The upsurge of interest in quantum key distribution(QKD) in recent years has motivated an extensive effort aiming at developing single-photon detectors(SPDs) at telecommunication wavelengths. A brief review is given of the major technologies for the SPDs, including temperature control and Geiger mode operation especially the gated mode operation, and the methods to choose from commercially available InGaAs/InP APDs for the SPDs are discussed.
The upsurge of interest in quantum key distribution(QKD) in recent years has motivated an extensive effort aiming at developing single-photon detectors(SPDs) at telecommunication wavelengths. A brief review is given of the major technologies for the SPDs, including temperature control and Geiger mode operation especially the gated mode operation, and the methods to choose from commercially available InGaAs/InP APDs for the SPDs are discussed.
Single-photon detectors (SPDs) are the most sensitive instruments for light detection. In the near-infrared range, SPDs based on III–V compound semiconductor avalanche photodiodes have been extensively used during the past two decades for diverse applications due to their advantages in practicality including small size, low cost and easy operation. In the past decade, the rapid developments and increasing demands in quantum information science have served as key drivers to improve the device performance of single-photon avalanche diodes and to invent new avalanche quenching techniques. This Review aims to introduce the technology advances of InGaAs/InP single-photon detector systems in the telecom wavelengths and the relevant quantum communication applications, and particularly to highlight recent emerging techniques such as high-frequency gating at GHz rates and free-running operation using negative-feedback avalanche diodes. Future perspectives of both the devices and quenching techniques are summarized. Recent progress in single-photon detectors for quantum communication based on III–V compound semiconductor avalanche photodiodes is reviewed. Specifically, Jun Zhang and Jian-Wei Pan at the University of Science and Technology of China and their colleagues in the USA and Switzerland introduce technological advances for InGaAs/InP single-photon detector systems in the telecommunication band along with their associated applications in quantum communication. III–V single-photon avalanche diodes are the most practical tools available for detecting ultraweak near-infrared light. The scientists overview important parameters for evaluating the performance of detector systems based on single-photon avalanche diodes and describe the experimental characterization of these parameters. They also consider emerging techniques, including high-frequency gating at gigahertz rates and free-running operation using negative-feedback avalanche diodes. Finally, the future prospects of these devices are considered.
Single-photon detectors (SPDs) are the most sensitive instruments for light detection. In the near-infrared range, SPDs based on III–V compound semiconductor avalanche photodiodes have been extensively used during the past two decades for diverse applications due to their advantages in practicality including small size, low cost and easy operation. In the past decade, the rapid developments and increasing demands in quantum information science have served as key drivers to improve the device performance of single-photon avalanche diodes and to invent new avalanche quenching techniques. This Review aims to introduce the technology advances of InGaAs/InP single-photon detector systems in the telecom wavelengths and the relevant quantum communication applications, and particularly to highlight recent emerging techniques such as high-frequency gating at GHz rates and free-running operation using negative-feedback avalanche diodes. Future perspectives of both the devices and quenching techniques are summarized.
The application of quantum key distribution (QKD) has raised particular demands for single-photon detectors. One of the most promising candidates at the low-loss optical fibre communications windows is the planar geometry InGaAs/InP single-photon avalanche diode. These detectors have been modelled, fabricated and characterised at 1.55 µm wavelength. Their performance in terms of single-photon detection efficiency, dark count rate, timing jitter and afterpulsing behaviour are reported and compared with the best commercially available, linear multiplication avalanche photodiodes operated in Geiger-mode. Their use in the application of QKD is discussed.
