitute a feasible method for diagnostic dosimetry using anthropomorphic phantoms. However, for single in vivo measurements (<1.7 mGy) the sensitivity is too low. PACS number: 87.50.wj PMID:26219008

The research of data acquisition system for Raman spectrometer

NASA Astrophysics Data System (ADS)

Cui, Xiao; Guo, Pan; Zhang, Yinchao; Chen, Siying; Chen, He; Chen, Wenbo

2011-11-01

Raman spectrometer has been widely used as an identification tool for analyzing material structure and composition in many fields. However, Raman scattering echo signal is very weak, about dozens of photons at most in one laser plus signal. Therefore, it is a great challenge to design a Raman spectrum data acquisition system which could accurately receive the weak echo signal. The system designed in this paper receives optical signals with the principle of photon counter and could detect single photon. The whole system consists of a photoelectric conversion module H7421-40 and a photo counting card including a field programmable gate array (FPGA) chip and a PCI9054 chip. The module H7421-40 including a PMT, an amplifier and a discriminator has high sensitivity on wavelength from 300nm to 720nm. The Center Wavelength is 580nm which is close to the excitation wavelength (532nm), QE 40% at peak wavelength, Count Sensitivity is 7.8*105(S-1PW-1) and Count Linearity is 1.5MHZ. In FPGA chip, the functions are divided into three parts: parameter setting module, controlling module, data collection and storage module. All the commands, parameters and data are transmitted between FPGA and computer by PCI9054 chip through the PCI interface. The result of experiment shows that the Raman spectrum data acquisition system is reasonable and efficient. There are three primary advantages of the data acquisition system: the first one is the high sensitivity with single photon detection capability; the second one is the high integrated level which means all the operation could be done by the photo counting card; and the last one is the high expansion ability because of the smart reconfigurability of FPGA chip.

Picosecond Acoustics in Single Quantum Wells of Cubic GaN /(Al ,Ga )N

NASA Astrophysics Data System (ADS)

Czerniuk, T.; Ehrlich, T.; Wecker, T.; As, D. J.; Yakovlev, D. R.; Akimov, A. V.; Bayer, M.

2017-01-01

A picosecond acoustic pulse is used to study the photoelastic interaction in single zinc-blende GaN /AlxGa1 -x N quantum wells. We use an optical time-resolved pump-probe setup and demonstrate that tuning the photon energy to the quantum well's lowest electron-hole transition makes the experiment sensitive to the quantum well only. Because of the small width, its temporal and spatial resolution allows us to track the few-picosecond-long transit of the acoustic pulse. We further deploy a model to analyze the unknown photoelastic coupling strength of the quantum well for different photon energies and find good agreement with the experiments.

Switching Dynamics of an Underdamped Josephson Junction Coupled to a Microwave Cavity

NASA Astrophysics Data System (ADS)

Oelsner, G.; Il'ichev, E.

2018-05-01

Current-biased Josephson junctions are promising candidates for the detection of single photons in the microwave frequency domain. With modern fabrication technologies, the switching properties of the junction can be adjusted to achieve quantum limited sensitivity. Namely, the width of the switching current distribution can be reduced well below the current amplitude produced by a single photon trapped inside a superconducting cavity. However, for an effective detection a strong junction cavity coupling is required, providing nonlinear system dynamics. We compare experimental findings for our prototype device with a theoretical analysis aimed to describe the switching dynamics of junctions under microwave irradiation. Measurements are found in qualitative agreement with our simulations.

Cytochrome c conformations resolved by the photon counting histogram: Watching the alkaline transition with single-molecule sensitivity

PubMed Central

Perroud, Thomas D.; Bokoch, Michael P.; Zare, Richard N.

2005-01-01

We apply the photon counting histogram (PCH) model, a fluorescence technique with single-molecule sensitivity, to study pH-induced conformational changes of cytochrome c. PCH is able to distinguish different protein conformations based on the brightness of a fluorophore sensitive to its local environment. We label cytochrome c through its single free cysteine with tetramethylrhodamine-5-maleimide (TMR), a fluorophore with specific brightnesses that we associate with specific protein conformations. Ensemble measurements demonstrate two different fluorescence responses with increasing pH: (i) a decrease in fluorescence intensity caused by the alkaline transition of cytochrome c (pH 7.0–9.5), and (ii) an increase in intensity when the protein unfolds (pH 9.5–10.8). The magnitudes of these two responses depend strongly on the molar ratio of TMR used to label cytochrome c. Using PCH we determine that this effect arises from the proportion of a nonfunctional conformation in the sample, which can be differentiated from the functional conformation. We further determine the causes of each ensemble fluorescence response: (i) during the alkaline transition, the fluorophore enters a dark state and discrete conformations are observed, and (ii) as cytochrome c unfolds, the fluorophore incrementally brightens, but discrete conformations are no longer resolved. Moreover, we also show that functional TMR-cytochrome c undergoes a response of identical magnitude regardless of the proportion of nonfunctional protein in the sample. As expected for a technique with single-molecule sensitivity, we demonstrate that PCH can directly observe the most relevant conformation, unlike ensemble fluorometry. PMID:16314563

High-sensitivity refractive index sensors based on fused tapered photonic crystal fiber

NASA Astrophysics Data System (ADS)

Fu, Xing-hu; Xie, Hai-yang; Yang, Chuan-qing; Qu, Yu-wei; Zhang, Shun-yang; Fu, Guang-wei; Guo, Xuan; Bi, Wei-hong

2016-05-01

In this paper, a novel liquid refractive index (RI) sensor based on fused tapered photonic crystal fiber (PCF) is proposed. It is fabricated by fusing and tapering a section of PCF which is spliced with two single-mode fibers (SMFs). Due to the fused biconical taper method, the sensor becomes longer and thinner, to make the change of the outside RI has more direct effects on the internal optical field of the PCF, which finally enhances the sensitivity of this sensor. Experimental results show that the transmission spectra of the sensor are red-shifted obviously with the increase of RI. The longer the tapered region of the sensor, the higher the sensitivity is. This sensor has the advantages of simple structure, easy fabrication, high performance and so on, so it has potential applications in RI measurement.

Photonic polarization gears for ultra-sensitive angular measurements

PubMed Central

D'Ambrosio, Vincenzo; Spagnolo, Nicolò; Del Re, Lorenzo; Slussarenko, Sergei; Li, Ying; Kwek, Leong Chuan; Marrucci, Lorenzo; Walborn, Stephen P.; Aolita, Leandro; Sciarrino, Fabio

2013-01-01

Quantum metrology bears a great promise in enhancing measurement precision, but is unlikely to become practical in the near future. Its concepts can nevertheless inspire classical or hybrid methods of immediate value. Here we demonstrate NOON-like photonic states of m quanta of angular momentum up to m=100, in a setup that acts as a ‘photonic gear’, converting, for each photon, a mechanical rotation of an angle θ into an amplified rotation of the optical polarization by mθ, corresponding to a ‘super-resolving’ Malus’ law. We show that this effect leads to single-photon angular measurements with the same precision of polarization-only quantum strategies with m photons, but robust to photon losses. Moreover, we combine the gear effect with the quantum enhancement due to entanglement, thus exploiting the advantages of both approaches. The high ‘gear ratio’ m boosts the current state of the art of optical non-contact angular measurements by almost two orders of magnitude. PMID:24045270

High-performance semiconductor quantum-dot single-photon sources

NASA Astrophysics Data System (ADS)

Senellart, Pascale; Solomon, Glenn; White, Andrew

2017-11-01

Single photons are a fundamental element of most quantum optical technologies. The ideal single-photon source is an on-demand, deterministic, single-photon source delivering light pulses in a well-defined polarization and spatiotemporal mode, and containing exactly one photon. In addition, for many applications, there is a quantum advantage if the single photons are indistinguishable in all their degrees of freedom. Single-photon sources based on parametric down-conversion are currently used, and while excellent in many ways, scaling to large quantum optical systems remains challenging. In 2000, semiconductor quantum dots were shown to emit single photons, opening a path towards integrated single-photon sources. Here, we review the progress achieved in the past few years, and discuss remaining challenges. The latest quantum dot-based single-photon sources are edging closer to the ideal single-photon source, and have opened new possibilities for quantum technologies.

Confocal Microscopy Imaging with an Optical Transition Edge Sensor

NASA Astrophysics Data System (ADS)

Fukuda, D.; Niwa, K.; Hattori, K.; Inoue, S.; Kobayashi, R.; Numata, T.

2018-05-01

Fluorescence color imaging at an extremely low excitation intensity was performed using an optical transition edge sensor (TES) embedded in a confocal microscope for the first time. Optical TES has the ability to resolve incident single photon energy; therefore, the wavelength of each photon can be measured without spectroscopic elements such as diffraction gratings. As target objects, animal cells labeled with two fluorescent dyes were irradiated with an excitation laser at an intensity below 1 μW. In our confocal system, an optical fiber-coupled TES device is used to detect photons instead of the pinhole and photomultiplier tube used in typical confocal microscopes. Photons emitted from the dyes were collected by the objective lens, and sent to the optical TES via the fiber. The TES measures the wavelength of each photon arriving in an exposure time of 70 ms, and a fluorescent photon spectrum is constructed. This measurement is repeated by scanning the target sample, and finally a two-dimensional RGB-color image is obtained. The obtained image showed that the photons emitted from the dyes of mitochondria and cytoskeletons were clearly resolved at a detection intensity level of tens of photons. TES exhibits ideal performance as a photon detector with a low dark count rate (< 1 Hz) and wavelength resolving power. In the single-mode fiber-coupled system, the confocal microscope can be operated in the super-resolution mode. These features are very promising to realize high-sensitivity and high-resolution photon spectral imaging, and would help avoid cell damage and photobleaching of fluorescence dyes.

Time domain diffuse Raman spectrometer based on a TCSPC camera for the depth analysis of diffusive media.

PubMed

Konugolu Venkata Sekar, S; Mosca, S; Tannert, S; Valentini, G; Martelli, F; Binzoni, T; Prokazov, Y; Turbin, E; Zuschratter, W; Erdmann, R; Pifferi, A

2018-05-01

We present a time domain diffuse Raman spectrometer for depth probing of highly scattering media. The system is based on, to the best of our knowledge, a novel time-correlated single-photon counting (TCSPC) camera that simultaneously acquires both spectral and temporal information of Raman photons. A dedicated non-contact probe was built, and time domain Raman measurements were performed on a tissue mimicking bilayer phantom. The fluorescence contamination of the Raman signal was eliminated by early time gating (0-212 ps) the Raman photons. Depth sensitivity is achieved by time gating Raman photons at different delays with a gate width of 106 ps. Importantly, the time domain can provide time-dependent depth sensitivity leading to a high contrast between two layers of Raman signal. As a result, an enhancement factor of 2170 was found for our bilayer phantom which is much higher than the values obtained by spatial offset Raman spectroscopy (SORS), frequency offset Raman spectroscopy (FORS), or hybrid FORS-SORS on a similar phantom.

System-level integration of active silicon photonic biosensors

NASA Astrophysics Data System (ADS)

Laplatine, L.; Al'Mrayat, O.; Luan, E.; Fang, C.; Rezaiezadeh, S.; Ratner, D. M.; Cheung, K.; Dattner, Y.; Chrostowski, L.

2017-02-01

Biosensors based on silicon photonic integrated circuits have attracted a growing interest in recent years. The use of sub-micron silicon waveguides to propagate near-infrared light allows for the drastic reduction of the optical system size, while increasing its complexity and sensitivity. Using silicon as the propagating medium also leverages the fabrication capabilities of CMOS foundries, which offer low-cost mass production. Researchers have deeply investigated photonic sensor devices, such as ring resonators, interferometers and photonic crystals, but the practical integration of silicon photonic biochips as part of a complete system has received less attention. Herein, we present a practical system-level architecture which can be employed to integrate the aforementioned photonic biosensors. We describe a system based on 1 mm2 dies that integrate germanium photodetectors and a single light coupling device. The die are embedded into a 16x16 mm2 epoxy package to enable microfluidic and electrical integration. First, we demonstrate a simple process to mimic Fan-Out Wafer-level-Packaging, which enables low-cost mass production. We then characterize the photodetectors in the photovoltaic mode, which exhibit high sensitivity at low optical power. Finally, we present a new grating coupler concept to relax the lateral alignment tolerance down to +/- 50 μm at 1-dB (80%) power penalty, which should permit non-experts to use the biochips in a"plug-and-play" style. The system-level integration demonstrated in this study paves the way towards the mass production of low-cost and highly sensitive biosensors, and can facilitate their wide adoption for biomedical and agro-environmental applications.

Single photon source with individualized single photon certifications

NASA Astrophysics Data System (ADS)

Migdall, Alan L.; Branning, David A.; Castelletto, Stefania; Ware, M.

2002-12-01

As currently implemented, single-photon sources cannot be made to produce single photons with high probability, while simultaneously suppressing the probability of yielding two or more photons. Because of this, single photon sources cannot really produce single photons on demand. We describe a multiplexed system that allows the probabilities of producing one and more photons to be adjusted independently, enabling a much better approximation of a source of single photons on demand. The scheme uses a heralded photon source based on parametric downconversion, but by effectively breaking the trigger detector area into multiple regions, we are able to extract more information about a heralded photon than is possible with a conventional arrangement. This scheme allows photons to be produced along with a quantitative 'certification' that they are single photons. Some of the single-photon certifications can be significantly better than what is possible with conventional downconversion sources, as well as being better than faint laser sources. With such a source of more tightly certified single photons, it should be possible to improve the maximum secure bit rate possible over a quantum cryptographic link. We present an analysis of the relative merits of this method over the conventional arrangement.

Single photon emission computed tomography (SPECT) in epilepsy

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

Leroy, R.F.

1991-12-31

Epilepsy is a common neurologic disorder which has just begun to be studied with single photon emission computerized tomography (SPECT). Epilepsy usually is studied with electroencephalographic (EEG) techniques that demonstrate the physiologic changes that occur during seizures, and with neuroimaging techniques that show the brain structures where seizures originate. Neither method alone has been adequate to describe the pathophysiology of the patient with epilepsy. EEG techniques lack anatomic sensitivity, and there are no structural abnormalities shown by neuroimaging which are specific for epilepsy. Functional imaging (FI) has developed as a physiologic tool with anatomic sensitivity, and SPECT has been promotedmore » as a FI technique because of its potentially wide availability. However, SPECT is early in its development and its clinical utility for epilepsy still has to be demonstrated. To understand this role of SPECT, consideration must be given to the pathophysiology of epilepsy, brain physiology, types of seizure, epileptic syndromes, and the SPECT technique itself. 44 refs., 2 tabs.« less

Infrared engineering for the advancement of science: A UK perspective

NASA Astrophysics Data System (ADS)

Baker, Ian M.

2017-02-01

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

Comparison of 32 x 128 and 32 x 32 Geiger-mode APD FPAs for single photon 3D LADAR imaging

NASA Astrophysics Data System (ADS)

Itzler, Mark A.; Entwistle, Mark; Owens, Mark; Patel, Ketan; Jiang, Xudong; Slomkowski, Krystyna; Rangwala, Sabbir; Zalud, Peter F.; Senko, Tom; Tower, John; Ferraro, Joseph

2011-05-01

We present results obtained from 3D imaging focal plane arrays (FPAs) employing planar-geometry InGaAsP/InP Geiger-mode avalanche photodiodes (GmAPDs) with high-efficiency single photon sensitivity at 1.06 μm. We report results obtained for new 32 x 128 format FPAs with 50 μm pitch and compare these results to those obtained for 32 x 32 format FPAs with 100 μm pitch. We show excellent pixel-level yield-including 100% pixel operability-for both formats. The dark count rate (DCR) and photon detection efficiency (PDE) performance is found to be similar for both types of arrays, including the fundamental DCR vs. PDE tradeoff. The optical crosstalk due to photon emission induced by pixel-level avalanche detection events is found to be qualitatively similar for both formats, with some crosstalk metrics for the 32 x 128 format found to be moderately elevated relative to the 32 x 32 FPA results. Timing jitter measurements are also reported for the 32 x 128 FPAs.

VCSEL-based oxygen spectroscopy for structural analysis of pharmaceutical solids

NASA Astrophysics Data System (ADS)

Svensson, T.; Andersson, M.; Rippe, L.; Svanberg, S.; Andersson-Engels, S.; Johansson, J.; Folestad, S.

2008-02-01

We present a minimalistic and flexible single-beam instrumentation based on sensitive tunable diode laser absorption spectroscopy (TDLAS) and its use in structural analysis of highly scattering pharmaceutical solids. By utilising a vertical cavity surface emitting laser (VCSEL) for sensing of molecular oxygen dispersed in tablets, we address structural properties such as porosity. Experiments involve working with unknown path lengths, severe backscattering and diffuse light. These unusual experimental conditions has led to the use of the term gas in scattering media absorption spectroscopy (GASMAS). By employing fully digital wavelength modulation spectroscopy and coherent sampling, system sensitivity in ambient air experiments reaches the 10-7 range. Oxygen absorption exhibited by our tablets, being influenced by both sample porosity and scattering, was in the range 8×10-5 to 2×10-3, and corresponds to 2-50 mm of path length through ambient air (Leq). The day-to-day reproducibility was on average 1.8% (0.3 mm Leq), being limited by mechanical positioning. This is the first time sub-millimetre sensitivity is reached in GASMAS. We also demonstrate measurements on gas transport on a 1-s time scale. By employing pulsed illumination and time-correlated single-photon counting, we reveal that GASMAS exhibits excellent correlation with time-domain photon migration. In addition, we introduce an optical measure of porosity by relating oxygen absorption to average photon time-of-flight. Finally, the simplicity, robustness and low cost of this novel TDLAS instrumentation provide industrial potential.

Er:Yb phosphate glass laser with nonlinear absorber for phase-sensitive optical time domain reflectometry

NASA Astrophysics Data System (ADS)

Zhirnov, A. A.; Pnev, A. B.; Svelto, C.; Norgia, M.; Pesatori, A.; Galzerano, G.; Laporta, P.; Shelestov, D. A.; Karasik, V. E.

2017-11-01

A novel laser for phase-sensitive optical time-domain reflectometry (Φ-OTDR) is presented. The advantages of a compact solid-state laser are listed, current problems are shown. Experiments with a microchip single-optical-element laser, from setup construction to usage in Φ-OTDR system, are presented. New laser scheme with two-photon intracavity absorber is suggested and its advantages are described.

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

PubMed

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

2013-01-01

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

Photon transport in a dissipative chain of nonlinear cavities

NASA Astrophysics Data System (ADS)

Biella, Alberto; Mazza, Leonardo; Carusotto, Iacopo; Rossini, Davide; Fazio, Rosario

2015-05-01

By means of numerical simulations and the input-output formalism, we study photon transport through a chain of coupled nonlinear optical cavities subject to uniform dissipation. Photons are injected from one end of the chain by means of a coherent source. The propagation through the array of cavities is sensitive to the interplay between the photon hopping strength and the local nonlinearity in each cavity. We characterize photon transport by studying the populations and the photon correlations as a function of the cavity position. When complemented with input-output theory, these quantities provide direct information about photon transmission through the system. The position of single-photon and multiphoton resonances directly reflects the structure of the many-body energy levels. This shows how a study of transport along a coupled cavity array can provide rich information about the strongly correlated (many-body) states of light even in presence of dissipation. The numerical algorithm we use, based on the time-evolving block decimation scheme adapted to mixed states, allows us to simulate large arrays (up to 60 cavities). The scaling of photon transmission with the number of cavities does depend on the structure of the many-body photon states inside the array.

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

PubMed

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

2015-01-07

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

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

DOE PAGES

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

2014-12-12

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

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

NASA Astrophysics Data System (ADS)

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

2015-01-01

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

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

PubMed Central

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

2017-01-01

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

Old and new results about single-photon sensitivity in human vision

NASA Astrophysics Data System (ADS)

Nelson, Philip C.

2016-04-01

It is sometimes said that ‘our eyes can see single photons’. This article begins by finding a more precise version of that claim and reviewing evidence gathered for it up to around 1985 in two distinct realms, those of human psychophysics and single-cell physiology. Finding a single framework that accommodates both kinds of result is then a nontrivial challenge, and one that sets severe quantitative constraints on any model of dim-light visual processing. This article presents one such model and compares it to a recent experiment.

Single-silicon CCD-CMOS platform for multi-spectral detection from terahertz to x-rays.

PubMed

Shalaby, Mostafa; Vicario, Carlo; Hauri, Christoph P

2017-11-15

Charge-coupled devices (CCDs) are a well-established imaging technology in the visible and x-ray frequency ranges. However, the small quantum photon energies of terahertz radiation have hindered the use of this mature semiconductor technological platform in this frequency range, leaving terahertz imaging totally dependent on low-resolution bolometer technologies. Recently, it has been shown that silicon CCDs can detect terahertz photons at a high field, but the detection sensitivity is limited. Here we show that silicon, complementary metal-oxide-semiconductor (CMOS) technology offers enhanced detection sensitivity of almost two orders of magnitude, compared to CCDs. Our findings allow us to extend the low-frequency terahertz cutoff to less than 2 THz, nearly closing the technological gap with electronic imagers operating up to 1 THz. Furthermore, with the silicon CCD/CMOS technology being sensitive to mid-infrared (mid-IR) and the x-ray ranges, we introduce silicon as a single detector platform from 1 EHz to 2 THz. This overcomes the present challenge in spatially overlapping a terahertz/mid-IR pump and x-ray probe radiation at facilities such as free electron lasers, synchrotron, and laser-based x-ray sources.

Applications of Photonic Crystals to Photovoltaic Devices

NASA Astrophysics Data System (ADS)

Foster, Stephen

Photonic crystals are structures that exhibit wavelength-scale spatial periodicity in their dielectric function. They are best known for their ability to exhibit complete photonic band gaps (PBGs) - spectral regions over which no light can propagate within the crystal. PBGs are specific instances of a more general phenomenon, in which the local photonic density of states can be enhanced or suppressed over different frequency ranges by tuning the properties of the crystal. This can be used to redirect, concentrate, or even trap light incident on the crystal. In this thesis, we investigate how photonic crystals can be used to enhance the efficiency of photovoltaic devices by trapping light. Due to the many different types of photovoltaic devices in existence (varying widely in materials used, modes of operation, and internal structure), there is no single light trapping architecture that can be applied to all photovoltaics. In this work we study a number of different devices: dye-sensitized solar cells, polymer solar cells, silicon-perovskite tandem cells, and single-junction silicon cells. We propose novel photonic crystal-based light trapping designs for each type of device, and evaluate these designs numerically to demonstrate their effectiveness. Full-field optical simulations of the cell are performed for each design, using either finite element method (FEM) or finite-difference time-domain (FDTD) techniques. Where appropriate, electrical modelling of the cell is also performed, through either the use of a simple one-diode model, or by obtaining full solutions to the semiconductor drift-diffusion equations within the cell. In all cases we find that the photonic crystal-based designs significantly outperform their non-nanostructured counterparts. In the case of dye-sensitized and polymer cells, enhancements in light absorption of 33% and 40% (respectively) are seen, relative to reference cells with planar geometries. In the case of silicon-perovskite tandem cells and silicon cells, projected power conversion efficiencies of over 30% are obtained, well beyond the current world record for silicon-based cells. We conclude the thesis with a discussion on the overall prospects for photonic crystal-based solar cells, with a focus on the factors that make solar cell technologies amenable to light trapping.

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

NASA Technical Reports Server (NTRS)

Vasile, Stefan; Shera, Suzanne; Shamo, Denis

1998-01-01

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

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

PubMed Central

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

2011-01-01

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

Real-time computational photon-counting LiDAR

NASA Astrophysics Data System (ADS)

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

2018-03-01

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

Square array photonic crystal fiber-based surface plasmon resonance refractive index sensor

NASA Astrophysics Data System (ADS)

Liu, Min; Yang, Xu; Zhao, Bingyue; Hou, Jingyun; Shum, Ping

2017-12-01

Based on surface plasmon resonance (SPR), a novel refractive index (RI) sensor comprising a square photonic crystal fiber (PCF) is proposed to realize the detection of the annular analyte. Instead of hexagon structure, four large air-holes in a square array are introduced to enhance the sensitivity by allowing two polarization directions of the core mode to be more sensitive. The gold is used as the only plasmonic material. The design purpose is to reduce the difficulty in gold deposition and enhance the RI sensitivity. The guiding properties and the effects of the parameters on the performance of the sensor are numerically investigated by the Finite Element Method (FEM). By optimizing the structure, the sensor can exhibit remarkable sensitivity up to 7250 nm/RIU and resolution of 1.0638 × 10-5 RIU with only one plasmonic material, which is very competitive compared with the other reported externally coated and single-layer coated PCF-based SPR (PCF-SPR) sensors, to our best knowledge.

Recent Advances in Biosensing With Photonic Crystal Surfaces: A Review

PubMed Central

Cunningham, B.T.; Zhang, M.; Zhuo, Y.; Kwon, L.; Race, C.

2016-01-01

Photonic 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 photon-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 detection 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 photonic crystal biosensor detection instrumentation and device structures that are being applied towards direct detection of small molecules in the context of high throughput drug screening, photonic crystal fluorescence enhancement as utilized for high sensitivity multiplexed cancer biomarker detection, 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

Methods for reducing ghost rays on the Wolter-I focusing figures of the FOXSI rocket payload

NASA Astrophysics Data System (ADS)

Buitrago-Casas, Juan Camilo; Glesener, Lindsay; Christe, Steven; Ramsey, Brian; Elsner, Ronald; Courtade, Sasha; Vievering, Juliana; Subramania, Athiray; Krucker, Sam; Bale, Stuart

2017-08-01

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

Second generation OH suppression filters using multicore fibers

NASA Astrophysics Data System (ADS)

Haynes, R.; Birks, T. A.; Bland-Hawthorn, J.; Cruz, J. L.; Diez, A.; Ellis, S. C.; Haynes, D.; Krämer, R. G.; Mangan, B. J.; Min, S.; Murphy, D. F.; Nolte, S.; Olaya, J. C.; Thomas, J. U.; Trinh, C. Q.; Tünnermann, A.; Voigtländer, Christian

2012-09-01

Ground based near-infrared observations have long been plagued by poor sensitivity when compared to visible observations as a result of the bright narrow line emission from atmospheric OH molecules. The GNOSIS instrument recently commissioned at the Australian Astronomical Observatory uses Photonic Lanterns in combination with individually printed single mode fibre Bragg gratings to filter out the brightest OH-emission lines between 1.47 and 1.70μm. GNOSIS, reported in a separate paper in this conference, demonstrates excellent OH-suppression, providing very “clean” filtering of the lines. It represents a major step forward in the goal to improve the sensitivity of ground based near-infrared observation to that possible at visible wavelengths, however, the filter units are relatively bulky and costly to produce. The 2nd generation fibre OH-Suppression filters based on multicore fibres are currently under development. The development aims to produce high quality, cost effective, compact and robust OH-Suppression units in a single optical fibre with numerous isolated single mode cores that replicate the function and performance of the current generation of “conventional” photonic lantern based devices. In this paper we present the early results from the multicore fibre development and multicore fibre Bragg grating imprinting process.

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.

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

Weak Value Amplification of a Post-Selected Single Photon

NASA Astrophysics Data System (ADS)

Hallaji, Matin

Weak value amplification (WVA) is a measurement technique in which the effect of a pre- and post-selected system on a weakly interacting probe is magnified. In this thesis, I present the first experimental observation of WVA of a single photon. We observed that a signal photon --- sent through a polarization interferometer and post-selected by photodetection in the almost-dark port --- can act like eight photons. The effect of this single photon is measured as a nonlinear phase shift on a separate laser beam. The interaction between the two is mediated by a sample of laser- cooled 85Rb atoms. Electromagnetically induced transparency (EIT) is used to enhance the nonlinearity and overcome resonant absorption. I believe this work to be the first demonstration of WVA where a deterministic interaction is used to entangle two distinct optical systems. In WVA, the amplification is contingent on discarding a large portion of the original data set. While amplification increases measurement sensitivity, discarding data worsens it. Questioning whether these competing effects conspire to improve or diminish measurement accuracy has resulted recently in controversy. I address this question by calculating the maximum amount of information achievable with the WVA technique. By comparing this information to that achievable by the standard technique, where no post-selection is employed, I show that the WVA technique can be advantageous under a certain class of noise models. Finally, I propose a way to optimally apply the WVA technique.

Measurement of the Two-photon Absorption Coefficient of Gallium Phosphide (GaP) Using a Dispersion-minimized Sub-10 Femtosecond Z-scan Measurement System

DTIC Science & Technology

2012-09-01

bandwidth of the pulse. Using the standard laboratory and analysis methods of Sheik- Bahae et al., we obtain a two-photon absorption coefficient, β, of...organic thin-film materials deposited on various substrates. 15 6. References 1. Sheik- Bahae , M.; Said, A. A.; Van Stryland, E. W. High...sensitivity, Single-beam n2 Measurements. Optics Letters 1989, 14 (17). 2. Sheik- Bahae , M.; Said, A. A.; Van Stryland, E. W.; Wei, T-H; Hagan, D. J

Photon-Counting Kinetic Inductance Detectors for the Origins Space Telescope

NASA Astrophysics Data System (ADS)

Noroozian, Omid

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

Heralded noiseless amplification for single-photon entangled state with polarization feature

NASA Astrophysics Data System (ADS)

Wang, Dan-Dan; Jin, Yu-Yu; Qin, Sheng-Xian; Zu, Hao; Zhou, Lan; Zhong, Wei; Sheng, Yu-Bo

2018-03-01

Heralded noiseless amplification is a promising method to overcome the transmission photon loss in practical noisy quantum channel and can effectively lengthen the quantum communication distance. Single-photon entanglement is an important resource in current quantum communications. Here, we construct two single-photon-assisted heralded noiseless amplification protocols for the single-photon two-mode entangled state and single-photon three-mode W state, respectively, where the single-photon qubit has an arbitrary unknown polarization feature. After the amplification, the fidelity of the single-photon entangled state can be increased, while the polarization feature of the single-photon qubit can be well remained. Both the two protocols only require the linear optical elements, so that they can be realized under current experimental condition. Our protocols may be useful in current and future quantum information processing.

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

NASA Technical Reports Server (NTRS)

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

2011-01-01

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

Quantum State Transfer via Noisy Photonic and Phononic Waveguides

NASA Astrophysics Data System (ADS)

Vermersch, B.; Guimond, P.-O.; Pichler, H.; Zoller, P.

2017-03-01

We describe a quantum state transfer protocol, where a quantum state of photons stored in a first cavity can be faithfully transferred to a second distant cavity via an infinite 1D waveguide, while being immune to arbitrary noise (e.g., thermal noise) injected into the waveguide. We extend the model and protocol to a cavity QED setup, where atomic ensembles, or single atoms representing quantum memory, are coupled to a cavity mode. We present a detailed study of sensitivity to imperfections, and apply a quantum error correction protocol to account for random losses (or additions) of photons in the waveguide. Our numerical analysis is enabled by matrix product state techniques to simulate the complete quantum circuit, which we generalize to include thermal input fields. Our discussion applies both to photonic and phononic quantum networks.

Investigating and Improving Student Understanding of Quantum Mechanics in the Context of Single Photon Interference

ERIC Educational Resources Information Center

Marshman, Emily; Singh, Chandralekha

2017-01-01

Single photon experiments involving a Mach-Zehnder interferometer can illustrate the fundamental principles of quantum mechanics, e.g., the wave-particle duality of a single photon, single photon interference, and the probabilistic nature of quantum measurement involving single photons. These experiments explicitly make the connection between the…

Quantum optics. All-optical routing of single photons by a one-atom switch controlled by a single photon.

PubMed

Shomroni, Itay; Rosenblum, Serge; Lovsky, Yulia; Bechler, Orel; Guendelman, Gabriel; Dayan, Barak

2014-08-22

The prospect of quantum networks, in which quantum information is carried by single photons in photonic circuits, has long been the driving force behind the effort to achieve all-optical routing of single photons. We realized a single-photon-activated switch capable of routing a photon from any of its two inputs to any of its two outputs. Our device is based on a single atom coupled to a fiber-coupled, chip-based microresonator. A single reflected control photon toggles the switch from high reflection (R ~ 65%) to high transmission (T ~ 90%), with an average of ~1.5 control photons per switching event (~3, including linear losses). No additional control fields are required. The control and target photons are both in-fiber and practically identical, making this scheme compatible with scalable architectures for quantum information processing. Copyright © 2014, American Association for the Advancement of Science.

A novel photonic crystal fiber Mach-Zehnder interferometer for enhancing refractive index measurement sensitivity

NASA Astrophysics Data System (ADS)

Zhao, Yong; Xia, Feng; Hu, Hai-feng; Chen, Mao-qing

2017-11-01

A novel refractive index (RI) sensor based on photonic crystal fiber Mach-Zehnder interferometer (PCF-MZI) was proposed. It was realized by cascading a section of PCF with half-taper collapse regions (HTCRs) between two single mode fibers (SMFs). The relationship between RI sensitivity and interference length of the PCF-MZI was firstly investigated. Both simulation and experimental results showed that RI sensitivity increased with the increase of interference length. Afterwards, influence of HTCR parameters on RI sensitivity was experimentally investigated to further improve the sensitivity. With intensification of arc discharge intensity in HTCR fabrication process, HTCR with larger maximum taper diameter and longer collapsed region length was obtained, which enhanced evanescent field of the PCF-MZI and then generated higher RI sensitivity. Consequently, a high RI sensitivity of 181.96 nm/refractive index unit (RIU) was achieved in the RI range of 1.3333-1.3574. Increasing arc discharge intensity in HTCR fabrication process has the capacity to improve RI sensitivity of PCF-MZI and meanwhile provides higher mechanical strength and longer sensor life compared to the traditional method of tapering the fiber, which improves the RI sensitivity at the cost of reducing mechanical strength of the sensor. This PCF-MZI was characterized by high RI sensitivity, ease of fabrication, high mechanical strength, and robustness.

Photon-counting-based diffraction phase microscopy combined with single-pixel imaging

NASA Astrophysics Data System (ADS)

Shibuya, Kyuki; Araki, Hiroyuki; Iwata, Tetsuo

2018-04-01

We propose a photon-counting (PC)-based quantitative-phase imaging (QPI) method for use in diffraction phase microscopy (DPM) that is combined with a single-pixel imaging (SPI) scheme (PC-SPI-DPM). This combination of DPM with the SPI scheme overcomes a low optical throughput problem that has occasionally prevented us from obtaining quantitative-phase images in DPM through use of a high-sensitivity single-channel photodetector such as a photomultiplier tube (PMT). The introduction of a PMT allowed us to perform PC with ease and thus solved a dynamic range problem that was inherent to SPI. As a proof-of-principle experiment, we performed a comparison study of analogue-based SPI-DPM and PC-SPI-DPM for a 125-nm-thick indium tin oxide (ITO) layer coated on a silica glass substrate. We discuss the basic performance of the method and potential future modifications of the proposed system.

Time-resolved scattering of a single photon by a single atom

PubMed Central

Leong, Victor; Seidler, Mathias Alexander; Steiner, Matthias; Cerè, Alessandro; Kurtsiefer, Christian

2016-01-01

Scattering of light by matter has been studied extensively in the past. Yet, the most fundamental process, the scattering of a single photon by a single atom, is largely unexplored. One prominent prediction of quantum optics is the deterministic absorption of a travelling photon by a single atom, provided the photon waveform matches spatially and temporally the time-reversed version of a spontaneously emitted photon. Here we experimentally address this prediction and investigate the influence of the photon's temporal profile on the scattering dynamics using a single trapped atom and heralded single photons. In a time-resolved measurement of atomic excitation we find a 56(11)% increase of the peak excitation by photons with an exponentially rising profile compared with a decaying one. However, the overall scattering probability remains unchanged within the experimental uncertainties. Our results demonstrate that envelope tailoring of single photons enables precise control of the photon–atom interaction. PMID:27897173

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

NASA Technical Reports Server (NTRS)

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

2002-01-01

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

Deterministic and storable single-photon source based on a quantum memory.

PubMed

Chen, Shuai; Chen, Yu-Ao; Strassel, Thorsten; Yuan, Zhen-Sheng; Zhao, Bo; Schmiedmayer, Jörg; Pan, Jian-Wei

2006-10-27

A single-photon source is realized with a cold atomic ensemble (87Rb atoms). A single excitation, written in an atomic quantum memory by Raman scattering of a laser pulse, is retrieved deterministically as a single photon at a predetermined time. It is shown that the production rate of single photons can be enhanced considerably by a feedback circuit while the single-photon quality is conserved. Such a single-photon source is well suited for future large-scale realization of quantum communication and linear optical quantum computation.

Ultrafast detection in particle physics and positron emission tomography using SiPMs

NASA Astrophysics Data System (ADS)

Dolenec, R.; Korpar, S.; Križan, P.; Pestotnik, R.

2017-12-01

Silicon photomultiplier (SiPM) photodetectors perform well in many particle and medical physics applications, especially where good efficiency, insensitivity to magnetic field and precise timing are required. In Cherenkov time-of-flight positron emission tomography the requirements for photodetector performance are especially high. On average only a couple of photons are available for detection and the best possible timing resolution is needed. Using SiPMs as photodetectors enables good detection efficiency, but the large sensitive area devices needed have somewhat limited time resolution for single photons. We have observed an additional degradation of the timing at very low light intensities due to delayed events in distribution of signals resulting from multiple fired micro cells. In this work we present the timing properties of AdvanSiD ASD-NUV3S-P-40 SiPM at single photon level picosecond laser illumination and a simple modification of the time-walk correction algorithm, that resulted in reduced degradation of timing resolution due to the delayed events.

Label-Free Biosensor Imaging on Photonic Crystal Surfaces.

PubMed

Zhuo, Yue; Cunningham, Brian T

2015-08-28

We review the development and application of nanostructured photonic crystal surfaces and a hyperspectral reflectance imaging detection instrument which, when used together, represent a new form of optical microscopy that enables label-free, quantitative, and kinetic monitoring of biomaterial interaction with substrate surfaces. Photonic Crystal Enhanced Microscopy (PCEM) has been used to detect broad classes of materials which include dielectric nanoparticles, metal plasmonic nanoparticles, biomolecular layers, and live cells. Because PCEM does not require cytotoxic stains or photobleachable fluorescent dyes, it is especially useful for monitoring the long-term interactions of cells with extracellular matrix surfaces. PCEM is only sensitive to the attachment of cell components within ~200 nm of the photonic crystal surface, which may correspond to the region of most interest for adhesion processes that involve stem cell differentiation, chemotaxis, and metastasis. PCEM has also demonstrated sufficient sensitivity for sensing nanoparticle contrast agents that are roughly the same size as protein molecules, which may enable applications in "digital" diagnostics with single molecule sensing resolution. We will review PCEM's development history, operating principles, nanostructure design, and imaging modalities that enable tracking of optical scatterers, emitters, absorbers, and centers of dielectric permittivity.

Label-Free Biosensor Imaging on Photonic Crystal Surfaces

PubMed Central

Zhuo, Yue; Cunningham, Brian T.

