- 标题
- 摘要
- 关键词
- 实验方案
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A Low-Power, Inductorless Wideband Cryogenic Amplifier For Supercondcting Nanowire Single Photon Detector
摘要： This paper presents a low-power, inductorless wideband cryogenic amplifier for superconducting nanowire single photon detector (SNSPD). To achieve wide bandwidth, low power consumption and small chip area, a modified Cherry-Hooper amplifier topology is used. With good input and output match, at 4.2 K temperature the measurement results show that the amplifier achieves 23-dB gain with a flat gain response, a 3-dB bandwidth (BW) of over 3.4 GHz, which covers frequencies as low as 130 kHz. Fabricated in a 0.13-μm silicon germanium (SiGe) BiCMOS technology, the amplifier core occupies a silicon area of only 0.075 mm2 and consumes a power of only 4 mW.
关键词： low power,Cryogenic amplifier,wideband,Superconducting Nanowire Single Photon Detectors,SNSPD
更新于2025-09-23 15:23:52
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Minimal Timing Jitter in Superconducting Nanowire Single-Photon Petectors
摘要： Using a two-temperature model coupled with the modified time-dependent Ginzburg-Landau equation, we calculate the delay time τd in the appearance of a growing normal domain in the current-biased superconducting strip after absorption of the single photon. We demonstrate that τd depends on the place in the strip where the photon is absorbed and monotonically decreases with an increasing current. We argue that the variation of τd (timing jitter), connected either with position-dependent response or Fano fluctuations, could be as small as the lowest relaxation time of the superconducting order parameter, approximately ?/kBTc (Tc is the critical temperature of the superconductor), when the current approaches the depairing current.
关键词： position-dependent response,timing jitter,superconducting nanowire single-photon detectors,delay time,Fano fluctuations
更新于2025-09-23 15:23:52
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Calibration of free-space and fiber-coupled single-photon detectors
摘要： We measure the detection efficiency of single-photon detectors at wavelengths near 851 nm and 1533.6 nm. We investigate the spatial uniformity of one free-space-coupled single-photon avalanche diode and present a comparison between fusion-spliced and connectorized fiber-coupled single-photon detectors. We find that our expanded relative uncertainty for a single measurement of the detection efficiency is as low as 0.70 % for fiber-coupled measurements at 1533.6 nm and as high as 1.78 % for our free-space characterization at 851.7 nm. The detection-efficiency determination includes corrections for afterpulsing, dark count, and count-rate effects of the single-photon detector with the detection efficiency interpolated to operation at a specified detected count rate.
关键词： dark count,single-photon detectors,free-space-coupled,afterpulsing,detection efficiency,fiber-coupled
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE International Conference on Space Optical Systems and Applications (ICSOS) - Portland, OR, USA (2019.10.14-2019.10.16)] 2019 IEEE International Conference on Space Optical Systems and Applications (ICSOS) - Real Time Photon-Counting Receiver for High Photon Efficiency Optical Communications
摘要： We present a scalable design for a photon-counting ground receiver based on superconducting nanowire single photon detectors (SNSPDs) and field programmable gate array (FPGA) real-time processing for applications to space-to-ground photon starved links, such as the Orion EM-2 Optical Communication Demonstration (O2O) [1], and future deep space or low transmitter power missions. The receiver is designed to receive a serially concatenated pulse position modulation (SCPPM) waveform [2], which follows the Consultative Committee for Space Data Systems (CCSDS) Optical Communications Coding and Synchronization Red Book standard [3]. The receiver design uses multiple individually fiber coupled, 80% detection efficiency commercial SNSPDs in parallel to scale to a required data rate, and is capable of achieving data rates up to 528 Mbps. For efficient fiber coupling from the telescope to the array of parallel detectors that can be scaled both to telescope aperture size and the number of detectors, we use either a single mode fiber (SMF) photonic lantern or a few-mode fiber (FMF) photonic lantern [4]. In this paper we give an overview of the receiver system design, the characteristics of the photonic lanterns, the performance of the SNSPDs, and system level tests. We show that 40 Mbps can be received using a single SNSPD, and discuss aspects for scaling to higher data rates.
