Fully integrated InGaAs/InP single-photon detector module with gigahertz sine wave gating

InGaAs/InP single-photon avalanche diodes (SPADs) working in the regime of GHz clock rates are crucial components for the high-speed quantum key distribution (QKD). We have developed for the first time a compact, stable, and user-friendly tabletop InGaAs/InP single-photon detector system operating at a 1.25 GHz gate rate that fully integrates functions for controlling and optimizing SPAD performance. We characterize the key parameters of the detector system and test the long-term stability of the system for continuous operation of 75 h. The detector system can substantially enhance QKD performance and our present work paves the way for practical high-speed QKD applications.     

BCD工艺下光电集成的单光子雪崩光电二极管及前端电路的研制

提出一种基于BCD工艺用于检测微弱光信号的单光子雪崩光电二极管(SPAD)及前端淬灭-复位电路(QRC).为减小边缘击穿的风险,提高响应度,设计了一种圆形P+/Nwell/Deep Nwell结构SPAD,Deep Nwell和衬底之间形成的pn结,能够有效减少p衬底流向雪崩区的暗电流,降低暗计数率,也保证了较小的纵向...     

Operation of silicon single photon avalanche diodes at cryogenic temperature

This article reports a complete characterization of single photon avalanche diodes (SPADs) at temperatures down to 120 K. We show that deep cooling of the device by means of a compact liquid-nitrogen Dewar brings several advantages, such as extremely low dark counting rates (down to 1 counts/s), better time resolution, and higher quantum efficiency in the visible range. By using a special current pick-off circuit, we achieved a time resolution of 20 ps full width at half maximum at 120 K for a 50 mum diameter SPAD. Afterpulsing effects are avoided by using a sufficiently long hold-off time (microseconds).     

Self-suppression of reset induced triggering in picosecond SPAD timing circuits

We present a new photon timing circuit that achieves a time resolution of 35 ps full width at half maximum with single photon avalanche diodes having active area diameters up to 200 microm. The timing circuit is based on a double avalanche current sensing network that makes it particularly suited to operation at high photon counting rates. Thanks to its self-adjusting capabilities, no trimming is needed even when changing the photodetector operating conditions over a wide range.     

Performance trade-offs in single-photon avalanche diode miniaturization

Single-photon avalanche diodes (SPADs) provide photons' time of arrival for various applications. In recent years, attempts have been made to miniaturize SPADs in order to facilitate large-array integration and in order to reduce the dead time of the device. We investigate the benefits and drawbacks of device miniaturization by characterizing a new fast SPAD in a commercial 0.18 microm complementary metal oxide semiconductor technology. The device employs a novel and efficient guard ring, resulting in a high fill factor. Thanks to its small size, the dead time is only 5 ns, resulting in the fastest reported SPAD to date. However, the short dead time is accompanied by a high after-pulsing rate, which we show to be a limiting parameter for SPAD miniaturization. We describe a new and compact active-recharge scheme which improves signal-to-noise tenfold compared with the passive configuration, using a fraction of the area of state-of-the-art active-recharge circuits, and without increasing the dead time. The performance of compact SPADs stands to benefit such applications as high-resolution fluorescence-lifetime imaging, active-illumination three-dimensional imagers, and quantum key distribution systems.     

FLIM and FCS detection in laser‐scanning microscopes: Increased efficiency by GaAsP hybrid detectors

Photon counting detectors currently used in fluorescence lifetime microscopy have a number of deficiencies that result in less‐than‐ideal signal‐to‐noise ratio of the lifetimes obtained: Either the quantum efficiency is unsatisfactory or the active area is too small, and afterpulsing or tails in the temporal response contribute to overall timing inaccuracy. We have therefore developed a new FLIM detector based on a GaAsP hybrid photomultiplier. Compared with conventional PMTs and SPADs, GaAsP hybrid detectors have a number of advantages: The detection quantum efficiency reaches or surpasses the efficiency of fast SPADs, and the active area is on the order of 5 mm², compared with 2.5 10^?3 mm² for a SPAD. The TCSPC response is clean, without the bumps and the diffusion tails typical for PMTs and SPADs. Most important, the hybrid detector is intrinsically free of afterpulsing. FLIM results are therefore free of signal‐dependent background, and FCS curves are free of the known afterpulsing peak. We demonstrate the performance of the new detector for multiphoton NDD FLIM and for FCS. Microsc. Res. Tech., 2011. © 2010 Wiley‐Liss, Inc.     

