High efficiency single photon detection via frequency up-conversion

Abstract

We propose a method of single photon detection of infrared (IR) photons at potentially higher efficiencies and lower noise than allowed by traditional IR band avalanche photodiodes (APDs). By up-converting the photon from the IR, e.g. 1550 nm, to a visible wavelength in a nonlinear crystal, we can utilize the much higher efficiency of silicon APDs at these wavelengths. We have used a periodically poled lithium niobate (PPLN) crystal and a pulsed 1064 nm Nd:YAG laser to perform the up-conversion to a 631 nm photon. We observed conversion efficiencies as high as ～ 80%, and demonstrated scaling down to the single photon level while maintaining a background of 3 ×s; 10^?4 dark counts per count. We also propose a 2-crystal extension of this scheme, whereby orthogonal polarizations may be up-converted coherently, thus enabling complete quantum state transduction of arbitrary states.     

Avalanche photodiodes as large dynamic range detectors for synchrotron radiation

We investigated silicon-based avalanche photodiodes (APDs) as X-ray detectors in terms of their linearity, maximum counting rates, and dynamic range with 8.4 keV synchrotron radiation. Measurements resulted in counting rates that extend from the APD's noise level of 10⁻² Hz to saturation counting rates in excess of 10⁸ Hz. In addition, by monitoring the APD's noise level and photon counting efficiency between synchrotron bursts, we demonstrate nine orders of magnitude dynamic range.     

Recent achievements in single photon detectors and their applications

Abstract

Solid state single photon detectors are receiving more and more attention in a number of areas of applied physics: optical sensors, communications, quantum cryptography, optical ranging and Lidar, time resolved spectroscopy, opaque media imaging and ballistic photon identification. This paper reports on results of research and development in the field of solid state single photon detectors at the Czech Technical University in Prague over the last 20 years. Avalanche photodiodes specifically designed for single photon counting devices have been developed based on various semiconductor materials: Si, Ge, GaP, GaAs and InGaAs. Electronic circuits for biasing, quenching and control of these detectors have been developed and optimized for different applications. The sensitivity of solid state photon counters spans from 0.1 nanometre X-rays up to 1800 nanometres in the near infrared region. Timing resolution of solid state photon counters as high as 50 picoseconds full width at a half maximum has been achieved when detecting single photon signals. Circuits permitting operation of solid state photon counters in both single and multiple photon signal regimes have been developed and applied. The compact and rugged design, radiation resistance, and low operating voltage are attractive features of solid state photon counters in various space projects.     

Number‐Resolved Single‐Photon Detection with Ultralow Noise van der Waals Hybrid

Van der Waals hybrids of graphene and transition metal dichalcogenides exhibit an extremely large response to optical excitation, yet counting of photons with single‐photon resolution is not achieved. Here, a dual‐gated bilayer graphene (BLG) and molybdenum disulphide (MoS₂) hybrid are demonstrated, where opening a band gap in the BLG allows extremely low channel (receiver) noise and large optical gain (≈10¹⁰) simultaneously. The resulting device is capable of unambiguous determination of the Poissonian emission statistics of an optical source with single‐photon resolution at an operating temperature of 80 K, dark count rate 0.07 Hz, and linear dynamic range of ≈40 dB. Single‐shot number‐resolved single‐photon detection with van der Waals heterostructures may impact multiple technologies, including the linear optical quantum computation.     

Single photon detection of degenerate photon pairs at 1.55 μm from a periodically poled lithium niobate parametric downconverter

Abstract

The performance of a communication system that uses 1.55 μm correlated photon pairs is analysed experimentally in terms of achievable coincidence rates, optimal pump rates, and the performance of custom-built photon-counting detectors at 1.55 μm. The testbed considered in this study uses standard telecom fibre, twin photons, and photon-counting detectors. Degenerate cw time-frequency entangled photon pairs are produced via quasiphase-matched spontaneous parametric downconversion in bulk periodically poled lithium niobate. The photon pairs are efficiently collected into a single-mode fibre and are sent to a pair of custom-built InGaAs photon-counting avalanche photodiodes that are passively quenched, gated in Geiger mode, and thermoelectrically cooled to temperatures as low as - 60°C. Reliable photoncounting operation with a quantum efficiency of 20% at a dark count probability of 0.04% per gate (20 ns) and negligible afterpulses is reported.     

Photon number resolving in geiger mode avalanche photodiode photon counters

Abstract

The paper reports on research and development in the field of avalanche photodiodes operated as photon counters in a Geiger mode. A technique has been developed and tested that permits estimation of the photon number involved in a detection process. It can be applied in a time correlated photon counting experiment simultaneously with original required time interval estimation. A time walk compensation circuit provides uniform electrical pulses, and the time interval between them is related to the number of photons detected. Employing a picosecond event timing device, the photon number can be estimated within the dynamic range 1–1000 photons with resolution better than a factor of three.     

