运行双协议相位调制的量子密钥分发系统  

A phase modulated QKD system with two quantum cryptography protocols

作　　者：陈霞[1] 王发强[1] 路轶群[1] 赵峰[1] 李明明[1] 米景隆[1] 梁瑞生[1] 刘颂豪[1] 

机构地区：[1]华南师范大学信息光电子科技学院光子信息技术广东省高校重点实验室,广州510631

出　　处：《物理学报》2007年第11期6434-6440,共7页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:10404007)资助的课题.~~

摘　　要：基于差分编码方式提出一种改进方案.在Alice端用光纤马赫-曾德干涉仪产生双脉冲差分信号;在Bob端,用双法拉第反射式麦克尔逊干涉仪代替光纤马赫-曾德干涉仪,这种干涉仪能自动补偿环境引起的偏振抖动和光纤双折射引起的相位漂移,从而提高系统稳定性.双协议(即双脉冲差分协议联合BB84协议)的使用,增强了系统的安全性.该系统具有高效、安全、简洁、稳定等优点,在实验上实现了长期稳定的密钥分发和量子保密通信,误码率<5%,传输距离达80km.　An improved DPS-QKD scheme is proposed and demonstrated in this paper.At Alice＇s site,we use a M-Z interferometer to produce two coherent pulses.At Bob＇s site,a Faraday-mirrors-based Michelson interferometer is used instead of a M-Z interferometer to auto-compensate for the phase drifts and polarization mode dispersions in the fiber.It enhances the security of the whole system to use the two quantum cryptography protocols（namely the two pulse DPS-QKD scheme associated with the BB84 scheme）.It is shown in our experiment that such a system features perfect stability with a quantum bit error rate less than 5% and high key generation rate.This scheme has been implemented successfully during the 80km fiber transmission.

关 键 词：量子保密通信 量子密钥分发 差分相位编码 双协议 

分 类 号：O413.2[理学—理论物理]