2015-01-01

We review the development and application of nanostructured photonic crystal surfaces and a hyperspectral reflectance imaging detection instrument which, when used together, represent a new form of optical microscopy that enables label-free, quantitative, and kinetic monitoring of biomaterial interaction with substrate surfaces. Photonic Crystal Enhanced Microscopy (PCEM) has been used to detect broad classes of materials which include dielectric nanoparticles, metal plasmonic nanoparticles, biomolecular layers, and live cells. Because PCEM does not require cytotoxic stains or photobleachable fluorescent dyes, it is especially useful for monitoring the long-term interactions of cells with extracellular matrix surfaces. PCEM is only sensitive to the attachment of cell components within ~200 nm of the photonic crystal surface, which may correspond to the region of most interest for adhesion processes that involve stem cell differentiation, chemotaxis, and metastasis. PCEM has also demonstrated sufficient sensitivity for sensing nanoparticle contrast agents that are roughly the same size as protein molecules, which may enable applications in “digital” diagnostics with single molecule sensing resolution. We will review PCEM’s development history, operating principles, nanostructure design, and imaging modalities that enable tracking of optical scatterers, emitters, absorbers, and centers of dielectric permittivity. PMID:26343684

Photonic crystal fiber interferometric pH sensor based on polyvinyl alcohol/polyacrylic acid hydrogel coating.

PubMed

Hu, Pengbing; Dong, Xinyong; Wong, Wei Chang; Chen, Li Han; Ni, Kai; Chan, Chi Chiu

2015-04-01

We present a simple photonic crystal fiber interferometer (PCFI) that operates in reflection mode for pH measurement. The sensor is made by coating polyvinyl alcohol/polyacrylic acid (PVA/PAA) hydrogel onto the surface of the PCFI, constructed by splicing a stub of PCF at the distal end of a single-mode fiber with its free end airhole collapsed. The experimental results demonstrate a high average sensitivity of 0.9 nm/pH unit for the 11 wt.% PVA/PAA coated sensor in the pH range from 2.5 to 6.5. The sensor also displays high repeatability and stability and low cross-sensitivity to temperature. Fast, reversible rise and fall times of 12 s and 18 s, respectively, are achieved for the sensor time response.

A 72 × 60 Angle-Sensitive SPAD Imaging Array for Lens-less FLIM.

PubMed

Lee, Changhyuk; Johnson, Ben; Jung, TaeSung; Molnar, Alyosha

2016-09-02

We present a 72 × 60, angle-sensitive single photon avalanche diode (A-SPAD) array for lens-less 3D fluorescence lifetime imaging. An A-SPAD pixel consists of (1) a SPAD to provide precise photon arrival time where a time-resolved operation is utilized to avoid stimulus-induced saturation, and (2) integrated diffraction gratings on top of the SPAD to extract incident angles of the incoming light. The combination enables mapping of fluorescent sources with different lifetimes in 3D space down to micrometer scale. Futhermore, the chip presented herein integrates pixel-level counters to reduce output data-rate and to enable a precise timing control. The array is implemented in standard 180 nm complementary metal-oxide-semiconductor (CMOS) technology and characterized without any post-processing.

Discrimination of chemical vapor and temperature using an in-line modal interferometer based on an exterior hole-assisted polarization-maintaining photonic crystal fiber

NASA Astrophysics Data System (ADS)

Yoon, Min-Seok; Jun, Naram; Lee, Sang Bae; Han, Young-Geun

2014-05-01

A reflective in-line modal interferometer based on a polarization-maintaining photonic crystal fiber (PM-PCF) with two exterior air holes is proposed for simultaneous measurement of chemical vapor and temperature. After fusion-splicing the PM-PCF with a standard single-mode fiber, we collapse all of air holes in the PM-PCF resulting in two types of interference patterns between the core and the cladding modes in the PM-PCF depending on two polarization states. Since two large air holes at the facet of the proposed modal interferometer are left open, a chemical vapor can be infiltrated into the voids. Different sensitivities corresponding to input polarization states are utilized for discrimination between chemical vapor and temperature sensitivities.

A 72 × 60 Angle-Sensitive SPAD Imaging Array for Lens-less FLIM

PubMed Central

Lee, Changhyuk; Johnson, Ben; Jung, TaeSung; Molnar, Alyosha

2016-01-01

We present a 72 × 60, angle-sensitive single photon avalanche diode (A-SPAD) array for lens-less 3D fluorescence lifetime imaging. An A-SPAD pixel consists of (1) a SPAD to provide precise photon arrival time where a time-resolved operation is utilized to avoid stimulus-induced saturation, and (2) integrated diffraction gratings on top of the SPAD to extract incident angles of the incoming light. The combination enables mapping of fluorescent sources with different lifetimes in 3D space down to micrometer scale. Futhermore, the chip presented herein integrates pixel-level counters to reduce output data-rate and to enable a precise timing control. The array is implemented in standard 180 nm complementary metal-oxide-semiconductor (CMOS) technology and characterized without any post-processing. PMID:27598170

Autocorrelation analysis for the unbiased determination of power-law exponents in single-quantum-dot blinking.

PubMed

Houel, Julien; Doan, Quang T; Cajgfinger, Thomas; Ledoux, Gilles; Amans, David; Aubret, Antoine; Dominjon, Agnès; Ferriol, Sylvain; Barbier, Rémi; Nasilowski, Michel; Lhuillier, Emmanuel; Dubertret, Benoît; Dujardin, Christophe; Kulzer, Florian

2015-01-27

We present an unbiased and robust analysis method for power-law blinking statistics in the photoluminescence of single nanoemitters, allowing us to extract both the bright- and dark-state power-law exponents from the emitters' intensity autocorrelation functions. As opposed to the widely used threshold method, our technique therefore does not require discriminating the emission levels of bright and dark states in the experimental intensity timetraces. We rely on the simultaneous recording of 450 emission timetraces of single CdSe/CdS core/shell quantum dots at a frame rate of 250 Hz with single photon sensitivity. Under these conditions, our approach can determine ON and OFF power-law exponents with a precision of 3% from a comparison to numerical simulations, even for shot-noise-dominated emission signals with an average intensity below 1 photon per frame and per quantum dot. These capabilities pave the way for the unbiased, threshold-free determination of blinking power-law exponents at the microsecond time scale.

Singlet oxygen and ROS in a new light: low-dose subcellular photodynamic treatment enhances proliferation at the single cell level.

PubMed

Blázquez-Castro, Alfonso; Breitenbach, Thomas; Ogilby, Peter R

2014-09-01

Two-photon excitation of a sensitizer with a focused laser beam was used to create a spatially-localized subcellular population of reactive oxygen species, ROS, in single HeLa cells. The sensitizer used was protoporphyrin IX, PpIX, endogenously derived from 5-aminolevulinic acid delivered to the cells. Although we infer that singlet oxygen, O2(a(1)Δg), is one ROS produced upon irradiation of PpIX under these conditions, it is possible that the superoxide ion, O2(-˙), may also play a role in this system. With a "high" dose of PpIX-sensitized ROS, the expected death of the cell was observed. However, under "low dose" conditions, clear signs of cell proliferation were observed. The present results facilitate studies of ROS-mediated signalling in imaging-based single cell experiments.

Generation of Single Photons and Entangled Photon Pairs from a Quantum Dot

NASA Astrophysics Data System (ADS)

Yamamoto, Y.; Pelton, M.; Santori, C.; Solomon, G. S.

2002-10-01

Current quantum cryptography systems are limited by the Poissonian photon statistics of a standard light source: a security loophole is opened up by the possibility of multiple-photon pulses. By replacing the source with a single-photon emitter, transmission rates of secure information can be improved. A single photon source is also essential to implement a linear optics quantum computer. We have investigated the use of single self-assembled InAs/GaAs quantum dots as such single-photon sources, and have seen a hundred-fold reduction in the multi-photon probability as compared to Poissonian pulses. An extension of our experiment should also allow for the generation of triggered, polarizationentangled photon pairs.

Detectors for single-molecule fluorescence imaging and spectroscopy

PubMed Central

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

2010-01-01

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

Iodine-123 metaiodobenzylguanidine scintigraphy and iodine-123 ioflupane single photon emission computed tomography in Lewy body diseases: complementary or alternative techniques?

PubMed

Treglia, Giorgio; Cason, Ernesto; Cortelli, Pietro; Gabellini, Anna; Liguori, Rocco; Bagnato, Antonio; Giordano, Alessandro; Fagioli, Giorgio

2014-01-01

To compare myocardial sympathetic imaging using (123)I-Metaiodobenzylguanidine (MIBG) scintigraphy and striatal dopaminergic imaging using (123)I-Ioflupane (FP-CIT) single photon emission computed tomography (SPECT) in patients with suspected Lewy body diseases (LBD). Ninety-nine patients who performed both methods within 2 months for differential diagnosis between Parkinson's disease (PD) and other parkinsonism (n = 68) or between dementia with Lewy bodies (DLB) and other dementia (n = 31) were enrolled. Sensitivity, specificity, accuracy, positive and negative predictive values of both methods were calculated. For (123) I-MIBG scintigraphy, the overall sensitivity, specificity, accuracy, positive and negative predictive values in LBD were 83%, 79%, 82%, 86%, and 76%, respectively. For (123)I-FP-CIT SPECT, the overall sensitivity, specificity, accuracy, positive and negative predictive values in LBD were 93%, 41%, 73%, 71%, and 80%, respectively. There was a statistically significant difference between these two methods in patients without LBD, but not in patients with LBD. LBD usually present both myocardial sympathetic and striatal dopaminergic impairments. (123)I-FP-CIT SPECT presents high sensitivity in the diagnosis of LBD; (123)I-MIBG scintigraphy may have a complementary role in differential diagnosis between PD and other parkinsonism. These scintigraphic methods showed similar diagnostic accuracy in differential diagnosis between DLB and other dementia. Copyright © 2012 by the American Society of Neuroimaging.

Single-photon superradiant beating from a Doppler-broadened ladder-type atomic ensemble

NASA Astrophysics Data System (ADS)

Lee, Yoon-Seok; Lee, Sang Min; Kim, Heonoh; Moon, Han Seb

2017-12-01

We report on heralded-single-photon superradiant beating in the spontaneous four-wave mixing process of Doppler-broadened ladder-type 87Rb atoms. When Doppler-broadened atoms contribute to two-photon coherence, the detection probability amplitudes of the heralded single photons are coherently superposed despite inhomogeneous broadened atomic media. Single-photon superradiant beating is observed, which constitutes evidence for the coherent superposition of two-photon amplitudes from different velocity classes in the Doppler-broadened atomic ensemble. We present a theoretical model in which the single-photon superradiant beating originates from the interference between wavelength-separated two-photon amplitudes via the reabsorption filtering effect.

SU-E-T-137: The Response of TLD-100 in Mixed Fields of Photons and Electrons.

PubMed

Lawless, M; Junell, S; Hammer, C; DeWerd, L

2012-06-01

Thermoluminescent dosimeters are used routinely for dosimetric measurements of photon and electron fields. However, no work has been published characterizing TLDs for use in combined photon and electron fields. This work investigates the response of TLD-100 (LiF:Mg,Ti) in mixed fields of photon and electron beam qualities. TLDs were irradiated in a 6 MV photon beam, 6 MeV electron beam, and a NIST traceable cobalt-60 beam. TLDs were also irradiated in a mixed field of the electron and photon beams. All irradiations were normalized to absorbed dose to water as defined in the AAPM TG-51 report. The average response per dose (nC/Gy) for each linac beam quality was normalized to the average response per dose of the TLDs irradiated by the cobalt-60 standard.Irradiations were performed in a water tank and a Virtual Water™ phantom. Two TLD dose calibration curves for determining absorbed dose to water were generated using photon and electron field TLD response data. These individual beam quality dose calibration curves were applied to the TLDs irradiated in the mixed field. The TLD response in the mixed field was less sensitive than the response in the photon field and more sensitive than the response in the electron field. TLD determination of dose in the mixed field using the dose calibration curve generated by TLDs irradiated by photons resulted in an underestimation of the delivered dose, while the use of a dose calibration curve generated using electrons resulted in an overestimation of the delivered dose. The relative response of TLD-100 in mixed fields fell consistently between the photon nd electron relative responses. When using TLD-100 in mixed fields, the user must account for this intermediate response to avoid an over- or underestimation of the dose due to calibration in a single photon or electron field. © 2012 American Association of Physicists in Medicine.

Deterministic and robust generation of single photons from a single quantum dot with 99.5% indistinguishability using adiabatic rapid passage.

PubMed

Wei, Yu-Jia; He, Yu-Ming; Chen, Ming-Cheng; Hu, Yi-Nan; He, Yu; Wu, Dian; Schneider, Christian; Kamp, Martin; Höfling, Sven; Lu, Chao-Yang; Pan, Jian-Wei

2014-11-12

Single photons are attractive candidates of quantum bits (qubits) for quantum computation and are the best messengers in quantum networks. Future scalable, fault-tolerant photonic quantum technologies demand both stringently high levels of photon indistinguishability and generation efficiency. Here, we demonstrate deterministic and robust generation of pulsed resonance fluorescence single photons from a single semiconductor quantum dot using adiabatic rapid passage, a method robust against fluctuation of driving pulse area and dipole moments of solid-state emitters. The emitted photons are background-free, have a vanishing two-photon emission probability of 0.3% and a raw (corrected) two-photon Hong-Ou-Mandel interference visibility of 97.9% (99.5%), reaching a precision that places single photons at the threshold for fault-tolerant surface-code quantum computing. This single-photon source can be readily scaled up to multiphoton entanglement and used for quantum metrology, boson sampling, and linear optical quantum computing.

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

PubMed

Lamb, D C; Müller, B K; Bräuchle, C

2005-10-01

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

Taking single virus detection and sizing to the limit with molecular sensitivity: the birth of nanoplasmonic-microcavity hybrid sensors

NASA Astrophysics Data System (ADS)

Arnold, S.

2013-03-01

The BioPhotonics community is buzzing at the prospect that ulta-small bio-nanoparticles such as Polio virus and protein can be detected label-free in their native state and sized one at a time. As the awareness that the claim of label-free single protein sensing through the frequency shift of a bare microcavity by A.M. Armani et al in Science in 2007 fades from lack of independent experimental confirmation or a viable physical mechanism to account for the magnitude of the reported wavelength shifts, a new approach has captured the community's interest. It is a product of a marriage between nano-optics and micro-photonics, and is poised to take label-free sensing to the limit.

X-ray luminescence computed tomography using a focused x-ray beam.

PubMed

Zhang, Wei; Lun, Michael C; Nguyen, Alex Anh-Tu; Li, Changqing

2017-11-01

Due to the low x-ray photon utilization efficiency and low measurement sensitivity of the electron multiplying charge coupled device camera setup, the collimator-based narrow beam x-ray luminescence computed tomography (XLCT) usually requires a long measurement time. We, for the first time, report a focused x-ray beam-based XLCT imaging system with measurements by a single optical fiber bundle and a photomultiplier tube (PMT). An x-ray tube with a polycapillary lens was used to generate a focused x-ray beam whose x-ray photon density is 1200 times larger than a collimated x-ray beam. An optical fiber bundle was employed to collect and deliver the emitted photons on the phantom surface to the PMT. The total measurement time was reduced to 12.5 min. For numerical simulations of both single and six fiber bundle cases, we were able to reconstruct six targets successfully. For the phantom experiment, two targets with an edge-to-edge distance of 0.4 mm and a center-to-center distance of 0.8 mm were successfully reconstructed by the measurement setup with a single fiber bundle and a PMT. (2017) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

A bright cyan-excitable orange fluorescent protein facilitates dual-emission microscopy and enhances bioluminescence imaging in vivo

PubMed Central

Chu, Jun; Oh, Young-Hee; Sens, Alex; Ataie, Niloufar; Dana, Hod; Macklin, John J.; Laviv, Tal; Welf, Erik S.; Dean, Kevin M.; Zhang, Feijie; Kim, Benjamin B.; Tang, Clement Tran; Hu, Michelle; Baird, Michelle A.; Davidson, Michael W.; Kay, Mark A.; Fiolka, Reto; Yasuda, Ryohei; Kim, Douglas S.; Ng, Ho-Leung; Lin, Michael Z.

2016-01-01

Orange-red fluorescent proteins (FPs) are widely used in biomedical research for multiplexed epifluorescence microscopy with GFP-based probes, but their different excitation requirements make multiplexing with new advanced microscopy methods difficult. Separately, orange-red FPs are useful for deep-tissue imaging in mammals due to the relative tissue transmissibility of orange-red light, but their dependence on illumination limits their sensitivity as reporters in deep tissues. Here we describe CyOFP1, a bright engineered orange-red FP that is excitable by cyan light. We show that CyOFP1 enables single-excitation multiplexed imaging with GFP-based probes in single-photon and two-photon microscopy, including time-lapse imaging in light-sheet systems. CyOFP1 also serves as an efficient acceptor for resonance energy transfer from the highly catalytic blue-emitting luciferase NanoLuc. An optimized fusion of CyOFP1 and NanoLuc, called Antares, functions as a highly sensitive bioluminescent reporter in vivo, producing substantially brighter signals from deep tissues than firefly luciferase and other bioluminescent proteins. PMID:27240196

Single-photon emitting diode in silicon carbide.

PubMed

Lohrmann, A; Iwamoto, N; Bodrog, Z; Castelletto, S; Ohshima, T; Karle, T J; Gali, A; Prawer, S; McCallum, J C; Johnson, B C

2015-07-23

Electrically driven single-photon emitting devices have immediate applications in quantum cryptography, quantum computation and single-photon metrology. Mature device fabrication protocols and the recent observations of single defect systems with quantum functionalities make silicon carbide an ideal material to build such devices. Here, we demonstrate the fabrication of bright single-photon emitting diodes. The electrically driven emitters display fully polarized output, superior photon statistics (with a count rate of >300 kHz) and stability in both continuous and pulsed modes, all at room temperature. The atomic origin of the single-photon source is proposed. These results provide a foundation for the large scale integration of single-photon sources into a broad range of applications, such as quantum cryptography or linear optics quantum computing.

Ultracompact bottom-up photonic crystal lasers on silicon-on-insulator.

PubMed

Lee, Wook-Jae; Kim, Hyunseok; You, Jong-Bum; Huffaker, Diana L

2017-08-25

Compact on-chip light sources lie at the heart of practical nanophotonic devices since chip-scale photonic circuits have been regarded as the next generation computing tools. In this work, we demonstrate room-temperature lasing in 7 × 7 InGaAs/InGaP core-shell nanopillar array photonic crystals with an ultracompact footprint of 2300 × 2300 nm 2 , which are monolithically grown on silicon-on-insulator substrates. A strong lateral confinement is achieved by a photonic band-edge mode, which is leading to a strong light-matter interaction in the 7 × 7 nanopillar array, and by choosing an appropriate thickness of a silicon-on-insulator layer the band-edge mode can be trapped vertically in the nanopillars. The nanopillar array band-edge lasers exhibit single-mode operation, where the mode frequency is sensitive to the diameter of the nanopillars. Our demonstration represents an important first step towards developing practical and monolithic III-V photonic components on a silicon platform.

Estimation of sensitivity and specificity of brain magnetic resonance imaging and single photon emission computed tomography in the diagnosis of olfactory dysfunction after head traumas.

PubMed

Atighechi, Saeid; Zolfaghari, Aliasghar; Baradaranfar, Mohammadhossein; Dadgarnia, Mohammadhossein

2013-01-01

Olfactory dysfunction has an incidence of 5-10% after head injury. Several objective and subjective tests had been proposed. Recent studies showed that brain single photon emission computed tomography (SPECT) and brain magnetic resonance imaging (MRI) have good diagnostic value in this era in which the most common sites of involvement were olfactory bulb and olfactory nerve in MRI and frontal lobe in SPECT. This study aimed to estimate the sensitivity and specificity of brain MRI and brain SPECT in the diagnosis of traumatic hyposmia and anosmia. From February 2009 to March 2011, 63 patients with head injury and smell complaint were selected for this study. Using an identification test and a threshold smell test, 28 were anosmic and 27 had hyposmia and the remaining 8 were normosmic. All of them underwent brain MRI and SPECT. The sensitivity of SPECT was 81.5 and 85.7% in hyposmia and anosmia, respectively. Its specificity was 87.5% in anosmia and 87.7% in anosmia. MRI sensitivity was 66.7% in hyposmia but 82.1% in anosmia. Its specificity was 85.7% in anosmia and 87.7% in anosmia. If MRI and SPECT were considered together, the sensitivity was 92.3% in hyposmia and 92% in anosmia, but the specificity was 87% in both cases. According to our study, both brain MRI and SPECT have high sensitivity and specificity in the diagnosis of traumatic anosmia, although brain SPECT is slightly superior to MRI. If the two techniques are applied together, the accuracy will be increased.

Photoionization of environmentally polluting aromatic chlorides and nitrides on the water surface by laser and synchrotron radiations.

PubMed

Sato, Miki; Maeda, Yuki; Ishioka, Toshio; Harata, Akira

2017-11-20

The detection limits and photoionization thresholds of polycyclic aromatic hydrocarbons and their chlorides and nitrides on the water surface are examined using laser two-photon ionization and single-photon ionization, respectively. The laser two-photon ionization methods are highly surface-selective, with a high sensitivity for aromatic hydrocarbons tending to accumulate on the water surface in the natural environment due to their highly hydrophobic nature. The dependence of the detection limits of target aromatic molecules on their physicochemical properties (photoionization thresholds relating to excess energy, molar absorptivity, and the octanol-water partition coefficient) is discussed. The detection limit clearly depends on the product of the octanol-water partition coefficient and molar absorptivity, and no clear dependence was found on excess energy. The detection limits of laser two-photon ionization for these types of molecules on the water surface are formulated.

Dark-count-less photon-counting x-ray computed tomography system using a YAP-MPPC detector

NASA Astrophysics Data System (ADS)

Sato, Eiichi; Sato, Yuich; Abudurexiti, Abulajiang; Hagiwara, Osahiko; Matsukiyo, Hiroshi; Osawa, Akihiro; Enomoto, Toshiyuki; Watanabe, Manabu; Kusachi, Shinya; Sato, Shigehiro; Ogawa, Akira; Onagawa, Jun

2012-10-01

A high-sensitive X-ray computed tomography (CT) system is useful for decreasing absorbed dose for patients, and a dark-count-less photon-counting CT system was developed. X-ray photons are detected using a YAP(Ce) [cerium-doped yttrium aluminum perovskite] single crystal scintillator and an MPPC (multipixel photon counter). Photocurrents are amplified by a high-speed current-voltage amplifier, and smooth event pulses from an integrator are sent to a high-speed comparator. Then, logical pulses are produced from the comparator and are counted by a counter card. Tomography is accomplished by repeated linear scans and rotations of an object, and projection curves of the object are obtained by the linear scan. The image contrast of gadolinium medium slightly fell with increase in lower-level voltage (Vl) of the comparator. The dark count rate was 0 cps, and the count rate for the CT was approximately 250 kcps.

[123I]N-ω-fluoropropyl-2β-carbomethoxy-3β-(4-iodophenyl)nortropane single-photon emission computed tomography brain imaging in the diagnosis of dementia with Lewy bodies.

PubMed

Walker, Zuzana; Cummings, Jeffrey L

2012-01-01

Early, accurate diagnosis of dementia with Lewy bodies (DLB), in particular its differentiation from Alzheimer's disease, is important for optimal management, providing patients/carers with information about the likely symptomatology and illness course, allowing initiation of effective pharmacotherapy, and avoiding the consequences of neuroleptic sensitivity. Clinical diagnosis of DLB has high specificity but low sensitivity. Clinical trials of [(123)I]N-ω-fluoropropyl-2β-carbomethoxy-3β-(4-iodophenyl)nortropane single-photon emission computed tomography ([(123)I]FP-CIT SPECT) indicate high positive and negative percent agreement with reference to clinical diagnosis, and high sensitivity and specificity in patients with neuropathologically confirmed diagnoses of DLB. An abnormal [(123)I]FP-CIT SPECT image in patients fulfilling criteria for possible DLB advances the certainty of a diagnosis to probable DLB. [(123)I]FP-CIT SPECT, by identifying the striatal dopaminergic deficit, can be a valuable diagnostic aid and can provide support to a clinical diagnosis of DLB in patients with dementia. The technique is likely to be of particular utility in patients with dementia with an uncertain diagnosis. Copyright © 2012 The Alzheimer's Association. Published by Elsevier Inc. All rights reserved.

Single photon sources with single semiconductor quantum dots

NASA Astrophysics Data System (ADS)

Shan, Guang-Cun; Yin, Zhang-Qi; Shek, Chan Hung; Huang, Wei

2014-04-01

In this contribution, we briefly recall the basic concepts of quantum optics and properties of semiconductor quantum dot (QD) which are necessary to the understanding of the physics of single-photon generation with single QDs. Firstly, we address the theory of quantum emitter-cavity system, the fluorescence and optical properties of semiconductor QDs, and the photon statistics as well as optical properties of the QDs. We then review the localization of single semiconductor QDs in quantum confined optical microcavity systems to achieve their overall optical properties and performances in terms of strong coupling regime, efficiency, directionality, and polarization control. Furthermore, we will discuss the recent progress on the fabrication of single photon sources, and various approaches for embedding single QDs into microcavities or photonic crystal nanocavities and show how to extend the wavelength range. We focus in particular on new generations of electrically driven QD single photon source leading to high repetition rates, strong coupling regime, and high collection efficiencies at elevated temperature operation. Besides, new developments of room temperature single photon emission in the strong coupling regime are reviewed. The generation of indistinguishable photons and remaining challenges for practical single-photon sources are also discussed.

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.

Micromanipulation and physiological monitoring of cells using two-photon excited fluorescence in cw laser tweezers

NASA Astrophysics Data System (ADS)

Sonek, Gregory J.; Liu, Yagang; Berns, Michael W.; Tromberg, Bruce J.

1996-05-01

We report the observation of two-photon fluorescence excitation and cell confinement, simultaneously, in a continuous-wave (cw) single-beam gradient force optical trap, and demonstrate its use as an in-situ probe to study the physiological state of an optically confined cell sample. At the wavelength of 1064 nm, a single focused gaussian laser beam is used to simultaneously confine, and excite visible fluorescence from, a human sperm cell that has been tagged with propidium iodide, a exogenous fluorescent dye that functions as a viability assay of cellular physiological state. The intensity at the dye peak emission wavelength of 620 nm exhibits a near-square-law dependence on incident trapping beam photon laser power, a behavior consistent with a two-photon absorption process. In addition, for a sperm cell held stationary in the optical tweezers for a period of several minutes at a constant trapping power, red fluorescence emission was observed to increase the time, indicating that the cell has gradually transitioned between a live and dead state. Two-photon excited fluorescence was also observed in chinese hamster ovary cells that were confined by cw laser tweezers and stained with either propidium iodide or Snarf, a pH-sensitive dye probe. These results suggest that, for samples suitably tagged with fluorescent probes and vital stains, optical tweezers can be used to generate their own in-situ diagnostic optical probes of cellular viability or induced photodamage, via two-photon processes.

Experimental Demonstration of Quantum Stationary Light Pulses in an Atomic Ensemble

NASA Astrophysics Data System (ADS)

Park, Kwang-Kyoon; Cho, Young-Wook; Chough, Young-Tak; Kim, Yoon-Ho

2018-04-01

We report an experimental demonstration of the nonclassical stationary light pulse (SLP) in a cold atomic ensemble. A single collective atomic excitation is created and heralded by detecting a Stokes photon in the spontaneous Raman scattering process. The heralded single atomic excitation is converted into a single stationary optical excitation or the single-photon SLP, whose effective group velocity is zero, effectively forming a trapped single-photon pulse within the cold atomic ensemble. The single-photon SLP is then released from the atomic ensemble as an anti-Stokes photon after a specified trapping time. The second-order correlation measurement between the Stokes and anti-Stokes photons reveals the nonclassical nature of the single-photon SLP. Our work paves the way toward quantum nonlinear optics without a cavity.

REVIEW: Optics of globular photonic crystals

NASA Astrophysics Data System (ADS)

Gorelik, V. S.

2007-05-01

The results of experimental and theoretical studies of the optical properties of globular photonic crystals - new physical objects having a crystal structure with the lattice period exceeding considerably the atomic size, are presented. As globular photonic crystals, artificial opal matrices consisting of close-packed silica globules of diameter ~200 nm were used. The reflection spectra of these objects characterising the parameters of photonic bands existing in these crystals in the visible spectral region are presented. The idealised models of the energy band structure of photonic crystals investigated in the review give analytic dispersion dependences for the group velocity and the effective photon mass in a globular photonic crystal. The characteristics of secondary emission excited in globular photonic crystals by monochromatic and broadband radiation are presented. The results of investigations of single-photon-excited delayed scattering of light observed in globular photonic crystals exposed to cw UV radiation and radiation from a repetitively pulsed copper vapour laser are presented. The possibilities of using globular photonic crystals as active media for lasing in different spectral regions are considered. It is proposed to use globular photonic crystals as sensitive sensors in optoelectronic devices for molecular analysis of organic and inorganic materials by the modern methods of laser spectroscopy. The results of experimental studies of spontaneous and stimulated globular scattering of light are discussed. The conditions for observing resonance and two-photon-excited delayed scattering of light are found. The possibility of accumulation and localisation of the laser radiation energy inside a globular photonic crystal is reported.

Single-Atom Single-Photon Quantum Interface

NASA Astrophysics Data System (ADS)

Moehring, David; Bochmann, Joerg; Muecke, Martin; Specht, Holger; Weber, Bernhard; Wilk, Tatjana; Rempe, Gerhard

2008-05-01

By combining atom trapping techniques and cavity cooling schemes we are able to trap a single neutral atom inside a high-finesse cavity for several tens of seconds. We show that our coupled atom-cavity system can be used to generate single photons in a controlled way. With our long trapping times and high single-photon production efficiency, the non-classical properties of the emitted light can be shown in the photon correlations of a single atom. In a similar atom-cavity setup, we investigate the interface between atoms and photons by entangling a single atom with a single photon emitted into the cavity and by further mapping the quantum state of the atom onto a second single photon. These schemes are intrinsically deterministic and establish the basic element required to realize a distributed quantum network with individual atoms at rest as quantum memories and single flying photons as quantum messengers. This work was supported by the Deutsche Forschungsgemeinschaft, and the European Union SCALA and CONQUEST programs. D. L. M. acknowledges support from the Alexander von Humboldt Foundation.

Instrumentation in molecular imaging.

PubMed

Wells, R Glenn

2016-12-01

In vivo molecular imaging is a challenging task and no single type of imaging system provides an ideal solution. Nuclear medicine techniques like SPECT and PET provide excellent sensitivity but have poor spatial resolution. Optical imaging has excellent sensitivity and spatial resolution, but light photons interact strongly with tissues and so only small animals and targets near the surface can be accurately visualized. CT and MRI have exquisite spatial resolution, but greatly reduced sensitivity. To overcome the limitations of individual modalities, molecular imaging systems often combine individual cameras together, for example, merging nuclear medicine cameras with CT or MRI to allow the visualization of molecular processes with both high sensitivity and high spatial resolution.

Tracking capabilities of SPADs for laser ranging

NASA Technical Reports Server (NTRS)

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

1993-01-01

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

Long-Distance Single Photon Transmission from a Trapped Ion via Quantum Frequency Conversion

NASA Astrophysics Data System (ADS)

Walker, Thomas; Miyanishi, Koichiro; Ikuta, Rikizo; Takahashi, Hiroki; Vartabi Kashanian, Samir; Tsujimoto, Yoshiaki; Hayasaka, Kazuhiro; Yamamoto, Takashi; Imoto, Nobuyuki; Keller, Matthias

2018-05-01

Trapped atomic ions are ideal single photon emitters with long-lived internal states which can be entangled with emitted photons. Coupling the ion to an optical cavity enables the efficient emission of single photons into a single spatial mode and grants control over their temporal shape. These features are key for quantum information processing and quantum communication. However, the photons emitted by these systems are unsuitable for long-distance transmission due to their wavelengths. Here we report the transmission of single photons from a single 40Ca+ ion coupled to an optical cavity over a 10 km optical fiber via frequency conversion from 866 nm to the telecom C band at 1530 nm. We observe nonclassical photon statistics of the direct cavity emission, the converted photons, and the 10 km transmitted photons, as well as the preservation of the photons' temporal shape throughout. This telecommunication-ready system can be a key component for long-distance quantum communication as well as future cloud quantum computation.

On-Chip Waveguide Coupling of a Layered Semiconductor Single-Photon Source.

PubMed

Tonndorf, Philipp; Del Pozo-Zamudio, Osvaldo; Gruhler, Nico; Kern, Johannes; Schmidt, Robert; Dmitriev, Alexander I; Bakhtinov, Anatoly P; Tartakovskii, Alexander I; Pernice, Wolfram; Michaelis de Vasconcellos, Steffen; Bratschitsch, Rudolf

2017-09-13

Fully integrated quantum technology based on photons is in the focus of current research, because of its immense potential concerning performance and scalability. Ideally, the single-photon sources, the processing units, and the photon detectors are all combined on a single chip. Impressive progress has been made for on-chip quantum circuits and on-chip single-photon detection. In contrast, nonclassical light is commonly coupled onto the photonic chip from the outside, because presently only few integrated single-photon sources exist. Here, we present waveguide-coupled single-photon emitters in the layered semiconductor gallium selenide as promising on-chip sources. GaSe crystals with a thickness below 100 nm are placed on Si 3 N 4 rib or slot waveguides, resulting in a modified mode structure efficient for light coupling. Using optical excitation from within the Si 3 N 4 waveguide, we find nonclassicality of generated photons routed on the photonic chip. Thus, our work provides an easy-to-implement and robust light source for integrated quantum technology.

Active temporal multiplexing of indistinguishable heralded single photons

PubMed Central

Xiong, C.; Zhang, X.; Liu, Z.; Collins, M. J.; Mahendra, A.; Helt, L. G.; Steel, M. J.; Choi, D. -Y.; Chae, C. J.; Leong, P. H. W.; Eggleton, B. J.

2016-01-01

It is a fundamental challenge in quantum optics to deterministically generate indistinguishable single photons through non-deterministic nonlinear optical processes, due to the intrinsic coupling of single- and multi-photon-generation probabilities in these processes. Actively multiplexing photons generated in many temporal modes can decouple these probabilities, but key issues are to minimize resource requirements to allow scalability, and to ensure indistinguishability of the generated photons. Here we demonstrate the multiplexing of photons from four temporal modes solely using fibre-integrated optics and off-the-shelf electronic components. We show a 100% enhancement to the single-photon output probability without introducing additional multi-photon noise. Photon indistinguishability is confirmed by a fourfold Hong–Ou–Mandel quantum interference with a 91±16% visibility after subtracting multi-photon noise due to high pump power. Our demonstration paves the way for scalable multiplexing of many non-deterministic photon sources to a single near-deterministic source, which will be of benefit to future quantum photonic technologies. PMID:26996317

Response of TLD-100 in mixed fields of photons and electrons

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

Lawless, Michael J.; Junell, Stephanie; Hammer, Cliff

Purpose: Thermoluminescent dosimeters (TLDs) are routinely used for dosimetric measurements of high energy photon and electron fields. However, TLD response in combined fields of photon and electron beam qualities has not been characterized. This work investigates the response of TLD-100 (LiF:Mg,Ti) to sequential irradiation by high-energy photon and electron beam qualities. Methods: TLDs were irradiated to a known dose by a linear accelerator with a 6 MV photon beam, a 6 MeV electron beam, and a NIST-traceable {sup 60}Co beam. TLDs were also irradiated in a mixed field of the 6 MeV electron beam and the 6 MV photon beam.more » The average TLD response per unit dose of the TLDs for each linac beam quality was normalized to the average response per unit dose of the TLDs irradiated by the {sup 60}Co beam. Irradiations were performed in water and in a Virtual Water Trade-Mark-Sign phantom. The 6 MV photon beam and 6 MeV electron beam were used to create dose calibration curves relating TLD response to absorbed dose to water, which were applied to the TLDs irradiated in the mixed field. Results: TLD relative response per unit dose in the mixed field was less sensitive than the relative response in the photon field and more sensitive than the relative response in the electron field. Application of the photon dose calibration curve to the TLDs irradiated in a mixed field resulted in an underestimation of the delivered dose, while application of the electron dose calibration curve resulted in an overestimation of the dose. Conclusions: The relative response of TLD-100 in mixed fields fell between the relative response in the photon-only and electron-only fields. TLD-100 dosimetry of mixed fields must account for this intermediate response to minimize the estimation errors associated with calibration factors obtained from a single beam quality.« less

Response of TLD-100 in mixed fields of photons and electrons.

PubMed

Lawless, Michael J; Junell, Stephanie; Hammer, Cliff; DeWerd, Larry A

2013-01-01

Thermoluminescent dosimeters (TLDs) are routinely used for dosimetric measurements of high energy photon and electron fields. However, TLD response in combined fields of photon and electron beam qualities has not been characterized. This work investigates the response of TLD-100 (LiF:Mg,Ti) to sequential irradiation by high-energy photon and electron beam qualities. TLDs were irradiated to a known dose by a linear accelerator with a 6 MV photon beam, a 6 MeV electron beam, and a NIST-traceable (60)Co beam. TLDs were also irradiated in a mixed field of the 6 MeV electron beam and the 6 MV photon beam. The average TLD response per unit dose of the TLDs for each linac beam quality was normalized to the average response per unit dose of the TLDs irradiated by the (60)Co beam. Irradiations were performed in water and in a Virtual Water™ phantom. The 6 MV photon beam and 6 MeV electron beam were used to create dose calibration curves relating TLD response to absorbed dose to water, which were applied to the TLDs irradiated in the mixed field. TLD relative response per unit dose in the mixed field was less sensitive than the relative response in the photon field and more sensitive than the relative response in the electron field. Application of the photon dose calibration curve to the TLDs irradiated in a mixed field resulted in an underestimation of the delivered dose, while application of the electron dose calibration curve resulted in an overestimation of the dose. The relative response of TLD-100 in mixed fields fell between the relative response in the photon-only and electron-only fields. TLD-100 dosimetry of mixed fields must account for this intermediate response to minimize the estimation errors associated with calibration factors obtained from a single beam quality.

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.

Single-Photon-Triggered Quantum Phase Transition

NASA Astrophysics Data System (ADS)

Lü, Xin-You; Zheng, Li-Li; Zhu, Gui-Lei; Wu, Ying

2018-06-01

We propose a hybrid quantum model combining cavity QED and optomechanics, which allows the occurrence of an equilibrium superradiant quantum phase transition (QPT) triggered by a single photon. This single-photon-triggered QPT exists in the cases of both ignoring and including the so-called A2 term; i.e., it is immune to the no-go theorem. It originally comes from the photon-dependent quantum criticality featured by the proposed hybrid quantum model. Moreover, a reversed superradiant QPT is induced by the competition between the introduced A2 term and the optomechanical interaction. This work offers an approach to manipulate QPT with a single photon, which should inspire the exploration of single-photon quantum-criticality physics and the engineering of new single-photon quantum devices.