Energy Collection Efficiency of Tungsten Transition-Edge Sensors in the Near-Infrared

Single-photon detectors operating at visible and near-infrared wavelengths with high detection efficiency and low noise are a requirement for many quantum-information applications. Detection of visible and near-infrared light at the single-photon level and discrimination between one- and two-photon absorption events place stringent requirements on TES design in terms of heat capacity, thermometry, and optical detection efficiency. Energy loss in the conversion of the photon energy in tungsten TESs to heat degrades the performance of these devices. By fabricating TESs on surface-micromachined Si₃N₄ membranes we improved the energy collection efficiency by a factor of two, to ∼80% energy efficiency.      

Photon counting at telecom wavelengths with commercial InGaAs/InP avalanche photodiodes: Current performance

Abstract

InGaAs/InP avalanche photodiodes operated in the so-called Geiger mode currently represent the best solution to detect single-photon beyond 900nm. They cover the 1100–1650nm wavelength interval, which includes in particular the two windows used for optical communications (1310 and 1550nm). A detection efficiency at 1550nm of 10% with a dark count probability of 10^?5 ns^?1 is common, although significant variations can be encountered. At this efficiency, a FWHM temporal response of 300 ps can be achieved. Afterpulses caused by charges trapped by defects in the high field region of the junction constitute the main performance impairment phenomenon. They enhance the dark count probability and reduce out-of-gate detector blindness. These photon counting detectors can be used in optical time-domain reflectometry to improve the spatial resolution and reduce dead-zone effects. Quantum key distribution over metropolitan area networks also constitutes an important application.     

Photon signal detection and evaluation in the adaptive optics scanning laser ophthalmoscope

To select a suitable photodetector for an adaptive optics scanning laser ophthalmoscope (AOSLO) and evaluate its performance, we characterized the signal and noise properties in the AOSLO photon detection and derived the signal-to-noise ratio (SNR). Using the SNR as the main criterion, we chose the best detector from a selection of four photomultiplier tubes (PMTs) and three avalanche photodiodes (APDs). We conducted a comprehensive evaluation of the performance of the selected detector on our AOSLO. The study presents a practical strategy that can be used to test the photodetector for either initial evaluation or subsequent performance in in-line inspection.     

Photon-number-resolving detection using time-multiplexing

Abstract

Detectors that can resolve photon number are needed in many quantum information technologies. In order to be useful in quantum information processing, such detectors should be simple, easy to use, and be scalable to resolve any number of photons, as the application may require great portability such as in quantum cryptography. Here we describe the construction of a time-multiplexed detector, which uses a pair of standard avalanche photodiodes operated in Geiger mode. The detection technique is analysed theoretically and tested experimentally using a pulsed source of weak coherent light.     

Determination of electron currents below 1 nA in the storage ring BESSY by measurement of the synchrotron radiation of single electrons

Since the electron storage ring BESSY is suitable for use as a calculable radiation standard of extremely low photon flux, currents below 1 nA have to be measured exactly. For this we installed two different photon detection systems for monitoring the stepwise decrease in the photon flux as the number of stored electrons is reduced one by one. The performances of a photon counter, accepting a large solid angle of the visible and near-UV synchrotron radiation, and an array of photodiodes, sensitive mostly in the soft X-ray region, were investigated for different operational conditions of the storage ring. With a computerized data analysis routinely up to 1000 electrons are counted unambiguously allowing the determination of electron currents up to 0.77 nA with an uncertainty of 3 × 10⁻⁷ of the measured current.     

Avalanche photodiodes and quenching circuits for single-photon detection

Avalanche photodiodes, which operate above the breakdown voltage in Geiger mode connected with avalanche-quenching circuits, can be used to detect single photons and are therefore called singlephoton avalanche diodes SPAD's. Circuit configurations suitable for this operation mode are critically analyzed and their relative merits in photon counting and timing applications are assessed. Simple passive-quenching circuits (PQC's), which are useful for SPAD device testing and selection, have fairly limited application. Suitably designed active-quenching circuits (AQC's) make it possible to exploit the best performance of SPAD's. Thick silicon SPAD's that operate at high voltages (250-450 V) have photon detection efficiency higher than 50% from 540- to 850-nm wavelength and still ~3% at 1064 nm. Thin silicon SPAD's that operate at low voltages (10-50 V) have 45% efficiency at 500 nm, declining to 10% at 830 nm and to as little as 0.1% at 1064 nm. The time resolution achieved in photon timing is 20 ps FWHM with thin SPAD's; it ranges from 350 to 150 ps FWHM with thick SPAD's. The achieved minimum counting dead time and maximum counting rate are 40 ns and 10 Mcps with thick silicon SPAD's, 10 ns and 40 Mcps with thin SPAD's. Germanium and III-V compound semiconductor SPAD's extend the range of photon-counting techniques in the near-infrared region to at least 1600-nm wavelength.     

