Single-photon detection,which is the core of weak light detection,plays key role in the fields of quantum information,physics,biology,chemistry and astronomy.The low sensibility and the high dark count rate of traditional single-photon detectors which base on photomultiplier tube or avalanche photodiode limit the improvement of the signal noise ratio and the low counting rate limits the detecting speed and the dynamic range.Here we review the single-photon detecting technology using superconducting materials as light sensitive apparatus.Their quantum efficiency,dark count rate and counting rate outclass the traditional single-photon detector.Their appearances certainly will bring a great influence to the subjects relating to the single-photon detection.
Single-photon detection,which is the core of weak light detection,plays key role in the fields of quantum information,physics,biology,chemistry and astronomy.The low sensibility and the high dark count rate of traditional single-photon detectors which base on photomultiplier tube or avalanche photodiode limit the improvement of the signal noise ratio and the low counting rate limits the detecting speed and the dynamic range.Here we review the single-photon detecting technology using superconducting materials as light sensitive apparatus.Their quantum efficiency,dark count rate and counting rate outclass the traditional single-photon detector.Their appearances certainly will bring a great influence to the subjects relating to the single-photon detection.
In the last decade,more and more quantum information applications such as quantum key distribution have been extensively demonstrated.These emerging applications place rigorous demands on detector performance such as detection efficiency,intrinsic photon number resolving ability etc.that go beyond the capabilities of traditional single-photon detectors composed of either photomultiplier tubes(PMTs) or avalanche photodiodes(APDs).Fortunately,several new types of cryogenic detectors such as superconducting transition edge sensor(TES),superconducting nanowire single photon detector(SNSPD),and quantum-dot based single photon detector(QD SPD)have been realized recently.Here we review all kinds of single photon detector technologies at the present time. Advantages,disadvantages,and potential improvement of these techniques for quantum information applications are also discussed.
Photon detectors connect optical and electrical systems by converting light to electrical signals. Single photon detectors detect single photons which measure ultra-weak light. Traditional semiconductor single-photon detectors suffer from high dark count rates, low infrared detection efficiency, and poor temporal resolution. Superconducting-nanowire single-photon detectors (SNSPDs) overcome these limitations using the hotspot effect. SNSPDs have created a solid foundation for optical technologies and become key in quantum information, LiDARs and Deep-Space Communications. This paper reviews working principles and performance metrics: system detection efficiency, dark count rate, recovery time, and timing jitter. The study summarizes applications in quantum information (quantum key distribution, optical quantum computing), single-photon LiDAR, and deep-space optical communication, replacing most single-photon avalanche diodes (SPADs). Recent experiments show that SNSPD-based systems can achieve meter-scale detection of sea fog, interplanetary laser communication over billions of kilometers, and boson sampling with 20 photons. Ongoing research is expected to improve performance in maximum count rate, system integration, and cryogenic operation, as well as to find applications in emerging fields such as environmental monitoring.
Superconducting devices offer the potential to perform at speeds and detection efficiencies higher than what is possible using conventional technologies (such as semiconducting avalanche photodiodes and photomultiplier tubs) for wavelengths from the ultraviolet to the mid-infrared. As a result, there has been increasing interest in using superconducting optical photon detectors in a variety of applications. There has been significant progress in using these types of detectors in areas of basic research such as quantum information science and quantum optics. These applications require detectors that have extremely low dark count rates, high count rates, and high quantum efficiency. I will begin by describing some of our earlier work on superconducting Transition-Edge Sensor (TES). In particular, I will describe some of the engineering involved in the cryogenic, electrical, and optical packaging so that these devices can be easily coupled into fiber-based optics. I will also describe our recent work on developing superconducting nanowire single photon detectors (SNSPD or SSPD). An SNSPD is an ultra-thin, ultra-narrow (nm scale) superconducting meander that is current biased just below its critical current density. When one or more photon is absorbed, a hot spot is formed that causes the superconductor to develop a resistance and consequently a voltage pulse. At NIST and JPL, we have been developing nanowire detectors using an amorphous alloy of tungsten-silicide. We will describe to construct systems using tungsten-silicide nanowires to achieve high detection efficiency (>90% at 1550nm). I will also describe our work to improve the performance of the device by fabricating multiple nanowires in an electrically parallel structure to implement a superconducting nanowire avalanche photodiode (SNAP)[1]. One example of this type of detector is shown in Fig 1. In this case, there are two tungsten silicide layers separated by a dielectric layer to optimize detection of light for any polarization[2]. In addition, progress on other types of SNAP detectors will be described to increase the signal size from a single photon, reduce the recovery time of the device, and to improve the jitter.
Over the past decade, there have been increasing demand on and interest in high performance single photon detectors in many new applications in quantum information technology. Compared with conventional single photon detectors, superconducting transition edge sensor (TES) based single photon detectors have great advantages in the performance of detection efficiency, energy resolution, photon number resolving capability, dark count rate, etc. They have been successfully used in quantum optics experiments and quantum key distribution systems, and they will play a more important role in the research field of quantum information science and technology. In this paper we review the operating principle, fabrication process, performance, measurement system and the research progress on superconducting TES based single photon detectors.
Superconducting single-photon detectors (SSPDs) are nanostructured devices made from ultrathin superconducting films. They are typically operated at liquid helium temperature and exhibit high detection efficiency, in combination with very low dark counts, fast response time, and extremely low timing jitter, within a broad wavelength range from ultraviolet to mid-infrared (up to 6mum). SSPDs are very attractive for applications such as fiber-based telecommunication, where single-photon sensitivity and high photon-counting rates are required. We review the current state-of-the-art in the SSPD research and development, and compare the SSPD performance to the best semiconducting avalanche photodiodes and other superconducting photon detectors. Furthermore, we demonstrate that SSPDs can also be successfully implemented in photon-energy-resolving experiments. Our approach is based on the fact that the size of the hotspot, a nonsuperconducting region generated upon photon absorption, is linearly dependent on the photon energy. We introduce a statistical method, where, by measuring the SSPD system detection efficiency at different bias currents, we are able to resolve the wavelength of the incident photons with a resolution of 50 nm.