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

• 量子光学 • 上一篇    下一篇

量子密钥分发系统中高精度同步方案设计

万旭 崔珂 高原 张鸿飞 罗春丽 王坚   

  1. 中国科学技术大学近代物理系,安徽省物理电子学重点实验室,中国科学院核探测技术与核电子学重点实验室, 安徽 合肥 230026
  • 收稿日期:2010-05-10 修回日期:2010-06-17 出版日期:2011-05-28 发布日期:2011-05-20
  • 通讯作者: 王坚(1975- ),博士,副教授,研究方向为物理电子学. E-mail:wangjian@ustc.edu.cn
  • 作者简介:万旭(1985- ),研究生,研究方向为物理电子学,wanxu@mail.ustc.edu.cn
  • 基金资助:

    973重大项目子课题(2006CB921904)和安徽高校省级自然科学研究重点项目(KJ2009A133)资助

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

摘要:

针对光纤量子密钥分发(QKD)系统中信号同步的关键问题,提出了一种光同步方案。发送方通过现场可编程门阵列(FPGA)产生一定特征的同步脉冲序列驱动同步激光器,产生的同步光和信号光耦合到一根光纤传给接收方。接收方经过高速甄别后使用高频时钟来“采样”接收到的同步脉冲序列,使得双方达到严格同步;同时经过高精度延时调整后提供给单光子探测器作为门控信号,最大限度地去除暗计数。该方案具有高精度,低成本,容错性好的特点,已经成功应用于城域量子通信网络。

关键词: 量子信息, 光同步, FPGA, 高精度可调延时, 量子密钥分发

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

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