Generation, storage, and retrieval of nonclassical states of light using atomic ensembles

NASA Astrophysics Data System (ADS)

Eisaman, Matthew D.

This thesis presents the experimental demonstration of several novel methods for generating, storing, and retrieving nonclassical states of light using atomic ensembles, and describes applications of these methods to frequency-tunable single-photon generation, single-photon memory, quantum networks, and long-distance quantum communication. We first demonstrate emission of quantum-mechanically correlated pulses of light with a time delay between the pulses that is coherently controlled by utilizing 87Rb atoms. The experiment is based on Raman scattering, which produces correlated pairs of excited atoms and photons, followed by coherent conversion of the atomic states into a different photon field after a controllable delay. We then describe experiments demonstrating a novel approach for conditionally generating nonclassical pulses of light with controllable photon numbers, propagation direction, timing, and pulse shapes. We observe nonclassical correlations in relative photon number between correlated pairs of photons, and create few-photon light pulses with sub-Poissonian photon-number statistics via conditional detection on one field of the pair. Spatio-temporal control over the pulses is obtained by exploiting long-lived coherent memory for photon states and electromagnetically induced transparency (EIT) in an optically dense atomic medium. Finally, we demonstrate the use of EIT for the controllable generation, transmission, and storage of single photons with tunable frequency, timing, and bandwidth. To this end, we study the interaction of single photons produced in a "source" ensemble of 87Rb atoms at room temperature with another "target" ensemble. This allows us to simultaneously probe the spectral and quantum statistical properties of narrow-bandwidth single-photon pulses, revealing that their quantum nature is preserved under EIT propagation and storage. We measure the time delay associated with the reduced group velocity of the single-photon pulses and report observations of their storage and retrieval. Together these experiments utilize atomic ensembles to realize a narrow-bandwidth single-photon source, single-photon memory that preserves the quantum nature of the single photons, and a primitive quantum network comprised of two atomic-ensemble quantum memories connected by a single photon in an optical fiber. Each of these experimental demonstrations represents an essential element for the realization of long-distance quantum communication.

Dosimetric properties of germanium doped calcium borate glass subjected to 6 MV and 10 MV X-ray irradiations

NASA Astrophysics Data System (ADS)

Tengku Kamarul Bahri, T. N. H.; Wagiran, H.; Hussin, R.; Saeed, M. A.; Hossain, I.; Ali, H.

2014-10-01

Germanium doped calcium borate glasses are investigated in term of thermoluminescence properties to seek their possibility to use as glass radiation dosimeter. The samples were exposed to 6 MV, and 10 MV photon beams in a dose range of 0.5-4.0 Gy. There is a single and broad thermoluminescence glow curve that exhibits its maximum intensity at about 300 °C. Linear dose response behavior has been found in this dose range for the both photon energies. Effective atomic number, TL sensitivity, and reproducibility have also been studied. It is found that the sensitivity of germanium doped sample at 6 MV is only 1.28% and it is superior to the sensitivity at 10 MV. The reproducibility of germanium doped sample is good with a percentage of relative error less than 10%. The results indicate that this glass has a potential to be used as a radiation dosimetry, especially for application in radiotherapy.

Single-photon-level quantum image memory based on cold atomic ensembles

PubMed Central

Ding, Dong-Sheng; Zhou, Zhi-Yuan; Shi, Bao-Sen; Guo, Guang-Can

2013-01-01

A quantum memory is a key component for quantum networks, which will enable the distribution of quantum information. Its successful development requires storage of single-photon light. Encoding photons with spatial shape through higher-dimensional states significantly increases their information-carrying capability and network capacity. However, constructing such quantum memories is challenging. Here we report the first experimental realization of a true single-photon-carrying orbital angular momentum stored via electromagnetically induced transparency in a cold atomic ensemble. Our experiments show that the non-classical pair correlation between trigger photon and retrieved photon is retained, and the spatial structure of input and retrieved photons exhibits strong similarity. More importantly, we demonstrate that single-photon coherence is preserved during storage. The ability to store spatial structure at the single-photon level opens the possibility for high-dimensional quantum memories. PMID:24084711

Retrieving transient conformational molecular structure information from inner-shell photoionization of laser-aligned molecules

PubMed Central

Wang, Xu; Le, Anh-Thu; Yu, Chao; Lucchese, R. R.; Lin, C. D.

2016-01-01

We discuss a scheme to retrieve transient conformational molecular structure information using photoelectron angular distributions (PADs) that have averaged over partial alignments of isolated molecules. The photoelectron is pulled out from a localized inner-shell molecular orbital by an X-ray photon. We show that a transient change in the atomic positions from their equilibrium will lead to a sensitive change in the alignment-averaged PADs, which can be measured and used to retrieve the former. Exploiting the experimental convenience of changing the photon polarization direction, we show that it is advantageous to use PADs obtained from multiple photon polarization directions. A simple single-scattering model is proposed and benchmarked to describe the photoionization process and to do the retrieval using a multiple-parameter fitting method. PMID:27025410

Retrieving transient conformational molecular structure information from inner-shell photoionization of laser-aligned molecules

NASA Astrophysics Data System (ADS)

Wang, Xu; Le, Anh-Thu; Yu, Chao; Lucchese, R. R.; Lin, C. D.

2016-03-01

We discuss a scheme to retrieve transient conformational molecular structure information using photoelectron angular distributions (PADs) that have averaged over partial alignments of isolated molecules. The photoelectron is pulled out from a localized inner-shell molecular orbital by an X-ray photon. We show that a transient change in the atomic positions from their equilibrium will lead to a sensitive change in the alignment-averaged PADs, which can be measured and used to retrieve the former. Exploiting the experimental convenience of changing the photon polarization direction, we show that it is advantageous to use PADs obtained from multiple photon polarization directions. A simple single-scattering model is proposed and benchmarked to describe the photoionization process and to do the retrieval using a multiple-parameter fitting method.

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

PubMed

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

2014-07-01

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

Room temperature single photon generation at 1. 5 μ m from covalent dopant states of carbon nanotubes

NASA Astrophysics Data System (ADS)

Htoonb, Han; He, Xiaowei; Hartmann, Nicolai; Ma, Xuedan; Doorn, Stephen; CenterIntegrated Nanotechnologies, Los Alamos National Laboratory Team

Recent demonstration that oxygen dopant states covalently attached to the single-walled carbon nanotubes (SWCNTs) are capable of emitting single photons at room-T (RT) opens the possibility of building room-T electrically-driven single photon sources for quantum communication applications. The RT single photon generation was not observed only at wavelength beyond 1.3 μ m. Here in this work we demonstrate RT single photon generation at 1. 5 μ m from diazonium dopant states of (10,3) nanotubes.

Measuring Single Photons

Science.gov Websites

Explore the World of Particle Physics Measuring Single Photons The web pages that follow presume phenomenon and then return to our study of single photon measurement. Your choices include: These choices University of Colorado. A Java applet by Phillip Warner. Dive right into the single photon pages here

The predictive value of single-photon emission computed tomography/computed tomography for sentinel lymph node localization in head and neck cutaneous malignancy.

PubMed

Remenschneider, Aaron K; Dilger, Amanda E; Wang, Yingbing; Palmer, Edwin L; Scott, James A; Emerick, Kevin S

2015-04-01

Preoperative localization of sentinel lymph nodes in head and neck cutaneous malignancies can be aided by single-photon emission computed tomography/computed tomography (SPECT/CT); however, its true predictive value for identifying lymph nodes intraoperatively remains unquantified. This study aims to understand the sensitivity, specificity, and positive and negative predictive values of SPECT/CT in sentinel lymph node biopsy for cutaneous malignancies of the head and neck. Blinded retrospective imaging review with comparison to intraoperative gamma probe confirmed sentinel lymph nodes. A consecutive series of patients with a head and neck cutaneous malignancy underwent preoperative SPECT/CT followed by sentinel lymph node biopsy with a gamma probe. Two nuclear medicine physicians, blinded to clinical data, independently reviewed each SPECT/CT. Activity within radiographically defined nodal basins was recorded and compared to intraoperative gamma probe findings. Sensitivity, specificity, and negative and positive predictive values were calculated with subgroup stratification by primary tumor site. Ninety-two imaging reads were performed on 47 patients with cutaneous malignancy who underwent SPECT/CT followed by sentinel lymph node biopsy. Overall sensitivity was 73%, specificity 92%, positive predictive value 54%, and negative predictive value 96%. The predictive ability of SPECT/CT to identify the basin or an adjacent basin containing the single hottest node was 92%. SPECT/CT overestimated uptake by an average of one nodal basin. In the head and neck, SPECT/CT has higher reliability for primary lesions of the eyelid, scalp, and cheek. SPECT/CT has high sensitivity, specificity, and negative predictive value, but may overestimate relevant nodal basins in sentinel lymph node biopsy. © 2014 The American Laryngological, Rhinological and Otological Society, Inc.

Proposed Ultra-High Sensitivity High-Frequency Gravitational Wave Detector

NASA Astrophysics Data System (ADS)

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

2008-01-01

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

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

PubMed

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

2015-12-28

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

Hong-Ou-Mandel Interference between Two Deterministic Collective Excitations in an Atomic Ensemble

NASA Astrophysics Data System (ADS)

Li, Jun; Zhou, Ming-Ti; Jing, Bo; Wang, Xu-Jie; Yang, Sheng-Jun; Jiang, Xiao; Mølmer, Klaus; Bao, Xiao-Hui; Pan, Jian-Wei

2016-10-01

We demonstrate deterministic generation of two distinct collective excitations in one atomic ensemble, and we realize the Hong-Ou-Mandel interference between them. Using Rydberg blockade we create single collective excitations in two different Zeeman levels, and we use stimulated Raman transitions to perform a beam-splitter operation between the excited atomic modes. By converting the atomic excitations into photons, the two-excitation interference is measured by photon coincidence detection with a visibility of 0.89(6). The Hong-Ou-Mandel interference witnesses an entangled NOON state of the collective atomic excitations, and we demonstrate its two times enhanced sensitivity to a magnetic field compared with a single excitation. Our work implements a minimal instance of boson sampling and paves the way for further multimode and multiexcitation studies with collective excitations of atomic ensembles.

Ultra-weak photon emission of hands in aging prediction.

PubMed

Zhao, Xin; van Wijk, Eduard; Yan, Yu; van Wijk, Roeland; Yang, Huanming; Zhang, Yan; Wang, Jian

2016-09-01

Aging has been one of the several topics intensely investigated during recent decades. More scientists have been scrutinizing mechanisms behind the human aging process. Ultra-weak photon emission is known as one type of spontaneous photon emission that can be detected with a highly sensitive single photon counting photomultiplier tube (PMT) from the surface of human bodies. It may reflect the body's oxidative damage. Our aim was to examine whether ultra-weak photon emission from a human hand is able to predict one's chronological age. Sixty subjects were recruited and grouped by age. We examined four areas of each hand: palm side of fingers, palm side of hand, dorsum side of fingers, and dorsum side of hand. Left and right hand were measured synchronously with two independent PMTs. Mean strength and Fano factor values of photon counts were utilized to compare the UPE patterns of males and females of different age groups. Subsequently, we utilized UPE data from the most sensitive PMT to develop an age prediction model. We randomly picked 49 subjects to construct the model, whereas the remaining 11 subjects were utilized for validation. The results demonstrated that the model was a good regression compared to the observed values (Pearson's r=0.6, adjusted R square=0.4, p=9.4E-7, accuracy=49/60). Further analysis revealed that the average difference between the chronological age and predicted age was only 7.6±0.8years. It was concluded that this fast and non-invasive photon technology is sufficiently promising to be developed for the estimation of biological aging. Copyright © 2016 Elsevier B.V. All rights reserved.

Single photon laser altimeter data processing, analysis and experimental validation

NASA Astrophysics Data System (ADS)

Vacek, Michael; Peca, Marek; Michalek, Vojtech; Prochazka, Ivan

2015-10-01

Spaceborne laser altimeters are common instruments on-board the rendezvous spacecraft. This manuscript deals with the altimeters using a single photon approach, which belongs to the family of time-of-flight range measurements. Moreover, the single photon 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 photon altimeters evaluate actual altitude through the repetitive detections of single photons of the reflected laser pulses. We propose the single photon 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 photon 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 photon altitude reading, namely that the photon detection measurement statistics must be gathered. The developed algorithm deduces the actual altitude on the basis of a single photon detection; thus, being optimal in the sense that each detected signal photon 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 photon 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).

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.

Two-photon voltage imaging using a genetically encoded voltage indicator

PubMed Central

Akemann, Walther; Sasaki, Mari; Mutoh, Hiroki; Imamura, Takeshi; Honkura, Naoki; Knöpfel, Thomas

2013-01-01

Voltage-sensitive fluorescent proteins (VSFPs) are a family of genetically-encoded voltage indicators (GEVIs) reporting membrane voltage fluctuation from genetically-targeted cells in cell cultures to whole brains in awake mice as demonstrated earlier using 1-photon (1P) fluorescence excitation imaging. However, in-vivo 1P imaging captures optical signals only from superficial layers and does not optically resolve single neurons. Two-photon excitation (2P) imaging, on the other hand, has not yet been convincingly applied to GEVI experiments. Here we show that 2P imaging of VSFP Butterfly 1.2 expresssing pyramidal neurons in layer 2/3 reports optical membrane voltage in brain slices consistent with 1P imaging but with a 2–3 larger ΔR/R value. 2P imaging of mouse cortex in-vivo achieved cellular resolution throughout layer 2/3. In somatosensory cortex we recorded sensory responses to single whisker deflections in anesthetized mice at full frame video rate. Our results demonstrate the feasibility of GEVI-based functional 2P imaging in mouse cortex. PMID:23868559

Graphene Josephson Junction Single Photon Detector

NASA Astrophysics Data System (ADS)

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

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

An algorithm for charge-integration, pulse-shape discrimination and estimation of neutron/photon misclassification in organic scintillators

NASA Astrophysics Data System (ADS)

Polack, J. K.; Flaska, M.; Enqvist, A.; Sosa, C. S.; Lawrence, C. C.; Pozzi, S. A.

2015-09-01

Organic scintillators are frequently used for measurements that require sensitivity to both photons and fast neutrons because of their pulse shape discrimination capabilities. In these measurement scenarios, particle identification is commonly handled using the charge-integration pulse shape discrimination method. This method works particularly well for high-energy depositions, but is prone to misclassification for relatively low-energy depositions. A novel algorithm has been developed for automatically performing charge-integration pulse shape discrimination in a consistent and repeatable manner. The algorithm is able to estimate the photon and neutron misclassification corresponding to the calculated discrimination parameters, and is capable of doing so using only the information measured by a single organic scintillator. This paper describes the algorithm and assesses its performance by comparing algorithm-estimated misclassification to values computed via a more traditional time-of-flight estimation. A single data set was processed using four different low-energy thresholds: 40, 60, 90, and 120 keVee. Overall, the results compared well between the two methods; in most cases, the algorithm-estimated values fell within the uncertainties of the TOF-estimated values.

Time-Correlated Single-Photon Counting Fluorescence Imaging of Lipid Domains In Raft-Mimicking Giant Unilamellar Vesicles

NASA Astrophysics Data System (ADS)

Clarke, James; Cheng, Kwan; Shindell, Orrin; Wang, Exing

We have designed and constructed a high-throughput electrofusion chamber and an incubator to fabricate Giant Unilamellar Vesicles (GUVs) consisting of high-melting lipids, low-melting lipids, cholesterol and both ordered and disordered phase sensitive fluorescent probes (DiIC12, dehydroergosterol and BODIPY-Cholesterol). GUVs were formed in a 3 stage pulse sequence electrofusion process with voltages ranging from 50mVpp to 2.2Vpp and frequencies from 5Hz to 10Hz. Steady state and time-correlated single-photon counting (TCSPC) fluorescence lifetime (FLIM) based confocal and/or multi-photon microscopic techniques were used to characterize phase separated lipid domains in GUVs. Confocal imaging measures the probe concentration and the chemical environment of the system. TCSPC techniques determine the chemical environment through the perturbation of fluorescent lifetimes of the probes in the system. The above techniques will be applied to investigate the protein-lipid interactions involving domain formation. Specifically, the mechanisms governing lipid domain formations in the above systems that mimic the lipid rafts in cells will be explored. Murchison Fellowship at Trinity University.

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

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

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

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

Enhanced Single-Photon Emission from Carbon-Nanotube Dopant States Coupled to Silicon Microcavities.

PubMed

Ishii, Akihiro; He, Xiaowei; Hartmann, Nicolai F; Machiya, Hidenori; Htoon, Han; Doorn, Stephen K; Kato, Yuichiro K

2018-06-13

Single-walled carbon nanotubes are a promising material as quantum light sources at room temperature and as nanoscale light sources for integrated photonic circuits on silicon. Here, we show that the integration of dopant states in carbon nanotubes and silicon microcavities can provide bright and high-purity single-photon emitters on a silicon photonics platform at room temperature. We perform photoluminescence spectroscopy and observe the enhancement of emission from the dopant states by a factor of ∼50, and cavity-enhanced radiative decay is confirmed using time-resolved measurements, in which a ∼30% decrease of emission lifetime is observed. The statistics of photons emitted from the cavity-coupled dopant states are investigated by photon-correlation measurements, and high-purity single photon generation is observed. The excitation power dependence of photon emission statistics shows that the degree of photon antibunching can be kept high even when the excitation power increases, while the single-photon emission rate can be increased to ∼1.7 × 10 7 Hz.

Enhanced Single-Photon Emission from Carbon-Nanotube Dopant States Coupled to Silicon Microcavities

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

Ishii, Akihiro; He, Xiaowei; Hartmann, Nicolai F.

Single-walled carbon nanotubes are a promising material as quantum light sources at room temperature and as nanoscale light sources for integrated photonic circuits on silicon. Here, we show that the integration of dopant states in carbon nanotubes and silicon microcavities can provide bright and high-purity single-photon emitters on a silicon photonics platform at room temperature. We perform photoluminescence spectroscopy and observe the enhancement of emission from the dopant states by a factor of ~50, and cavity-enhanced radiative decay is confirmed using time-resolved measurements, in which a ~30% decrease of emission lifetime is observed. The statistics of photons emitted from themore » cavity-coupled dopant states are investigated by photon-correlation measurements, and high-purity single photon generation is observed. The excitation power dependence of photon emission statistics shows that the degree of photon antibunching can be kept high even when the excitation power increases, while the single-photon emission rate can be increased to ~1.7 × 10 7 Hz.« less

Enhanced Single-Photon Emission from Carbon-Nanotube Dopant States Coupled to Silicon Microcavities

DOE PAGES

Ishii, Akihiro; He, Xiaowei; Hartmann, Nicolai F.; ...

2018-05-21

Single-walled carbon nanotubes are a promising material as quantum light sources at room temperature and as nanoscale light sources for integrated photonic circuits on silicon. Here, we show that the integration of dopant states in carbon nanotubes and silicon microcavities can provide bright and high-purity single-photon emitters on a silicon photonics platform at room temperature. We perform photoluminescence spectroscopy and observe the enhancement of emission from the dopant states by a factor of ~50, and cavity-enhanced radiative decay is confirmed using time-resolved measurements, in which a ~30% decrease of emission lifetime is observed. The statistics of photons emitted from themore » cavity-coupled dopant states are investigated by photon-correlation measurements, and high-purity single photon generation is observed. The excitation power dependence of photon emission statistics shows that the degree of photon antibunching can be kept high even when the excitation power increases, while the single-photon emission rate can be increased to ~1.7 × 10 7 Hz.« less

A quantum dot single-photon source with on-the-fly all-optical polarization control and timed emission.

PubMed

Heinze, Dirk; Breddermann, Dominik; Zrenner, Artur; Schumacher, Stefan

2015-10-05

Sources of single photons are key elements for applications in quantum information science. Among the different sources available, semiconductor quantum dots excel with their integrability in semiconductor on-chip solutions and the potential that photon emission can be triggered on demand. Usually, the photon is emitted from a single-exciton ground state. Polarization of the photon and time of emission are either probabilistic or pre-determined by electronic properties of the system. Here, we study the direct two-photon emission from the biexciton. The two-photon emission is enabled by a laser pulse driving the system into a virtual state inside the band gap. From this intermediate state, the single photon of interest is then spontaneously emitted. We show that emission through this higher-order transition provides a versatile approach to generate a single photon. Through the driving laser pulse, polarization state, frequency and emission time of the photon can be controlled on-the-fly.

Tuning single-photon sources for telecom multi-photon experiments.

PubMed

Greganti, Chiara; Schiansky, Peter; Calafell, Irati Alonso; Procopio, Lorenzo M; Rozema, Lee A; Walther, Philip

2018-02-05

Multi-photon state generation is of great interest for near-future quantum simulation and quantum computation experiments. To-date spontaneous parametric down-conversion is still the most promising process, even though two major impediments still exist: accidental photon noise (caused by the probabilistic non-linear process) and imperfect single-photon purity (arising from spectral entanglement between the photon pairs). In this work, we overcome both of these difficulties by (1) exploiting a passive temporal multiplexing scheme and (2) carefully optimizing the spectral properties of the down-converted photons using periodically-poled KTP crystals. We construct two down-conversion sources in the telecom wavelength regime, finding spectral purities of > 91%, while maintaining high four-photon count rates. We use single-photon grating spectrometers together with superconducting nanowire single-photon detectors to perform a detailed characterization of our multi-photon source. Our methods provide practical solutions to produce high-quality multi-photon states, which are in demand for many quantum photonics applications.

Multi-photon absorption limits to heralded single photon sources

PubMed Central

Husko, Chad A.; Clark, Alex S.; Collins, Matthew J.; De Rossi, Alfredo; Combrié, Sylvain; Lehoucq, Gaëlle; Rey, Isabella H.; Krauss, Thomas F.; Xiong, Chunle; Eggleton, Benjamin J.

2013-01-01

Single photons are of paramount importance to future quantum technologies, including quantum communication and computation. Nonlinear photonic devices using parametric processes offer a straightforward route to generating photons, however additional nonlinear processes may come into play and interfere with these sources. Here we analyse spontaneous four-wave mixing (SFWM) sources in the presence of multi-photon processes. We conduct experiments in silicon and gallium indium phosphide photonic crystal waveguides which display inherently different nonlinear absorption processes, namely two-photon (TPA) and three-photon absorption (ThPA), respectively. We develop a novel model capturing these diverse effects which is in excellent quantitative agreement with measurements of brightness, coincidence-to-accidental ratio (CAR) and second-order correlation function g(2)(0), showing that TPA imposes an intrinsic limit on heralded single photon sources. We build on these observations to devise a new metric, the quantum utility (QMU), enabling further optimisation of single photon sources. PMID:24186400

Time-Bin-Encoded Boson Sampling with a Single-Photon Device.

PubMed

He, Yu; Ding, X; Su, Z-E; Huang, H-L; Qin, J; Wang, C; Unsleber, S; Chen, C; Wang, H; He, Y-M; Wang, X-L; Zhang, W-J; Chen, S-J; Schneider, C; Kamp, M; You, L-X; Wang, Z; Höfling, S; Lu, Chao-Yang; Pan, Jian-Wei

2017-05-12

Boson sampling is a problem strongly believed to be intractable for classical computers, but can be naturally solved on a specialized photonic quantum simulator. Here, we implement the first time-bin-encoded boson sampling using a highly indistinguishable (∼94%) single-photon source based on a single quantum-dot-micropillar device. The protocol requires only one single-photon source, two detectors, and a loop-based interferometer for an arbitrary number of photons. The single-photon pulse train is time-bin encoded and deterministically injected into an electrically programmable multimode network. The observed three- and four-photon boson sampling rates are 18.8 and 0.2 Hz, respectively, which are more than 100 times faster than previous experiments based on parametric down-conversion.

On-Demand Single Photons with High Extraction Efficiency and Near-Unity Indistinguishability from a Resonantly Driven Quantum Dot in a Micropillar.

PubMed

Ding, Xing; He, Yu; Duan, Z-C; Gregersen, Niels; Chen, M-C; Unsleber, S; Maier, S; Schneider, Christian; Kamp, Martin; Höfling, Sven; Lu, Chao-Yang; Pan, Jian-Wei

2016-01-15

Scalable photonic quantum technologies require on-demand single-photon sources with simultaneously high levels of purity, indistinguishability, and efficiency. These key features, however, have only been demonstrated separately in previous experiments. Here, by s-shell pulsed resonant excitation of a Purcell-enhanced quantum dot-micropillar system, we deterministically generate resonance fluorescence single photons which, at π pulse excitation, have an extraction efficiency of 66%, single-photon purity of 99.1%, and photon indistinguishability of 98.5%. Such a single-photon source for the first time combines the features of high efficiency and near-perfect levels of purity and indistinguishabilty, and thus opens the way to multiphoton experiments with semiconductor quantum dots.

Ultrafast single photon emitting quantum photonic structures based on a nano-obelisk.

PubMed

Kim, Je-Hyung; Ko, Young-Ho; Gong, Su-Hyun; Ko, Suk-Min; Cho, Yong-Hoon

2013-01-01

A key issue in a single photon source is fast and efficient generation of a single photon flux with high light extraction efficiency. Significant progress toward high-efficiency single photon sources has been demonstrated by semiconductor quantum dots, especially using narrow bandgap materials. Meanwhile, there are many obstacles, which restrict the use of wide bandgap semiconductor quantum dots as practical single photon sources in ultraviolet-visible region, despite offering free space communication and miniaturized quantum information circuits. Here we demonstrate a single InGaN quantum dot embedded in an obelisk-shaped GaN nanostructure. The nano-obelisk plays an important role in eliminating dislocations, increasing light extraction, and minimizing a built-in electric field. Based on the nano-obelisks, we observed nonconventional narrow quantum dot emission and positive biexciton binding energy, which are signatures of negligible built-in field in single InGaN quantum dots. This results in efficient and ultrafast single photon generation in the violet color region.

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.

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.

Integrating photonics with silicon nanoelectronics for the next generation of systems on a chip.

PubMed

Atabaki, Amir H; Moazeni, Sajjad; Pavanello, Fabio; Gevorgyan, Hayk; Notaros, Jelena; Alloatti, Luca; Wade, Mark T; Sun, Chen; Kruger, Seth A; Meng, Huaiyu; Al Qubaisi, Kenaish; Wang, Imbert; Zhang, Bohan; Khilo, Anatol; Baiocco, Christopher V; Popović, Miloš A; Stojanović, Vladimir M; Ram, Rajeev J

2018-04-01

Electronic and photonic technologies have transformed our lives-from computing and mobile devices, to information technology and the internet. Our future demands in these fields require innovation in each technology separately, but also depend on our ability to harness their complementary physics through integrated solutions 1,2 . This goal is hindered by the fact that most silicon nanotechnologies-which enable our processors, computer memory, communications chips and image sensors-rely on bulk silicon substrates, a cost-effective solution with an abundant supply chain, but with substantial limitations for the integration of photonic functions. Here we introduce photonics into bulk silicon complementary metal-oxide-semiconductor (CMOS) chips using a layer of polycrystalline silicon deposited on silicon oxide (glass) islands fabricated alongside transistors. We use this single deposited layer to realize optical waveguides and resonators, high-speed optical modulators and sensitive avalanche photodetectors. We integrated this photonic platform with a 65-nanometre-transistor bulk CMOS process technology inside a 300-millimetre-diameter-wafer microelectronics foundry. We then implemented integrated high-speed optical transceivers in this platform that operate at ten gigabits per second, composed of millions of transistors, and arrayed on a single optical bus for wavelength division multiplexing, to address the demand for high-bandwidth optical interconnects in data centres and high-performance computing 3,4 . By decoupling the formation of photonic devices from that of transistors, this integration approach can achieve many of the goals of multi-chip solutions 5 , but with the performance, complexity and scalability of 'systems on a chip' 1,6-8 . As transistors smaller than ten nanometres across become commercially available 9 , and as new nanotechnologies emerge 10,11 , this approach could provide a way to integrate photonics with state-of-the-art nanoelectronics.

Interferometric Quantum-Nondemolition Single-Photon Detectors

NASA Technical Reports Server (NTRS)

Kok, Peter; Lee, Hwang; Dowling, Jonathan

2007-01-01

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

Single colloidal quantum dots as sources of single photons for quantum cryptography

NASA Astrophysics Data System (ADS)

Pisanello, Ferruccio; Qualtieri, Antonio; Leménager, Godefroy; Martiradonna, Luigi; Stomeo, Tiziana; Cingolani, Roberto; Bramati, Alberto; De Vittorio, Massimo

2011-02-01

Colloidal nanocrystals, i.e. quantum dots synthesized trough wet-chemistry approaches, are promising nanoparticles for photonic applications and, remarkably, their quantum nature makes them very promising for single photon emission at room temperature. In this work we describe two approaches to engineer the emission properties of these nanoemitters in terms of radiative lifetime and photon polarization, drawing a viable strategy for their exploitation as room-temperature single photon sources for quantum information and quantum telecommunications.

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

PubMed

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

2012-01-01

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

Compact photonic crystal fiber refractometer based on modal interference

NASA Astrophysics Data System (ADS)

Wong, Wei Chang; Chan, Chi Chiu; Tou, Zhi Qiang; Chen, Li Han; Leong, Kam Chew

2011-05-01

A compact photonic crystal fiber (PCF) refractometer based on modal interference has been proposed by the use of commercial fusion splicer to collapse the holes of PCF to form a Mach Zehnder interferometer by splitting the fundamental core mode into cladding and core modes in the PCF. Collapsed of holes was done at the interface between the single mode fiber and PCF, and the PCF's end. The shift of the interference fringes was measured when the sensor was placed into different refractive index liquid. High linear sensitivity of 253.13nm/RIU with resolution of 3.950×10-5RIU was obtained.

Fiber Fabry-Perot tip sensor based on multimode photonic crystal fiber

NASA Astrophysics Data System (ADS)

Wu, Di; Huang, Yu; Fu, Jian-Yu; Wang, Guo-Yin

2015-03-01

We propose a novel Fabry-Perot interferometer (FPI) sensor for simultaneous measurement of refractive index (RI) and temperature based on Fresnel reflection and the thermo-optic effect of silica. The sensor head consists of a short section of multimode photonic crystal fiber (MPCF) and a conventional single mode fiber (SMF), where two thin films are formed by collapsing the air holes of MPCF with a commercialized fusion splicer. Experimental results show that such a device has a linear RI sensitivity of ~21.52 dB/RIU (RI unit) and a linear optical path difference (OPD) temperature sensitivity of ~25 nm/°C. In addition, a high RI resolution of about ~1.7×10-5 is obtained by using the Fourier transformation to decompose the spectral response in different spatial frequencies. Low-cost, easy fabrication and high resolution make it appropriate for practical applications.

Generating single microwave photons in a circuit.

PubMed

Houck, A A; Schuster, D I; Gambetta, J M; Schreier, J A; Johnson, B R; Chow, J M; Frunzio, L; Majer, J; Devoret, M H; Girvin, S M; Schoelkopf, R J

2007-09-20

Microwaves have widespread use in classical communication technologies, from long-distance broadcasts to short-distance signals within a computer chip. Like all forms of light, microwaves, even those guided by the wires of an integrated circuit, consist of discrete photons. To enable quantum communication between distant parts of a quantum computer, the signals must also be quantum, consisting of single photons, for example. However, conventional sources can generate only classical light, not single photons. One way to realize a single-photon source is to collect the fluorescence of a single atom. Early experiments measured the quantum nature of continuous radiation, and further advances allowed triggered sources of photons on demand. To allow efficient photon collection, emitters are typically placed inside optical or microwave cavities, but these sources are difficult to employ for quantum communication on wires within an integrated circuit. Here we demonstrate an on-chip, on-demand single-photon source, where the microwave photons are injected into a wire with high efficiency and spectral purity. This is accomplished in a circuit quantum electrodynamics architecture, with a microwave transmission line cavity that enhances the spontaneous emission of a single superconducting qubit. When the qubit spontaneously emits, the generated photon acts as a flying qubit, transmitting the quantum information across a chip. We perform tomography of both the qubit and the emitted photons, clearly showing that both the quantum phase and amplitude are transferred during the emission. Both the average power and voltage of the photon source are characterized to verify performance of the system. This single-photon source is an important addition to a rapidly growing toolbox for quantum optics on a chip.

Hong-Ou-Mandel Interference Between Triggered And Heralded Single Photons From Separate Atomic Systems

NASA Astrophysics Data System (ADS)

Cere, Alessandro; Leong, Victor; Kaur Gulati, Gurpreet; Srivathsan, Bharath; Kosen, Sandoko; Kurtsiefer, Christian

2015-05-01

The realization of quantum networks and long distance quantum communication rely on the capability of generating entanglement between separated nodes. We demonstrate the compatibility of two different sources of single photons: a single atom and four-wave mixing in a cold cloud of atoms. The four-wave mixing process in a cloud of cold 87Rb generates photon pairs. The cascade level scheme used ensures the generation of heralded single photons with exponentially decaying temporal envelope. The temporal shape of the heralding photons matches the shape of photons emitted by spontaneous decay but for the shorter coherence time A single 87Rb atom is trapped in an far-off-resonance optical dipole trap and can be excited with high probability using a short (~3 ns) intense pulse of resonant light, emitting a single photon by spontaneous decay. A large numerical aperture lens collects ~4% of the total fluorescence. The heralded and the triggered photons are launched into a Houng-Ou-Mandel interferometer: a symmetrical beam-splitter with outputs connected to single photon detectors. Scanning the relative delay between the two sources we observe the HOM dip with a maximum visibility of 70 +/-4%.

Boson Sampling with Single-Photon Fock States from a Bright Solid-State Source.

PubMed

Loredo, J C; Broome, M A; Hilaire, P; Gazzano, O; Sagnes, I; Lemaitre, A; Almeida, M P; Senellart, P; White, A G

2017-03-31

A boson-sampling device is a quantum machine expected to perform tasks intractable for a classical computer, yet requiring minimal nonclassical resources as compared to full-scale quantum computers. Photonic implementations to date employed sources based on inefficient processes that only simulate heralded single-photon statistics when strongly reducing emission probabilities. Boson sampling with only single-photon input has thus never been realized. Here, we report on a boson-sampling device operated with a bright solid-state source of single-photon Fock states with high photon-number purity: the emission from an efficient and deterministic quantum dot-micropillar system is demultiplexed into three partially indistinguishable single photons, with a single-photon purity 1-g^{(2)}(0) of 0.990±0.001, interfering in a linear optics network. Our demultiplexed source is between 1 and 2 orders of magnitude more efficient than current heralded multiphoton sources based on spontaneous parametric down-conversion, allowing us to complete the boson-sampling experiment faster than previous equivalent implementations.

Quantum State Transfer from a Single Photon to a Distant Quantum-Dot Electron Spin

NASA Astrophysics Data System (ADS)

He, Yu; He, Yu-Ming; Wei, Yu-Jia; Jiang, Xiao; Chen, Kai; Lu, Chao-Yang; Pan, Jian-Wei; Schneider, Christian; Kamp, Martin; Höfling, Sven

2017-08-01

Quantum state transfer from flying photons to stationary matter qubits is an important element in the realization of quantum networks. Self-assembled semiconductor quantum dots provide a promising solid-state platform hosting both single photon and spin, with an inherent light-matter interface. Here, we develop a method to coherently and actively control the single-photon frequency bins in superposition using electro-optic modulators, and measure the spin-photon entanglement with a fidelity of 0.796 ±0.020 . Further, by Greenberger-Horne-Zeilinger-type state projection on the frequency, path, and polarization degrees of freedom of a single photon, we demonstrate quantum state transfer from a single photon to a single electron spin confined in an InGaAs quantum dot, separated by 5 m. The quantum state mapping from the photon's polarization to the electron's spin is demonstrated along three different axes on the Bloch sphere, with an average fidelity of 78.5%.

Room temperature single photon source using fiber-integrated hexagonal boron nitride

NASA Astrophysics Data System (ADS)

Vogl, Tobias; Lu, Yuerui; Lam, Ping Koy

2017-07-01

Single photons are a key resource for quantum optics and optical quantum information processing. The integration of scalable room temperature quantum emitters into photonic circuits remains to be a technical challenge. Here we utilize a defect center in hexagonal boron nitride (hBN) attached by Van der Waals force onto a multimode fiber as a single photon source. We perform an optical characterization of the source in terms of spectrum, state lifetime, power saturation and photostability. A special feature of our source is that it allows for easy switching between fiber-coupled and free space single photon generation modes. In order to prove the quantum nature of the emission we measure the second-order correlation function {{g}(2)}≤ft(τ \\right) . For both fiber-coupled and free space emission, the {{g}(2)}≤ft(τ \\right) dips below 0.5 indicating operation in the single photon regime. The results so far demonstrate the feasibility of 2D material single photon sources for scalable photonic quantum information processing.

Tunable and high-purity room temperature single-photon emission from atomic defects in hexagonal boron nitride

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

Grosso, Gabriele; Moon, Hyowon; Lienhard, Benjamin

Two-dimensional van der Waals materials have emerged as promising platforms for solid-state quantum information processing devices with unusual potential for heterogeneous assembly. Recently, bright and photostable single photon emitters were reported from atomic defects in layered hexagonal boron nitride (hBN), but controlling inhomogeneous spectral distribution and reducing multi-photon emission presented open challenges. Here, we demonstrate that strain control allows spectral tunability of hBN single photon emitters over 6 meV, and material processing sharply improves the single photon purity. We observe high single photon count rates exceeding 7 × 10 6 counts per second at saturation, after correcting for uncorrelated photonmore » background. Furthermore, these emitters are stable to material transfer to other substrates. High-purity and photostable single photon emission at room temperature, together with spectral tunability and transferability, opens the door to scalable integration of high-quality quantum emitters in photonic quantum technologies.« less

Tunable and high-purity room temperature single-photon emission from atomic defects in hexagonal boron nitride

DOE PAGES

Grosso, Gabriele; Moon, Hyowon; Lienhard, Benjamin; ...

2017-09-26

Two-dimensional van der Waals materials have emerged as promising platforms for solid-state quantum information processing devices with unusual potential for heterogeneous assembly. Recently, bright and photostable single photon emitters were reported from atomic defects in layered hexagonal boron nitride (hBN), but controlling inhomogeneous spectral distribution and reducing multi-photon emission presented open challenges. Here, we demonstrate that strain control allows spectral tunability of hBN single photon emitters over 6 meV, and material processing sharply improves the single photon purity. We observe high single photon count rates exceeding 7 × 10 6 counts per second at saturation, after correcting for uncorrelated photonmore » background. Furthermore, these emitters are stable to material transfer to other substrates. High-purity and photostable single photon emission at room temperature, together with spectral tunability and transferability, opens the door to scalable integration of high-quality quantum emitters in photonic quantum technologies.« less

Spin-based single-photon transistor, dynamic random access memory, diodes, and routers in semiconductors

NASA Astrophysics Data System (ADS)

Hu, C. Y.

2016-12-01

The realization of quantum computers and quantum Internet requires not only quantum gates and quantum memories, but also transistors at single-photon levels to control the flow of information encoded on single photons. Single-photon transistor (SPT) is an optical transistor in the quantum limit, which uses a single photon to open or block a photonic channel. In sharp contrast to all previous SPT proposals which are based on single-photon nonlinearities, here I present a design for a high-gain 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 photon 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.

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

Integrated spatial multiplexing of heralded single-photon sources

PubMed Central

Collins, M.J.; Xiong, C.; Rey, I.H.; Vo, T.D.; He, J.; Shahnia, S.; Reardon, C.; Krauss, T.F.; Steel, M.J.; Clark, A.S.; Eggleton, B.J.

2013-01-01

The non-deterministic nature of photon sources is a key limitation for single-photon quantum processors. Spatial multiplexing overcomes this by enhancing the heralded single-photon yield without enhancing the output noise. Here the intrinsic statistical limit of an individual source is surpassed by spatially multiplexing two monolithic silicon-based correlated photon pair sources in the telecommunications band, demonstrating a 62.4% increase in the heralded single-photon output without an increase in unwanted multipair generation. We further demonstrate the scalability of this scheme by multiplexing photons generated in two waveguides pumped via an integrated coupler with a 63.1% increase in the heralded photon rate. This demonstration paves the way for a scalable architecture for multiplexing many photon sources in a compact integrated platform and achieving efficient two-photon interference, required at the core of optical quantum computing and quantum communication protocols. PMID:24107840

An on-chip coupled resonator optical waveguide single-photon buffer

PubMed Central

Takesue, Hiroki; Matsuda, Nobuyuki; Kuramochi, Eiichi; Munro, William J.; Notomi, Masaya

2013-01-01

Integrated quantum optical circuits are now seen as one of the most promising approaches with which to realize single-photon quantum information processing. Many of the core elements for such circuits have been realized, including sources, gates and detectors. However, a significant missing function necessary for photonic quantum information processing on-chip is a buffer, where single photons are stored for a short period of time to facilitate circuit synchronization. Here we report an on-chip single-photon buffer based on coupled resonator optical waveguides (CROW) consisting of 400 high-Q photonic crystal line-defect nanocavities. By using the CROW, a pulsed single photon is successfully buffered for 150 ps with 50-ps tunability while maintaining its non-classical properties. Furthermore, we show that our buffer preserves entanglement by storing and retrieving one photon from a time-bin entangled state. This is a significant step towards an all-optical integrated quantum information processor. PMID:24217422

On-chip low loss heralded source of pure single photons.

PubMed

Spring, Justin B; Salter, Patrick S; Metcalf, Benjamin J; Humphreys, Peter C; Moore, Merritt; Thomas-Peter, Nicholas; Barbieri, Marco; Jin, Xian-Min; Langford, Nathan K; Kolthammer, W Steven; Booth, Martin J; Walmsley, Ian A

2013-06-03

A key obstacle to the experimental realization of many photonic quantum-enhanced technologies is the lack of low-loss sources of single photons in pure quantum states. We demonstrate a promising solution: generation of heralded single photons in a silica photonic chip by spontaneous four-wave mixing. A heralding efficiency of 40%, corresponding to a preparation efficiency of 80% accounting for detector performance, is achieved due to efficient coupling of the low-loss source to optical fibers. A single photon purity of 0.86 is measured from the source number statistics without narrow spectral filtering, and confirmed by direct measurement of the joint spectral intensity. We calculate that similar high-heralded-purity output can be obtained from visible to telecom spectral regions using this approach. On-chip silica sources can have immediate application in a wide range of single-photon quantum optics applications which employ silica photonics.

Light Controlling at Subwavelength Scales in Nanophotonic Systems: Physics and Applications

NASA Astrophysics Data System (ADS)

Shen, Yuecheng

The capability of controlling light at scales that are much smaller than the operating wave-length enables new optical functionalities, and opens up a wide range of applications. Such a capability is out of the realm of conventional optical approaches. This dissertation aims to explore the light-matter interactions at nanometer scale, and to investigate the novel scien-tific and industrial applications. In particular, we will explain how to detect nanoparticles using an ultra-sensitive nano-sensor; we will also describe a photonic diode which gener-ates a unidirectional flow of single photons; Moreover, in an one-dimensional waveguide QED system where the fermionic degree of freedom is present, we will show that strong photon-photon interactions can be generated through scattering means, leading to photonic bunching and anti-bunching with various applications. Finally, we will introduce a mecha-nism to achieve super-resolution to discern fine features that are orders of magnitude smaller than the illuminating wavelength. These research projects incorporate recent advances in quantum nanophotonics, nanotechnologies, imaging reconstruction techniques, and rigorous numerical simulations.

Single-photon absorption by single photosynthetic light-harvesting complexes

NASA Astrophysics Data System (ADS)

Chan, Herman C. H.; Gamel, Omar E.; Fleming, Graham R.; Whaley, K. Birgitta

2018-03-01

We provide a unified theoretical approach to the quantum dynamics of absorption of single photons and subsequent excitonic energy transfer in photosynthetic light-harvesting complexes. Our analysis combines a continuous mode < n > -photon quantum optical master equation for the chromophoric system with the hierarchy of equations of motion describing excitonic dynamics in presence of non-Markovian coupling to vibrations of the chromophores and surrounding protein. We apply the approach to simulation of absorption of single-photon coherent states by pigment-protein complexes containing between one and seven chromophores, and compare with results obtained by excitation using a thermal radiation field. We show that the values of excitation probability obtained under single-photon absorption conditions can be consistently related to bulk absorption cross-sections. Analysis of the timescale and efficiency of single-photon absorption by light-harvesting systems within this full quantum description of pigment-protein dynamics coupled to a quantum radiation field reveals a non-trivial dependence of the excitation probability and the excited state dynamics induced by exciton-phonon coupling during and subsequent to the pulse, on the bandwidth of the incident photon pulse. For bandwidths equal to the spectral bandwidth of Chlorophyll a, our results yield an estimation of an average time of ˜0.09 s for a single chlorophyll chromophore to absorb the energy equivalent of one (single-polarization) photon under irradiation by single-photon states at the intensity of sunlight.

Quantum Computers

DTIC Science & Technology

2010-03-04

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

Adaptations for vision in dim light: impulse responses and bumps in nocturnal spider photoreceptor cells (Cupiennius salei Keys).

PubMed

Pirhofer-Walzl, Karin; Warrant, Eric; Barth, Friedrich G

2007-10-01

The photoreceptor cells of the nocturnal spider Cupiennius salei were investigated by intracellular electrophysiology. (1) The responses of photoreceptor cells of posterior median (PM) and anterior median (AM) eyes to short (2 ms) light pulses showed long integration times in the dark-adapted and shorter integration times in the light-adapted state. (2) At very low light intensities, the photoreceptors responded to single photons with discrete potentials, called bumps, of high amplitude (2-20 mV). When measured in profoundly dark-adapted photoreceptor cells of the PM eyes these bumps showed an integration time of 128 +/- 35 ms (n = 7) whereas in dark-adapted photoreceptor cells of AM eyes the integration time was 84 +/- 13 ms (n = 8), indicating that the AM eyes are intrinsically faster than the PM eyes. (3) Long integration times, which improve visual reliability in dim light, and large responses to single photons in the dark-adapted state, contribute to a high visual sensitivity in Cupiennius at night. This conclusion is underlined by a calculation of sensitivity that accounts for both anatomical and physiological characteristics of the eye.

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

NASA Astrophysics Data System (ADS)

Ripamonti, Giancarlo; Lacaita, Andrea L.

1993-03-01

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

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

Retrieving transient conformational molecular structure information from inner-shell photoionization of laser-aligned molecules

DOE PAGES

Wang, Xu; Le, Anh -Thu; Yu, Chao; ...

2016-03-30

We discuss a scheme to retrieve transient conformational molecular structure information using photoelectron angular distributions (PADs) that have averaged over partial alignments of isolated molecules. The photoelectron is pulled out from a localized inner-shell molecular orbital by an X-ray photon. We show that a transient change in the atomic positions from their equilibrium will lead to a sensitive change in the alignment-averaged PADs, which can be measured and used to retrieve the former. Exploiting the experimental convenience of changing the photon polarization direction, we show that it is advantageous to use PADs obtained from multiple photon polarization directions. Lastly, amore » simple single-scattering model is proposed and benchmarked to describe the photoionization process and to do the retrieval using a multiple-parameter fitting method.« less

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.

Comparison of 16-Channel Laser Photoreceivers for Topographic Mapping

NASA Technical Reports Server (NTRS)

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

Ultrasensitive hot-electron nanobolometers for terahertz astrophysics.

PubMed

Wei, Jian; Olaya, David; Karasik, Boris S; Pereverzev, Sergey V; Sergeev, Andrei V; Gershenson, Michael E

2008-08-01

The submillimetre or terahertz region of the electromagnetic spectrum contains approximately half of the total luminosity of the Universe and 98% of all the photons emitted since the Big Bang. This radiation is strongly absorbed in the Earth's atmosphere, so space-based terahertz telescopes are crucial for exploring the evolution of the Universe. Thermal emission from the primary mirrors in these telescopes can be reduced below the level of the cosmic background by active cooling, which expands the range of faint objects that can be observed. However, it will also be necessary to develop bolometers-devices for measuring the energy of electromagnetic radiation-with sensitivities that are at least two orders of magnitude better than the present state of the art. To achieve this sensitivity without sacrificing operating speed, two conditions are required. First, the bolometer should be exceptionally well thermally isolated from the environment; second, its heat capacity should be sufficiently small. Here we demonstrate that these goals can be achieved by building a superconducting hot-electron nanobolometer. Its design eliminates the energy exchange between hot electrons and the leads by blocking electron outdiffusion and photon emission. The thermal conductance between hot electrons and the thermal bath, controlled by electron-phonon interactions, becomes very small at low temperatures ( approximately 1 x 10-16 W K-1 at 40 mK). These devices, with a heat capacity of approximately 1 x 10-19 J K-1, are sufficiently sensitive to detect single terahertz photons in submillimetre astronomy and other applications based on quantum calorimetry and photon counting.

Computer simulation of gene detection without PCR by single molecule detection

NASA Astrophysics Data System (ADS)

Davis, Lloyd M.; Williams, John G.; Lamb, Don T.

1999-01-01

Pioneer Hi-Bred is developing a low-cost method for rapid screening of DNA, for use in research on elite crop seed genetics. Unamplified genomic DNA with the requisite base sequence is simultaneously labeled by two different colored fluorescent probes, which hybridize near the selected gene. Dual-channel single molecule detection (SMD) within a flow cell, then provides a sensitive and specific assay for the gene. The technique has been demonstrated using frequency- doubled Nd:YAG laser excitation of two visible-wavelength dyes. A prototype instrument employing infrared fluorophores and laser diodes for excitation has been developed. Here, we report results from a Monte Carlo simulation of the new instrument, in which experimentally determined photophysical parameters for candidate infrared dyes are used for parametric studies of experimental operating conditions. Fluorophore photostability is found to be a key factor in determining the instrument sensitivity. Most infrared dyes have poor photostability, resulting in inefficient SMD. However, the normalized cross-correlation function of the photon signals from each of the two channels can still yield a discernable peak, provided that the concentration of dual- labeled molecules is sufficiently high. Further, for low concentrations, processing of the two photon streams with Gaussian -weighted sliding sum digital filters and selection of simultaneously occurring peaks can also provide a sensitive indicator of the presence of dual-labeled molecules, although accidental coincidences must be considered in the interpretation of results.

Quantum Logic with Cavity Photons From Single Atoms.

PubMed

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

2016-07-08

We demonstrate quantum logic using narrow linewidth photons 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 photonic chip to entangle these photons, and we observe nonclassical correlations between photon detection 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 photon sources and integrated quantum photonics.

Single-Photon Routing for a L-Shaped Channel

NASA Astrophysics Data System (ADS)

Yang, Xiong; Hou, Jiao-Jiao; Wu, Chun

2018-02-01

We have investigated the transport properties of a single photon scattered by a two-level atom embedded in a L-shaped waveguide, which is made of two one-dimensional (1D) semi-infinite coupled-resonator waveguides (CRWs). Single photons can be directed from one CRW to the other due to spontaneous emission of the atom. The result shows that the spontaneous emission of the TLS still routes single photon from one CRW to the other; the boundary existing makes the probability of finding single photon in a CRW could reach one. Our the scheme is helpful to construct a ring quantum networks.

Single photon at a configurable quantum-memory-based beam splitter

NASA Astrophysics Data System (ADS)

Guo, Xianxin; Mei, Yefeng; Du, Shengwang

2018-06-01

We report the demonstration of a configurable coherent quantum-memory-based beam splitter (BS) for a single-photon wave packet making use of laser-cooled 85Rb atoms and electromagnetically induced transparency. The single-photon wave packet is converted (stored) into a collective atomic spin state and later retrieved (split) into two nearly opposing directions. The storage time, beam-splitting ratio, and relative phase are configurable and can be dynamically controlled. We experimentally confirm that such a BS preserves the quantum particle nature of the single photon and the coherence between the two split wave packets of the single photon.

A Flight Photon Counting Camera for the WFIRST Coronagraph

NASA Astrophysics Data System (ADS)

Morrissey, Patrick

2018-01-01

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

Dementia of frontal lobe type.

PubMed Central

Neary, D; Snowden, J S; Northen, B; Goulding, P

1988-01-01

A significant proportion of patients with presenile dementia due to primary cerebral atrophy do not have Alzheimer's disease. One form of non-Alzheimer dementia may be designated as dementia of frontal lobe type (DFT), on the basis of a characteristic neuropsychological picture suggestive of frontal lobe disorder, confirmed by findings on single photon emission tomography. The case histories of seven patients exemplify the disorder: a presentation of social misconduct and personality change, unconcern and disinhibition, in the presence of physical well-being and few neurological signs. Assessment revealed economic and concrete speech with verbal stereotypes, variable memory impairment, and marked abnormalities on tasks sensitive to frontal lobe function. Visuo-spatial disorder was invariably absent. Comparisons of DFT and Alzheimer patients revealed qualitative differences in clinical presentation, neurological signs, profile of psychological disability, electroencephalography, single photon emission tomography and demography. DFT, which may represent forms of Pick's disease, may be more common than is often recognised. PMID:3258902

Tuning the nonlinear response of (6,5)-enriched single-wall carbon nanotubes dispersions

NASA Astrophysics Data System (ADS)

Aréstegui, O. S.; Silva, E. C. O.; Baggio, A. L.; Gontijo, R. N.; Hickmann, J. M.; Fantini, C.; Alencar, M. A. R. C.; Fonseca, E. J. S.

2017-04-01

Ultrafast nonlinear optical properties of (6,5)-enriched single-wall carbon nanotubes (SWCNTs) dispersions are investigated using the thermally managed Z-scan technique. As the (6,5) SWCNTs presented a strong resonance in the range of 895-1048 nm, the nonlinear refractive index (n2) and the absorption coefficients (β) measurements were performed tuning the laser exactly around absorption peak of the (6,5) SWCNTs. It is observed that the nonlinear response is very sensitive to the wavelength and the spectral behavior of n2 is strongly correlated to the tubes one-photon absorption band, presenting also a peak when the laser photon energy is near the tube resonance energy. This result suggests that a suitable selection of nanotubes types may provide optimized nonlinear optical responses in distinct regions of the electromagnetic spectrum. Analysis of the figures of merit indicated that this material is promising for ultrafast nonlinear optical applications under near infrared excitation.

Nanobridge SQUIDs as calorimetric inductive particle detectors

NASA Astrophysics Data System (ADS)

Gallop, John; Cox, David; Hao, Ling

2015-08-01

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

Human Visual System as a Double-Slit Single Photon Interference Sensor: A Comparison between Modellistic and Biophysical Tests

PubMed Central

Pizzi, Rita; Wang, Rui; Rossetti, Danilo

2016-01-01

This paper describes a computational approach to the theoretical problems involved in the Young's single-photon double-slit experiment, focusing on a simulation of this experiment in the absence of measuring devices. Specifically, the human visual system is used in place of a photomultiplier or similar apparatus. Beginning with the assumption that the human eye perceives light in the presence of very few photons, we measure human eye performance as a sensor in a double-slit one-photon-at-a-time experimental setup. To interpret the results, we implement a simulation algorithm and compare its results with those of human subjects under identical experimental conditions. In order to evaluate the perceptive parameters exactly, which vary depending on the light conditions and on the subject’s sensitivity, we first review the existing literature on the biophysics of the human eye in the presence of a dim light source, and then use the known values of the experimental variables to set the parameters of the computational simulation. The results of the simulation and their comparison with the experiment involving human subjects are reported and discussed. It is found that, while the computer simulation indicates that the human eye has the capacity to detect the corpuscular nature of photons under these conditions, this was not observed in practice. The possible reasons for the difference between theoretical prediction and experimental results are discussed. PMID:26816029

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

NASA Astrophysics Data System (ADS)

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

2013-09-01

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

Single-photon frequency conversion via cascaded quadratic nonlinear processes

NASA Astrophysics Data System (ADS)

Xiang, Tong; Sun, Qi-Chao; Li, Yuanhua; Zheng, Yuanlin; Chen, Xianfeng

2018-06-01

Frequency conversion of single photons is an important technology for quantum interface and quantum communication networks. Here, single-photon frequency conversion in the telecommunication band is experimentally demonstrated via cascaded quadratic nonlinear processes. Using cascaded quasi-phase-matched sum and difference frequency generation in a periodically poled lithium niobate waveguide, the signal photon of a photon pair from spontaneous down-conversion is precisely shifted to identically match its counterpart, i.e., the idler photon, in frequency to manifest a clear nonclassical dip in the Hong-Ou-Mandel interference. Moreover, quantum entanglement between the photon pair is maintained after the frequency conversion, as is proved in time-energy entanglement measurement. The scheme is used to switch single photons between dense wavelength-division multiplexing channels, which holds great promise in applications in realistic quantum networks.

Modification of emission photon statistics from single quantum dots using metal/SiO2 core/shell nanostructures.

PubMed

Naiki, Hiroyuki; Oikawa, Hidetoshi; Masuo, Sadahiro

2017-04-12

Emission photon statistics, i.e., single-photon and multi-photon emissions, of isolated QDs is required for tailoring optoelectronic applications. In this article, we demonstrate that the emission photon statistics can be modified by the control of the spectral overlap of the QDs with the localized surface plasmon resonance (LSPR) of the metal nanoparticle (metal NP) and by the distance between the QD and the metal NP. Moreover, the contribution to the modification of the emission photon statistics, which is the excitation and emission enhancements and the quenching generated by the spectral overlap and the distance, is elucidated. By fabricating well-defined SiO 2 -coated AgNPs and AuNPs (metal/SiO 2 ), the spectral overlap originated from the metal species of Ag and Au and the distance constituted by the thickness of the SiO 2 shell are controlled. The probability of single-photon emission of single QD was increased by the enhancement of the excitation rate via adjusting the distance using Ag/SiO 2 while the single-photon emission was converted to multi-photon emission by the effect of exciton quenching at a short distance and a small spectral overlap. By contrast, the probability of multi-photon emission was increased by enhancement of the multi-photon emission rate and the quenching via the spectral overlap using Au/SiO 2 . These results indicated the fundamental finding to control emission photon statistics in single QDs by controlling the spectral overlap and the distance, and understand the interaction of plasmonic nanostructures and single QD systems.

Entanglement and quantum superposition induced by a single photon

NASA Astrophysics Data System (ADS)

Lü, Xin-You; Zhu, Gui-Lei; Zheng, Li-Li; Wu, Ying

2018-03-01

We predict the occurrence of single-photon-induced entanglement and quantum superposition in a hybrid quantum model, introducing an optomechanical coupling into the Rabi model. Originally, it comes from the photon-dependent quantum property of the ground state featured by the proposed hybrid model. It is associated with a single-photon-induced quantum phase transition, and is immune to the A2 term of the spin-field interaction. Moreover, the obtained quantum superposition state is actually a squeezed cat state, which can significantly enhance precision in quantum metrology. This work offers an approach to manipulate entanglement and quantum superposition with a single photon, which might have potential applications in the engineering of new single-photon quantum devices, and also fundamentally broaden the regime of cavity QED.

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

PubMed Central

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

2012-01-01

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

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.

Single-Photon Nanoantennas

PubMed Central

2017-01-01

Single-photon nanoantennas are broadband strongly scattering nanostructures placed in the near field of a single quantum emitter, with the goal to enhance the coupling between the emitter and far-field radiation channels. Recently, great strides have been made in the use of nanoantennas to realize fluorescence brightness enhancements, and Purcell enhancements, of several orders of magnitude. This perspective reviews the key figures of merit by which single-photon nanoantenna performance is quantified and the recent advances in measuring these metrics unambiguously. Next, this perspective discusses what the state of the art is in terms of fluoresent brightness enhancements, Purcell factors, and directivity control on the level of single photons. Finally, I discuss future challenges for single-photon nanoantennas. PMID:29354664

Design of highly sensitive multichannel bimetallic photonic crystal fiber biosensor

NASA Astrophysics Data System (ADS)

Hameed, Mohamed Farhat O.; Alrayk, Yassmin K. A.; Shaalan, Abdelhamid A.; El Deeb, Walid S.; Obayya, Salah S. A.

2016-10-01

A design of a highly sensitive multichannel biosensor based on photonic crystal fiber is proposed and analyzed. The suggested design has a silver layer as a plasmonic material coated by a gold layer to protect silver oxidation. The reported sensor is based on detection using the quasi transverse electric (TE) and quasi transverse magnetic (TM) modes, which offers the possibility of multichannel/multianalyte sensing. The numerical results are obtained using a finite element method with perfect matched layer boundary conditions. The sensor geometrical parameters are optimized to achieve high sensitivity for the two polarized modes. High-refractive index sensitivity of about 4750 nm/RIU (refractive index unit) and 4300 nm/RIU with corresponding resolutions of 2.1×10-5 RIU, and 2.33×10-5 RIU can be obtained according to the quasi TM and quasi TE modes of the proposed sensor, respectively. Further, the reported design can be used as a self-calibration biosensor within an unknown analyte refractive index ranging from 1.33 to 1.35 with high linearity and high accuracy. Moreover, the suggested biosensor has advantages in terms of compactness and better integration of microfluidics setup, waveguide, and metallic layers into a single structure.

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.

Single Photon Counting Performance and Noise Analysis of CMOS SPAD-Based Image Sensors.

PubMed

Dutton, Neale A W; Gyongy, Istvan; Parmesan, Luca; Henderson, Robert K

2016-07-20

SPAD-based solid state CMOS image sensors utilising analogue integrators have attained deep sub-electron read noise (DSERN) permitting single photon counting (SPC) imaging. A new method is proposed to determine the read noise in DSERN image sensors by evaluating the peak separation and width (PSW) of single photon peaks in a photon counting histogram (PCH). The technique is used to identify and analyse cumulative noise in analogue integrating SPC SPAD-based pixels. The DSERN of our SPAD image sensor is exploited to confirm recent multi-photon threshold quanta image sensor (QIS) theory. Finally, various single and multiple photon spatio-temporal oversampling techniques are reviewed.

Cryogenic photodetectors

NASA Astrophysics Data System (ADS)

Chardin, G.

2000-03-01

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

Optofluidics for handling and analysis of single living cells

NASA Astrophysics Data System (ADS)

Perozziello, Gerardo; Candeloro, Patrizio; Coluccio, Maria Laura; Di Fabrizio, Enzo

2017-11-01

Optofluidics is a field with important applications in areas such as biotechnology, chemical synthesis and analytical chemistry. Optofluidic devices combine optical elements into microfluidic devices in ways that increase portability and sensitivity of analysis for diagnostic or screening purposes .In fact in these devices fluids give fine adaptability, mobility and accessibility to nanoscale photonic devices which otherwise could not be realized using conventional devices. This review describes several cases inwhich optical or microfluidic approaches are used to trap single cells in proximity of integrated optical sensor for being analysed.

Analysis of deterministic swapping of photonic and atomic states through single-photon Raman interaction

NASA Astrophysics Data System (ADS)

Rosenblum, Serge; Borne, Adrien; Dayan, Barak

2017-03-01

The long-standing goal of deterministic quantum interactions between single photons and single atoms was recently realized in various experiments. Among these, an appealing demonstration relied on single-photon Raman interaction (SPRINT) in a three-level atom coupled to a single-mode waveguide. In essence, the interference-based process of SPRINT deterministically swaps the qubits encoded in a single photon and a single atom, without the need for additional control pulses. It can also be harnessed to construct passive entangling quantum gates, and can therefore form the basis for scalable quantum networks in which communication between the nodes is carried out only by single-photon pulses. Here we present an analytical and numerical study of SPRINT, characterizing its limitations and defining parameters for its optimal operation. Specifically, we study the effect of losses, imperfect polarization, and the presence of multiple excited states. In all cases we discuss strategies for restoring the operation of SPRINT.

Fused Silica Ion Trap Chip with Efficient Optical Collection System for Timekeeping, Sensing, and Emulation

DTIC Science & Technology

2015-01-22

applications in fast single photon sources, quantum repeater circuitry, and high fidelity remote entanglement of atoms for quantum information protocols. We...fluorescence for motion/force sensors through Doppler velocimetry; and for the efficient collection of single photons from trapped ions for...Doppler velocimetry; and for the efficient collection of single photons from trapped ions for applications in fast single photon sources, quantum

Single photon quantum cryptography.

PubMed

Beveratos, Alexios; Brouri, Rosa; Gacoin, Thierry; Villing, André; Poizat, Jean-Philippe; Grangier, Philippe

2002-10-28

We report the full implementation of a quantum cryptography protocol using a stream of single photon pulses generated by a stable and efficient source operating at room temperature. The single photon pulses are emitted on demand by a single nitrogen-vacancy color center in a diamond nanocrystal. The quantum bit error rate is less that 4.6% and the secure bit rate is 7700 bits/s. The overall performances of our system reaches a domain where single photons have a measurable advantage over an equivalent system based on attenuated light pulses.

Quantum Probability Cancellation Due to a Single-Photon State

NASA Technical Reports Server (NTRS)

Ou, Z. Y.

1996-01-01

When an N-photon state enters a lossless symmetric beamsplitter from one input port, the photon 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 photon state at the other input port can dramatically change the photon 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-photon state is replaced by an arbitrary state of light. A special case is the coherent state which corresponds to homodyne detection of a single photon state and can lead to the measurement of the wave function of a single photon state.

Electro-optic routing of photons from a single quantum dot in photonic integrated circuits

NASA Astrophysics Data System (ADS)

Midolo, Leonardo; Hansen, Sofie L.; Zhang, Weili; Papon, Camille; Schott, Rüdiger; Ludwig, Arne; Wieck, Andreas D.; Lodahl, Peter; Stobbe, Søren

2017-12-01

Recent breakthroughs in solid-state photonic quantum technologies enable generating and detecting single photons with near-unity efficiency as required for a range of photonic quantum technologies. The lack of methods to simultaneously generate and control photons 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 photonics. Here we propose and demonstrate an integrated voltage-controlled phase shifter based on the electro-optic effect in suspended photonic 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. Photons 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-photon-source de-multiplexing, fiber-loop boson sampling, and linear optical quantum computing.

Two-photon interference at telecom wavelengths for time-bin-encoded single photons from quantum-dot spin qubits

NASA Astrophysics Data System (ADS)

Yu, Leo; Natarajan, Chandra M.; Horikiri, Tomoyuki; Langrock, Carsten; Pelc, Jason S.; Tanner, Michael G.; Abe, Eisuke; Maier, Sebastian; Schneider, Christian; Höfling, Sven; Kamp, Martin; Hadfield, Robert H.; Fejer, Martin M.; Yamamoto, Yoshihisa

2015-11-01

Practical quantum communication between remote quantum memories rely on single photons at telecom wavelengths. Although spin-photon entanglement has been demonstrated in atomic and solid-state qubit systems, the produced single photons at short wavelengths and with polarization encoding are not suitable for long-distance communication, because they suffer from high propagation loss and depolarization in optical fibres. Establishing entanglement between remote quantum nodes would further require the photons generated from separate nodes to be indistinguishable. Here, we report the observation of correlations between a quantum-dot spin and a telecom single photon across a 2-km fibre channel based on time-bin encoding and background-free frequency downconversion. The downconverted photon at telecom wavelengths exhibits two-photon interference with another photon from an independent source, achieving a mean wavepacket overlap of greater than 0.89 despite their original wavelength mismatch (900 and 911 nm). The quantum-networking operations that we demonstrate will enable practical communication between solid-state spin qubits across long distances.

Heralded wave packet manipulation and storage of a frequency-converted pair photon at telecom wavelength

NASA Astrophysics Data System (ADS)

Kroh, Tim; Ahlrichs, Andreas; Sprenger, Benjamin; Benson, Oliver

2017-09-01

Future quantum networks require a hybrid platform of dissimilar quantum systems. Within the platform, joint quantum states have to be mediated either by single photons, photon pairs or entangled photon pairs. The photon wavelength has to lie within the telecommunication band to enable long-distance fibre transmission. In addition, the temporal shape of the photons needs to be tailored to efficiently match the involved quantum systems. Altogether, this requires the efficient coherent wavelength-conversion of arbitrarily shaped single-photon wave packets. Here, we demonstrate the heralded temporal filtering of single photons as well as the synchronisation of state manipulation and detection as key elements in a typical experiment, besides of delaying a photon in a long fibre. All three are realised by utilising commercial telecommunication fibre-optical components which will permit the transition of quantum networks from the lab to real-world applications. The combination of these renders a temporally filtering single-photon storage in a fast switchable fibre loop possible.

Two-photon interference at telecom wavelengths for time-bin-encoded single photons from quantum-dot spin qubits.

PubMed

Yu, Leo; Natarajan, Chandra M; Horikiri, Tomoyuki; Langrock, Carsten; Pelc, Jason S; Tanner, Michael G; Abe, Eisuke; Maier, Sebastian; Schneider, Christian; Höfling, Sven; Kamp, Martin; Hadfield, Robert H; Fejer, Martin M; Yamamoto, Yoshihisa

2015-11-24

Practical quantum communication between remote quantum memories rely on single photons at telecom wavelengths. Although spin-photon entanglement has been demonstrated in atomic and solid-state qubit systems, the produced single photons at short wavelengths and with polarization encoding are not suitable for long-distance communication, because they suffer from high propagation loss and depolarization in optical fibres. Establishing entanglement between remote quantum nodes would further require the photons generated from separate nodes to be indistinguishable. Here, we report the observation of correlations between a quantum-dot spin and a telecom single photon across a 2-km fibre channel based on time-bin encoding and background-free frequency downconversion. The downconverted photon at telecom wavelengths exhibits two-photon interference with another photon from an independent source, achieving a mean wavepacket overlap of greater than 0.89 despite their original wavelength mismatch (900 and 911 nm). The quantum-networking operations that we demonstrate will enable practical communication between solid-state spin qubits across long distances.

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

Quantum noise reduction in intensity-sensitive surface-plasmon-resonance sensors

NASA Astrophysics Data System (ADS)

Lee, Joong-Sung; Huynh, Trung; Lee, Su-Yong; Lee, Kwang-Geol; Lee, Jinhyoung; Tame, Mark; Rockstuhl, Carsten; Lee, Changhyoup

2017-09-01

We investigate the use of twin-mode quantum states of light with symmetric statistical features in their photon number for improving intensity-sensitive surface plasmon resonance (SPR) sensors. For this purpose, one of the modes is sent into a prism setup where the Kretschmann configuration is employed as a sensing platform and the analyte to be measured influences the SPR excitation conditions. This influence modifies the output state of light that is subsequently analyzed by an intensity-difference measurement scheme. We show that quantum noise reduction is achieved not only as a result of the sub-Poissonian statistical nature of a single mode, but also as a result of the nonclassical correlation of the photon number between the two modes. When combined with the high sensitivity of the SPR sensor, we show that the use of twin-mode quantum states of light notably enhances the estimation precision of the refractive index of an analyte. With this we are able to identify a clear strategy to further boost the performance of SPR sensors, which are already a mature technology in biochemical and medical sensing applications.

Loading a single photon into an optical cavity

NASA Astrophysics Data System (ADS)

Du, Shengwang; Liu, Chang; Sun, Yuan; Zhao, Luwei; Zhang, Shanchao; Loy, M. M. T.

2015-05-01

Confining and manipulating single photons inside a reflective optical cavity is an essential task of cavity quantum electrodynamics (CQED) for probing the quantum nature of light quanta. Such systems are also elementary building blocks for many protocols of quantum network, where remote cavity quantum nodes are coupled through flying photons. The connectivity and scalability of such a quantum network strongly depends on the efficiency of loading a single photon into cavity. In this work we demonstrate that a single photon with an optimal temporal waveform can be efficiently loaded into a cavity. Using heralded narrow-band single photons with exponential growth wave packet whose time constant matches the photon lifetime in the cavity, we demonstrate a loading efficiency of more than 87 percent from free space to a single-sided Fabry-Perot cavity. Our result and approach may enable promising applications in realizing large-scale CQED-based quantum networks. The work was supported by the Hong Kong RGC (Project No. 601411).

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.

On-demand semiconductor single-photon source with near-unity indistinguishability.

PubMed

He, Yu-Ming; He, Yu; Wei, Yu-Jia; Wu, Dian; Atatüre, Mete; Schneider, Christian; Höfling, Sven; Kamp, Martin; Lu, Chao-Yang; Pan, Jian-Wei

2013-03-01

Single-photon sources based on semiconductor quantum dots offer distinct advantages for quantum information, including a scalable solid-state platform, ultrabrightness and interconnectivity with matter qubits. A key prerequisite for their use in optical quantum computing and solid-state networks is a high level of efficiency and indistinguishability. Pulsed resonance fluorescence has been anticipated as the optimum condition for the deterministic generation of high-quality photons with vanishing effects of dephasing. Here, we generate pulsed single photons on demand from a single, microcavity-embedded quantum dot under s-shell excitation with 3 ps laser pulses. The π pulse-excited resonance-fluorescence photons have less than 0.3% background contribution and a vanishing two-photon emission probability. Non-postselective Hong-Ou-Mandel interference between two successively emitted photons is observed with a visibility of 0.97(2), comparable to trapped atoms and ions. Two single photons are further used to implement a high-fidelity quantum controlled-NOT gate.

An integrated single- and two-photon non-diffracting light-sheet microscope

NASA Astrophysics Data System (ADS)

Lau, Sze Cheung; Chiu, Hoi Chun; Zhao, Luwei; Zhao, Teng; Loy, M. M. T.; Du, Shengwang

2018-04-01

We describe a fluorescence optical microscope with both single-photon and two-photon non-diffracting light-sheet excitations for large volume imaging. With a special design to accommodate two different wavelength ranges (visible: 400-700 nm and near infrared: 800-1200 nm), we combine the line-Bessel sheet (LBS, for single-photon excitation) and the scanning Bessel beam (SBB, for two-photon excitation) light sheet together in a single microscope setup. For a transparent thin sample where the scattering can be ignored, the LBS single-photon excitation is the optimal imaging solution. When the light scattering becomes significant for a deep-cell or deep-tissue imaging, we use SBB light-sheet two-photon excitation with a longer wavelength. We achieved nearly identical lateral/axial resolution of about 350/270 nm for both imagings. This integrated light-sheet microscope may have a wide application for live-cell and live-tissue three-dimensional high-speed imaging.

Sensitizers in EUV chemically amplified resist: mechanism of sensitivity improvement

NASA Astrophysics Data System (ADS)

Vesters, Yannick; Jiang, Jing; Yamamoto, Hiroki; De Simone, Danilo; Kozawa, Takahiro; De Gendt, Stefan; Vandenberghe, Geert

2018-03-01

EUV lithography utilizes photons with 91.6 eV energy to ionize resists, generate secondary electrons, and enable electron driven reactions that produce acid in chemically amplified photoresist. Efficiently using the available photons is of key importance. Unlike DUV lithography, where photons are selectively utilized by photoactive compounds, photons at 13.5nm wavelength ionize almost all materials. Nevertheless, specific elements have a significantly higher atomic photon-absorption cross section at 91.6 eV. To increase photon absorption, sensitizer molecules, containing highly absorbing elements, can be added to photoresist formulations. These sensitizers have gained growing attention in recent years, showing significant sensitivity improvement. But there are few experimental evidences that the sensitivity improvement is due to the higher absorption only, as adding metals salts into the resist formulation can induce other mechanisms, like modification of the dissolution rate, potentially affecting patterning performance. In this work, we used different sensitizers in chemically amplified resist. We measured experimentally the absorption of EUV light, the acid yield, the dissolution rate and the patterning performance of the resists. Surprisingly, the absorption of EUV resist was decreased with addition of metal salt sensitizers. Nevertheless, the resist with sensitizer showed a higher acid yield. Sensitizer helps achieving higher PAG conversion to acid, notably due to an increase of the secondary electron generation. Patterning data confirm a significant sensitivity improvement, but at the cost of roughness degradation at high sensitizer loading. This can be explained by the chemical distribution of the sensitizer in the resist combined with a modification of the dissolution contrast, as observed by Dissolution Rate Monitor.

Apertureless near-field/far-field CW two-photon microscope for biological and material imaging and spectroscopic applications.

PubMed

Nowak, Derek B; Lawrence, A J; Sánchez, Erik J

2010-12-10

We present the development of a versatile spectroscopic imaging tool to allow for imaging with single-molecule sensitivity and high spatial resolution. The microscope allows for near-field and subdiffraction-limited far-field imaging by integrating a shear-force microscope on top of a custom inverted microscope design. The instrument has the ability to image in ambient conditions with optical resolutions on the order of tens of nanometers in the near field. A single low-cost computer controls the microscope with a field programmable gate array data acquisition card. High spatial resolution imaging is achieved with an inexpensive CW multiphoton excitation source, using an apertureless probe and simplified optical pathways. The high-resolution, combined with high collection efficiency and single-molecule sensitive optical capabilities of the microscope, are demonstrated with a low-cost CW laser source as well as a mode-locked laser source.

Quantum optics with nanowires (Conference Presentation)

NASA Astrophysics Data System (ADS)

Zwiller, Val

2017-02-01

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

Real-time myocardial perfusion imaging for pharmacologic stress testing: added value to single photon emission computed tomography.

PubMed

Korosoglou, Grigorios; Dubart, Alain-Eric; DaSilva, K Gaspar C; Labadze, Nino; Hardt, Stefan; Hansen, Alexander; Bekeredjian, Raffi; Zugck, Christian; Zehelein, Joerg; Katus, Hugo A; Kuecherer, Helmut

2006-01-01

Little is known about the incremental value of real-time myocardial contrast echocardiography (MCE) as an adjunct to pharmacologic stress testing. This study was performed to evaluate the diagnostic value of MCE to detect abnormal myocardial perfusion by technetium Tc 99m sestamibi-single photon emission computed tomography (SPECT) and anatomically significant coronary artery disease (CAD) by angiography. Myocardial contrast echocardiography was performed at rest and during vasodilator stress in consecutive patients (N = 120) undergoing SPECT imaging for known or suspected CAD. Myocardial opacification, wall motion, and tracer uptake were visually analyzed in 12 myocardial segments by 2 pairs of blinded observers. Concordance between the 2 methods was assessed using the kappa statistic. Of 1356 segments, 1025 (76%) were interpretable by MCE, wall motion, and SPECT. Sensitivity of wall motion was 75%, specificity 83%, and accuracy 81% for detecting abnormal myocardial perfusion by SPECT (kappa = 0.53). Myocardial contrast echocardiography and wall motion together yielded significantly higher sensitivity (85% vs 74%, P < .05), specificity of 83%, and accuracy of 85% (kappa = 0.64) for the detection of abnormal myocardial perfusion. In 89 patients who underwent coronary angiography, MCE and wall motion together yielded higher sensitivity (83% vs 64%, P < .05) and accuracy (77% vs 68%, P < .05) but similar specificity (72%) compared with SPECT for the detection of high-grade, stenotic (> or = 75%) coronary lesions. Assessment of myocardial perfusion adds value to conventional stress echocardiography by increasing its sensitivity for the detection of functionally abnormal myocardial perfusion. Myocardial contrast echocardiography and wall motion together provide higher sensitivity and accuracy for detection of CAD compared with SPECT.

Widefield High Frame Rate Single-Photon SPAD Imagers for SPIM-FCS.

PubMed

Buchholz, Jan; Krieger, Jan; Bruschini, Claudio; Burri, Samuel; Ardelean, Andrei; Charbon, Edoardo; Langowski, Jörg

2018-05-22

Photon-counting sensors based on standard complementary metal-oxide-semiconductor single-photon avalanche diodes (SPADs) represent an emerging class of imagers that enable the counting and/or timing of single photons at zero readout noise (better than high-speed electron-multiplying charge-coupling devices) and over large arrays. They have seen substantial progress over the last 15 years, increasing their spatial resolution, timing accuracy, and sensitivity while reducing spurious signals such as afterpulsing and dark counts. They are increasingly being applied for time-resolved applications with the added advantage of enabling real-time options such as autocorrelation. We report in this study on the use of such a state-of-the-art 512 × 128 SPAD array, capable of a time resolution of 10 -5 -10 -6 s for full frames while retaining acceptable photosensitivity thanks to the use of dedicated microlenses, in a selective plane illumination-fluorescence correlation spectroscopy setup. The latter allows us to perform thousands of fluorescence-correlation spectroscopy measurements simultaneously in a two-dimensional slice of the sample. This high-speed SPAD imager enables the measurement of molecular motion of small fluorescent particles such as single chemical dye molecules. Inhomogeneities in the molecular detection efficiency were compensated for by means of a global fit of the auto- and cross-correlation curves, which also made a calibration-free measurement of various samples possible. The afterpulsing effect could also be mitigated, making the measurement of the diffusion of Alexa-488 possible, and the overall result quality was further improved by spatial binning. The particle concentrations in the focus tend to be overestimated by a factor of 1.7 compared to a confocal setup; a calibration is thus required if absolute concentrations need to be measured. The first high-speed selective plane illumination-fluorescence correlation spectroscopy in vivo measurements to our knowledge were also recorded: although two-component fit models could not be employed because of noise, the diffusion of eGFP oligomers in HeLa cells could be measured. Sensitivity and noise will be further improved in the next generation of SPAD-based widefield sensors, which are currently under testing. Copyright © 2018 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Efficient fiber-coupled single-photon source based on quantum dots in a photonic-crystal waveguide

PubMed Central

DAVEAU, RAPHAËL S.; BALRAM, KRISHNA C.; PREGNOLATO, TOMMASO; LIU, JIN; LEE, EUN H.; SONG, JIN D.; VERMA, VARUN; MIRIN, RICHARD; NAM, SAE WOO; MIDOLO, LEONARDO; STOBBE, SØREN; SRINIVASAN, KARTIK; LODAHL, PETER

2017-01-01

Many photonic quantum information processing applications would benefit from a high brightness, fiber-coupled source of triggered single photons. Here, we present a fiber-coupled photonic-crystal waveguide single-photon source relying on evanescent coupling of the light field from a tapered out-coupler to an optical fiber. A two-step approach is taken where the performance of the tapered out-coupler is recorded first on an independent device containing an on-chip reflector. Reflection measurements establish that the chip-to-fiber coupling efficiency exceeds 80 %. The detailed characterization of a high-efficiency photonic-crystal waveguide extended with a tapered out-coupling section is then performed. The corresponding overall single-photon source efficiency is 10.9 % ± 2.3 %, which quantifies the success probability to prepare an exciton in the quantum dot, couple it out as a photon in the waveguide, and subsequently transfer it to the fiber. The applied out-coupling method is robust, stable over time, and broadband over several tens of nanometers, which makes it a highly promising pathway to increase the efficiency and reliability of planar chip-based single-photon sources. PMID:28584859

Optimizing single-nanoparticle two-photon microscopy by in situ adaptive control of femtosecond pulses

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

Li, Donghai; Deng, Yongkai; Chu, Saisai

2016-07-11

Single-nanoparticle two-photon microscopy shows great application potential in super-resolution cell imaging. Here, we report in situ adaptive optimization of single-nanoparticle two-photon luminescence signals by phase and polarization modulations of broadband laser pulses. For polarization-independent quantum dots, phase-only optimization was carried out to compensate the phase dispersion at the focus of the objective. Enhancement of the two-photon excitation fluorescence intensity under dispersion-compensated femtosecond pulses was achieved. For polarization-dependent single gold nanorod, in situ polarization optimization resulted in further enhancement of two-photon photoluminescence intensity than phase-only optimization. The application of in situ adaptive control of femtosecond pulse provides a way for object-orientedmore » optimization of single-nanoparticle two-photon microscopy for its future applications.« less

Wiring up pre-characterized single-photon emitters by laser lithography

NASA Astrophysics Data System (ADS)

Shi, Q.; Sontheimer, B.; Nikolay, N.; Schell, A. W.; Fischer, J.; Naber, A.; Benson, O.; Wegener, M.

2016-08-01

Future quantum optical chips will likely be hybrid in nature and include many single-photon emitters, waveguides, filters, as well as single-photon detectors. Here, we introduce a scalable optical localization-selection-lithography procedure for wiring up a large number of single-photon emitters via polymeric photonic wire bonds in three dimensions. First, we localize and characterize nitrogen vacancies in nanodiamonds inside a solid photoresist exhibiting low background fluorescence. Next, without intermediate steps and using the same optical instrument, we perform aligned three-dimensional laser lithography. As a proof of concept, we design, fabricate, and characterize three-dimensional functional waveguide elements on an optical chip. Each element consists of one single-photon emitter centered in a crossed-arc waveguide configuration, allowing for integrated optical excitation and efficient background suppression at the same time.

Teleporting photonic qudits using multimode quantum scissors.

PubMed

Goyal, Sandeep K; Konrad, Thomas

2013-12-19

Teleportation plays an important role in the communication of quantum information between the nodes of a quantum network and is viewed as an essential ingredient for long-distance Quantum Cryptography. We describe a method to teleport the quantum information carried by a photon in a superposition of a number d of light modes (a "qudit") by the help of d additional photons based on transcription. A qudit encoded into a single excitation of d light modes (in our case Laguerre-Gauss modes which carry orbital angular momentum) is transcribed to d single-rail photonic qubits, which are spatially separated. Each single-rail qubit consists of a superposition of vacuum and a single photon in each one of the modes. After successful teleportation of each of the d single-rail qubits by means of "quantum scissors" they are converted back into a qudit carried by a single photon which completes the teleportation scheme.

Teleporting photonic qudits using multimode quantum scissors

NASA Astrophysics Data System (ADS)

Goyal, Sandeep K.; Konrad, Thomas

2013-12-01

Teleportation plays an important role in the communication of quantum information between the nodes of a quantum network and is viewed as an essential ingredient for long-distance Quantum Cryptography. We describe a method to teleport the quantum information carried by a photon in a superposition of a number d of light modes (a ``qudit'') by the help of d additional photons based on transcription. A qudit encoded into a single excitation of d light modes (in our case Laguerre-Gauss modes which carry orbital angular momentum) is transcribed to d single-rail photonic qubits, which are spatially separated. Each single-rail qubit consists of a superposition of vacuum and a single photon in each one of the modes. After successful teleportation of each of the d single-rail qubits by means of ``quantum scissors'' they are converted back into a qudit carried by a single photon which completes the teleportation scheme.

Coherent control of the single-photon multichannel scattering in the dissipation case

NASA Astrophysics Data System (ADS)

Shi, Yun-Xia; Wang, Hang-Yu; Ma, Jin-Lou; Li, Qing; Tan, Lei

2018-03-01

Based on the quasi-boson approach, a model of a Λ-type three-level atom coupled to a X-shaped coupled cavity arrays (CCAs) is used to study the transport properties of a single-photon in the dissipative case, and a classical field is introduced to motivate the one transition of the Λ-type three-level atom (ΛTLA). The analytical expressions of transmission and transfer rate are obtained. Our results show that the cavity dissipation will obviously weaken the single-photon transfer rate where the incident energy of the single photon is resonant with the excited energy of the atom. Whether the cavity dissipation exists or not, the single photon can be almost confined in the incident channel at large detuning, and we can regulate the intensity of the classical field to control the total transmission of the single-photon.

Single Photon Counting Performance and Noise Analysis of CMOS SPAD-Based Image Sensors

PubMed Central

Dutton, Neale A. W.; Gyongy, Istvan; Parmesan, Luca; Henderson, Robert K.

2016-01-01

SPAD-based solid state CMOS image sensors utilising analogue integrators have attained deep sub-electron read noise (DSERN) permitting single photon counting (SPC) imaging. A new method is proposed to determine the read noise in DSERN image sensors by evaluating the peak separation and width (PSW) of single photon peaks in a photon counting histogram (PCH). The technique is used to identify and analyse cumulative noise in analogue integrating SPC SPAD-based pixels. The DSERN of our SPAD image sensor is exploited to confirm recent multi-photon threshold quanta image sensor (QIS) theory. Finally, various single and multiple photon spatio-temporal oversampling techniques are reviewed. PMID:27447643

Single photon generation through exciton-exciton annihilation in air-suspended carbon nanotubes

NASA Astrophysics Data System (ADS)

Ishii, Akihiro; Uda, Takushi; Kato, Yuichiro K.

Carbon nanotubes have great potential for single photon sources as they have stable exciton states even at room temperature and their emission wavelengths cover the telecommunication bands. In recent years, single photon emission from carbon nanotubes has been achieved by creating localized states of excitons. In contrast to such an approach, here we utilize mobile excitons and show that single photons can be generated in air-suspended carbon nanotubes, where exciton diffusion length is as long as several hundred nanometers and exciton-exciton annihilation is efficient. We perform photoluminescence microscopy on as-grown air-suspended carbon nanotubes in order to determine their chirality and suspended length. Photon correlation measurements are performed on nanotube emission at room temperature using a Hanbury-Brown-Twiss setup with InGaAs/InP single photon detectors. We observe antibunching with a clear excitation power dependence, where we obtain g (2) (0) value less than 0.5 at low excitation powers, indicating single photon generation. We show such g (2) (0) data with different chiralities and suspended lengths, and the effects of exciton diffusion on single photon generation processes are discussed. Work supported by KAKENHI (26610080, 16H05962), The Canon Foundation, and MEXT (Photon Frontier Network Program, Nanotechnology Platform). A.I. is supported by MERIT and JSPS Research Fellowship, and T.U. is supported by ALPS.

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.

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

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

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

2016-10-06

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

Up-conversion multiwave (White) luminescence in the visible spectral range under excitation by IR laser diodes in the active BaY2F8:Yb3+,Pr3+ medium

NASA Astrophysics Data System (ADS)

Pushkar', A. A.; Uvarova, T. V.; Kiiko, V. V.

2011-08-01

The possibilities of occupying high-lying 4 f states of Pr3+ ions in the active BaY2F8:Yb3+,Pr3+ medium according to the photon avalanche and step-by-step sensitization mechanisms are compared. It is shown that the photon avalanche is unlikely to occur in the BaY2F8:Yb3+,Pr3+ crystal. The multiband luminescence spectra in the visible spectral range (white emission) under single- and multiwave pumping of BaY2F8:Yb3+,Pr3+ crystal by IR laser diodes are reported.

High-energy x-ray diffraction from surfaces and nanoparticles

NASA Astrophysics Data System (ADS)

Hejral, U.; Müller, P.; Shipilin, M.; Gustafson, J.; Franz, D.; Shayduk, R.; Rütt, U.; Zhang, C.; Merte, L. R.; Lundgren, E.; Vonk, V.; Stierle, A.

2017-11-01

High-energy surface-sensitive x-ray diffraction (HESXRD) is a powerful high-energy photon technique (E > 70 keV) that has in recent years proven to allow a fast data acquisition for the 3D structure determination of surfaces and nanoparticles under in situ and operando conditions. The use of a large-area detector facilitates the direct collection of nearly distortion-free diffraction patterns over a wide q range, including crystal truncation rods perpendicular to the surface and large-area reciprocal space maps from epitaxial nanoparticles, which is not possible in the conventional low-photon energy approach (E =10 -20 keV ). Here, we present a comprehensive mathematical approach, explaining the working principle of HESXRD for both single-crystal surfaces and epitaxial nanostructures on single-crystal supports. The angular calculations used in conventional crystal truncation rod measurements at low-photon energies are adopted for the high-photon-energy regime, illustrating why and to which extent large reciprocal-space areas can be probed in stationary geometry with fixed sample rotation. We discuss how imperfections such as mosaicity and finite domain size aid in sampling a substantial part of reciprocal space without the need of rotating the sample. An exact account is given of the area probed in reciprocal space using such a stationary mode, which is essential for in situ or operando time-resolved experiments on surfaces and nanostructures.

A new membrane inlet interface of a vacuum ultraviolet lamp ionization miniature mass spectrometer for on-line rapid measurement of volatile organic compounds in air.

PubMed

Hou, Keyong; Wang, Junde; Li, Haiyang

2007-01-01

A novel membrane inlet interface coupled to a single-photon ionization (SPI) miniature time-of-flight mass spectrometer has been developed for on-line rapid measurement of volatile organic compounds (VOCs). The vacuum ultraviolet (VUV) light source for SPI was a commercial krypton discharge lamp with photon energy of 10.6 eV and photon flux of 10(10) photons/s. The experimental results showed that the sensitivity was 5 times as high as obtained with the traditional membrane inlet. The enrichment efficiency could be adjusted in the range of 10 to 20 times for different VOCs when a buffer cell was added to the inlet interface, and the memory effect was effectively eliminated. A detection limit as low as 25 parts-per-billion by volume (ppbv) for benzene has been achieved, with a linear dynamic range of three orders of magnitude. The rise times were 6 s, 10 s and 15 s for benzene, toluene and p-xylene, respectively, and the fall time was only 6 s for all of these compounds. The analytical capacity of this system was demonstrated by the on-line analysis of VOCs in single puff mainstream cigarette smoke, in which more than 50 compounds were detected in 2 s. Copyright 2007 John Wiley & Sons, Ltd.

The design of rapid turbidity measurement system based on single photon detection techniques

NASA Astrophysics Data System (ADS)

Yang, Yixin; Wang, Huanqin; Cao, Yangyang; Gui, Huaqiao; Liu, Jianguo; Lu, Liang; Cao, Huibin; Yu, Tongzhu; You, Hui

2015-10-01

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 photons by adopting the single photon detection 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.

Open-Ended Recursive Approach for the Calculation of Multiphoton Absorption Matrix Elements

PubMed Central

2015-01-01

We present an implementation of single residues for response functions to arbitrary order using a recursive approach. Explicit expressions in terms of density-matrix-based response theory for the single residues of the linear, quadratic, cubic, and quartic response functions are also presented. These residues correspond to one-, two-, three- and four-photon transition matrix elements. The newly developed code is used to calculate the one-, two-, three- and four-photon absorption cross sections of para-nitroaniline and para-nitroaminostilbene, making this the first treatment of four-photon absorption in the framework of response theory. We find that the calculated multiphoton absorption cross sections are not very sensitive to the size of the basis set as long as a reasonably large basis set with diffuse functions is used. The choice of exchange–correlation functional, however, significantly affects the calculated cross sections of both charge-transfer transitions and other transitions, in particular, for the larger para-nitroaminostilbene molecule. We therefore recommend the use of a range-separated exchange–correlation functional in combination with the augmented correlation-consistent double-ζ basis set aug-cc-pVDZ for the calculation of multiphoton absorption properties. PMID:25821415

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

NASA Astrophysics Data System (ADS)

Zhou, Feng; Ji, Wei

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

Josephson Photodetectors via Temperature-to-Phase Conversion

NASA Astrophysics Data System (ADS)

Virtanen, P.; Ronzani, A.; Giazotto, F.

2018-05-01

We theoretically investigate the temperature-to-phase conversion (TPC) process occurring in dc superconducting quantum interferometers based on superconductor-normal-metal-superconductor (S -N -S ) mesoscopic Josephson junctions. In particular, we predict the temperature-driven rearrangement of the phase gradients in the interferometer under the fixed constraints of fluxoid quantization and supercurrent conservation. This mechanism allows sizeable phase variations across the junctions for suitable structure parameters and temperatures. We show that the TPC can be a basis for sensitive single-photon sensors or bolometers. We propose a radiation detector realizable with conventional materials and state-of-the-art nanofabrication techniques. Integrated with a superconducting quantum-interference proximity transistor as a readout setup, an aluminum-based TPC calorimeter can provide a large signal-to-noise ratio >100 in the 10-GHz-10-THz frequency range and a resolving power larger than 1 02 below 50 mK for terahertz photons. In the bolometric operation, electrical noise equivalent power of approximately 10-22 W /√{Hz } is predicted at 50 mK. This device can be attractive as a cryogenic single-photon sensor operating in the giga- and terahertz regime with applications in dark-matter searches.

Mechanism and applications of new fluorescent compounds produced by femtosecond laser surgery in biological tissue (Conference Presentation)

NASA Astrophysics Data System (ADS)

Qu, Jianan Y.; Sun, Qiqi

2017-02-01

The single or multi-photon microscopy based on fluorescent labelling and staining is a sensitive and quantitative method that is widely used in molecular biology and medical research for a variety of experimental, analytical, and quality control applications. However, label-free method is highly desirable in biology and medicine when performing long term live imaging of biological system and obtaining instant tissue examination during surgery procedures. Recently, our group found that femtosecond laser surgery turned a variety of biological tissues and protein samples into highly fluorescent substances. The newly formed fluorescent compounds produced during the laser surgery can be excited via single- and two-photon processes over broad wavelength ranges. We developed a combined confocal and two-photon spectroscopic microscope to characterize the fluorescence from the new compound systematically. The structures of the femtosecond laser treated tissue were studied using Raman spectroscopy and transmission electron microscopy. Our study revealed the mechanisms of the fluorescence emission form the new compound. Furthermore, we demonstrated the applications of the fluorescent compounds for instant evaluation of femtosecond laser microsurgery, study of stem cell responses to muscle injury and neuro-regeneration after spinal cord injury.

A glimpse of gluons through deeply virtual compton scattering on the proton.

PubMed

Defurne, M; Jiménez-Argüello, A Martí; Ahmed, Z; Albataineh, H; Allada, K; Aniol, K A; Bellini, V; Benali, M; Boeglin, W; Bertin, P; Brossard, M; Camsonne, A; Canan, M; Chandavar, S; Chen, C; Chen, J-P; de Jager, C W; de Leo, R; Desnault, C; Deur, A; El Fassi, L; Ent, R; Flay, D; Friend, M; Fuchey, E; Frullani, S; Garibaldi, F; Gaskell, D; Giusa, A; Glamazdin, O; Golge, S; Gomez, J; Hansen, O; Higinbotham, D; Holmstrom, T; Horn, T; Huang, J; Huang, M; Hyde, C E; Iqbal, S; Itard, F; Kang, H; Kelleher, A; Keppel, C; Koirala, S; Korover, I; LeRose, J J; Lindgren, R; Long, E; Magne, M; Mammei, J; Margaziotis, D J; Markowitz, P; Mazouz, M; Meddi, F; Meekins, D; Michaels, R; Mihovilovic, M; Camacho, C Muñoz; Nadel-Turonski, P; Nuruzzaman, N; Paremuzyan, R; Puckett, A; Punjabi, V; Qiang, Y; Rakhman, A; Rashad, M N H; Riordan, S; Roche, J; Russo, G; Sabatié, F; Saenboonruang, K; Saha, A; Sawatzky, B; Selvy, L; Shahinyan, A; Sirca, S; Solvignon, P; Sperduto, M L; Subedi, R; Sulkosky, V; Sutera, C; Tobias, W A; Urciuoli, G M; Wang, D; Wojtsekhowski, B; Yao, H; Ye, Z; Zhan, X; Zhang, J; Zhao, B; Zhao, Z; Zheng, X; Zhu, P

2017-11-10

The internal structure of nucleons (protons and neutrons) remains one of the greatest outstanding problems in modern nuclear physics. By scattering high-energy electrons off a proton we are able to resolve its fundamental constituents and probe their momenta and positions. Here we investigate the dynamics of quarks and gluons inside nucleons using deeply virtual Compton scattering (DVCS)-a highly virtual photon scatters off the proton, which subsequently radiates a photon. DVCS interferes with the Bethe-Heitler (BH) process, where the photon is emitted by the electron rather than the proton. We report herein the full determination of the BH-DVCS interference by exploiting the distinct energy dependences of the DVCS and BH amplitudes. In the regime where the scattering is expected to occur off a single quark, measurements show an intriguing sensitivity to gluons, the carriers of the strong interaction.

Wireless Data Transmission at Terahertz Carrier Waves Generated from a Hybrid InP-Polymer Dual Tunable DBR Laser Photonic Integrated Circuit.

PubMed

Carpintero, Guillermo; Hisatake, Shintaro; de Felipe, David; Guzman, Robinson; Nagatsuma, Tadao; Keil, Norbert

2018-02-14

We report for the first time the successful wavelength stabilization of two hybrid integrated InP/Polymer DBR lasers through optical injection. The two InP/Polymer DBR lasers are integrated into a photonic integrated circuit, providing an ideal source for millimeter and Terahertz wave generation by optical heterodyne technique. These lasers offer the widest tuning range of the carrier wave demonstrated to date up into the Terahertz range, about 20 nm (2.5 THz) on a single photonic integrated circuit. We demonstrate the application of this source to generate a carrier wave at 330 GHz to establish a wireless data transmission link at a data rate up to 18 Gbit/s. Using a coherent detection scheme we increase the sensitivity by more than 10 dB over direct detection.

Spatial EPR entanglement in atomic vapor quantum memory

NASA Astrophysics Data System (ADS)

Parniak, Michal; Dabrowski, Michal; Wasilewski, Wojciech

Spatially-structured quantum states of light are staring to play a key role in modern quantum science with the rapid development of single-photon sensitive cameras. In particular, spatial degree of freedom holds a promise to enhance continous-variable quantum memories. Here we present the first demonstration of spatial entanglement between an atomic spin-wave and a photon measured with an I-sCMOS camera. The system is realized in a warm atomic vapor quantum memory based on rubidium atoms immersed in inert buffer gas. In the experiment we create and characterize a 12-dimensional entangled state exhibiting quantum correlations between a photon and an atomic ensemble in position and momentum bases. This state allows us to demonstrate the Einstein-Podolsky-Rosen paradox in its original version, with an unprecedented delay time of 6 μs between generation of entanglement and detection of the atomic state.

Two-photon microscopy using fiber-based nanosecond excitation.

PubMed

Karpf, Sebastian; Eibl, Matthias; Sauer, Benjamin; Reinholz, Fred; Hüttmann, Gereon; Huber, Robert

2016-07-01

Two-photon excitation fluorescence (TPEF) microscopy is a powerful technique for sensitive tissue imaging at depths of up to 1000 micrometers. However, due to the shallow penetration, for in vivo imaging of internal organs in patients beam delivery by an endoscope is crucial. Until today, this is hindered by linear and non-linear pulse broadening of the femtosecond pulses in the optical fibers of the endoscopes. Here we present an endoscope-ready, fiber-based TPEF microscope, using nanosecond pulses at low repetition rates instead of femtosecond pulses. These nanosecond pulses lack most of the problems connected with femtosecond pulses but are equally suited for TPEF imaging. We derive and demonstrate that at given cw-power the TPEF signal only depends on the duty cycle of the laser source. Due to the higher pulse energy at the same peak power we can also demonstrate single shot two-photon fluorescence lifetime measurements.

Properties of GaAs:Cr-based Timepix detectors

NASA Astrophysics Data System (ADS)

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

2018-02-01

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

On the passive probing of fiber optic quantum communication channels

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

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

2010-04-15

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

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.

Phonon counting and intensity interferometry of a nanomechanical resonator

NASA Astrophysics Data System (ADS)

Cohen, Justin D.; Meenehan, Seán M.; Maccabe, Gregory S.; Gröblacher, Simon; Safavi-Naeini, Amir H.; Marsili, Francesco; Shaw, Matthew D.; Painter, Oskar

2015-04-01

In optics, the ability to measure individual quanta of light (photons) enables a great many applications, ranging from dynamic imaging within living organisms to secure quantum communication. Pioneering photon counting experiments, such as the intensity interferometry performed by Hanbury Brown and Twiss to measure the angular width of visible stars, have played a critical role in our understanding of the full quantum nature of light. As with matter at the atomic scale, the laws of quantum mechanics also govern the properties of macroscopic mechanical objects, providing fundamental quantum limits to the sensitivity of mechanical sensors and transducers. Current research in cavity optomechanics seeks to use light to explore the quantum properties of mechanical systems ranging in size from kilogram-mass mirrors to nanoscale membranes, as well as to develop technologies for precision sensing and quantum information processing. Here we use an optical probe and single-photon detection to study the acoustic emission and absorption processes in a silicon nanomechanical resonator, and perform a measurement similar to that used by Hanbury Brown and Twiss to measure correlations in the emitted phonons as the resonator undergoes a parametric instability formally equivalent to that of a laser. Owing to the cavity-enhanced coupling of light with mechanical motion, this effective phonon counting technique has a noise equivalent phonon sensitivity of 0.89 +/- 0.05. With straightforward improvements to this method, a variety of quantum state engineering tasks using mesoscopic mechanical resonators would be enabled, including the generation and heralding of single-phonon Fock states and the quantum entanglement of remote mechanical elements.

Experimental optimal maximum-confidence discrimination and optimal unambiguous discrimination of two mixed single-photon states

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

Steudle, Gesine A.; Knauer, Sebastian; Herzog, Ulrike

2011-05-15

We present an experimental implementation of optimum measurements for quantum state discrimination. Optimum maximum-confidence discrimination and optimum unambiguous discrimination of two mixed single-photon polarization states were performed. For the latter the states of rank 2 in a four-dimensional Hilbert space are prepared using both path and polarization encoding. Linear optics and single photons from a true single-photon source based on a semiconductor quantum dot are utilized.

High-Performance Single-Photon Sources via Spatial Multiplexing

DTIC Science & Technology

2014-01-01

ingredient for tasks such as quantum cryptography , quantum repeater, quantum teleportation, quantum computing, and truly-random number generation. Recently...SECURITY CLASSIFICATION OF: Single photons sources are desired for many potential quantum information applications. One common method to produce...photons sources are desired for many potential quantum information applications. One common method to produce single photons is based on a “heralding

Scalable Quantum Information Processing and Applications

DTIC Science & Technology

2008-01-19

qubit logic gates, and finally emitting an entangled photon from the single- photon emitter. For the program, we proposed to demonstrate the...coherent, single photon transmitter/receiver system. These requirements included careful tailoring of the g factor for conduction band electrons in...physics required for the realization of a spin-coherent, single photon transmitter/receiver system. These requirements included careful tailoring of

Practical single-photon-assisted remote state preparation with non-maximally entanglement

NASA Astrophysics Data System (ADS)

Wang, Dong; Huang, Ai-Jun; Sun, Wen-Yang; Shi, Jia-Dong; Ye, Liu

2016-08-01

Remote state preparation (RSP) and joint remote state preparation (JRSP) protocols for single-photon states are investigated via linear optical elements with partially entangled states. In our scheme, by choosing two-mode instances from a polarizing beam splitter, only the sender in the communication protocol needs to prepare an ancillary single-photon and operate the entanglement preparation process in order to retrieve an arbitrary single-photon state from a photon pair in partially entangled state. In the case of JRSP, i.e., a canonical model of RSP with multi-party, we consider that the information of the desired state is split into many subsets and in prior maintained by spatially separate parties. Specifically, with the assistance of a single-photon state and a three-photon entangled state, it turns out that an arbitrary single-photon state can be jointly and remotely prepared with certain probability, which is characterized by the coefficients of both the employed entangled state and the target state. Remarkably, our protocol is readily to extend to the case for RSP and JRSP of mixed states with the all optical means. Therefore, our protocol is promising for communicating among optics-based multi-node quantum networks.

Single-photon-multi-layer-interference lithography for high-aspect-ratio and three-dimensional SU-8 micro-/nanostructures.

PubMed

Ghosh, Siddharth; Ananthasuresh, G K

2016-01-04

We report microstructures of SU-8 photo-sensitive polymer with high-aspect-ratio, which is defined as the ratio of height to in-plane feature size. The highest aspect ratio achieved in this work exceeds 250. A multi-layer and single-photon lithography approach is used in this work to expose SU-8 photoresist of thickness up to 100 μm. Here, multi-layer and time-lapsed writing is the key concept that enables nanometer localised controlled photo-induced polymerisation. We use a converging monochromatic laser beam of 405 nm wavelength with a controllable aperture. The reflection of the converging optics from the silicon substrate underneath is responsible for a trapezoidal edge profile of SU-8 microstructure. The reflection induced interfered point-spread-function and multi-layer-single-photon exposure helps to achieve sub-wavelength feature sizes. We obtained a 75 nm tip diameter on a pyramid shaped microstructure. The converging beam profile determines the number of multiple optical focal planes along the depth of field. These focal planes are scanned and exposed non-concurrently with varying energy dosage. It is notable that an un-automated height axis control is sufficient for this method. All of these contribute to realising super-high-aspect-ratio and 3D micro-/nanostructures using SU-8. Finally, we also address the critical problems of photoresist-based micro-/nanofabrication and their solutions.

Advances in optoplasmonic sensors - combining optical nano/microcavities and photonic crystals with plasmonic nanostructures and nanoparticles

NASA Astrophysics Data System (ADS)

Xavier, Jolly; Vincent, Serge; Meder, Fabian; Vollmer, Frank

2018-01-01

Nanophotonic device building blocks, such as optical nano/microcavities and plasmonic nanostructures, lie at the forefront of sensing and spectrometry of trace biological and chemical substances. A new class of nanophotonic architecture has emerged by combining optically resonant dielectric nano/microcavities with plasmonically resonant metal nanostructures to enable detection at the nanoscale with extraordinary sensitivity. Initial demonstrations include single-molecule detection and even single-ion sensing. The coupled photonic-plasmonic resonator system promises a leap forward in the nanoscale analysis of physical, chemical, and biological entities. These optoplasmonic sensor structures could be the centrepiece of miniaturised analytical laboratories, on a chip, with detection capabilities that are beyond the current state of the art. In this paper, we review this burgeoning field of optoplasmonic biosensors. We first focus on the state of the art in nanoplasmonic sensor structures, high quality factor optical microcavities, and photonic crystals separately before proceeding to an outline of the most recent advances in hybrid sensor systems. We discuss the physics of this modality in brief and each of its underlying parts, then the prospects as well as challenges when integrating dielectric nano/microcavities with metal nanostructures. In Section 5, we hint to possible future applications of optoplasmonic sensing platforms which offer many degrees of freedom towards biomedical diagnostics at the level of single molecules.

Waveguide-Coupled Superconducting Nanowire Single-Photon Detectors

NASA Technical Reports Server (NTRS)

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

2015-01-01

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

Characteristic of EBT-XD and EBT3 radiochromic film dosimetry for photon and proton beams

NASA Astrophysics Data System (ADS)

Khachonkham, Suphalak; Dreindl, Ralf; Heilemann, Gerd; Lechner, Wolfgang; Fuchs, Hermann; Palmans, Hugo; Georg, Dietmar; Kuess, Peter

2018-03-01

Recently, a new type of radiochromic film, the EBT-XD film, has been introduced for high dose radiotherapy. The EBT-XD film contains the same structure as the EBT3 film but has a slightly different composition and a thinner active layer. This study benchmarks the EBT-XD against EBT3 film for 6 MV and 10 MV photon beams, as well as for 97.4 MeV and 148.2 MeV proton beams and 15-100 kV x-rays. Dosimetric and film reading characteristics, such as post irradiation darkening, film orientation effect, lateral response artifact (LRA), film sensitivity, energy and beam quality dependency were investigated. Furthermore, quenching effects in the Bragg peak were investigated for a single proton beam energy for both film types, in addition measurements were performed in a spread-out Bragg peak. EBT-XD films showed the same characteristic on film darkening as EBT3. The effects between portrait and landscape orientation were reduced by 3.1% (in pixel value) for EBT-XD compared to EBT3 at a dose of 2000 cGy. The LRA is reduced for EBT-XD films for all investigated dose ranges. The sensitivity of EBT-XD films is superior to EBT3 for doses higher than 500 cGy. In addition, EBT-XD showed a similar dosimetric response for photon and proton irradiation with low energy and beam quality dependency. A quenching effect of 10% was found for both film types. The slight decrease in the thickness of the active layer and different composition configuration of EBT-XD resulted in a reduced film orientation effect and LRA, as well as a sensitivity increase in high-dose regions for both photon and proton beams. Overall, the EBT-XD film improved regarding film reading characteristics and showed advantages in the high-dose region for photon and proton beams.

Characteristic of EBT-XD and EBT3 radiochromic film dosimetry for photon and proton beams.

PubMed

Khachonkham, Suphalak; Dreindl, Ralf; Heilemann, Gerd; Lechner, Wolfgang; Fuchs, Hermann; Palmans, Hugo; Georg, Dietmar; Kuess, Peter

2018-03-15

Recently, a new type of radiochromic film, the EBT-XD film, has been introduced for high dose radiotherapy. The EBT-XD film contains the same structure as the EBT3 film but has a slightly different composition and a thinner active layer. This study benchmarks the EBT-XD against EBT3 film for 6 MV and 10 MV photon beams, as well as for 97.4 MeV and 148.2 MeV proton beams and 15-100 kV x-rays. Dosimetric and film reading characteristics, such as post irradiation darkening, film orientation effect, lateral response artifact (LRA), film sensitivity, energy and beam quality dependency were investigated. Furthermore, quenching effects in the Bragg peak were investigated for a single proton beam energy for both film types, in addition measurements were performed in a spread-out Bragg peak. EBT-XD films showed the same characteristic on film darkening as EBT3. The effects between portrait and landscape orientation were reduced by 3.1% (in pixel value) for EBT-XD compared to EBT3 at a dose of 2000 cGy. The LRA is reduced for EBT-XD films for all investigated dose ranges. The sensitivity of EBT-XD films is superior to EBT3 for doses higher than 500 cGy. In addition, EBT-XD showed a similar dosimetric response for photon and proton irradiation with low energy and beam quality dependency. A quenching effect of 10% was found for both film types. The slight decrease in the thickness of the active layer and different composition configuration of EBT-XD resulted in a reduced film orientation effect and LRA, as well as a sensitivity increase in high-dose regions for both photon and proton beams. Overall, the EBT-XD film improved regarding film reading characteristics and showed advantages in the high-dose region for photon and proton beams.

Detecting skin malignancy using elastic light scattering spectroscopy

NASA Astrophysics Data System (ADS)

Canpolat, Murat; Akman, Ayşe; Çiftçioğlu, M. Akif; Alpsoy, Erkan

2007-07-01

We have used elastic light scattering spectroscopy to differentiate between malign and benign skin lesions. The system consists of a UV spectrometer, a single optical fiber probe and a laptop. The single optical fiber probe was used for both delivery and detection of white light to tissue and from the tissue. The single optical fiber probe received singly scattered photons rather than diffused photons in tissue. Therefore, the spectra are correlated with morphological differences of the cells. It has been shown that spectra of malign skin lesions are different than spectra of benign skin lesions. While slopes of the spectra taken on benign lesions or normal skin tissues were positive, slopes of the spectra taken on malign skin lesions tissues were negative. In vivo experiments were conducted on 20 lesions from 18 patients (11 men with mean age of 68 +/- 9 years and 7 women with mean age of 52 +/- 20 years) applied to the Department of Dermatology and Venerology. Before the biopsy, spectra were taken on the lesion and adjacent (approximately 1 cm distant) normal-appearing skin. Spectra of the normal skin were used as a control group. The spectra were correlated to the pathology results with sensitivity and specificity of 82% and 89%, respectively. Due to small diameter of fiber probe and limited number of sampling (15), some positive cases are missed, which is lowered the sensitivity of the system. The results are promising and could suggest that the system may be able to detect malignant skin lesion non-invasively and in real time.

Two-photon interference at telecom wavelengths for time-bin-encoded single photons from quantum-dot spin qubits

PubMed Central

Yu, Leo; Natarajan, Chandra M.; Horikiri, Tomoyuki; Langrock, Carsten; Pelc, Jason S.; Tanner, Michael G.; Abe, Eisuke; Maier, Sebastian; Schneider, Christian; Höfling, Sven; Kamp, Martin; Hadfield, Robert H.; Fejer, Martin M.; Yamamoto, Yoshihisa

2015-01-01

Practical quantum communication between remote quantum memories rely on single photons at telecom wavelengths. Although spin-photon entanglement has been demonstrated in atomic and solid-state qubit systems, the produced single photons at short wavelengths and with polarization encoding are not suitable for long-distance communication, because they suffer from high propagation loss and depolarization in optical fibres. Establishing entanglement between remote quantum nodes would further require the photons generated from separate nodes to be indistinguishable. Here, we report the observation of correlations between a quantum-dot spin and a telecom single photon across a 2-km fibre channel based on time-bin encoding and background-free frequency downconversion. The downconverted photon at telecom wavelengths exhibits two-photon interference with another photon from an independent source, achieving a mean wavepacket overlap of greater than 0.89 despite their original wavelength mismatch (900 and 911 nm). The quantum-networking operations that we demonstrate will enable practical communication between solid-state spin qubits across long distances. PMID:26597223

What are single photons good for?

NASA Astrophysics Data System (ADS)

Sangouard, Nicolas; Zbinden, Hugo

2012-10-01

In a long-held preconception, photons play a central role in present-day quantum technologies. But what are sources producing photons one by one good for precisely? Well, in opposition to what many suggest, we show that single-photon sources are not helpful for point to point quantum key distribution because faint laser pulses do the job comfortably. However, there is no doubt about the usefulness of sources producing single photons for future quantum technologies. In particular, we show how single-photon sources could become the seed of a revolution in the framework of quantum communication, making the security of quantum key distribution device-independent or extending quantum communication over many hundreds of kilometers. Hopefully, these promising applications will provide a guideline for researchers to develop more and more efficient sources, producing narrowband, pure and indistinguishable photons at appropriate wavelengths.