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

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

A method for automatic tuning and stabilization of the energy threshold in scintillation detectors

A method is proposed for automatic tuning and stabilization of the energy threshold in scintillation detectors by maintaining the constancy of the average detector counting rate from ?? rays of natural radiation background or cosmic rays. Stabilization is automatically performed by controlling the photodetector supply voltage, which makes it possible to stabilize the detector threshold with an error of 0.73?C2.40%, depending on the used circuitry. The stabilization electronics for scintillation detectors with avalanche multipixel photodiodes and photomultipliers is described. A circuit ensuring the increased precision of threshold stabilization is also proposed.     

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

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.     

Application of a specific integrated circuit for readout and analog processing of signals from silicon multiplier arrays

A multichannel integrated circuit intended for readout and analog preprocessing of signals from multielement photodetectors has been designed and evaluated. It is optimized for use with silicon photomultiplier arrays. The chip includes current-signal and voltage-signal processing channels. Except for the front end, all of the channels are identical. Each of them contains a code-controlled current amplifier, an integrator, two digitally controlled variable gain amplifiers, a filter, a peak detector, an output buffer with a level shifter, an amplitude discriminator, two timers, and a control unit. The device is configured and tuned by uploading data via a serial interface. The chip is part of a chipset that also includes a multichannel analog-todigital converter with a buffer memory and voltage reference. This chipset makes it possible to build a fullfeatured multielement photodetector signal-processing system, as well as signal processing systems for multichannel detectors of other types. The integrated circuit is implemented in the 0.35 μm CMOS process. This paper also describes the features of the circuits of the device, analyzes the parameters of several of its basic units, and discusses the test results.     

High power, low-noise, and multiply resonant photodetector for interferometric gravitational wave detectors

We have developed a new photodetector circuit for use in interferometric gravitational wave detectors. The circuit can detect high laser power with low noise and provide multiple outputs for different signal frequencies. The dynamic range of this circuit is increased in comparison with the photodetector design used until the end of 2005.     

Imaging visible light with Medipix2

A need exists for high-speed single-photon counting optical imaging detectors. Single-photon counting high-speed detection of x rays is possible by using Medipix2 with pixelated silicon photodiodes. In this article, we report on a device that exploits the Medipix2 chip for optical imaging. The fabricated device is capable of imaging at >3000 frames/s over a 256×256 pixel matrix. The imaging performance of the detector device via the modulation transfer function is measured, and the presence of ion feedback and its degradation of the imaging properties are discussed.     

Using single-photon detectors for quantum key distribution in an experimental fiber-optic communication system

This paper gives experimental results of quantum key distribution on a fiber-optic setup at a telecom wavelength of 1555 nm. A self-compensated two-channel optical circuit is used. Quantum key distribution was performed by coding the phase states of single photons radiated by a pulsed semiconductor laser in two alternative nonorthogonal bases. Specially developed single photon counters based on InGaAs: InP avalanche photodiodes were employed as high-sensitivity photodetectors. The results of investigation of the quantum efficiency, probability of afterpulses, and noise level for various operating modes of the detectors at temperatures from −40 to −60°C are given. A key distribution rate of 450 bit/s was obtained for a single-mode fiber-optic quantum communication channel between the receiver and sender 25 km long at a laser pulse clock frequency of 5 MHz and an average number of photons per pulse of about 0.2. For the achieved photodetector characteristics, the average number of errors in the quantum key did not exceed 3.7%.     

Fully programmable single-photon detection module for InGaAs/InP single-photon avalanche diodes with clean and sub-nanosecond gating transitions

We present the design and characterization of a modern near-infrared photon counting module, able to exploit the best performance of InGaAs/InP single-photon avalanche diodes for the detection of fast and faint optical signals up to 1.7 μm. Such instrument is suitable for many applications, thanks to the user-friendly interface and the fully adjustable settings of all operating parameters. We extensively characterized both the electronics and the detector, and we validated such instrument up to 133 MHz gate repetition frequency, for photon-counting and photon-timing applications, with very clean temporal response and excellent timing performance of less than 100 ps.     

Ultra-low noise single-photon detector based on Si avalanche photodiode

We report operation and characterization of a lab-assembled single-photon detector based on commercial silicon avalanche photodiodes (PerkinElmer C30902SH, C30921SH). Dark count rate as low as 5 Hz was achieved by cooling the photodiodes down to -80 °C. While afterpulsing increased as the photodiode temperature was decreased, total afterpulse probability did not become significant due to detector's relatively long deadtime in a passively-quenched scheme. We measured photon detection efficiency >50% at 806 nm.     

