Development of Single-photon Detectors for Practical Quantum Cryptography

Shuichiro Inoue, Naoto Namekata

Akio Yoshizawa

I review the recent progress on single-photon detectors developed for detecting 1550-nm photons. Thermoelectrically cooled single-photon detectors based on indium-gallium-arsenide avalanche photodiodes are simple to operate and are desirable for practical applications. Methods for reducing the dark count rate and after-pulsing probability are discussed. I also briefly explain the concepts of upconversion-based singlephoton detectors and ultra-low-noise superconducting single-photon detectors.

Robert H. Hadfield

A. Verevkin, Carlo Kosik Williams, Gregory N Gol'tsman +2 more

We have developed an ultrafast superconducting single-photon detector with negligible dark counting rate. The detector is based on an ultrathin, submicron-wide NbN meander-type stripe and can detect individual photons in the visible to near-infrared wavelength range at a rate of at least 10 Gb/s. The above counting rate allows us to implement the NbN device to unconditionally secret quantum key distribution in a practical, high-speed system using real-time Vernam enciphering.

Shiji Yang, Lixing You, Ming Zhang +1 more

Akio Tajima, Akihiro Tanaka, Y. Nambu +4 more