All-Optical Fiber Hanbury Brown & Twiss Interferometer to study 1300 nm single photon emission of a metamorphic InAs Quantum Dot

PubMed Central

Muñoz-Matutano, G.; Barrera, D.; Fernández-Pousa, C.R.; Chulia-Jordan, R.; Seravalli, L.; Trevisi, G.; Frigeri, P.; Sales, S.; Martínez-Pastor, J.

2016-01-01

New optical fiber based spectroscopic tools open the possibility to develop more robust and efficient characterization experiments. Spectral filtering and light reflection have been used to produce compact and versatile fiber based optical cavities and sensors. Moreover, these technologies would be also suitable to study N-photon correlations, where high collection efficiency and frequency tunability is desirable. We demonstrated single photon emission of a single quantum dot emitting at 1300 nm, using a Fiber Bragg Grating for wavelength filtering and InGaAs Avalanche Photodiodes operated in Geiger mode for single photon detection. As we do not observe any significant fine structure splitting for the neutral exciton transition within our spectral resolution (46 μeV), metamorphic QD single photon emission studied with our all-fiber Hanbury Brown & Twiss interferometer could lead to a more efficient analysis of entangled photon sources at telecom wavelength. This all-optical fiber scheme opens the door to new first and second order interferometers to study photon indistinguishability, entangled photon and photon cross correlation in the more interesting telecom wavelengths. PMID:27257122

Quantum-dot spin-photon entanglement via frequency downconversion to telecom wavelength.

PubMed

De Greve, Kristiaan; Yu, Leo; McMahon, Peter L; Pelc, Jason S; Natarajan, Chandra M; Kim, Na Young; Abe, Eisuke; Maier, Sebastian; Schneider, Christian; Kamp, Martin; Höfling, Sven; Hadfield, Robert H; Forchel, Alfred; Fejer, M M; Yamamoto, Yoshihisa

2012-11-15

Long-distance quantum teleportation and quantum repeater technologies require entanglement between a single matter quantum bit (qubit) and a telecommunications (telecom)-wavelength photonic qubit. Electron spins in III-V semiconductor quantum dots are among the matter qubits that allow for the fastest spin manipulation and photon emission, but entanglement between a single quantum-dot spin qubit and a flying (propagating) photonic qubit has yet to be demonstrated. Moreover, many quantum dots emit single photons at visible to near-infrared wavelengths, where silica fibre losses are so high that long-distance quantum communication protocols become difficult to implement. Here we demonstrate entanglement between an InAs quantum-dot electron spin qubit and a photonic qubit, by frequency downconversion of a spontaneously emitted photon from a singly charged quantum dot to a wavelength of 1,560 nanometres. The use of sub-10-picosecond pulses at a wavelength of 2.2 micrometres in the frequency downconversion process provides the necessary quantum erasure to eliminate which-path information in the photon energy. Together with previously demonstrated indistinguishable single-photon emission at high repetition rates, the present technique advances the III-V semiconductor quantum-dot spin system as a promising platform for long-distance quantum communication.

A stable wavelength-tunable triggered source of single photons and cascaded photon pairs at the telecom C-band

NASA Astrophysics Data System (ADS)

Zeuner, Katharina D.; Paul, Matthias; Lettner, Thomas; Reuterskiöld Hedlund, Carl; Schweickert, Lucas; Steinhauer, Stephan; Yang, Lily; Zichi, Julien; Hammar, Mattias; Jöns, Klaus D.; Zwiller, Val

2018-04-01

The implementation of fiber-based long-range quantum communication requires tunable sources of single photons at the telecom C-band. Stable and easy-to-implement wavelength-tunability of individual sources is crucial to (i) bring remote sources into resonance, (ii) define a wavelength standard, and (iii) ensure scalability to operate a quantum repeater. So far, the most promising sources for true, telecom single photons are semiconductor quantum dots, due to their ability to deterministically and reliably emit single and entangled photons. However, the required wavelength-tunability is hard to attain. Here, we show a stable wavelength-tunable quantum light source by integrating strain-released InAs quantum dots on piezoelectric substrates. We present triggered single-photon emission at 1.55 μm with a multi-photon emission probability as low as 0.097, as well as photon pair emission from the radiative biexciton-exciton cascade. We achieve a tuning range of 0.25 nm which will allow us to spectrally overlap remote quantum dots or tuning distant quantum dots into resonance with quantum memories. This opens up realistic avenues for the implementation of photonic quantum information processing applications at telecom wavelengths.

Fiber-Coupled Cavity-QED Source of Identical Single Photons

NASA Astrophysics Data System (ADS)

Snijders, H.; Frey, J. A.; Norman, J.; Post, V. P.; Gossard, A. C.; Bowers, J. E.; van Exter, M. P.; Löffler, W.; Bouwmeester, D.

2018-03-01

We present a fully fiber-coupled source of high-fidelity single photons. An (In,Ga)As semiconductor quantum dot is embedded in an optical Fabry-Perot microcavity with a robust design and rigidly attached single-mode fibers, which enables through-fiber cross-polarized resonant laser excitation and photon extraction. Even without spectral filtering, we observe that the incident coherent light pulses are transformed into a stream of single photons with high purity (97%) and indistinguishability (90%), which is measured at an in-fiber brightness of 5% with an excellent cavity-mode-to-fiber coupling efficiency of 85%. Our results pave the way for fully fiber-integrated photonic quantum networks. Furthermore, our method is equally applicable to fiber-coupled solid-state cavity-QED-based photonic quantum gates.

Entangling quantum-logic gate operated with an ultrabright semiconductor single-photon source.

PubMed

Gazzano, O; Almeida, M P; Nowak, A K; Portalupi, S L; Lemaître, A; Sagnes, I; White, A G; Senellart, P

2013-06-21

We demonstrate the unambiguous entangling operation of a photonic quantum-logic gate driven by an ultrabright solid-state single-photon source. Indistinguishable single photons emitted by a single semiconductor quantum dot in a micropillar optical cavity are used as target and control qubits. For a source brightness of 0.56 photons per pulse, the measured truth table has an overlap with the ideal case of 68.4±0.5%, increasing to 73.0±1.6% for a source brightness of 0.17 photons per pulse. The gate is entangling: At a source brightness of 0.48, the Bell-state fidelity is above the entangling threshold of 50% and reaches 71.0±3.6% for a source brightness of 0.15.

Spin-photon interface and spin-controlled photon switching in a nanobeam waveguide

NASA Astrophysics Data System (ADS)

Javadi, Alisa; Ding, Dapeng; Appel, Martin Hayhurst; Mahmoodian, Sahand; Löbl, Matthias Christian; Söllner, Immo; Schott, Rüdiger; Papon, Camille; Pregnolato, Tommaso; Stobbe, Søren; Midolo, Leonardo; Schröder, Tim; Wieck, Andreas Dirk; Ludwig, Arne; Warburton, Richard John; Lodahl, Peter

2018-05-01

The spin of an electron is a promising memory state and qubit. Connecting spin states that are spatially far apart will enable quantum nodes and quantum networks based on the electron spin. Towards this goal, an integrated spin-photon interface would be a major leap forward as it combines the memory capability of a single spin with the efficient transfer of information by photons. Here, we demonstrate such an efficient and optically programmable interface between the spin of an electron in a quantum dot and photons in a nanophotonic waveguide. The spin can be deterministically prepared in the ground state with a fidelity of up to 96%. Subsequently, the system is used to implement a single-spin photonic switch, in which the spin state of the electron directs the flow of photons through the waveguide. The spin-photon interface may enable on-chip photon-photon gates, single-photon transistors and the efficient generation of a photonic cluster state.

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

PubMed

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

2016-01-21

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

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.

Controlling single-photon transport in an optical waveguide coupled to an optomechanical cavity with a Λ-type three-level atom

NASA Astrophysics Data System (ADS)

Zhang, Yu-Qing; Zhu, Zhong-Hua; Peng, Zhao-Hui; Jiang, Chun-Lei; Chai, Yi-Feng; Hai, Lian; Tan, Lei

2018-06-01

We theoretically study the single-photon transport along a one-dimensional optical waveguide coupled to an optomechanical cavity containing a Λ-type three-level atom. Our numerical results show that the transmission spectra of the incident photon can be well controlled by such a hybrid atom-optomechanical system. The effects of the optomechanical coupling strength, the classical laser beam applied to the atom, atom-cavity detuning, and atomic dissipation on the single-photon transport properties are analyzed. It is of particular interest that an analogous double electromagnetically induced transparency emerges in the single-photon transmission spectra.

Dynamics of Single-Photon Emission from Electrically Pumped Color Centers

NASA Astrophysics Data System (ADS)

Khramtsov, Igor A.; Agio, Mario; Fedyanin, Dmitry Yu.

2017-08-01

Low-power, high-speed, and bright electrically driven true single-photon sources, which are able to operate at room temperature, are vital for the practical realization of quantum-communication networks and optical quantum computations. Color centers in semiconductors are currently the best candidates; however, in spite of their intensive study in the past decade, the behavior of color centers in electrically controlled systems is poorly understood. Here we present a physical model and establish a theoretical approach to address single-photon emission dynamics of electrically pumped color centers, which interprets experimental results. We support our analysis with self-consistent numerical simulations of a single-photon emitting diode based on a single nitrogen-vacancy center in diamond and predict the second-order autocorrelation function and other emission characteristics. Our theoretical findings demonstrate remarkable agreement with the experimental results and pave the way to the understanding of single-electron and single-photon processes in semiconductors.

Photonic quantum information: science and technology.

PubMed

Takeuchi, Shigeki

2016-01-01

Recent technological progress in the generation, manipulation and detection of individual single photons has opened a new scientific field of photonic quantum information. This progress includes the realization of single photon switches, photonic quantum circuits with specific functions, and the application of novel photonic states to novel optical metrology beyond the limits of standard optics. In this review article, the recent developments and current status of photonic quantum information technology are overviewed based on the author's past and recent works.

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

PubMed

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

2018-06-04

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

Processing multiphoton states through operation on a single photon: Methods and applications

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

Lin Qing; He Bing; Bergou, Janos A.

2009-10-15

Multiphoton states are widely applied in quantum information technology. By the methods presented in this paper, the structure of a multiphoton state in the form of multiple single-photon qubit products can be mapped to a single-photon qudit, which could also be in a separable product with other photons. This makes possible the manipulation of such multiphoton states by processing single-photon states. The optical realization of unknown qubit discrimination [B. He, J. A. Bergou, and Y.-H. Ren, Phys. Rev. A 76, 032301 (2007)] is simplified with the transformation methods. Another application is the construction of quantum logic gates, where the inversemore » transformations back to the input state spaces are also necessary. We especially show that the modified setups to implement the transformations can realize the deterministic multicontrol gates (including Toffoli gate) operating directly on the products of single-photon qubits.« less

Engineering Microorganisms for Energy Production

DTIC Science & Technology

2006-06-01

the oxygen sensi- tivity of fuel-forming catalysts in biological systems. Hydrogenases, nitrogenases, and rubisco in C3 plants are all oxygen...sensitive. Indeed, C4 plants are more efficient because they developed an independent mechanism to isolate the rubisco from oxygen. Photodamage is a key...single CO 2 to sugars requires 8 photons. The reactions converting CO 2 to sugars are catalyzed by the enzyme rubisco (ribulose 1,5-bisphosphate 33

A photon-photon quantum gate based on a single atom in an optical resonator.

PubMed

Hacker, Bastian; Welte, Stephan; Rempe, Gerhard; Ritter, Stephan

2016-08-11

That two photons pass each other undisturbed in free space is ideal for the faithful transmission of information, but prohibits an interaction between the photons. Such an interaction is, however, required for a plethora of applications in optical quantum information processing. The long-standing challenge here is to realize a deterministic photon-photon gate, that is, a mutually controlled logic operation on the quantum states of the photons. This requires an interaction so strong that each of the two photons can shift the other's phase by π radians. For polarization qubits, this amounts to the conditional flipping of one photon's polarization to an orthogonal state. So far, only probabilistic gates based on linear optics and photon detectors have been realized, because "no known or foreseen material has an optical nonlinearity strong enough to implement this conditional phase shift''. Meanwhile, tremendous progress in the development of quantum-nonlinear systems has opened up new possibilities for single-photon experiments. Platforms range from Rydberg blockade in atomic ensembles to single-atom cavity quantum electrodynamics. Applications such as single-photon switches and transistors, two-photon gateways, nondestructive photon detectors, photon routers and nonlinear phase shifters have been demonstrated, but none of them with the ideal information carriers: optical qubits in discriminable modes. Here we use the strong light-matter coupling provided by a single atom in a high-finesse optical resonator to realize the Duan-Kimble protocol of a universal controlled phase flip (π phase shift) photon-photon quantum gate. We achieve an average gate fidelity of (76.2 ± 3.6) per cent and specifically demonstrate the capability of conditional polarization flipping as well as entanglement generation between independent input photons. This photon-photon quantum gate is a universal quantum logic element, and therefore could perform most existing two-photon operations. The demonstrated feasibility of deterministic protocols for the optical processing of quantum information could lead to new applications in which photons are essential, especially long-distance quantum communication and scalable quantum computing.

Acousto-optical imaging using a powerful long pulse laser

NASA Astrophysics Data System (ADS)

Rousseau, Guy; Blouin, Alain; Monchalin, Jean-Pierre

2008-06-01

Acousto-optical imaging is an emerging biodiagnostic technique which provides an optical spectroscopic signature and a spatial localization of an optically absorbing target embedded in a strongly scattering medium. The transverse resolution of the technique is determined by the lateral extent of ultrasound beam focal zone while the axial resolution is obtained by using short ultrasound pulses. Although very promising for medical diagnostic, the practical application of this technique is presently limited by its poor sensitivity. Moreover, any method to enhance the signal-to-noise ratio must obviously satisfy the in vivo safety limits regarding the acceptable power level of both the ultrasonic pressure wave and the laser beam. In this paper, we propose to improve the sensitivity by using a pulsed single-frequency laser source to raise the optical peak power applied to the scattering medium and to collect more ultrasonically tagged photons. Such a laser source also allows illuminating the tissues mainly during the transit time of the ultrasonic wave to maintain the average optical power below the maximum permissible exposure. In our experiment, a single-frequency Nd:YAG laser emitting 500-μs pulses with a peak power superior to 100 W was used. Photons were tagged in few-cm thick optical phantoms with tone bursts generated by an ultrasonic transducer. Tagged photons were detected with a GaAs photorefractive interferometer characterized by a large optical etendue to process simultaneously a large number of speckle grains. When pumped by high intensity laser pulses, such an interferometer also provides the fast response time essential to obtain an apparatus insensitive to the speckle decorrelation due to mechanical vibrations or tissues movements. The use of a powerful long pulse laser appears promising to enhance the signal level in ultrasound modulated optical imaging. When combined with a photorefractive interferometer of large optical etendue, such a source could allow obtaining both the sensitivity and the fast response time necessary for biodiagnostic applications.

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 turned to advantage. Depending on the wavelength, an antenna or other component would be used to couple radiation into the reservoir, wherein the absorption of photons would break Cooper pairs, thereby creating quasiparticles that, in turn, would tunnel to the island, creating a 1-e signal. On the basis of conservative estimates of device parameters derived from experimental data and computational simulations that fit the data, it has been estimated that the noise equivalent power of a device according to the proposal could be as low as 6 10(exp -22) W/Hz(exp 1/2). It has also been estimated that the spectroscopic resolution (photon energy divided by increment of photon energy) of such a device in visible light would exceed 100.

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

Optimal antibunching in passive photonic devices based on coupled nonlinear resonators

NASA Astrophysics Data System (ADS)

Ferretti, S.; Savona, V.; Gerace, D.

2013-02-01

We propose the use of weakly nonlinear passive materials for prospective applications in integrated quantum photonics. It is shown that strong enhancement of native optical nonlinearities by electromagnetic field confinement in photonic crystal resonators can lead to single-photon generation only exploiting the quantum interference of two coupled modes and the effect of photon blockade under resonant coherent driving. For realistic system parameters in state of the art microcavities, the efficiency of such a single-photon source is theoretically characterized by means of the second-order correlation function at zero-time delay as the main figure of merit, where major sources of loss and decoherence are taken into account within a standard master equation treatment. These results could stimulate the realization of integrated quantum photonic devices based on non-resonant material media, fully integrable with current semiconductor technology and matching the relevant telecom band operational wavelengths, as an alternative to single-photon nonlinear devices based on cavity quantum electrodynamics with artificial atoms or single atomic-like emitters.

Generation of single photons with highly tunable wave shape from a cold atomic ensemble

PubMed Central

Farrera, Pau; Heinze, Georg; Albrecht, Boris; Ho, Melvyn; Chávez, Matías; Teo, Colin; Sangouard, Nicolas; de Riedmatten, Hugues

2016-01-01

The generation of ultra-narrowband, pure and storable single photons with widely tunable wave shape is an enabling step toward hybrid quantum networks requiring interconnection of remote disparate quantum systems. It allows interaction of quantum light with several material systems, including photonic quantum memories, single trapped ions and opto-mechanical systems. Previous approaches have offered a limited tuning range of the photon duration of at most one order of magnitude. Here we report on a heralded single photon source with controllable emission time based on a cold atomic ensemble, which can generate photons with temporal durations varying over three orders of magnitude up to 10 μs without a significant change of the readout efficiency. We prove the nonclassicality of the emitted photons, show that they are emitted in a pure state, and demonstrate that ultra-long photons with nonstandard wave shape can be generated, which are ideally suited for several quantum information tasks. PMID:27886166

Observation of quantum entanglement between a photon and a single electron spin confined to an InAs quantum dot

NASA Astrophysics Data System (ADS)

Schaibley, John; Burgers, Alex; McCracken, Greg; Duan, Luming; Berman, Paul; Steel, Duncan; Bracker, Allan; Gammon, Daniel; Sham, Lu

2013-03-01

A single electron spin confined to a single InAs quantum dot (QD) can serve as a qubit for quantum information processing. By utilizing the QD's optically excited trion states in the presence of an externally applied magnetic field, the QD spin can be rapidly initialized, manipulated and read out. A key resource for quantum information is the ability to entangle distinct QD spins. One approach relies on intermediate spin-photon entanglement to mediate the entanglement between distant QD spin qubits. We report a demonstration of quantum entanglement between a photon's polarization state and the spin state of a single electron confined to a single QD. Here, the photon is spontaneously emitted from one of the QD's trion states. The emitted photon's polarization along the detection axis is entangled with the resulting spin state of the QD. By performing projective measurements on the photon's polarization state and correlating these measurements with the state of the QD spin in two different bases, we obtain a lower bound on the entanglement fidelity of 0.59 (after background correction). The fidelity bound is limited almost entirely by the timing resolution of our single photon detector. The spin-photon entanglement generation rate is 3 ×103 s-1. Supported by: NSF, MURI, AFOSR, DARPA, ARO.

A semiconductor photon-sorter

NASA Astrophysics Data System (ADS)

Bennett, A. J.; Lee, J. P.; Ellis, D. J. P.; Farrer, I.; Ritchie, D. A.; Shields, A. J.

2016-10-01

Obtaining substantial nonlinear effects at the single-photon 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 photons. We report effective interactions between photons, 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 photons in number. This is used to create strong correlations between detection events and to create polarization-correlated photons from an uncorrelated stream using a single spin. These results pave the way for semiconductor optical switches operated by single quanta of light.

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

NASA Astrophysics Data System (ADS)

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

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

Integrated quantum photonic sensor based on Hong-Ou-Mandel interference.

PubMed

Basiri-Esfahani, Sahar; Myers, Casey R; Armin, Ardalan; Combes, Joshua; Milburn, Gerard J

2015-06-15

Photonic-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 photonic 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 photonic 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 detection. 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 photon 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 photonic crystal cavities as an example and find that this system, which only relies on photon coincidence detection 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 photonic architectures can achieve comparable sensor performance to semiclassical devices.

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.

Photonic quantum information: science and technology

PubMed Central

TAKEUCHI, Shigeki

2016-01-01

Recent technological progress in the generation, manipulation and detection of individual single photons has opened a new scientific field of photonic quantum information. This progress includes the realization of single photon switches, photonic quantum circuits with specific functions, and the application of novel photonic states to novel optical metrology beyond the limits of standard optics. In this review article, the recent developments and current status of photonic quantum information technology are overviewed based on the author’s past and recent works. PMID:26755398

Photonic band gaps from a stack of right- and left-hand chiral photonic crystal layers.

PubMed

Gevorgyan, A H

2012-02-01

In the present paper we investigated the optical properties of a stack of right- and left- hand chiral photonic crystal layers. The problem is solved by Ambartsumian's layer addition modified method. We investigated the reflection spectra peculiarities of this system and showed that in contrast to a single cholesteric liquid crystal (CLC) layer this system has multiple photonic band gaps (PBGs) (at light normal incidence). We showed that this system has unique polarization properties, particularly the eigenpolarizations (EPs) of the system are degenerated (i.e., the two EPs coincide) for an even number of layers and, in contrast to ordinary gyrotropic systems, the polarization plane rotation decreases if the system thickness is increased, the rotation sign depends on the first sublayer chirality sign, the system is very sensitive to the change of the sublayer number in the system, etc. We also investigated the influence of sublayer thicknesses, incidence angle, the sublayer local dielectric anisotropies, the sublayer helix pitches on the reflection peculiarities, and other optical parameters of the system. © 2012 American Physical Society

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

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

Faby, Sebastian; Maier, Joscha; Sawall, Stefan

2016-07-15

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

Indistinguishable near-infrared single photons from an individual organic molecule

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

Trebbia, Jean-Baptiste; Tamarat, Philippe; Lounis, Brahim

2010-12-15

By using the zero-phonon line emission of an individual organic molecule, we realized a source of indistinguishable single photons in the near infrared. A Hong-Ou-Mandel interference experiment is performed and a two-photon coalescence probability higher than 50% at 2 K is obtained. The contribution of the temperature-dependent dephasing processes to the two-photon interference contrast is studied. We show that the molecule delivers nearly ideal indistinguishable single photons at the lowest temperatures when the dephasing is nearly lifetime limited. This source is used to generate postselected polarization-entangled photon pairs as a test bench for applications in quantum information.

On investigation of optical and spin properties of NV centers in aggregates of detonation nanodiamonds

NASA Astrophysics Data System (ADS)

Bolshedvorskii, S. V.; Vorobyov, V. V.; Soshenko, V. V.; Zeleneev, A.; Sorokin, V. N.; Smolyaninov, A. N.; Akimov, A. V.

2018-02-01

Quickly developing application of nitrogen-vacancy color centers in diamond sets demands on cheap and high optical and spin properties nanodiamonds. Among other types, detonation nanodiamonds are easiest for production but often show no NV color centers inside. In this work we show, that aggregates of detonation nanodiamonds could be as good, or even better in terms of brightness and spin properties, than more expensive single crystal nanodiamonds. This way aggregates of detonation nanodiamonds could efficiently serve as cheap and bright source of single photon radiation or sensitive element of biocompatible sensor.

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

NASA Technical Reports Server (NTRS)

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

2002-01-01

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

QUANTUM CRYPTOGRAPHY: Single Photons.

PubMed

Benjamin, S

2000-12-22

Quantum cryptography offers the potential of totally secure transfer of information, but as Benjamin discusses in this Perspective, its practical implementation hinges on being able to generate single photons (rather than two or more) at a time. Michler et al. show how this condition can be met in a quantum dot microdisk structure. Single molecules were also recently shown to allow controlled single-photon emission.

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

PubMed

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

2018-05-01

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

Joining the quantum state of two photons into one

NASA Astrophysics Data System (ADS)

Vitelli, Chiara; Spagnolo, Nicolò; Aparo, Lorenzo; Sciarrino, Fabio; Santamato, Enrico; Marrucci, Lorenzo

2013-07-01

Photons are the ideal carriers of quantum information for communication. Each photon can have a single or multiple qubits encoded in its internal quantum state, as defined by optical degrees of freedom such as polarization, wavelength, transverse modes and so on. However, as photons do not interact, multiplexing and demultiplexing the quantum information across photons has not been possible hitherto. Here, we introduce and demonstrate experimentally a physical process, named `quantum joining', in which the two-dimensional quantum states (qubits) of two input photons are combined into a single output photon, within a four-dimensional Hilbert space. The inverse process is also proposed, in which the four-dimensional quantum state of a single photon is split into two photons, each carrying a qubit. Both processes can be iterated, and hence provide a flexible quantum interconnect to bridge multiparticle protocols of quantum information with multidegree-of-freedom ones, with possible applications in future quantum networking.

Factors affecting the sensitivity of Tc-99m methoxyisobutylisonitrile dual-phase parathyroid single photon emission computed tomography in primary hyperparathyroidism.

PubMed

Araz, Mine; Çayir, Derya; Erdoğan, Mehmet; Uçan, Bekir; Çakal, Erman

2017-02-01

The aim of this study was to investigate the effects of thyroid diseases and regularly used medications on the sensitivity of Tc-99m methoxyisobutylisonitrile (MIBI) dual-phase parathyroid single photon emission computed tomography (SPECT) and to define indicatives of the result of the study. Overall, 218 primary hyperparathyroidism patients (190 women, 28 men, mean age: 57±14 years) with thyroid-parathyroid ultrasonography and Tc-99m MIBI dual-phase parathyroid SPECT were retrospectively enrolled. Patients were divided as follows: a positive SPECT group [119 (54.6%) patients] and a negative SPECT group [99 (45.4%) patients]. The effects of thyroid diseases and use of calcium channel blockers, β-blockers, angiotensin-converting enzyme inhibitors/angiotensin receptor blockers, oral antidiabetics, thyroid hormone preparates, nonsteroidal anti-inflammatory drugs, and proton pump inhibitors on the sensitivity of Tc-99m MIBI dual-phase parathyroid SPECT were investigated. The frequency of NSAID usage was higher in the negative scan group (P<0.001). No significant difference was detected in terms of coexisting thyroid disease or usage of other medications. Overall sensitivity, specificity, positive, and negative predictive value of Tc-99m MIBI dual-phase parathyroid SPECT were calculated to be 89.6, 92.5, 94.1, and 86.9%. The sensitivity was low only in nonsteroidal anti-inflammatory drug users (75.6%) compared with nonusers (96.5%). Logistic regression showed that ultrasonography was indicative of a positive scan and the possibility of a negative result was increased by regular usage of nonsteroid anti-inflammatory drugs (odds ratio: 0.262, confidence interval: 0.128-0.538; P<0.001) CONCLUSION: Among various drug groups, NSAIDs may decrease the sensitivity of Tc-99m MIBI SPECT and, provided that these novel data are supported by other studies, patient preparation may be modified to stop NSAIDs before Tc-99m MIBI dual-phase parathyroid SPECT.

Experimental Realization of Efficient, Room Temperature Single-Photon Sources with Definite Circular and Linear Polarizations

NASA Astrophysics Data System (ADS)

Boutsidis, Christos

In this thesis I present experimental demonstrations of room-temperature, single-photon sources with definite linear and circular polarizations. Definite photon polarization increases the efficiency of quantum communication systems. In contrast with cryogenic-temperature single-photon sources based on epitaxial quantum dots requiring expensive MBE and nanofabrication, my method utilizes a mature liquid crystal technology, which I made consistent with single-emitter fluorescence microscopy. The structures I have prepared are planar-aligned cholesteric liquid crystals forming 1-D photonic bandgaps for circularly-polarized light, which were used to achieve definite circularly-polarized fluorescence of single emitters doped in this environment. I also used planar-aligned nematic liquid crystals to align single molecules with linear dipole moments and achieved definite linearly-polarized fluorescence. I used single nanocrystal quantum dots, single nanodiamond color-centers, rare-earth-doped nanocrystals, and single terrylene and DiIC18(3) dye molecules as emitters. For nanocrystal quantum dots I observed circular polarization dissymmetry factors as large as ge = --1.6. In addition, I observed circularly-polarized resonances in the fluorescence of emitters within a cholesteric microcavity, with cavity quality factors of up to Q ˜ 250. I also showed that the fluorescence of DiIC18(3) dye molecules in planar-aligned nematic cells exhibits definite linear polarization, with a degree of polarization of rho = --0.58 +/- 0.03. Distributed Bragg reflectors form another type of microcavity that can be used to realize a single-photon source. I characterized the fluorescence from nanocrystal quantum dots doped in the defect layers of such microcavites, both organic and inorganic. Finally, to demonstrate the single-photon properties of single-emitter-doped cholesteric and nematic liquid crystal structures and distributed Bragg reflector microcavities, I present observations of photon antibunching from emitters doped in each of these structures. These experimental observations include photon antibunching from: nanocrystal quantum dots and nanodiamond color-centers doped in a cholesteric microcavity; terrylene and DiIC 18(3) dye molecules doped in nematic structures, and nanocrystal quantum dots doped in the distributed Bragg reflector microcavity. A value of the zero-time second-order coherence as low as g(2)(0) = 0.001 +/- 0.03 was measured. These results represent an important step forward in the realization of room temperature single-photon sources with definite polarization for secure quantum communication.

Performance Considerations for the SIMPL Single Photon, Polarimetric, Two-Color Laser Altimeter as Applied to Measurements of Forest Canopy Structure and Composition

NASA Technical Reports Server (NTRS)

Dabney, Philip W.; Harding, David J.; Valett, Susan R.; Vasilyev, Aleksey A.; Yu, Anthony W.

2012-01-01

The Slope Imaging Multi-polarization Photon-counting Lidar (SIMPL) is a multi-beam, micropulse airborne laser altimeter that acquires active and passive polarimetric optical remote sensing measurements at visible and near-infrared wavelengths. SIMPL was developed to demonstrate advanced measurement approaches of potential benefit for improved, more efficient spaceflight laser altimeter missions. SIMPL data have been acquired for wide diversity of forest types in the summers of 2010 and 2011 in order to assess the potential of its novel capabilities for characterization of vegetation structure and composition. On each of its four beams SIMPL provides highly-resolved measurements of forest canopy structure by detecting single-photons with 15 cm ranging precision using a narrow-beam system operating at a laser repetition rate of 11 kHz. Associated with that ranging data SIMPL provides eight amplitude parameters per beam unlike the single amplitude provided by typical laser altimeters. Those eight parameters are received energy that is parallel and perpendicular to that of the plane-polarized transmit pulse at 532 nm (green) and 1064 nm (near IR), for both the active laser backscatter retro-reflectance and the passive solar bi-directional reflectance. This poster presentation will cover the instrument architecture and highlight the performance of the SIMPL instrument with examples taken from measurements for several sites with distinct canopy structures and compositions. Specific performance areas such as probability of detection, after pulsing, and dead time, will be highlighted and addressed, along with examples of their impact on the measurements and how they limit the ability to accurately model and recover the canopy properties. To assess the sensitivity of SIMPL's measurements to canopy properties an instrument model has been implemented in the FLIGHT radiative transfer code, based on Monte Carlo simulation of photon transport. SIMPL data collected in 2010 over the Smithsonian Environmental Research Center, MD are currently being modelled and compared to other remote sensing and in situ data sets. Results on the adaptation of FLIGHT to model micropulse, single'photon ranging measurements are presented elsewhere at this conference. NASA's ICESat-2 spaceflight mission, scheduled for launch in 2016, will utilize a multi-beam, micropulse, single-photon ranging measurement approach (although non-polarimetric and only at 532 nm). Insights gained from the analysis and modelling of SIMPL data will help guide preparations for that mission, including development of calibration/validation plans and algorithms for the estimation of forest biophysical parameters.

On-chip III-V monolithic integration of heralded single photon sources and beamsplitters

NASA Astrophysics Data System (ADS)

Belhassen, J.; Baboux, F.; Yao, Q.; Amanti, M.; Favero, I.; Lemaître, A.; Kolthammer, W. S.; Walmsley, I. A.; Ducci, S.

2018-02-01

We demonstrate a monolithic III-V photonic circuit combining a heralded single photon source with a beamsplitter, at room temperature and telecom wavelength. Pulsed parametric down-conversion in an AlGaAs waveguide generates counterpropagating photons, one of which is used to herald the injection of its twin into the beamsplitter. We use this configuration to implement an integrated Hanbury-Brown and Twiss experiment, yielding a heralded second-order correlation gher(2 )(0 )=0.10 ±0.02 that confirms single-photon operation. The demonstrated generation and manipulation of quantum states on a single III-V semiconductor chip opens promising avenues towards real-world applications in quantum information.

Magneto-photonic crystal optical sensors with sensitive covers

NASA Astrophysics Data System (ADS)

Dissanayake, Neluka; Levy, Miguel; Chakravarty, A.; Heiden, P. A.; Chen, N.; Fratello, V. J.

2011-08-01

We report on a magneto-photonic crystal on-chip optical sensor for specific analyte detection with polypyrrole and gold nano particles as modified photonic 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-photonic crystal enhanced polarization rotation sensitive to the nature of the cover layer detects 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.

ON THE USE OF SHOT NOISE FOR PHOTON COUNTING

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

Zmuidzinas, Jonas, E-mail: jonas@caltech.edu

Lieu et al. have recently claimed that it is possible to substantially improve the sensitivity of radio-astronomical observations. In essence, their proposal is to make use of the intensity of the photon shot noise as a measure of the photon arrival rate. Lieu et al. provide a detailed quantum-mechanical calculation of a proposed measurement scheme that uses two detectors and conclude that this scheme avoids the sensitivity degradation that is associated with photon bunching. If correct, this result could have a profound impact on radio astronomy. Here I present a detailed analysis of the sensitivity attainable using shot-noise measurement schemesmore » that use either one or two detectors, and demonstrate that neither scheme can avoid the photon bunching penalty. I perform both semiclassical and fully quantum calculations of the sensitivity, obtaining consistent results, and provide a formal proof of the equivalence of these two approaches. These direct calculations are furthermore shown to be consistent with an indirect argument based on a correlation method that establishes an independent limit to the sensitivity of shot-noise measurement schemes. Furthermore, these calculations are directly applicable to the regime of interest identified by Lieu et al. Collectively, these results conclusively demonstrate that the photon-bunching sensitivity penalty applies to shot-noise measurement schemes just as it does to ordinary photon counting, in contradiction to the fundamental claim made by Lieu et al. The source of this contradiction is traced to a logical fallacy in their argument.« less

Hybrid Circuit Quantum Electrodynamics: Coupling a Single Silicon Spin Qubit to a Photon

DTIC Science & Technology

2015-01-01

HYBRID CIRCUIT QUANTUM ELECTRODYNAMICS: COUPLING A SINGLE SILICON SPIN QUBIT TO A PHOTON PRINCETON UNIVERSITY JANUARY 2015 FINAL...SILICON SPIN QUBIT TO A PHOTON 5a. CONTRACT NUMBER FA8750-12-2-0296 5b. GRANT NUMBER N/A 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Jason R. Petta...architectures. 15. SUBJECT TERMS Quantum Computing, Quantum Hybrid Circuits, Quantum Electrodynamics, Coupling a Single Silicon Spin Qubit to a Photon

Tapered fiber coupling of single photons emitted by a deterministically positioned single nitrogen vacancy center

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

Liebermeister, Lars, E-mail: lars.liebermeister@physik.uni-muenchen.de; Petersen, Fabian; Münchow, Asmus v.

2014-01-20

A diamond nano-crystal hosting a single nitrogen vacancy (NV) center is optically selected with a confocal scanning microscope and positioned deterministically onto the subwavelength-diameter waist of a tapered optical fiber (TOF) with the help of an atomic force microscope. Based on this nano-manipulation technique, we experimentally demonstrate the evanescent coupling of single fluorescence photons emitted by a single NV-center to the guided mode of the TOF. By comparing photon count rates of the fiber-guided and the free-space modes and with the help of numerical finite-difference time domain simulations, we determine a lower and upper bound for the coupling efficiency ofmore » (9.5 ± 0.6)% and (10.4 ± 0.7)%, respectively. Our results are a promising starting point for future integration of single photon sources into photonic quantum networks and applications in quantum information science.« less

A readout circuit dedicated for the detection of chemiluminescence using a silicon photomultiplier

NASA Astrophysics Data System (ADS)

Baszczyk, M.; Dorosz, P.; Mik, L.; Kucewicz, W.; Reczynski, W.; Sapor, M.

2018-05-01

A readout circuit dedicated for the detection of the chemiluminescence phenomenon using a silicon photomultiplier (SiPM) is presented. During chemiluminescence, light is generated as a result of chemical reaction. Chemiluminescence is used in many applications within medicine, chemistry, biology and biotechnology, and is one of the most important sensing techniques in biomedical science and clinical medicine. The front-end electronics consist of a preamplifier and a fast shaper—this produces pulses, the peaking time which is 3.6 ns for a single photon and the FWHM is 3.8 ns. The system has been optimised to measure chemiluminescence—it is sensitive at the level of single photons, it generates a low number of overlapping pulses and is accurate. Two methods of signal detection are analysed and compared: the counting of events and amplitude detection. The relationship between the chemiluminescence light intensity and the concentration of the chemical compound (luminol) is linear in the range of the tested concentrations and has strong linearity parameters and low prediction intervals.

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

DOEpatents

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

2011-12-06

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

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

PubMed Central

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

2015-01-01

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

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

PubMed Central

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

2016-01-01

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

Changing optical band structure with single photons

NASA Astrophysics Data System (ADS)

Albrecht, Andreas; Caneva, Tommaso; Chang, Darrick E.

2017-11-01

Achieving strong interactions between individual photons enables a wide variety of exciting possibilities in quantum information science and many-body physics. Cold atoms interfaced with nanophotonic structures have emerged as a platform to realize novel forms of nonlinear interactions. In particular, when atoms are coupled to a photonic crystal waveguide, long-range atomic interactions can arise that are mediated by localized atom-photon bound states. We theoretically show that in such a system, the absorption of a single photon can change the band structure for a subsequent photon. This occurs because the first photon affects the atoms in the chain in an alternating fashion, thus leading to an effective period doubling of the system and a new optical band structure for the composite atom-nanophotonic system. We demonstrate how this mechanism can be engineered to realize a single-photon switch, where the first incoming photon switches the system from being highly transmissive to highly reflective, and analyze how signatures can be observed via non-classical correlations of the outgoing photon field.

Indistinguishable and efficient single photons from a quantum dot in a planar nanobeam waveguide

NASA Astrophysics Data System (ADS)

KiršanskÄ--, Gabija; Thyrrestrup, Henri; Daveau, Raphaël S.; Dreeßen, Chris L.; Pregnolato, Tommaso; Midolo, Leonardo; Tighineanu, Petru; Javadi, Alisa; Stobbe, Søren; Schott, Rüdiger; Ludwig, Arne; Wieck, Andreas D.; Park, Suk In; Song, Jin D.; Kuhlmann, Andreas V.; Söllner, Immo; Löbl, Matthias C.; Warburton, Richard J.; Lodahl, Peter

2017-10-01

We demonstrate a high-purity source of indistinguishable single photons using a quantum dot embedded in a nanophotonic waveguide. The source features a near-unity internal coupling efficiency and the collected photons are efficiently coupled off chip by implementing a taper that adiabatically couples the photons to an optical fiber. By quasiresonant excitation of the quantum dot, we measure a single-photon purity larger than 99.4 % and a photon indistinguishability of up to 94 ±1 % by using p -shell excitation combined with spectral filtering to reduce photon jitter. A temperature-dependent study allows pinpointing the residual decoherence processes, notably the effect of phonon broadening. Strict resonant excitation is implemented as well as another means of suppressing photon jitter, and the additional complexity of suppressing the excitation laser source is addressed. The paper opens a clear pathway towards the long-standing goal of a fully deterministic source of indistinguishable photons, which is integrated on a planar photonic chip.