关键词： few-mode fibers,superconducting nanowire,optical communications,single photon detectors
更新于2025-09-19 17:13:59
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Development of SPAD Based on Thermoelectrically Controlled Silicon Carbide Avalanche Photodiode
摘要： Single photon detectors, which are capable of ultra-sensitive detection in a low light level, have been widely used in a variety of applications such as remote sensing, biochemical science, and quantum information science. In particular, the rapid development of quantum information science has greatly improved the development of single photon detectors because it played a key role in achieving successful results in quantum key distribution and quantum communication. The single photon avalanche photodiodes (SPADs) are most conventional devices to detect photons because the APDs, the core elements of SPADs, are known to be advantageous to achieve cheap production and robust structure. In recent years, as the demand for ultraviolet light detection has increased, there have been actively reported on the development of APD detectors based on silicon carbide (SiC), which has a high gain only in the deep ultraviolet wavelength band. Here we report on the performance evaluation of lab-assembled SPAD based on SiC-APD.
关键词： ultraviolet light detection,quantum information science,Single photon detectors,SPAD,SiC-APD
更新于2025-09-16 10:30:52
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Operational Description of Single-Photon Detectors Including Timing-Jitter Effects
摘要： Discrete variable quantum optics stands as one of the most prominent platform for quantum technologies with an increasing number of encouraging out-of-the-laboratory implementations [1]. The quest for competitive quantum photonic systems, compatible with future engineered systems, has promoted huge developments concerning both source and detection devices [2]. To date, a critical point lies in experiments’ operation rates. Time multiplexing technics allow in principle to pump photonic sources at rates on the order of the GHz [3]. However, a strong limitation to ultra-fast operation lies in timing errors at the detection stage. Limited resolution directly affects the quality of any time-correlated single photon counting or quantum state engineering operations [3]. In particular, single photon detector’s timing-jitters lead counts associated with a given optical clock cycle to appear as temporally indistinguishable from those corresponding to neighbouring ones [2]. Fast and accurate time-tagging is mandatory in multiple operations, such as quantum teleportation [1], quantum state engineering [3] and quantum random number generation. In anticipation to further technological advances, as well as in the perspective of promoting novel conceptual developments on existing quantum communication protocols, it is thus of the utmost importance to correctly describe the effects of detectors’ timing performances. In our work, we explicitly address the problem of detection temporal uncertainties by means of an original theoretical model able to describe the temporal behaviour of standard single photon detectors, with no photon-number resolving abilities [2], affected by non negligible timing-jitter and in presence of dead-time [4]. We consider the case of standard ON/OFF detectors, say detectors with no photon-number resolving abilities [2], and we adopt the formalism of positive operator-valued measurements (POVM) [5]. This approach has already been employed to describe detector with photon-number resolving abilities and has been successfully used to experimentally investigate the characteristics of unknown single photon detectors [6]. Our model exploits a multi-mode formalism to describe temporal degrees of freedom to fully describe timing-resolution effects in ON/OFF detectors by a fully operational POVM description, taking into account the effect of dead-time and finite detection efficiency, without any a priori restriction on the number of photons impinging on the detector. We apply our results to the quantitative study of timing-jitter effects in some usual quantum optics experiments, such as direct photon detection, coincidence measurements, and heralded quantum state preparation. As an example, for a time correlation experiment, considering a source of simultaneous twin photons, our model allows expressing explicitly the delay probability density function. As another example, this fully quantum approach allows expressing the density matrix of a single-photon state obtained in a heralded single-photon generation experiment [3], by taking into account the imperfections of the heralding detector. In conclusion, we believe that our work fills a gap in the discussion on practical quantum technologies by providing a full operational POVM description of practical detection stages, with non negligible timing-jitter and in presence of dead-time. Although we mostly provide simple examples involving one or two photons impinging on the detectors, our formalism is capable of describing general experimental situations. We therefore think that these characteristics stand as a valuable help for a better comprehension of the timing-jitter effect in the perspective of developing ultra-fast quantum communication, including when detector’s timing-jitter is not negligible with respect to repetition period.