We provide a direct comparison between the InGaAs avalanche photodiode (APD) and the NbN superconducting single photon detector (SSPD) for applications in fiber-based quantum cryptography. The quantum efficiency and dark count rate were measured for each detector, and used to calculate the quantum bit error rate (QBER) and shared key rate for a QKD link. The results indicate that, despite low quantum efficiency, the speed of the SSPD makes it a superior detector for quantum information applications. Finally, we present results of an initial integration of an SSPD into a receiver node of the DARPA quantum network to perform quantum key distribution. Encoding quantum information on single photons has enabled the realization of a number of unique communication schemes such as the implementation of the BB84 protocol for quantum key distribution 1 and quantum dense coding. 2 Furthermore, the implementation of these schemes using photons at telecommunication wavelengths has permitted their extension to fiber optic networks, 3,4 drastically increasing the practicality of quantum information processing. To date, the state of the art in commercially available single photon detection at telecommunication wavelengths (1550 nm) has been the thermo-electrically cooled InGaAs avalanche photodiode (APD). The cooled InGaAs APD is generally operated at T = -60°C in the reverse-biased Geiger mode. Though these detectors have been successfully implemented in operating QKD links in optical fiber, the InGaAs APD suffers from afterpulsing effects that limit the key exchange rates. New SPD (single photon detector) technologies based on superconducting materials are emerging that hold tremendous promise for drastically increasing the photon counting rate and eliminating dark noise.57 The SSPD consists of a NbN thin film (t ∼ 5 nm) patterned into a narrow (w ∼ 100 nm) microstrip meander that is ∼ 500μm in length. The detector is cooled to T < 4K in a closed cycle refrigeration unit and a bias current I b is supplied to the device just below the superconducting critical current (I c ). When a photon is incident upon the microstrip superconductivity is broken in the region local to photon absorption and a normal state region is formed in the device. The current passing through the device causes a measurable voltage pulse in the detector that can be amplified and shaped to act as an input for traditional logic circuitry. Due to the unique electronic bandstructure in a superconducting material the intrinsic response time of the device is on the order of picoseconds, so that the repetition rate may be increased above 1 GHz 8 without being susceptible to afterpulsing effects that plague the InGaAs APD. 9 To make a direct comparison between the InGaAs APD and the SSPD both were placed in a SPD characterization testbed to measure quantum efficiency and dark count rate at a variety of bias conditions. The QBER for a QKD link is calculated from the measured parameters and then compared to requirements for a provably secure QKD link. Following detector characterization, one of the nodes of the DARPA Quantum Network operated by BBN Technologies 3 utilized an SSPD in the receiver to transmit key material. The demonstration provides an in situ comparison between the InGaAs APD, normally operated in the BBN link, and the SSPD.
We present the latest results on two kinds of photon detectors: single photon detectors (SPDs) and photon number resolving detector (PNRD). We developed high speed and low noise SPDs using superconducting nano-wire (abbreviated by SNSPD) and semiconductor (InGaAs) avalanche photodiode (APD). The SNSPD system has totally four channels all of which have the detection eciency higher than 16% at 100Hz dark count rate. The InGaAs APD system also has four channels and the best performance is represented by the after-pulse probability of 0.61%, the dark count probability of 0.71×10-6 (~1kHz), and the detection eciency of 10.9%. Both systems were applied to wavelength division multiplexing quantum key distribution (WDM-QKD) operated at 1.2GHz repetition rate in a eld environment. The PNRD is made of superconducting transition edge sensor. It was applied to the implementation of quantum receiver which could beat the homodyne limit of the bit error rate of binary coherent states. We discuss future perspective of quantum communications with those photon detection technologies, including multi-user QKD networks and low-power high capacity communications.
In any quantum communication system, such as a quantum key distribution (QKD) system, data rates are mainly limited by the system clock rate and the various link losses. While the transmission clock rate is limited by the temporal resolution of the single-photon detectors, losses in a fiber-based quantum communication system can be minimized by operating in the near infrared range (NIR), at 1310 nm or 1550 nm. Commercially available InGaAs-based avalanche photo-diodes (APDs) can be operated as single-photon detectors in this wavelength range [Hadfield, 2009]. Due to the severe after-pulsing, InGaAs APDs are typically used in a gated mode and this can limit their application in high-speed quantum communications systems. Superconducting single-photon detectors (SSPDs) can work in the NIR wavelength range with good performance [Gol’tsman et al. 2001; Hadfield, 2009]. However, SSPDs require cryogenic temperatures, and are not widely available on the commercial market at present. In addition, InGaAs/InP based photomultiplier tubes (PMT) can operate in the NIR range, but its performance is limited by very low detection efficiency (1 % at 1600 nm) and large timing jitter (1.5 ns) [Hamamatsu, 2005]. Microchannel plates (MCP) are micro-capillary electron multipliers coated with an electron-emissive material and multiply photon-excited electrons from a photon cathode [Wiza, 1979]. MCPs usually have faster rise times and lower timing jitter than is achievable with PMTs. InGaAs MCPs can work in the NIR range. These MCPs, but are limited by low detection efficiency (~1 %) [Martin, J. & Hink P. 2003]. On the other hand, silicon based avalanche photo-diodes (Si APDs) are compact, relatively inexpensive, and can be operated at ambient temperatures with high detection efficiency and low noise in the visible or near-visible range. Unfortunately they do not work at wavelengths longer than 1000 nm. For those wavelengths, an up-conversion technique has been developed that uses sum-frequency generation (SFG) in a non-linear optical medium to convert the signal photons to a higher frequency (shorter wavelength) in the visible or near visible range. The up-converted photons can then be detected by a Si APD. Up-conversion detectors use commercially available components and devices, and are a practical solution for many applications in quantum communications. To date, several groups have successfully developed highly efficient up-conversion single-photon detectors in the nearinfrared range using periodically poled lithium niobate (PPLN) waveguides [Diamanti et al., 2005; Langrock et al., 2005; Thew et al., 2006; Tanzilli et al., 2005; Xu et al., 2007;] and bulk crystals [Vandevender & Kwiat, 2004].