Photon Shot Noise Limited Radio Frequency Electric Field Sensing Using Rydberg Atoms in Vapor Cells

NASA Astrophysics Data System (ADS)

Kumar, Santosh; Jahangiri, Akbar J.; Fan, Haoquan; Kuebler, Harald; Shaffer, James P.

2017-04-01

We report Rydberg atom-based radio frequency (RF) electrometry measurements at a sensitivity limited by probe laser photon shot noise. By utilizing the phenomena of electromagnetically induced transparency (EIT) in room temperature atomic vapor cells, Rydberg atoms can be used for absolute electric field measurements that significantly surpass conventional methods in utility, sensitivity and accuracy. We show that by using a Mach-Zehnder interferometer with homodyne detection or using frequency modulation spectroscopy with active control of residual amplitude modulation we can achieve a RF electric field detection sensitivity of 3 μVcm-1Hz/2. The sensitivity is limited by photon shot noise on the detector used to readout the probe laser of the EIT scheme. We suggest a new multi-photon scheme that can mitigate the effect of photon shot noise. The multi-photon approach allows an increase in probe laser power without decreasing atomic coherence times that result from collisions caused by an increase in Rydberg atom excitation. The multi-photon scheme also reduces Residual Doppler broadening enabling more accurate measurements to be carried out. This work is supported by DARPA, and NRO.

Site-controlled InGaN/GaN single-photon-emitting diode

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

Zhang, Lei; Deng, Hui, E-mail: dengh@umich.edu; Teng, Chu-Hsiang

2016-04-11

We report single-photon emission from electrically driven site-controlled InGaN/GaN quantum dots. The device is fabricated from a planar light-emitting diode structure containing a single InGaN quantum well, using a top-down approach. The location, dimension, and height of each single-photon-emitting diode are controlled lithographically, providing great flexibility for chip-scale integration.

Asymmetric Bidirectional Controlled Teleportation via Seven-Photon Entangled State

NASA Astrophysics Data System (ADS)

Nie, Yi-you; Sang, Ming-huang

2017-11-01

We propose a protocol of asymmetric bidirectional controlled teleportation by using a seven-photon entangled state. In our protocol, Alice can teleport an arbitrary single-photon state to Bob and at the same time Bob can teleport an arbitrary two-photon state to Alice via the control of the supervisor Charlie. In addition, ones only carry out the Bell-state measurements and single-photon measurement.

Deterministic photon-emitter coupling in chiral photonic circuits.

PubMed

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

2015-09-01

Engineering photon emission and scattering is central to modern photonics applications ranging from light harvesting to quantum-information processing. To this end, nanophotonic waveguides are well suited as they confine photons to a one-dimensional geometry and thereby increase the light-matter interaction. In a regular waveguide, a quantum emitter interacts equally with photons in either of the two propagation directions. This symmetry is violated in nanophotonic structures in which non-transversal local electric-field components imply that photon 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-photon emission in a specially engineered photonic-crystal waveguide. We observe single-photon emission into the waveguide with a directionality that exceeds 90% under conditions in which practically all the emitted photons are coupled to the waveguide. The chiral light-matter interaction enables deterministic and highly directional photon emission for experimentally achievable on-chip non-reciprocal photonic elements. These may serve as key building blocks for single-photon optical diodes, transistors and deterministic quantum gates. Furthermore, chiral photonic circuits allow the dissipative preparation of entangled states of multiple emitters for experimentally achievable parameters, may lead to novel topological photon states and could be applied for directional steering of light.

Deterministic photon-emitter coupling in chiral photonic circuits

NASA Astrophysics Data System (ADS)

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

2015-09-01

Engineering photon emission and scattering is central to modern photonics applications ranging from light harvesting to quantum-information processing. To this end, nanophotonic waveguides are well suited as they confine photons to a one-dimensional geometry and thereby increase the light-matter interaction. In a regular waveguide, a quantum emitter interacts equally with photons in either of the two propagation directions. This symmetry is violated in nanophotonic structures in which non-transversal local electric-field components imply that photon 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-photon emission in a specially engineered photonic-crystal waveguide. We observe single-photon emission into the waveguide with a directionality that exceeds 90% under conditions in which practically all the emitted photons are coupled to the waveguide. The chiral light-matter interaction enables deterministic and highly directional photon emission for experimentally achievable on-chip non-reciprocal photonic elements. These may serve as key building blocks for single-photon optical diodes, transistors and deterministic quantum gates. Furthermore, chiral photonic circuits allow the dissipative preparation of entangled states of multiple emitters for experimentally achievable parameters, may lead to novel topological photon states and could be applied for directional steering of light.

Tunable room-temperature single-photon emission at telecom wavelengths from sp 3 defects in carbon nanotubes

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

He, Xiaowei; Hartmann, Nicolai F.; Ma, Xuedan

Generating quantum light emitters that operate at room temperature and at telecom wavelengths remains a significant materials challenge. To achieve this goal requires light sources that emit in the near-infrared wavelength region and that, ideally, are tunable to allow desired output wavelengths to be accessed in a controllable manner. Here, we show that exciton localization at covalently introduced aryl sp 3 defect sites in single-walled carbon nanotubes provides a route to room-temperature single-photon emission with ultrahigh single-photon purity (99%) and enhanced emission stability approaching the shot-noise limit. Moreover, we demonstrate that the inherent optical tunability of single-walled carbon nanotubes, presentmore » in their structural diversity, allows us to generate room-temperature single-photon emission spanning the entire telecom band. Furthermore, single-photon emission deep into the centre of the telecom C band (1.55 um) is achieved at the largest nanotube diameters we explore (0.936 nm).« less

Tunable room-temperature single-photon emission at telecom wavelengths from sp 3 defects in carbon nanotubes

DOE PAGES

He, Xiaowei; Hartmann, Nicolai F.; Ma, Xuedan; ...

2017-07-31

Generating quantum light emitters that operate at room temperature and at telecom wavelengths remains a significant materials challenge. To achieve this goal requires light sources that emit in the near-infrared wavelength region and that, ideally, are tunable to allow desired output wavelengths to be accessed in a controllable manner. Here, we show that exciton localization at covalently introduced aryl sp 3 defect sites in single-walled carbon nanotubes provides a route to room-temperature single-photon emission with ultrahigh single-photon purity (99%) and enhanced emission stability approaching the shot-noise limit. Moreover, we demonstrate that the inherent optical tunability of single-walled carbon nanotubes, presentmore » in their structural diversity, allows us to generate room-temperature single-photon emission spanning the entire telecom band. Furthermore, single-photon emission deep into the centre of the telecom C band (1.55 um) is achieved at the largest nanotube diameters we explore (0.936 nm).« less

Fast Purcell-enhanced single photon source in 1,550-nm telecom band from a resonant quantum dot-cavity coupling

PubMed Central

Birowosuto, Muhammad Danang; Sumikura, Hisashi; Matsuo, Shinji; Taniyama, Hideaki; van Veldhoven, Peter J.; Nötzel, Richard; Notomi, Masaya

2012-01-01

High-bit-rate nanocavity-based single photon sources in the 1,550-nm telecom band are challenges facing the development of fibre-based long-haul quantum communication networks. Here we report a very fast single photon source in the 1,550-nm telecom band, which is achieved by a large Purcell enhancement that results from the coupling of a single InAs quantum dot and an InP photonic crystal nanocavity. At a resonance, the spontaneous emission rate was enhanced by a factor of 5 resulting a record fast emission lifetime of 0.2 ns at 1,550 nm. We also demonstrate that this emission exhibits an enhanced anti-bunching dip. This is the first realization of nanocavity-enhanced single photon emitters in the 1,550-nm telecom band. This coupled quantum dot cavity system in the telecom band thus provides a bright high-bit-rate non-classical single photon source that offers appealing novel opportunities for the development of a long-haul quantum telecommunication system via optical fibres. PMID:22432053

Fast Purcell-enhanced single photon source in 1,550-nm telecom band from a resonant quantum dot-cavity coupling.

PubMed

Birowosuto, Muhammad Danang; Sumikura, Hisashi; Matsuo, Shinji; Taniyama, Hideaki; van Veldhoven, Peter J; Nötzel, Richard; Notomi, Masaya

2012-01-01

High-bit-rate nanocavity-based single photon sources in the 1,550-nm telecom band are challenges facing the development of fibre-based long-haul quantum communication networks. Here we report a very fast single photon source in the 1,550-nm telecom band, which is achieved by a large Purcell enhancement that results from the coupling of a single InAs quantum dot and an InP photonic crystal nanocavity. At a resonance, the spontaneous emission rate was enhanced by a factor of 5 resulting a record fast emission lifetime of 0.2 ns at 1,550 nm. We also demonstrate that this emission exhibits an enhanced anti-bunching dip. This is the first realization of nanocavity-enhanced single photon emitters in the 1,550-nm telecom band. This coupled quantum dot cavity system in the telecom band thus provides a bright high-bit-rate non-classical single photon source that offers appealing novel opportunities for the development of a long-haul quantum telecommunication system via optical fibres.

Extracting the time scales of conformational dynamics from single-molecule single-photon fluorescence statistics.

PubMed

Shang, Jianyuan; Geva, Eitan

2007-04-26

The quenching rate of a fluorophore attached to a macromolecule can be rather sensitive to its conformational state. The decay of the corresponding fluorescence lifetime autocorrelation function can therefore provide unique information on the time scales of conformational dynamics. The conventional way of measuring the fluorescence lifetime autocorrelation function involves evaluating it from the distribution of delay times between photoexcitation and photon emission. However, the time resolution of this procedure is limited by the time window required for collecting enough photons in order to establish this distribution with sufficient signal-to-noise ratio. Yang and Xie have recently proposed an approach for improving the time resolution, which is based on the argument that the autocorrelation function of the delay time between photoexcitation and photon emission is proportional to the autocorrelation function of the square of the fluorescence lifetime [Yang, H.; Xie, X. S. J. Chem. Phys. 2002, 117, 10965]. In this paper, we show that the delay-time autocorrelation function is equal to the autocorrelation function of the square of the fluorescence lifetime divided by the autocorrelation function of the fluorescence lifetime. We examine the conditions under which the delay-time autocorrelation function is approximately proportional to the autocorrelation function of the square of the fluorescence lifetime. We also investigate the correlation between the decay of the delay-time autocorrelation function and the time scales of conformational dynamics. The results are demonstrated via applications to a two-state model and an off-lattice model of a polypeptide.

Global transients in ultraviolet and red-infrared ranges from data of Universitetsky-Tatiana-2 satellite

NASA Astrophysics Data System (ADS)

Garipov, G. K.; Khrenov, B. A.; Klimov, P. A.; Klimenko, V. V.; Mareev, E. A.; Martines, O.; Mendoza, E.; Morozenko, V. S.; Panasyuk, M. I.; Park, I. H.; Ponce, E.; Rivera, L.; Salazar, H.; Tulupov, V. I.; Vedenkin, N. N.; Yashin, I. V.

2013-01-01

Light detectors sensitive to wavelength ranges 240-400 nm and beyond 610 nm (which we refer to, for simplicity, as the UV and Red bands) on board Universitetsky-Tatiana-2 satellite have detected transient flashes in the atmosphere of duration 1-128 ms. Measured ratio of the number of Red photons to the number of UV photons indicates that source of transient radiation is at high atmosphere altitude (>50 km). Distribution of events with various photon numbers Qa in the atmosphere found to be different for "luminous" events Qa = 1023 - 1026 (with exponent of differential distribution -2.2) and for "faint" events Qa = 1021 - 1023 (with exponent - 0.97). Luminous event parameters (atmosphere altitude, energy released to radiation, and temporal profiles) are similar to observed elsewhere parameters of transient luminous events (TLE) of elves, sprites, halo, and gigantic blue jets types. Global map of luminous events demonstrates concentration to equatorial zones (latitudes 30°N to 30°S) above continents. Faint events (with number of photons Qa = 1020 - 5ṡ 1021) are distributed more uniformly over latitudes and longitudes. Phenomenon of series of transients registered every minute along satellite orbit (from 3 to 16 transients in one series) was observed. Most TLE-type events belonged to series. Single transients are in average fainter than serial ones. Some transients belonging to series occurs far away of thunderstorm regions. Origin of faint single transients is not clear; several hypothetical models of their production are discussed.

Catheter-based time-gated near-infrared fluorescence/OCT imaging system

NASA Astrophysics Data System (ADS)

Lu, Yuankang; Abran, Maxime; Cloutier, Guy; Lesage, Frédéric

2018-02-01

We developed a new dual-modality intravascular imaging system based on fast time-gated fluorescence intensity imaging and spectral domain optical coherence tomography (SD-OCT) for the purpose of interventional detection of atherosclerosis. A pulsed supercontinuum laser was used for fluorescence and OCT imaging. A double-clad fiber (DCF)- based side-firing catheter was designed and fabricated to have a 23 μm spot size at a 2.2 mm working distance for OCT imaging. Its single-mode core is used for OCT, while its inner cladding transports fluorescence excitation light and collects fluorescent photons. The combination of OCT and fluorescence imaging was achieved by using a DCF coupler. For fluorescence detection, we used a time-gated technique with a novel single-photon avalanche diode (SPAD) working in an ultra-fast gating mode. A custom-made delay chip was integrated in the system to adjust the delay between the excitation laser pulse and the SPAD gate-ON window. This technique allowed to detect fluorescent photons of interest while rejecting most of the background photons, thus leading to a significantly improved signal to noise ratio (SNR). Experiments were carried out in turbid media mimicking tissue with an indocyanine green (ICG) inclusion (1 mM and 100 μM) to compare the time-gated technique and the conventional continuous detection technique. The gating technique increased twofold depth sensitivity, and tenfold SNR at large distances. The dual-modality imaging capacity of our system was also validated with a silicone-based tissue-mimicking phantom.

Low-noise quantum frequency down-conversion of indistinguishable photons (Conference Presentation)

NASA Astrophysics Data System (ADS)

Kambs, Benjamin; Kettler, Jan; Bock, Matthias; Becker, Jonas; Arend, Carsten; Jetter, Michael; Michler, Peter; Becher, Christoph

2016-04-01

Single-photon sources based on quantum dots have been shown to exhibit almost ideal properties such as high brightness and purity in terms of clear anti-bunching as well as high two-photon interference visibilities of the emitted photons, making them promising candidates for different quantum information applications such as quantum computing, quantum communication and quantum teleportation. However, as most single-photon sources also quantum dots typically emit light at wavelengths of electronic transitions within the visible or the near infrared range. In order to establish quantum networks with remote building blocks, low-loss single photons at telecom wavelengths are preferable, though. Despite recent progress on emitters of telecom-photons, the most efficient single-photon sources still work at shorter wavelengths. On that matter, quantum frequency down-conversion, being a nonlinear optical process, has been used in recent years to alter the wavelength of single photons to the telecom wavelength range while conserving their nonclassical properties. Characteristics such as lifetime, first-order coherence, anti-bunching and entanglement have been shown to be conserved or even improved due to background suppression during the conversion process, while the conservation of indistinguishability was yet to be shown. Here we present our experimental results on quantum frequency down-conversion of single photons emitted by an InAs/GaAs quantum dot at 903.6 nm following a pulsed excitation of a p-shell exciton at 884 nm. The emitted fluorescence photons are mixed with a strong pump-field at 2155 nm inside a periodically poled lithium niobate ridge waveguide and converted to 1557 nm. Common issues of a large background due to Raman-scattered pump-light photons spectrally overlapping with the converted single photons could largely be avoided, as the pump-wavelength was chosen to be fairly longer than the target wavelength. Additional narrowband spectral filtering at the telecom regime as a result of the small conversion bandwidth and using a high-performance fiber-Bragg-grating solely left the detector dark counts as the only noise source in our setup. Therefore, we could achieve conversion efficiencies of more than 20 %. In order to test the indistinguishability, sequentially emitted photons were fed into a Mach-Zehnder interferometer and spatially as well as temporally overlapped at the output beam splitter. Cross-correlation measurements between both output-ports of the beam splitter exhibit two-photon interference contrasts of more than 40 % prior to and after the down-conversion step. Accordingly, we demonstrate that the process of quantum frequency conversion preserves photon indistinguishability and can be used to establish a versatile source of indistinguishable single photons at the telecom C-Band. Furthermore our scheme allows for converting photons in a wavelength band from 900 nm to 910 nm to the same telecom target wavelength. This enables us to test indistinguishability of frequency-converted photons, originally stemming from different sources with dinstinguishable wavelengths.

Single Quantum Dot with Microlens and 3D-Printed Micro-objective as Integrated Bright Single-Photon Source

PubMed Central

2017-01-01

Integrated single-photon sources with high photon-extraction efficiency are key building blocks for applications in the field of quantum communications. We report on a bright single-photon source realized by on-chip integration of a deterministic quantum dot microlens with a 3D-printed multilens micro-objective. The device concept benefits from a sophisticated combination of in situ 3D electron-beam lithography to realize the quantum dot microlens and 3D femtosecond direct laser writing for creation of the micro-objective. In this way, we obtain a high-quality quantum device with broadband photon-extraction efficiency of (40 ± 4)% and high suppression of multiphoton emission events with g(2)(τ = 0) < 0.02. Our results highlight the opportunities that arise from tailoring the optical properties of quantum emitters using integrated optics with high potential for the further development of plug-and-play fiber-coupled single-photon sources. PMID:28670600

Realization of a Cascaded Quantum System: Heralded Absorption of a Single Photon Qubit by a Single-Electron Charged Quantum Dot.

PubMed

Delteil, Aymeric; Sun, Zhe; Fält, Stefan; Imamoğlu, Atac

2017-04-28

Photonic losses pose a major limitation for the implementation of a quantum state transfer between nodes of a quantum network. A measurement that heralds a successful transfer without revealing any information about the qubit may alleviate this limitation. Here, we demonstrate the heralded absorption of a single photonic qubit, generated by a single neutral quantum dot, by a single-electron charged quantum dot that is located 5 m away. The transfer of quantum information to the spin degree of freedom takes place upon the emission of a photon; for a properly chosen or prepared quantum dot, the detection of this photon yields no information about the qubit. We show that this process can be combined with local operations optically performed on the destination node by measuring classical correlations between the absorbed photon color and the final state of the electron spin. Our work suggests alternative avenues for the realization of quantum information protocols based on cascaded quantum systems.

Time-reversal-symmetric single-photon wave packets for free-space quantum communication.

PubMed

Trautmann, N; Alber, G; Agarwal, G S; Leuchs, G

2015-05-01

Readout and retrieval processes are proposed for efficient, high-fidelity quantum state transfer between a matter qubit, encoded in the level structure of a single atom or ion, and a photonic qubit, encoded in a time-reversal-symmetric single-photon wave packet. They are based on controlling spontaneous photon emission and absorption of a matter qubit on demand in free space by stimulated Raman adiabatic passage. As these processes do not involve mode selection by high-finesse cavities or photon transport through optical fibers, they offer interesting perspectives as basic building blocks for free-space quantum-communication protocols.

Transition of lasing modes in polymeric opal photonic crystal resonating cavity.

PubMed

Shi, Lan-Ting; Zheng, Mei-Ling; Jin, Feng; Dong, Xian-Zi; Chen, Wei-Qiang; Zhao, Zhen-Sheng; Duan, Xuan-Ming

2016-06-10

We demonstrate the transition of lasing modes in the resonating cavity constructed by polystyrene opal photonic crystals and 7 wt. % tert-butyl Rhodamine B doped polymer film. Both single mode and multiple mode lasing emission are observed from the resonating cavity. The lasing threshold is determined to be 0.81  μJ/pulse for single mode lasing emission and 2.25  μJ/pulse for multiple mode lasing emission. The single mode lasing emission is attributed to photonic lasing resulting from the photonic bandgap effect of the opal photonic crystals, while the multiple mode lasing emission is assigned to random lasing due to the defects in the photonic crystals. The result would benefit the development of low threshold polymeric solid state photonic crystal lasers.

Photonic crystal enhanced fluorescence immunoassay on diatom biosilica.

PubMed

Squire, Kenneth; Kong, Xianming; LeDuff, Paul; Rorrer, Gregory L; Wang, Alan X

2018-05-16

Fluorescence biosensing is one of the most established biosensing methods, particularly fluorescence spectroscopy and microscopy. These are two highly sensitive techniques but require high grade electronics and optics to achieve the desired sensitivity. Efforts have been made to implement these methods using consumer grade electronics and simple optical setups for applications such as point-of-care diagnostics, but the sensitivity inherently suffers. Sensing substrates, capable of enhancing fluorescence are thus needed to achieve high sensitivity for such applications. In this paper, we demonstrate a photonic crystal-enhanced fluorescence immunoassay biosensor using diatom biosilica, which consists of silica frustules with sub-100 nm periodic pores. Utilizing the enhanced local optical field, the Purcell effect and increased surface area from the diatom photonic crystals, we create ultrasensitive immunoassay biosensors that can significantly enhance fluorescence spectroscopy as well as fluorescence imaging. Using standard antibody-antigen-labeled antibody immunoassay protocol, we experimentally achieved 100× and 10× better detection limit with fluorescence spectroscopy and fluorescence imaging respectively. The limit of detection of the mouse IgG goes down to 10 -16 M (14 fg/mL) and 10 -15 M (140 fg/mL) for the two respective detection modalities, virtually sensing a single mouse IgG molecule on each diatom frustule. The effectively enhanced fluorescence imaging in conjunction with the simple hot-spot counting analysis method used in this paper proves the great potential of diatom fluorescence immunoassay for point-of-care biosensing. Scanning electron microscope image of biosilica diatom frustule that enables significant enhancement of fluorescence spectroscopy and fluorescence image. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Internalization of aggregated photosensitizers by tumor cells: subcellular time-resolved fluorescence spectroscopy on derivatives of pyropheophorbide-a ethers and chlorin e6 under femtosecond one- and two-photon excitations.

PubMed

Kelbauskas, L; Dietel, W

2002-12-01

Amphiphilic sensitizers self-associate in aqueous environments and form aggregated species that exhibit no or only negligible photodynamic activity. However, amphiphilic photosensitizers number among the most potent agents of photodynamic therapy. The processes by which these sensitizers are internalized into tumor cells have yet to be fully elucidated and thus remain the subject of debate. In this study the uptake of photosensitizer aggregates into tumor cells was examined directly using subcellular time-resolved fluorescence spectroscopy with a high temporal resolution (20-30 ps) and high sensitivity (time-correlated single-photon counting). The investigations were performed on selected sensitizers that exhibit short fluorescence decay times (< 50 ps) in aggregated form. Derivatives of pyropheophorbide-a ether and chlorin e6 with varying lipophilicity were used for the study. The characteristic fluorescence decay times and spectroscopic features of the sensitizer aggregates measured in aqueous solution also could be observed in A431 human endothelial carcinoma cells administered with these photosensitizers. This shows that tumor cells can internalize sensitizers in aggregated form. Uptake of aggregates and their monomerization inside cells were demonstrated directly for the first time by means of fluorescence lifetime imaging with a high temporal resolution. Internalization of the aggregates seems to be endocytosis mediated. The degree of their monomerization in tumor cells is strongly influenced by the lipophilicity of the compounds.

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

NASA Astrophysics Data System (ADS)

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

2018-02-01

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

Coherent state amplification using frequency conversion and a single photon source

NASA Astrophysics Data System (ADS)

Kasture, Sachin

2017-11-01

Quantum state discrimination lies at the heart of quantum communication and quantum cryptography protocols. Quantum Key Distribution (QKD) using coherent states and homodyne detection has been shown to be a feasible method for quantum communication over long distances. However, this method is still limited because of optical losses. Noiseless coherent state amplification has been proposed as a way to overcome this. Photon addition using stimulated Spontaneous Parametric Down-conversion followed by photon subtraction has been used as a way to implement amplification. However, this process occurs with very low probability which makes it very difficult to implement cascaded stages of amplification due to dark count probability in the single photon detectors used to herald the addition and subtraction of single photons. We discuss a scheme using the χ (2) and χ (3) optical non-linearity and frequency conversion (sum and difference frequency generation) along with a single photon source to implement photon addition. Unlike the photon addition scheme using SPDC, this scheme allows us to tune the success probability at the cost of reduced amplification. The photon statistics of the converted field can be controlled using the power of the pump field and the interaction time.

Single-photon imager based on a superconducting nanowire delay line

NASA Astrophysics Data System (ADS)

Zhao, Qing-Yuan; Zhu, Di; Calandri, Niccolò; Dane, Andrew E.; McCaughan, Adam N.; Bellei, Francesco; Wang, Hao-Zhu; Santavicca, Daniel F.; Berggren, Karl K.

2017-03-01

Detecting spatial and temporal information of individual photons is critical to applications in spectroscopy, communication, biological imaging, astronomical observation and quantum-information processing. Here we demonstrate a scalable single-photon imager using a single continuous superconducting nanowire that is not only a single-photon detector but also functions as an efficient microwave delay line. In this context, photon-detection pulses are guided in the nanowire and enable the readout of the position and time of photon-absorption events from the arrival times of the detection pulses at the nanowire's two ends. Experimentally, we slowed down the velocity of pulse propagation to ∼2% of the speed of light in free space. In a 19.7 mm long nanowire that meandered across an area of 286 × 193 μm2, we were able to resolve ∼590 effective pixels with a temporal resolution of 50 ps (full width at half maximum). The nanowire imager presents a scalable approach for high-resolution photon imaging in space and time.

Electrically driven quantum light emission in electromechanically tuneable photonic crystal cavities

NASA Astrophysics Data System (ADS)

Petruzzella, M.; Pagliano, F. M.; Zobenica, Ž.; Birindelli, S.; Cotrufo, M.; van Otten, F. W. M.; van der Heijden, R. W.; Fiore, A.

2017-12-01

A single quantum dot deterministically coupled to a photonic crystal environment constitutes an indispensable elementary unit to both generate and manipulate single-photons in next-generation quantum photonic circuits. To date, the scaling of the number of these quantum nodes on a fully integrated chip has been prevented by the use of optical pumping strategies that require a bulky off-chip laser along with the lack of methods to control the energies of nano-cavities and emitters. Here, we concurrently overcome these limitations by demonstrating electrical injection of single excitonic lines within a nano-electro-mechanically tuneable photonic crystal cavity. When an electrically driven dot line is brought into resonance with a photonic crystal mode, its emission rate is enhanced. Anti-bunching experiments reveal the quantum nature of these on-demand sources emitting in the telecom range. These results represent an important step forward in the realization of integrated quantum optics experiments featuring multiple electrically triggered Purcell-enhanced single-photon sources embedded in a reconfigurable semiconductor architecture.

On-chip interference of single photons from an embedded quantum dot and an external laser

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

Prtljaga, N., E-mail: n.prtljaga@sheffield.ac.uk; Bentham, C.; O'Hara, J.

2016-06-20

In this work, we demonstrate the on-chip two-photon interference between single photons emitted by a single self-assembled InGaAs quantum dot and an external laser. The quantum dot is embedded within one arm of an air-clad directional coupler which acts as a beam-splitter for incoming light. Photons originating from an attenuated external laser are coupled to the second arm of the beam-splitter and then combined with the quantum dot photons, giving rise to two-photon quantum interference between dissimilar sources. We verify the occurrence of on-chip Hong-Ou-Mandel interference by cross-correlating the optical signal from the separate output ports of the directional coupler.more » This experimental approach allows us to use a classical light source (laser) to assess in a single step the overall device performance in the quantum regime and probe quantum dot photon indistinguishability on application realistic time scales.« less

Tomography of a displacement photon counter for discrimination of single-rail optical qubits

NASA Astrophysics Data System (ADS)

Izumi, Shuro; Neergaard-Nielsen, Jonas S.; Andersen, Ulrik L.

2018-04-01

We investigate the performance of a detection strategy composed of a displacement operation and a photon counter, which is known as a beneficial tool in optical coherent communications, to the quantum state discrimination of the two superpositions of vacuum and single photon states corresponding to the {\\hat{σ }}x eigenstates in the single-rail encoding of photonic qubits. We experimentally characterize the detection strategy in vacuum-single photon two-dimensional space using quantum detector tomography and evaluate the achievable discrimination error probability from the reconstructed measurement operators. We furthermore derive the minimum error rate obtainable with Gaussian transformations and homodyne detection. Our proof-of-principle experiment shows that the proposed scheme can achieve a discrimination error surpassing homodyne detection.

Solid-state single-photon emitters

NASA Astrophysics Data System (ADS)

Aharonovich, Igor; Englund, Dirk; Toth, Milos

2016-10-01

Single-photon emitters play an important role in many leading quantum technologies. There is still no 'ideal' on-demand single-photon emitter, but a plethora of promising material systems have been developed, and several have transitioned from proof-of-concept to engineering efforts with steadily improving performance. Here, we review recent progress in the race towards true single-photon emitters required for a range of quantum information processing applications. We focus on solid-state systems including quantum dots, defects in solids, two-dimensional hosts and carbon nanotubes, as these are well positioned to benefit from recent breakthroughs in nanofabrication and materials growth techniques. We consider the main challenges and key advantages of each platform, with a focus on scalable on-chip integration and fabrication of identical sources on photonic circuits.

Temperature insensitive bending sensor based on in-line Mach-Zehnder interferometer

NASA Astrophysics Data System (ADS)

Chen, Xue; Yu, Yongqin; Xu, Xiaomei; Huang, Quandong; Ou, Zhilong; Wang, Jishun; Yan, Peiguang; Du, Chenlin

2014-09-01

A simple and compact fiber bending sensor based on the Mach-Zehnder interferometer was proposed. A photonic crystal fiber (PCF) with a length of 10 mm was spliced by collapsing air holes with two conventional single mode fibers to consist of an all fiber bending sensor. The sensitivity of 0.53 nm/m-1 was obtained at 1586 nm for the curvature range from 0 to 8.514 m-1. The temperature sensitivity was very low. The measurement error due to the temperature effect was about 8.68×10-3 m-1/°c, and the temperature effect in the curvature measurement could be ignored. This device can avoid the cross sensitivity of the temperature in the curvature measurement.

Time-resolved measurements in diffuse reflectance: effects of the instrument response function of different detection systems on the depth sensitivity

NASA Astrophysics Data System (ADS)

Puszka, Agathe; Planat-Chrétien, Anne; Berger, Michel; Hervé, Lionel; Dinten, Jean-Marc

2014-02-01

We demonstrate the loss of depth sensitivity induced by the instrument response function on reflectance time-resolved diffuse optical tomography through the comparison of 3 detection systems: on one hand a photomultiplier tube (PMT) and a hybrid PMT coupled with a time-correlated single-photon counting card and on the other hand a high rate intensified camera. We experimentally evaluate the depth sensitivity achieved for each detection module with an absorbing inclusion embedded in a turbid medium. The different interfiber distances of 5, 10 and 15 mm are considered. Finally, we determine a maximal depth reached for each detection system by using 3D tomographic reconstructions based on the Mellin-Laplace transform.

Cooling in the single-photon strong-coupling regime of cavity optomechanics

NASA Astrophysics Data System (ADS)

Nunnenkamp, A.; Børkje, K.; Girvin, S. M.

2012-05-01

In this Rapid Communication we discuss how red-sideband cooling is modified in the single-photon strong-coupling regime of cavity optomechanics where the radiation pressure of a single photon displaces the mechanical oscillator by more than its zero-point uncertainty. Using Fermi's golden rule we calculate the transition rates induced by the optical drive without linearizing the optomechanical interaction. In the resolved-sideband limit we find multiple-phonon cooling resonances for strong single-photon coupling that lead to nonthermal steady states including the possibility of phonon antibunching. Our study generalizes the standard linear cooling theory.

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.

Elliptical quantum dots as on-demand single photons sources with deterministic polarization states

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

Teng, Chu-Hsiang; Demory, Brandon; Ku, Pei-Cheng, E-mail: peicheng@umich.edu

In quantum information, control of the single photon's polarization is essential. Here, we demonstrate single photon generation in a pre-programmed and deterministic polarization state, on a chip-scale platform, utilizing site-controlled elliptical quantum dots (QDs) synthesized by a top-down approach. The polarization from the QD emission is found to be linear with a high degree of linear polarization and parallel to the long axis of the ellipse. Single photon emission with orthogonal polarizations is achieved, and the dependence of the degree of linear polarization on the QD geometry is analyzed.

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

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

Ikuta, Rikizo; Kato, Hiroshi; Kusaka, Yoshiaki

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

Signatures of two-photon pulses from a quantum two-level system

NASA Astrophysics Data System (ADS)

Fischer, Kevin A.; Hanschke, Lukas; Wierzbowski, Jakob; Simmet, Tobias; Dory, Constantin; Finley, Jonathan J.; Vučković, Jelena; Müller, Kai

2017-07-01

A two-level atom can generate a strong many-body interaction with light under pulsed excitation. The best known effect is single-photon generation, where a short Gaussian laser pulse is converted into a Lorentzian single-photon wavepacket. However, recent studies suggested that scattering of intense laser fields off a two-level atom may generate oscillations in two-photon emission that come out of phase with the Rabi oscillations, as the power of the pulse increases. Here, we provide an intuitive explanation for these oscillations using a quantum trajectory approach and show how they may preferentially result in emission of two-photon pulses. Experimentally, we observe the signatures of these oscillations by measuring the bunching of photon pulses scattered off a two-level quantum system. Our theory and measurements provide insight into the re-excitation process that plagues on-demand single-photon sources while suggesting the possibility of producing new multi-photon states.

Enhancing a slow and weak optomechanical nonlinearity with delayed quantum feedback

NASA Astrophysics Data System (ADS)

Wang, Zhaoyou; Safavi-Naeini, Amir H.

2017-07-01

A central goal of quantum optics is to generate large interactions between single photons so that one photon can strongly modify the state of another one. In cavity optomechanics, photons interact with the motional degrees of freedom of an optical resonator, for example, by imparting radiation pressure forces on a movable mirror or sensing minute fluctuations in the position of the mirror. Here, we show that the optical nonlinearity arising from these effects, typically too small to operate on single photons, can be sufficiently enhanced with feedback to generate large interactions between single photons. We propose a protocol that allows photons propagating in a waveguide to interact with each other through multiple bounces off an optomechanical system. The protocol is analysed by evolving the full many-body quantum state of the waveguide-coupled system, illustrating that large photon-photon interactions mediated by mechanical motion may be within experimental reach.

Temporal interference with frequency-controllable long photons from independent cold atomic sources

NASA Astrophysics Data System (ADS)

Qian, Peng; Gu, Zhenjie; Wen, Rong; Zhang, Weiping; Chen, J. F.

2018-01-01

The interference of single photons from independent sources is an essential tool in quantum information processing. However, the interfering of photons with long temporal states in a time-resolved manner has rarely been studied. This is because without transmitting spectral filters or coupling to a cavity mode single photons generated in traditional nonlinear crystals suffer from a short temporal profile below 1 ns. With spectral correlation maintained in the biphotons generated from spontaneous four-wave mixing process in cold atom clouds, here we demonstrate the temporal interference of two frequency-tunable long photons from two independent cold atomic sources. We observe and analyze the interference of frequency-mismatched photons, where the phenomenon of the quantum beat at megahertz separation is displayed. Our paper provides more details for the quantum beat of two independent narrow-band single photons, which may find potential application in frequency-encoded photonic qubits in quantum information processing.

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).

Weak-field multiphoton femtosecond coherent control in the single-cycle regime.

PubMed

Chuntonov, Lev; Fleischer, Avner; Amitay, Zohar

2011-03-28

Weak-field coherent phase control of atomic non-resonant multiphoton excitation induced by shaped femtosecond pulses is studied theoretically in the single-cycle regime. The carrier-envelope phase (CEP) of the pulse, which in the multi-cycle regime does not play any control role, is shown here to be a new effective control parameter that its effect is highly sensitive to the spectral position of the ultrabroad spectrum. Rationally chosen position of the ultrabroadband spectrum coherently induces several groups of multiphoton transitions from the ground state to the excited state of the system: transitions involving only absorbed photons as well as Raman transitions involving both absorbed and emitted photons. The intra-group interference is controlled by the relative spectral phase of the different frequency components of the pulse, while the inter-group interference is controlled jointly by the CEP and the relative spectral phase. Specifically, non-resonant two- and three-photon excitation is studied in a simple model system within the perturbative frequency-domain framework. The developed intuition is then applied to weak-field multiphoton excitation of atomic cesium (Cs), where the simplified model is verified by non-perturbative numerical solution of the time-dependent Schrödinger equation. We expect this work to serve as a basis for a new line of femtosecond coherent control experiments.

A single-photon fluorescence and multi-photon spectroscopic study of atherosclerotic lesions

NASA Astrophysics Data System (ADS)

Smith, Michael S. D.; Ko, Alex C. T.; Ridsdale, Andrew; Schattka, Bernie; Pegoraro, Adrian; Hewko, Mark D.; Shiomi, Masashi; Stolow, Albert; Sowa, Michael G.

2009-06-01

In this study we compare the single-photon autofluorescence and multi-photon emission spectra obtained from the luminal surface of healthy segments of artery with segments where there are early atherosclerotic lesions. Arterial tissue was harvested from atherosclerosis-prone WHHL-MI rabbits (Watanabe heritable hyperlipidemic rabbit-myocardial infarction), an animal model which mimics spontaneous myocardial infarction in humans. Single photon fluorescence emission spectra of samples were acquired using a simple spectrofluorometer set-up with 400 nm excitation. Samples were also investigated using a home built multi-photon microscope based on a Ti:sapphire femto-second oscillator. The excitation wavelength was set at 800 nm with a ~100 femto-second pulse width. Epi-multi-photon spectroscopic signals were collected through a fibre-optics coupled spectrometer. While the single-photon fluorescence spectra of atherosclerotic lesions show minimal spectroscopic difference from those of healthy arterial tissue, the multi-photon spectra collected from atherosclerotic lesions show marked changes in the relative intensity of two-photon excited fluorescence (TPEF) and second-harmonic generation (SHG) signals when compared with those from healthy arterial tissue. The observed sharp increase of the relative SHG signal intensity in a plaque is in agreement with the known pathology of early lesions which have increased collagen content.