关键词： timing-jitter,quantum communication,POVM,quantum optics,single-photon detectors
更新于2025-09-16 10:30:52
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Superior properties in room-temperature colloidal-dot quantum emitters revealed by ultralow-dark-count detections of temporally-purified single photons
摘要： The realization of high-quality quantum emitters that can operate at room temperature is important for accelerating the application of quantum technologies, such as quantum communication, quantum information processing, and quantum metrology. In this work, we study the photon-antibunching properties on room-temperature emission from individual colloidal quantum dots (CQDs) using superconducting-nanowire single-photon detectors and temporal filtering of the photoluminescence decay curve. We find that high single-photon purities and high photon-generation rates can be simultaneously achieved by removing the signals originating from the sequential two-photon emission of biexcitons created by multiple excitation pulses. We successfully demonstrate that the ultrahigh performance of the room-temperature single-photon sources showing g(2)(0) ? 10?2 can be confirmed by the ultralow-dark-count detection of the temporally purified single photons. These findings provide strong evidence for the attractiveness of CQDs as candidates for high-quality room-temperature quantum light sources.
关键词： single-photon sources,room-temperature,superconducting-nanowire single-photon detectors,quantum emitters,colloidal quantum dots,temporal filtering
更新于2025-09-11 14:15:04
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Suppressing Dark Counts of Multimode-Fiber-Coupled Superconducting Nanowire Single-Photon Detector
摘要： Large active-area superconducting nanowire single-photon detectors (SNSPDs) coupled with multimode fibers (MMFs) can provide high light-gathering capacity, which is essential for free-space detection applications in photon-starved regimes. However, MMF-coupled SNSPDs often suffer from large system dark count rates (DCRsys) over kHz due to blackbody radiation of the MMF at room temperature. Such large DCRsys would significantly degrade signal-to-noise ratio (SNR) of the receiving system. This paper reports an MMF-coupled large-active-area SNSPD system with low DCRsys by using a homemade cryogenic MMF filter bench. The filter bench, which consists of lenses and optical filters, can provide a high transmittance of about 80% at the central wavelength of the passband (1550 ± 12.5 nm) and a wide blocking range from 500 nm to over 6000 nm at 40 K. With using the filter bench, the DCRsys of an MMF-coupled 9-pixel SNSPD array with an active area of 50 μm in diameter is greatly suppressed by 23 dB with 1 dB loss of system detection efficiency (SDE). The detector demonstrates an SDE of 51% at a DCRsys of 100 Hz for 1550 nm photons. Thus, SNR of the detector is enhanced by about 160 times and the noise equivalent power is improved to 3×10?19 W/Hz1/2.
关键词： cryogenic MMF filter bench,multimode fibers (MMFs),Superconducting nanowire single-photon detectors (SNSPDs),dark count rates (DCRsys),signal-to-noise ratio (SNR)
更新于2025-09-11 14:15:04
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[IEEE 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Paris, France (2018.7.8-2018.7.13)] 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Single-Photon Avalanche Detector Calibration at PTB
摘要： In this paper we present the traceable calibration of the detection efficiency of Si and InGaAs/InP single-photon avalanche detectors (SPADs). We describe the calibration facilities and the reference standard detectors used, as well as the traceability chain of the measurements to the primary standard for optical power (Cryogenic Radiometer) of PTB. As an example, the detection efficiency of a Si and InGaAs/InP SPAD detector measured at wavelengths of 850 nm and 1550 nm, respectively, for different photon flux rates is presented. The standard uncertainty of the measurements is ≤ 1 %.
关键词： Single-photon detectors,radiometry,calibration
更新于2025-09-10 09:29:36
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Monitoring coincident clicks in differential-quadrature-phase shift QKD to reveal detector blinding and control attacks
摘要： Side-channel attacks manipulating single-photon detectors (SPDs) have known to be loopholes in realistic quantum key distribution (QKD) systems. Although measurement-device-independent (MDI) QKD schemes have been proposed and studied to avoid those loopholes, they are not easy to implement in practice because they Require some synchronization between signals sent from two distant parties. In this paper, we propose a new countermeasure against a side-channel attack (control blinding and controlling attacks). It utilizes coincident clicks in differential-quadrature-phase shift (DQPS) QKD systems. Our scheme requires no change in the system configuration of the conventional protocol. Unlike MDI-QKD, side-channel attacks can be found without difficulty in practical implementations.
关键词： DQPS-QKD,quantum key distribution,side-channel attack,single-photon detectors,coincident clicks
更新于2025-09-04 15:30:14