J4 ›› 2011, Vol. 28 ›› Issue (3): 324-328.

• Quantum Optics • Previous Articles     Next Articles

Design of high-precision synchronization in quantum key distribution system

WAN Xu, CUI Ke, GAO Yuan, ZHANG Hong-fei, LUO Chun-li, WANG Jian   

  1. Anhui Key Laboratory of Physical Electronics, Department of Modern Physics, University of Science and Technology of China, Key Laboratory of Technologies of Particle Detection and Electronics, Chinese Academy of Sciences, Hefei 230026,China
  • Received:2010-05-10 Revised:2010-06-17 Published:2011-05-28 Online:2011-05-20

Abstract:

A light synchronization scheme to solve the key problem of signal synchronization in Quantum Key Distribution (QKD) system is proposed. At side of Transmitter, a field-programmable gate array (FPGA) chip is used to produce a synchronization pulse sequence which has certain characteristics to drive laser to transmit sync light pulse through one fiber coupled with signal light. A PIN-TIA is used to receive the sync light which is converted to electrical pulse that is used as gate control signal to the single-photon detectors after discriminating and delay adjusting. Simultaneously a high-frequency clock is used to sample the sync pulse sequence, synchronized the transmitter and receiver. The scheme has a high-precision, low-cost, high fault tolerance feature, and has been successfully applied to metro quantum communication network.

Key words: quantum optics, light synchronization, FPGA, high-precision adjustable delay, quantum key distribution

CLC Number: