单光子相位编码量子密钥分发系统中的偏振控制  

Polarization Control in Single Photons Phase Coding Quantum Key Distribution System

作　　者：刘令令 景明勇[1] 于波[1] 胡建勇[1] 肖连团[1] 贾锁堂[1] 

机构地区：[1]山西大学激光光谱研究所量子光学与光量子器件国家重点实验室,山西太原030006

出　　处：《激光与光电子学进展》2015年第7期256-260,共5页Laser & Optoelectronics Progress

基　　金：国家973计划(2012CB921603);国家863计划(2011AA010801);国家自然科学基金(11374196;11174187;10934004;11204166);教育部创新团队发展计划(IRT13076);高等学校博士学科点专项科研基金(20121401120016)

摘　　要：在量子密钥分发系统中,由于长距离光纤信道传输引入的偏振漂移将导致密钥分发效率下降。给出了一种基于遗传算法结合数控偏振控制器实现在单光子量级下对单光子偏振的优化控制与长时间锁定的方法。在25 km单模光纤传输每脉冲平均光子数小于0.1的单光子相位编码量子密钥分发系统中,将信号光偏振优化到最佳值,并实现了系统长期稳定运行,密钥分发成码率高于1.5 kb/s。In fiber-based quantum key distribution systems, the photons polarization fluctuation can lead to a decrease of the key generation rate. A method for polarization controlling, based on the genetic algorithm and the numerical control polarization controller is introduced. It is shown that the system could be quickly optimized and the polarization of signal beam has been locked in long term at the single-photons level. In our phase-modulated quantum key distribution system, the average photon number is less than 0.1 photon per pulse. After transmitted through 25 km single mode optical fiber, the polarization state of signal beam is realized to optimum value and keep the stable transmission for a long time, and the final key rate is up to 1.5 kpbs.

关 键 词：量子光学 量子保密通信 偏振控制 遗传算法 单光子 

分 类 号：O436[机械工程—光学工程]