基于单光子计数反馈的低噪声光纤信道波分复用实时偏振补偿系统  

Real-time polarization compensation system for wavelength division multiplexing in low noise fiber channel based on single photon counting feedback

作　　者：曹若琳 彭清轩 王金东[1] 陈勇杰 黄云飞 於亚飞[1] 魏正军[1] 张智明[1] Cao Ruo-Lin;Peng Qing-Xuan;Wang Jin-Dong;Chen Yong-Jie;Huang Yun-Fei;Yu Ya-Fei;Wei Zheng-Jun;Zhang Zhi-Ming(Guangdong Provincial Key Laboratory of Quantum Engineering and Materials,School of Information and Optoelectronic Science and Engineering,South China Normal University,Guangzhou 510006,China)

机构地区：[1]华南师范大学信息光电子科技学院,广东省量子调控工程与材料重点实验室,广州510006

出　　处：《物理学报》2022年第13期44-52,共9页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:62071186,61771205);广东省自然科学基金(批准号:2015A030313388);广东省科技计划(批准号:2015B010128012);广东省重点实验室基金(批准号:2020B1212060066)资助的课题。

摘　　要：光纤信道由于受环境影响产生的随机双折射等物理效应使得在其中传输的光信号具有敏感的偏振变化,严重影响了偏振编码量子密钥分发系统的性能.本文提出了一种利用单光子计数作为反馈信号的低噪声光纤信道波分复用实时偏振补偿系统,该系统通过探测共轭参考光的光子计数得到光纤信道偏振变化信息,设计补偿算法控制电动偏振控制器实时校准对应偏振基下量子信号光的偏振态,成功实现了稳定的光纤信道偏振补偿.为验证补偿系统的有效性,进行了传输距离为25.2 km的基于BB84协议的量子密钥分发测试,在实验室环境和模拟城域网地埋光纤环境下得到了长达8 h的稳定测试结果,平均量子比特误码率分别为0.52%和1.25%.该实验结果表明本系统可在城域网地埋光纤环境下保障偏振编码量子密钥分发的稳定工作.The physical effects such as random birefringence of fiber optic channels due to environmental influences make the optical signals transmitted in them have sensitive polarization variations,which seriously affects the performance of polarization biased code quantum key distribution systems.In this paper,a low-noise fiber channel wavelength division multiplexing real-time polarization compensation system is presented,where single photon counting is used as a feedback signal.The system can acquire the fiber channel polarization change information by detecting the photon counting of the conjugate reference light.In the system,the compensation algorithm is designed to control the electric polarization controller to calibrate the polarization state of the quantum signal light under the corresponding polarization base in real time,and the stable fiber channel polarization compensation is successfully achieved.In order to verify the effectiveness of the compensation system,a quantum key distribution test based on BB84 protocol with a transmission distance of 25.2 km is conducted,and stable test results of up to 8 hours are obtained in the laboratory environment and the simulated metropolitan area network buried fiber environment,with the average quantum bit error rate being 0.52%and 1.25%,respectively.The experimental results show that this system can guarantee the stable operation of polarization-encoded quantum key distribution in the buried fiber environment in urban areas.

关 键 词：量子密钥分发 偏振补偿 波分复用 地埋光纤 

分 类 号：O413[理学—理论物理] TN918.4[理学—物理]