Due to the limit of response speed of the present single-photon detector, the code rate is still too low to come into practical use for the present quantum key distribution (QKD) system. A new idea is put up to design a quick single-photon detector. This quick single-photon detector is composed of a multi-port optic-fiber splitter and many avalanche photo diodes (APDs). All of the ports with APDs work on the time division and cooperate with a logic discriminating and deciding unit driven by the clock signal. The operation frequency lies on the number N of ports, and can reach N times of the conventional single-photon detector. The single-photon prompt detection can come true for high repetition-rate pulses. The applying of this detector will largely raise the code rate of the QKD, and boost the commercial use.
© 2008 Chinese Optics Letters
(040.5160) Detectors : Photodetectors
(060.4510) Fiber optics and optical communications : Optical communications
(230.5160) Optical devices : Photodetectors
(270.5570) Quantum optics : Quantum detectors
Jian Peng, Yifei Fu, Li Yao, Xudong Shang, Zhixin Lu, Bojun Yang, and Li Yu, "Quick single-photon detector with many avalanche photo diodes working on the time division," Chin. Opt. Lett. 6, 320-322 (2008)