GaAs-based nanoneedle light emitting diode and avalanche photodiode monolithically integrated on a silicon substrate

Monolithic integration of III-V compound semiconductor devices with silicon CMOS integrated circuits has been hindered by large lattice mismatches and incompatible processing due to high III-V epitaxy temperatures. We report the first GaAs-based avalanche photodiodes (APDs) and light emitting diodes, directly grown on silicon at a very low, CMOS-compatible temperature and fabricated using conventional microfabrication techniques. The APDs exhibit an extraordinarily large multiplication factor at low voltage resulting from the unique needle shape and growth mode.     

A History of the Photographic Lens

Abstract

We investigate the transient and the steady-state behaviour of the photon statistics of a single-atom laser, consisting of a three-level Λ system, driven by an incoherent external pump field and strongly coupled to a single mode of an optical cavity. For several limiting cases we are able to obtain analytical results. A comparison with standard multi-atom laser theory reveals a surprisingly good agreement down to very small intracavity photon numbers. Under appropriate operating conditions a calculation of the second-order intensity correlation function yields sub-Poissonian statistics as well as strong antibunching induced by the nonlinear dynamics of the atom.     

量子外差精密测量及微弱信号感知技术综述

单光子探测技术和激光外差探测技术是探测微弱光信号的重要手段,通过微弱光信号提取目标多维信息是目前激光感知的重要领域。但是在实际应用中背景噪声以及信号光的退相干,会严重影响单光子探测技术以及外差探测技术对于目标多维信息的感知。在探测微弱光信号时的这些问题通过传统方案很难被有效的解决。量子外差精密测量方法是在单光子探测的基础上结合外差探测的一种新测量方法,可以解决单光子探测探测灵敏度受背景噪声限制的缺点。并且量子外差对本振光强度要求极低,可以有效降低大阵列外差探测对于本振强度的要求。文中进一步总结并分析了量子外差精密测量方法的研究动态。通过现有研究成果的梳理和分析有助于深入理解和把握目前量子外差精密测量方法的研究现状和问题,为量子外差精密测量方法未来发展奠定基础。     

Evolution and prospects for single-photon avalanche diodes and quenching circuits

Abstract

The evolution of solid-state avalanche detectors of single optical photons is outlined and the issues for further progress are discussed. Physical phenomena that underlay the operation of the single-photon avalanche diodes (SPAD) and determine the performance are considered and their role is assessed (detection efficiency; dark-counting rate; afterpulsing; photon timing resolution; etc.). The main technological issues that hamper the development of detectors with wide sensitive area and of array detectors with high filling factor are illustrated. Silicon SPADs are the main focus of attention; infrared-sensitive SPADs in germanium and in compound semiconductors are also dealt with. The role of the active-quenching circuits (AQC) is assessed and the evolution is outlined up to integrated AQCs, which offer the prospect of monolithic integration of complete photon counter instruments.     

14 MHz rate photon counting with room temperature InGaAs/InP avalanche photodiodes

Abstract

We have developed high speed gated-mode single-photon counters based on InGaAs/InP avalanche photodiodes for use at 1.55 μm wavelength. Operation at room temperature allows afterpulse probability to be below 0.2% for gate rates up to 14 MHz. We obtained optimum noise-equivalent power of 2.2 ×s; 10^?15 W Hz^?1/2 at 14% quantum efficiency with dark-count probability of 0.2%. We propose a metric (noise-equivalent power divided by gate frequency) for comparing high speed photon counters and show that for this metric our system outperforms previously reported counters at 1.55 μm wavelength. We demonstrate that for gate widths of a nanosecond or below, the differing amplitude distributions of dark versus light counts allow an optimal decision threshold to be set for a given bias voltage.     

Quantum information processing in localized modes of light within a photonic band-gap material

Abstract

The single photon occupation of a localized field mode within an engineered network of defects in a photonic band-gap (PBG) material is proposed as a unit of quantum information (qubit). Qubit operations are mediated by optically-excited atoms interacting with these localized states of light as the atoms traverse the connected void network of the PBG structure. We describe conditions under which this system can have independent qubits with controllable interactions and very low decoherence, as required for quantum computation.