Nonlinear absorption in single LaF3 and MgF2 layers at 193 nm measured by surface sensitive laser induced deflection technique

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

Muehlig, Christian; Bublitz, Simon; Kufert, Siegfried

2009-12-10

We report nonlinear absorption data of LaF3 and MgF2 single layers at 193 nm. A highly surface sensitive measurement strategy of the laser induced deflection technique is introduced and applied to measure the absorption of highly transparent thin films independently of the substrate absorption. Linear absorptions k=({alpha}x{lambda})/4{pi} of 2x10{sup -4} and 8.5x10{sup -4} (LaF3) and 1.8x10{sup -4} and 6.9x10{sup -4} (MgF2) are found. Measured two photon absorption (TPA) coefficients are {beta}=1x10{sup -4} cm/W (LaF3), 1.8x10{sup -5}, and 5.8x10{sup -5} cm/W (MgF2). The TPA coefficients are several orders of magnitude higher than typical values for fluoride single crystals, which is likelymore » to result from sequential two step absorption processes.« less

Investigating and improving student understanding of quantum mechanics in the context of single photon interference

NASA Astrophysics Data System (ADS)

Marshman, Emily; Singh, Chandralekha

2017-06-01

Single photon experiments involving a Mach-Zehnder interferometer can illustrate the fundamental principles of quantum mechanics, e.g., the wave-particle duality of a single photon, single photon interference, and the probabilistic nature of quantum measurement involving single photons. These experiments explicitly make the connection between the abstract quantum theory and concrete laboratory settings and have the potential to help students develop a solid grasp of the foundational issues in quantum mechanics. Here we describe students' conceptual difficulties with these topics in the context of Mach-Zehnder interferometer experiments with single photons and how the difficulties found in written surveys and individual interviews were used as a guide in the development of a Quantum Interactive Learning Tutorial (QuILT). The QuILT uses an inquiry-based approach to learning and takes into account the conceptual difficulties found via research to help upper-level undergraduate and graduate students learn about foundational quantum mechanics concepts using the concrete quantum optics context. It strives to help students learn the basics of quantum mechanics in the context of single photon experiment, develop the ability to apply fundamental quantum principles to experimental situations in quantum optics, and explore the differences between classical and quantum ideas in a concrete context. We discuss the findings from in-class evaluations suggesting that the QuILT was effective in helping students learn these abstract concepts.

TiO2 activity enhancement through synergistic effect of photons localization of photonic crystals and the sensitization of CdS quantum dots

NASA Astrophysics Data System (ADS)

Li, Ping; Wang, Yuan; Wang, Ai-Jun; Chen, Sheng-Li

2017-02-01

In this work, the enhancement of TiO2 photocatalytic activity was studied through synergistic effect of the photons localization of photonic crystals and the sensitization of CdS quantum dots (CdS QDs). CdS QDs sensitized TiO2 membrane (denoted as CdS QDs/TiO2) was synthesized through doping the TiO2 membrane with CdS QDs by chemical bath deposition method (CBD). After TiO2 was sensitized with CdS QDs, the edge of light absorption of TiO2 was red-shifted to 470 nm and the light absorption in the range of 400 600 nm was higher than that of plain TiO2 membrane. Another type of composite membrane, CdS QDs/TiO2/SiO2 opal composite membrane was prepared by coupling SiO2 opal (a kind of photonic crystal) layer onto the CdS QDs/TiO2 membrane, and the photonic band gap of the SiO2 opal photonic crystal layer was deliberately planned at the electronic band gap of the CdS QDs. The photodegradation of gaseous CH3CHO (acetaldehyde) was used as probe reaction to test the photocatalytic activity of the as-prepared membranes, and the results showed that the CdS QDs sensitization can significantly improve the photocatalytic activity of TiO2 membrane under visible light irradiation, with the acetaldehyde degradation rate constant (k) on CdS QDs/TiO2 membranes being 1.59 times of that on plain TiO2 membranes. The acetaldehyde degradation rate constant on CdS QDs/TiO2/SiO2 opal composite membrane reached 4 times of that on plain TiO2 membrane. The photocatalytic activity of TiO2 membrane can be improved through synergistic effect of the photons localization of photonic crystals and the sensitization of CdS QDs.

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

NASA Astrophysics Data System (ADS)

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

2016-11-01

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

Mid-infrared coincidence measurements on twin photons at room temperature

PubMed Central

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

2017-01-01

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

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

PubMed Central

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

2013-01-01

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

Self-Assembled Nanocrystals of Polycyclic Aromatic Hydrocarbons Show Photostable Single-Photon Emission.

PubMed

Pazzagli, Sofia; Lombardi, Pietro; Martella, Daniele; Colautti, Maja; Tiribilli, Bruno; Cataliotti, Francesco Saverio; Toninelli, Costanza

2018-05-22

Quantum technologies could largely benefit from the control of quantum emitters in sub-micrometric size crystals. These are naturally prone to integration in hybrid devices, including heterostructures and complex photonic devices. Currently available quantum emitters in nanocrystals suffer from spectral instability, preventing their use as single-photon sources for most quantum optics operations. In this work we report on the performances of single-photon emission from organic nanocrystals (average size of hundreds of nm), made of anthracene (Ac) and doped with dibenzoterrylene (DBT) molecules. The source has hours-long photostability with respect to frequency and intensity, both at room and at cryogenic temperature. When cooled to 3 K, the 00-zero phonon line shows linewidth values (50 MHz) close to the lifetime limit. Such optical properties in a nanocrystalline environment recommend the proposed organic nanocrystals as single-photon sources for integrated photonic quantum technologies.

Photonic transistor and router using a single quantum-dot-confined spin in a single-sided optical microcavity

NASA Astrophysics Data System (ADS)

Hu, C. Y.

2017-03-01

The future Internet is very likely the mixture of all-optical Internet with low power consumption and quantum Internet with absolute security guaranteed by the laws of quantum mechanics. Photons would be used for processing, routing and com-munication of data, and photonic transistor using a weak light to control a strong light is the core component as an optical analogue to the electronic transistor that forms the basis of modern electronics. In sharp contrast to previous all-optical tran-sistors which are all based on optical nonlinearities, here I introduce a novel design for a high-gain and high-speed (up to terahertz) photonic transistor and its counterpart in the quantum limit, i.e., single-photon transistor based on a linear optical effect: giant Faraday rotation induced by a single electronic spin in a single-sided optical microcavity. A single-photon or classical optical pulse as the gate sets the spin state via projective measurement and controls the polarization of a strong light to open/block the photonic channel. Due to the duality as quantum gate for quantum information processing and transistor for optical information processing, this versatile spin-cavity quantum transistor provides a solid-state platform ideal for all-optical networks and quantum networks.

Photonic transistor and router using a single quantum-dot-confined spin in a single-sided optical microcavity

PubMed Central

Hu, C. Y.

2017-01-01

The future Internet is very likely the mixture of all-optical Internet with low power consumption and quantum Internet with absolute security guaranteed by the laws of quantum mechanics. Photons would be used for processing, routing and com-munication of data, and photonic transistor using a weak light to control a strong light is the core component as an optical analogue to the electronic transistor that forms the basis of modern electronics. In sharp contrast to previous all-optical tran-sistors which are all based on optical nonlinearities, here I introduce a novel design for a high-gain and high-speed (up to terahertz) photonic transistor and its counterpart in the quantum limit, i.e., single-photon transistor based on a linear optical effect: giant Faraday rotation induced by a single electronic spin in a single-sided optical microcavity. A single-photon or classical optical pulse as the gate sets the spin state via projective measurement and controls the polarization of a strong light to open/block the photonic channel. Due to the duality as quantum gate for quantum information processing and transistor for optical information processing, this versatile spin-cavity quantum transistor provides a solid-state platform ideal for all-optical networks and quantum networks. PMID:28349960

Efficient room-temperature source of polarized single photons

DOEpatents

Lukishova, Svetlana G.; Boyd, Robert W.; Stroud, Carlos R.

2007-08-07

An efficient technique for producing deterministically polarized single photons uses liquid-crystal hosts of either monomeric or oligomeric/polymeric form to preferentially align the single emitters for maximum excitation efficiency. Deterministic molecular alignment also provides deterministically polarized output photons; using planar-aligned cholesteric liquid crystal hosts as 1-D photonic-band-gap microcavities tunable to the emitter fluorescence band to increase source efficiency, using liquid crystal technology to prevent emitter bleaching. Emitters comprise soluble dyes, inorganic nanocrystals or trivalent rare-earth chelates.

Radio frequency phototube and optical clock: High resolution, high rate and highly stable single photon timing technique

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

Margaryan, Amur

2011-10-01

A new timing technique for single photons based on the radio frequency phototube and optical clock or femtosecond optical frequency comb generator is proposed. The technique has a 20 ps resolution for single photons, is capable of operating with MHz frequencies and achieving 10 fs instability level.

Two-photon interference and coherent control of single InAs quantum dot emissions in an Ag-embedded structure

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

Liu, X., E-mail: iu.xiangming@nims.go.jp; National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044; Kumano, H.

2014-07-28

We have recently reported the successful fabrication of bright single-photon sources based on Ag-embedded nanocone structures that incorporate InAs quantum dots. The source had a photon collection efficiency as high as 24.6%. Here, we show the results of various types of photonic characterizations of the Ag-embedded nanocone structures that confirm their versatility as regards a broad range of quantum optical applications. We measure the first-order autocorrelation function to evaluate the coherence time of emitted photons, and the second-order correlation function, which reveals the strong suppression of multiple photon generation. The high indistinguishability of emitted photons is shown by the Hong-Ou-Mandel-typemore » two-photon interference. With quasi-resonant excitation, coherent population flopping is demonstrated through Rabi oscillations. Extremely high single-photon purity with a g{sup (2)}(0) value of 0.008 is achieved with π-pulse quasi-resonant excitation.« less

Orientationally ordered colloidal co-dispersions of gold nanorods and cellulose nanocrystals.

PubMed

Liu, Qingkun; Campbell, Michael G; Evans, Julian S; Smalyukh, Ivan I

2014-11-12

Nematic-like and helicoidally orientational self-assemblies of gold nanorods co-dispersed with cellulose nanocrystals to form liquid crystalline phases are developed. Polarization-sensitive extinction spectra and two-photon luminescence imaging are used to characterize orientations and spatial distributions of gold nanorods. Cholesteric-isotropic phase coexistence and continuous domains of single-phase regions are observed and qualitatively discussed on the basis of entropic and electrostatic interactions in co-dispersions of rigid rods of different aspect ratios. Potential applications include biologically compatible plasmonic composite nanomaterials for solar biofuel production and polarization-sensitive plasmonic papers and fabrics. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The Use of Ultrashort Picosecond Laser Pulses to Generate Quantum Optical Properties of Single Molecules in Biophysics

NASA Astrophysics Data System (ADS)

Ly, Sonny

Generation of quantum optical states from ultrashort laser-molecule interactions have led to fascinating discoveries in physics and chemistry. In recent years, these interactions have been extended to probe phenomena in single molecule biophysics. Photons emitted from a single fluorescent molecule contains important properties about how the molecule behave and function in that particular environment. Analysis of the second order coherence function through fluorescence correlation spectroscopy plays a pivotal role in quantum optics. At very short nanosecond timescales, the coherence function predicts photon antibunching, a purely quantum optical phenomena which states that a single molecule can only emit one photon at a time. Photon antibunching is the only direct proof of single molecule emission. From the nanosecond to microsecond timescale, the coherence function gives information about rotational diffusion coefficients, and at longer millisecond timescales, gives information regarding the translational diffusion coefficients. In addition, energy transfer between molecules from dipole-dipole interaction results in FRET, a highly sensitive method to probe conformational dynamics at nanometer distances. Here I apply the quantum optical techniques of photon antibunching, fluorescence correlation spectroscopy and FRET to probe how lipid nanodiscs form and function at the single molecule level. Lipid nanodiscs are particles that contain two apolipoprotein (apo) A-I circumventing a lipid bilayer in a belt conformation. From a technological point of view, nanodiscs mimics a patch of cell membrane that have recently been used to reconstitute a variety of membrane proteins including cytochrome P450 and bacteriorhodopsin. They are also potential drug transport vehicles due to its small and stable 10nm diameter size. Biologically, nanodiscs resemble to high degree, high density lipoproteins (HDL) in our body and provides a model platform to study lipid-protein interactions and their dynamic formation to lipoprotein particles without having to extract from human blood plasma. Although HDL has been studied extensively within the last thirty years, many questions still remain regarding the structure of apoA-I, the protein associated exclusively with it. Despite our ability to detect and image these nanodiscs by blotting, atomic force microscopy (AFM), or electron microscopy (EM), many basic properties such as their specific hydrated shape in solution, or the precise conformation of the apolipoproteins surrounding the particles are still unknown. The dynamic interactions of apoA-I with lipids are also rather poorly understood on a fundamental level, and are only characterized in bulk (biochemical blotting) or stationary methods (AFM, EM), making it impossible to study individual steps with high spatial or temporal resolution.

Two-photon interference of temporally separated photons.

PubMed

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

2016-10-06

We present experimental demonstrations of two-photon interference involving temporally separated photons within two types of interferometers: a Mach-Zehnder interferometer and a polarization-based Michelson interferometer. The two-photon states are probabilistically prepared in a symmetrically superposed state within the two interferometer arms by introducing a large time delay between two input photons; this state is composed of two temporally separated photons, which are in two different or the same spatial modes. We then observe two-photon interference fringes involving both the Hong-Ou-Mandel interference effect and the interference of path-entangled two-photon states simultaneously in a single interferometric setup. The observed two-photon interference fringes provide simultaneous observation of the interferometric properties of the single-photon and two-photon wavepackets. The observations can also facilitate a more comprehensive understanding of the origins of the interference phenomena arising from spatially bunched/anti-bunched two-photon states comprised of two temporally separated photons within the interferometer arms.

On-chip electrically controlled routing of photons from a single quantum dot

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

Bentham, C.; Coles, R. J.; Royall, B.

2015-06-01

Electrical control of on-chip routing of photons emitted by a single InAs/GaAs self-assembled quantum dot (SAQD) is demonstrated in a photonic crystal cavity-waveguide system. The SAQD is located inside an H1 cavity, which is coupled to two photonic crystal waveguides. The SAQD emission wavelength is electrically tunable by the quantum-confined Stark effect. When the SAQD emission is brought into resonance with one of two H1 cavity modes, it is preferentially routed to the waveguide to which that mode is selectively coupled. This proof of concept provides the basis for scalable, low-power, high-speed operation of single-photon routers for use in integratedmore » quantum photonic circuits.« less

Recent advances and progress in photonic crystal-based gas sensors

NASA Astrophysics Data System (ADS)

Goyal, Amit Kumar; Sankar Dutta, Hemant; Pal, Suchandan

2017-05-01

This review covers the recent progress made in the photonic crystal-based sensing technology for gas sensing applications. Photonic crystal-based sensing has tremendous potential because of its obvious advantages in sensitivity, stability, miniaturisation, portability, online use, remote monitoring etc. Several 1D and 2D photonic crystal structures including photonic crystal waveguides and cavities for gas sensing applications have been discussed in this review. For each kind of photonic crystal structure, the novelty, measurement principle and their respective gas sensing properties are presented. The reported works and the corresponding results predict the possibility to realize a commercially viable miniaturized and highly sensitive photonic crystal-based optical gas sensor having flexibility in the structure of ultra-compact size with excellent sensing properties.

Localised excitation of a single photon source by a nanowaveguide.

PubMed

Geng, Wei; Manceau, Mathieu; Rahbany, Nancy; Sallet, Vincent; De Vittorio, Massimo; Carbone, Luigi; Glorieux, Quentin; Bramati, Alberto; Couteau, Christophe

2016-01-29

Nowadays, integrated photonics is a key technology in quantum information processing (QIP) but achieving all-optical buses for quantum networks with efficient integration of single photon emitters remains a challenge. Photonic crystals and cavities are good candidates but do not tackle how to effectively address a nanoscale emitter. Using a nanowire nanowaveguide, we realise an hybrid nanodevice which locally excites a single photon source (SPS). The nanowire acts as a passive or active sub-wavelength waveguide to excite the quantum emitter. Our results show that localised excitation of a SPS is possible and is compared with free-space excitation. Our proof of principle experiment presents an absolute addressing efficiency ηa ~ 10(-4) only ~50% lower than the one using free-space optics. This important step demonstrates that sufficient guided light in a nanowaveguide made of a semiconductor nanowire is achievable to excite a single photon source. We accomplish a hybrid system offering great potentials for electrically driven SPSs and efficient single photon collection and detection, opening the way for optimum absorption/emission of nanoscale emitters. We also discuss how to improve the addressing efficiency of a dipolar nanoscale emitter with our system.

Localised excitation of a single photon source by a nanowaveguide

PubMed Central

Geng, Wei; Manceau, Mathieu; Rahbany, Nancy; Sallet, Vincent; De Vittorio, Massimo; Carbone, Luigi; Glorieux, Quentin; Bramati, Alberto; Couteau, Christophe

2016-01-01

Nowadays, integrated photonics is a key technology in quantum information processing (QIP) but achieving all-optical buses for quantum networks with efficient integration of single photon emitters remains a challenge. Photonic crystals and cavities are good candidates but do not tackle how to effectively address a nanoscale emitter. Using a nanowire nanowaveguide, we realise an hybrid nanodevice which locally excites a single photon source (SPS). The nanowire acts as a passive or active sub-wavelength waveguide to excite the quantum emitter. Our results show that localised excitation of a SPS is possible and is compared with free-space excitation. Our proof of principle experiment presents an absolute addressing efficiency ηa ~ 10−4 only ~50% lower than the one using free-space optics. This important step demonstrates that sufficient guided light in a nanowaveguide made of a semiconductor nanowire is achievable to excite a single photon source. We accomplish a hybrid system offering great potentials for electrically driven SPSs and efficient single photon collection and detection, opening the way for optimum absorption/emission of nanoscale emitters. We also discuss how to improve the addressing efficiency of a dipolar nanoscale emitter with our system. PMID:26822999

On-demand generation of background-free single photons from a solid-state source

NASA Astrophysics Data System (ADS)

Schweickert, Lucas; Jöns, Klaus D.; Zeuner, Katharina D.; Covre da Silva, Saimon Filipe; Huang, Huiying; Lettner, Thomas; Reindl, Marcus; Zichi, Julien; Trotta, Rinaldo; Rastelli, Armando; Zwiller, Val

2018-02-01

True on-demand high-repetition-rate single-photon sources are highly sought after for quantum information processing applications. However, any coherently driven two-level quantum system suffers from a finite re-excitation probability under pulsed excitation, causing undesirable multi-photon emission. Here, we present a solid-state source of on-demand single photons yielding a raw second-order coherence of g(2 )(0 )=(7.5 ±1.6 )×10-5 without any background subtraction or data processing. To this date, this is the lowest value of g(2 )(0 ) reported for any single-photon source even compared to the previously reported best background subtracted values. We achieve this result on GaAs/AlGaAs quantum dots embedded in a low-Q planar cavity by employing (i) a two-photon excitation process and (ii) a filtering and detection setup featuring two superconducting single-photon detectors with ultralow dark-count rates of (0.0056 ±0.0007 ) s-1 and (0.017 ±0.001 ) s-1, respectively. Re-excitation processes are dramatically suppressed by (i), while (ii) removes false coincidences resulting in a negligibly low noise floor.

On-chip coherent conversion of photonic quantum entanglement between different degrees of freedom

PubMed Central

Feng, Lan-Tian; Zhang, Ming; Zhou, Zhi-Yuan; Li, Ming; Xiong, Xiao; Yu, Le; Shi, Bao-Sen; Guo, Guo-Ping; Dai, Dao-Xin; Ren, Xi-Feng; Guo, Guang-Can

2016-01-01

In the quantum world, a single particle can have various degrees of freedom to encode quantum information. Controlling multiple degrees of freedom simultaneously is necessary to describe a particle fully and, therefore, to use it more efficiently. Here we introduce the transverse waveguide-mode degree of freedom to quantum photonic integrated circuits, and demonstrate the coherent conversion of a photonic quantum state between path, polarization and transverse waveguide-mode degrees of freedom on a single chip. The preservation of quantum coherence in these conversion processes is proven by single-photon and two-photon quantum interference using a fibre beam splitter or on-chip beam splitters. These results provide us with the ability to control and convert multiple degrees of freedom of photons for quantum photonic integrated circuit-based quantum information process. PMID:27321821

On-chip coherent conversion of photonic quantum entanglement between different degrees of freedom.

PubMed

Feng, Lan-Tian; Zhang, Ming; Zhou, Zhi-Yuan; Li, Ming; Xiong, Xiao; Yu, Le; Shi, Bao-Sen; Guo, Guo-Ping; Dai, Dao-Xin; Ren, Xi-Feng; Guo, Guang-Can

2016-06-20

In the quantum world, a single particle can have various degrees of freedom to encode quantum information. Controlling multiple degrees of freedom simultaneously is necessary to describe a particle fully and, therefore, to use it more efficiently. Here we introduce the transverse waveguide-mode degree of freedom to quantum photonic integrated circuits, and demonstrate the coherent conversion of a photonic quantum state between path, polarization and transverse waveguide-mode degrees of freedom on a single chip. The preservation of quantum coherence in these conversion processes is proven by single-photon and two-photon quantum interference using a fibre beam splitter or on-chip beam splitters. These results provide us with the ability to control and convert multiple degrees of freedom of photons for quantum photonic integrated circuit-based quantum information process.

Upconversion single-microbelt photodetector via two-photon absorption simultaneous

NASA Astrophysics Data System (ADS)

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

2018-05-01

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

On-Chip Single-Plasmon Nanocircuit Driven by a Self-Assembled Quantum Dot.

PubMed

Wu, Xiaofei; Jiang, Ping; Razinskas, Gary; Huo, Yongheng; Zhang, Hongyi; Kamp, Martin; Rastelli, Armando; Schmidt, Oliver G; Hecht, Bert; Lindfors, Klas; Lippitz, Markus

2017-07-12

Quantum photonics holds great promise for future technologies such as secure communication, quantum computation, quantum simulation, and quantum metrology. An outstanding challenge for quantum photonics is to develop scalable miniature circuits that integrate single-photon sources, linear optical components, and detectors on a chip. Plasmonic nanocircuits will play essential roles in such developments. However, for quantum plasmonic circuits, integration of stable, bright, and narrow-band single photon sources in the structure has so far not been reported. Here we present a plasmonic nanocircuit driven by a self-assembled GaAs quantum dot. Through a planar dielectric-plasmonic hybrid waveguide, the quantum dot efficiently excites narrow-band single plasmons that are guided in a two-wire transmission line until they are converted into single photons by an optical antenna. Our work demonstrates the feasibility of fully on-chip plasmonic nanocircuits for quantum optical applications.

Quantum Communication Systems

DTIC Science & Technology

2008-03-15

numbers make the observation of non -Poissonian features easier, which calls for higher pump power and better mode matching of the pump beam , more...heralded two-photon NOON states, we rely on the local photon- bunching effect of two heralded single photons at a beam splitter , as sketched in Fig. 1. Two...heralded single photons are sent to separate input ports of a 50:50 beam splitter (BS1). The photons bunch at the beam splitter , exiting together from

Bridging visible and telecom wavelengths with a single-mode broadband photon pair source

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

Soeller, C.; Brecht, B.; Mosley, P. J.

We present a spectrally decorrelated photon pair source bridging the visible and telecom wavelength regions. Tailored design and fabrication of a solid-core photonic crystal fiber (PCF) lead to the emission of signal and idler photons into only a single spectral and spatial mode. Thus no narrowband filtering is necessary and the heralded generation of pure photon number states in ultrafast wave packets at telecom wavelengths becomes possible.

The limit of photoreceptor sensitivity: molecular mechanisms of dark noise in retinal cones.

PubMed

Holcman, David; Korenbrot, Juan I

2005-06-01

Detection threshold in cone photoreceptors requires the simultaneous absorption of several photons because single photon photocurrent is small in amplitude and does not exceed intrinsic fluctuations in the outer segment dark current (dark noise). To understand the mechanisms that limit light sensitivity, we characterized the molecular origin of dark noise in intact, isolated bass single cones. Dark noise is caused by continuous fluctuations in the cytoplasmic concentrations of both cGMP and Ca(2+) that arise from the activity in darkness of both guanylate cyclase (GC), the enzyme that synthesizes cGMP, and phosphodiesterase (PDE), the enzyme that hydrolyzes it. In cones loaded with high concentration Ca(2+) buffering agents, we demonstrate that variation in cGMP levels arise from fluctuations in the mean PDE enzymatic activity. The rates of PDE activation and inactivation determine the quantitative characteristics of the dark noise power density spectrum. We developed a mathematical model based on the dynamics of PDE activity that accurately predicts this power spectrum. Analysis of the experimental data with the theoretical model allows us to determine the rates of PDE activation and deactivation in the intact photoreceptor. In fish cones, the mean lifetime of active PDE at room temperature is approximately 55 ms. In nonmammalian rods, in contrast, active PDE lifetime is approximately 555 ms. This remarkable difference helps explain why cones are noisier than rods and why cone photocurrents are smaller in peak amplitude and faster in time course than those in rods. Both these features make cones less light sensitive than rods.

Review of Recent Progress of Plasmonic Materials and Nano-Structures for Surface-Enhanced Raman Scattering

PubMed Central

Wang, Alan X.; Kong, Xianming

2015-01-01

Surface-enhanced Raman scattering (SERS) has demonstrated single-molecule sensitivity and is becoming intensively investigated due to its significant potential in chemical and biomedical applications. SERS sensing is highly dependent on the substrate, where excitation of the localized surface plasmons (LSPs) enhances the Raman scattering signals of proximate analyte molecules. This paper reviews research progress of SERS substrates based on both plasmonic materials and nano-photonic structures. We first discuss basic plasmonic materials, such as metallic nanoparticles and nano-rods prepared by conventional bottom-up chemical synthesis processes. Then, we review rationally-designed plasmonic nano-structures created by top-down approaches or fine-controlled synthesis with high-density hot-spots to provide large SERS enhancement factors (EFs). Finally, we discuss the research progress of hybrid SERS substrates through the integration of plasmonic nano-structures with other nano-photonic devices, such as photonic crystals, bio-enabled nanomaterials, guided-wave systems, micro-fluidics and graphene. PMID:26900428

Dark adaptation of toad rod photoreceptors following small bleaches.

PubMed

Leibrock, C S; Reuter, T; Lamb, T D

1994-11-01

The recovery of toad rod photoreceptors, following exposure to intense lights that bleached 0.02-3% of the rhodopsin, has been investigated using the suction pipette technique. The post-bleach period was accompanied by reduced flash sensitivity, accelerated kinetics, and spontaneous fluctuations (noise). The power spectrum of the fluctuations had substantially the form expected for the random occurrence of single-photon events, and the noise could therefore be expressed as a "photon-noise equivalent intensity". From the level of desensitization at any time, the after-effect of the bleach could also be expressed in terms of a "desensitization-equivalent intensity", and this was found to be at least a factor of 20 times higher than the noise-equivalent intensity at the corresponding time. Our results indicate that a bleach induces two closely-related phenomena: (a) a process indistinguishable from the effect of real light, and (b) another process which desensitizes and accelerates the response in the same way that light does, but without causing photon-like noise. We propose a mechanism underlying these processes.

Quantitative multiphoton imaging

NASA Astrophysics Data System (ADS)

König, Karsten; Weinigel, Martin; Breunig, Hans Georg; Uchugonova, Aisada

2014-02-01

Certified clinical multiphoton tomographs for label-free multidimensional high-resolution in vivo imaging have been introduced to the market several years ago. Novel tomographs include a flexible 360° scan head attached to a mechanooptical arm for autofluorescence and SHG imaging as well as a CARS module. Non-fluorescent lipids and water, mitochondrial fluorescent NAD(P)H, fluorescent elastin, keratin, and melanin as well as SHG-active collagen can be imaged in vivo with submicron resolution in human skin. Sensitive and rapid detectors allow single photon counting and the construction of 3D maps where the number of detected photons per voxel is depicted. Intratissue concentration profiles from endogenous as well exogenous substances can be generated when the number of detected photons can be correlated with the number of molecules with respect to binding and scattering behavior. Furthermore, the skin ageing index SAAID based on the ratio elastin/collagen as well as the epidermis depth based on the onset of SHG generation can be determined.

Extracellular oxygen concentration mapping with a confocal multiphoton laser scanning microscope and TCSPC card

NASA Astrophysics Data System (ADS)

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

2010-02-01

Extracellular oxygen concentrations influence cell metabolism and tissue function. Fluorescence Lifetime Imaging Microscopy (FLIM) offers a non-invasive method for quantifying local oxygen concentrations. However, existing methods show limited spatial resolution and/or require custom made systems. This study describes a new optimised approach for quantitative extracellular oxygen detection, providing an off-the-shelf system with high spatial resolution and an improved lifetime determination over previous techniques, while avoiding systematic photon pile-up. Fluorescence lifetime detection of an oxygen sensitive fluorescent dye, tris(2,2'-bipyridyl)ruthenium(II) chloride hexahydrate [Ru(bipy)3]2+, was measured using a Becker&Hickl time-correlated single photon counting (TCSPC) card with excitation provided by a multi-photon laser. This technique was able to identify a subpopulation of isolated chondrocyte cells, seeded in three-dimensional agarose gel, displaying a significant spatial oxygen gradient. Thus this technique provides a powerful tool for quantifying spatial oxygen gradients within three-dimensional cellular models.

Review of Recent Progress of Plasmonic Materials and Nano-Structures for Surface-Enhanced Raman Scattering.

PubMed

Wang, Alan X; Kong, Xianming

2015-06-01

Surface-enhanced Raman scattering (SERS) has demonstrated single-molecule sensitivity and is becoming intensively investigated due to its significant potential in chemical and biomedical applications. SERS sensing is highly dependent on the substrate, where excitation of the localized surface plasmons (LSPs) enhances the Raman scattering signals of proximate analyte molecules. This paper reviews research progress of SERS substrates based on both plasmonic materials and nano-photonic structures. We first discuss basic plasmonic materials, such as metallic nanoparticles and nano-rods prepared by conventional bottom-up chemical synthesis processes. Then, we review rationally-designed plasmonic nano-structures created by top-down approaches or fine-controlled synthesis with high-density hot-spots to provide large SERS enhancement factors (EFs). Finally, we discuss the research progress of hybrid SERS substrates through the integration of plasmonic nano-structures with other nano-photonic devices, such as photonic crystals, bio-enabled nanomaterials, guided-wave systems, micro-fluidics and graphene.

Accessing the Elastic Form-Factors of the $Delta(1232)$ Using the Beam-Normal Asymmetry

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

Dalton, Mark M.

2016-08-01

The beam-normal single-spin asymmetry,more » $$B_n$$, exists in the scattering of high energy electrons, polarized transverse to their direction of motion, from nuclear targets. To first order, this asymmetry is caused by the interference of the one-photon exchange amplitude with the imaginary part of the two-photon exchange amplitude. Measurements of $$B_n$$, for the production of a $$\\Delta(1232)$$ resonance from a proton target, will soon become available from the Qweak experiment at Jefferson Lab and the A4 experiment at Mainz. The imaginary part of two-photon exchange allows only intermediate states that are on-shell, including the $$\\Delta$$ itself. Therefore such data is sensitive to $$\\gamma\\Delta\\Delta$$, the elastic form-factors of the $$\\Delta$$. This article will introduce the form-factors of the $$\\Delta$$, discuss what might be learned about the elastic form-factors from these new data, describe ongoing efforts in calculation and measurement, and outline the possibility of future measurements.« less

Quantum routing of single optical photons with a superconducting flux qubit

NASA Astrophysics Data System (ADS)

Xia, Keyu; Jelezko, Fedor; Twamley, Jason

2018-05-01

Interconnecting optical photons with superconducting circuits is a challenging problem but essential for building long-range superconducting quantum networks. We propose a hybrid quantum interface between the microwave and optical domains where the propagation of a single-photon pulse along a nanowaveguide is controlled in a coherent way by tuning the electromagnetically induced transparency window with the quantum state of a flux qubit mediated by the spin in a nanodiamond. The qubit can route a single-photon pulse using the nanodiamond into a quantum superposition of paths without the aid of an optical cavity—simplifying the setup. By preparing the flux qubit in a superposition state our cavityless scheme creates a hybrid state-path entanglement between a flying single optical photon and a static superconducting qubit.

Low-resistivity photon-transparent window attached to photo-sensitive silicon detector

DOEpatents

Holland, Stephen Edward

2000-02-15

The invention comprises a combination of a low resistivity, or electrically conducting, silicon layer that is transparent to long or short wavelength photons and is attached to the backside of a photon-sensitive layer of silicon, such as a silicon wafer or chip. The window is applied to photon sensitive silicon devices such as photodiodes, charge-coupled devices, active pixel sensors, low-energy x-ray sensors and other radiation detectors. The silicon window is applied to the back side of a photosensitive silicon wafer or chip so that photons can illuminate the device from the backside without interference from the circuit printed on the frontside. A voltage sufficient to fully deplete the high-resistivity photosensitive silicon volume of charge carriers is applied between the low-resistivity back window and the front, patterned, side of the device. This allows photon-induced charge created at the backside to reach the front side of the device and to be processed by any circuitry attached to the front side. Using the inventive combination, the photon sensitive silicon layer does not need to be thinned beyond standard fabrication methods in order to achieve full charge-depletion in the silicon volume. In one embodiment, the inventive backside window is applied to high resistivity silicon to allow backside illumination while maintaining charge isolation in CCD pixels.

Phase sensitive optical coherence microscopy for photothermal imaging of gold nanorods

NASA Astrophysics Data System (ADS)

Hu, Yong; Podoleanu, Adrian G.; Dobre, George

2018-03-01

We describe a swept source based phase sensitive optical coherence microscopy (OCM) system for photothermal imaging of gold nanorods (GNR). The phase sensitive OCM system employed in the study has a displacement sensitivity of 0.17 nm to vibrations at single frequencies below 250 Hz. We demonstrate the generation of phase maps and confocal phase images. By displaying the difference between successive confocal phase images, we perform the confocal photothermal imaging of accumulated GNRs behind a glass coverslip and behind the scattering media separately. Compared with two-photon luminescence (TPL) detection techniques reported in literature, the technique in this study has the advantage of a simplified experimental setup and provides a more efficient method for imaging the aggregation of GNR. However, the repeatability performance of this technique suffers due to jitter noise from the swept laser source.

Two-photon sensitized recording materials for multilayer optical disk

NASA Astrophysics Data System (ADS)

Akiba, M.; Goto-Takahashi, E.; Takizawa, H.; Sasaki, T.; Mochizuki, H.; Mikami, T.; Kitahara, T.

2010-06-01

Two types of novel two-photon sensitized recording material writable at 405 nm and 522nm were developed. The fluorescent dye generation type (F-type) material consists of at least two-photon absorption dye (TPAD) and fluorescent dye precursor (FDP), which is non-fluorescent before two-photon recording and fluorescent after two-photon recording due to fluorescent dye generation. The fluorescence quench type (Q-type) material, on the other hand, consists of at least TPAD, fluorescent dye (FD) and fluorescent quencher precursor (QP), which is fluorescent before two-photon recording and the fluorescence intensity is reduced after two-photon recording at the recorded spot due to fluorescent quencher generation. Both types of material showed quadratic dependency of recording light intensity at 522 and 405 nm. A twenty-layer two-photon recording media was fabricated with the Q-type material, and two-photon recording and onephoton fluorescent signal readout was successfully conducted.

Single-photon decision maker

NASA Astrophysics Data System (ADS)

Naruse, Makoto; Berthel, Martin; Drezet, Aurélien; Huant, Serge; Aono, Masashi; Hori, Hirokazu; Kim, Song-Ju

2015-08-01

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 photons can be used to make decisions in uncertain, dynamically changing environments. Using a nitrogen-vacancy in a nanodiamond as a single-photon source, we demonstrate the decision-making capability by solving the multi-armed bandit problem. This capability is directly and immediately associated with single-photon detection 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.

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

NASA Astrophysics Data System (ADS)

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

2006-12-01

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

Bright nanowire single photon source based on SiV centers in diamond

DOE PAGES

Marseglia, L.; Saha, K.; Ajoy, A.; ...

2018-01-01

The practical implementation of quantum technologies such as quantum commu- nication and quantum cryptography relies on the development of indistinguishable, robust, and bright single photon sources that works at room temperature. The silicon- vacancy (SiV -) center in diamond has emerged as a possible candidate for a single photon source with all these characteristics. Unfortunately, due to the high refraction index mismatch between diamond and air, color centers in diamond show low photon out-coupling. This drawback can be overcome by fabrication of photonic structures that improve the in-coupling of excitation laser to the diamond defect as well as the out-couplingmore » emission from the color centers. An additional shortcoming is due to the random localization of native defects in the diamond sample. Here we demonstrate deterministic implantation of Si ions with high conversion effciency to single SiV -, targeted to fabricated nanowires. The co-localization of single SiV - defects with the nanostructures yields a ten times higher light coupling effciency as compared to single SiV - in the bulk. This result, with its intrinsic scalability, enables a new class of devices for integrated photonics and quantum information processing.« less

Nearly Blinking-Free, High-Purity Single-Photon Emission by Colloidal InP/ZnSe Quantum Dots.

PubMed

Chandrasekaran, Vigneshwaran; Tessier, Mickaël D; Dupont, Dorian; Geiregat, Pieter; Hens, Zeger; Brainis, Edouard

2017-10-11

Colloidal core/shell InP/ZnSe quantum dots (QDs), recently produced using an improved synthesis method, have a great potential in life-science applications as well as in integrated quantum photonics and quantum information processing as single-photon emitters. Single-particle spectroscopy of 10 nm QDs with 3.2 nm cores reveals strong photon antibunching attributed to fast (70 ps) Auger recombination of multiple excitons. The QDs exhibit very good photostability under strong optical excitation. We demonstrate that the antibunching is preserved when the QDs are excited above the saturation intensity of the fundamental-exciton transition. This result paves the way toward their usage as high-purity on-demand single-photon emitters at room temperature. Unconventionally, despite the strong Auger blockade mechanism, InP/ZnSe QDs also display very little luminescence intermittency ("blinking"), with a simple on/off blinking pattern. The analysis of single-particle luminescence statistics places these InP/ZnSe QDs in the class of nearly blinking-free QDs, with emission stability comparable to state-of-the-art thick-shell and alloyed-interface CdSe/CdS, but with improved single-photon purity.

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.

Single-shot time stretch stimulated Raman spectroscopy (Conference Presentation)

NASA Astrophysics Data System (ADS)

Saltarelli, Francesco; Kumar, Vikas; Viola, Daniele; Crisafi, Francesco; Preda, Fabrizio; Cerullo, Giulio; Polli, Dario

2017-02-01

Stimulated Raman scattering spectroscopy is a powerful technique for label-free molecular identification, but its broadband implementation is technically challenging. We introduce and experimentally demonstrate a novel approach based on photonic time stretch. The broadband femtosecond Stokes pulse, after interacting with the sample, is stretched by a telecom fiber to 15ns, mapping its spectrum in time. The signal is sampled through a fast analog-to-digital converter, providing single-shot spectra at 80-kHz rate. We demonstrate 10^-5 sensitivity over 500 cm-1 in the C-H region. Our results pave the way to high-speed broadband vibrational imaging for materials science and biophotonics.