自动补偿高效的差分相位编码QKD系统  

An auto-compensating and efficient differential phase shift quantum key distribution system

作　　者：林一满[1] 梁瑞生[1] 路轶群[1] 路洪[2] 郭邦红[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 [2]佛山科学技术学院光电子与物理学系,佛山528000

出　　处：《物理学报》2007年第7期3931-3936,共6页Acta Physica Sinica

基　　金：国家重点基础研究发展规划(973)项目(批准号:2007CB307001)资助的课题.~~

摘　　要：提出一种自动补偿高效实用的改进型差分相位编码量子密钥分发方案.在Alice端采用偏振型强度调制器对连续激光进行调制,产生任意个相干脉冲进行差分相位调制编码;在Bob端采用双FM干涉仪代替传统的M-Z干涉仪,自动补偿了环境引起的偏振抖动,提高了系统的干涉稳定度.简化了系统的结构,提高了密钥生成效率,增强了系统的安全性.在实验上实现了稳定的80km量子密钥分配,误码率<4%.We present an improved differential phase shift quantum key distribution scheme which features auto-compensation, high efficiency, and excellent practicality. Alice modulates continuous laser using an intensity modulator based on polarization to generate coherent pulse train. Bob employs a Fraday-Michelson interferometer instead of a traditional M-Z interferometer, which automatically compensates for the polarization mode dispersion caused by the changes of environment and improves the stability of the interference visibility. The present scheme not only has a simpler configuration, but also offers a higher key creation efficiency than traditional schemes. Furthermore, it enhances the security of the system. With the proposed experimental setup, a stable quantum key distribution was performed over 80 km fiber with a quantum bit-error rate of less than 4 %.

关 键 词：量子保密通信 量子密钥分发 差分相位编码 偏振型强度调制器 

分 类 号：TN918[电子电信—通信与信息系统]