工业过程电容层析成像系统的硬件设计

设计一个具有简化电路结构的8极板电容层析成像系统硬件部分。该系统不仅适合实验室研究用，亦适合工业应用。它的最明显特色是硬件电路结构简单，性能优良，主要论述了该系统的结构特色，包括整体方案，极板控制阵列，基于AC的微小电容检测系统，软件补偿CMOS开关的耦合电容，系统标定和通信电路。     

光电二极管型CMOS 有源图像传感器读出电路设计验证

分析了传统的光电二极管型CMOS有源图像传感器读出电路的优缺点;系统阐述了读出电路的设计;并基于开关电容同相放大器,给出一种结构简单、可有效抑制固定模式噪声的列读出电路,电路只需一条支路;HSpice环境下验证了读出电路的设计,结果表明达到了设计要求。系统具有动态范围高、读出速度快的特点。同时分析了电容工艺精度的影响,从中得到如下结论：电容工艺精度越高,噪声的抑制效果越好。     

Radiation detectors based on PbSnTe:In films,sensitive in the terahertz range of the spectrum

This paper presents a review of studies of the photoelectric properties of PbSnTe:In films obtained by molecular beam epitaxy and photosensitive structures in the far infrared and submillimeter ranges based on these films. The parameters of photodetector arrays of this type and detectors based on doped semiconductors and superconductors are compared. One-dimensional (2×128 elements) and two-dimensional (128 × 128 elements) PbSnTe:In based arrays with a sensitivity threshold of ~22 μm and an operating temperature of T ≤ 16 K are implemented. Under background-free conditions, the noise equivalent power (NEP) was NEP ≤ ^10?18 W/Hz^0.5 at T = 7 K for a black body radiation source at T_BB = 77 K. In the submillimeter range of the spectrum, sensitivity to laser radiation with a wavelength λ ≤ 205 μm and a value NEP ≤ 10^?12 W/Hz^0.5 was observed without optimization of the design of the photosensitive element and minimization of the measurement circuit noise. The directions of the development of PbSnTe:In based radiation detectors are considered..     

Improving the timing resolution of an electromagnetic calorimeter based on lead tungstate crystals

Results of the beam tests of the prototype photon spectrometer PHOS for the ALICE experiment at the Large Hadron Collider (CERN) are presented. The spectrometer is based on detector elements composed of lead tungstate (PbWO₄) crystals with dimensions of 22 × 22 × 180 mm and Hamamatsu S8664-55 (S8148) avalanche photodiodes. The beam tests have been performed on the secondary T10 beamline of the PS proton synchrotron. The main emphasis has been placed on the possibility of improving the PHOS timing resolution. Introduction of an additional timing channel with a silicon photomultiplier (SiPM) used as a photodetector is shown to improve the timing resolution for 1-GeV deposited energy from current value σ _t = 3 to 0.3 ns. Silicon photomultipliers of the Hamamatsu MPPC S10362-33 family with an active area of 3 × 3 mm² are used in these measurements. Using fast photomultiplier tubes with an 8-mm-diameter photocathode, the timing resolution attainable in electromagnetic shower development in a lead tungstate crystal has been measured for a large-area photodetector. The timing resolution for a deposited energy of 1 GeV is 150 ps. The effect of the detector channel temperature on the timing resolution is investigated. Cooling the crystal results in an increase both in the scintillation intensity and in the decay time of the scintillator and fails to substantially improve the timing resolution.     

10 ps resolution, 160 ns full scale range and less than 1.5% differential non-linearity time-to-digital converter module for high performance timing measurements

We present a compact high performance time-to-digital converter (TDC) module that provides 10 ps timing resolution, 160 ns dynamic range and a differential non-linearity better than 1.5% LSB(rms). The TDC can be operated either as a general-purpose time-interval measurement device, when receiving external START and STOP pulses, or in photon-timing mode, when employing the on-chip SPAD (single photon avalanche diode) detector for detecting photons and time-tagging them. The instrument precision is 15 ps(rms) (i.e., 36 ps(FWHM)) and in photon timing mode it is still better than 70 ps(FWHM). The USB link to the remote PC allows the easy setting of measurement parameters, the fast download of acquired data, and their visualization and storing via an user-friendly software interface. The module proves to be the best candidate for a wide variety of applications such as: fluorescence lifetime imaging, time-of-flight ranging measurements, time-resolved positron emission tomography, single-molecule spectroscopy, fluorescence correlation spectroscopy, diffuse optical tomography, optical time-domain reflectometry, quantum optics, etc.