Author Affiliations
Abstract
1 State Key Laboratory on Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
2 Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
3 Division of Quantum Materials and Devices, Beijing Academy of Quantum Information Sciences, Beijing 100193, China
4 Laboratory of Quantum Information, CAS, University of Science and Technology of China, Hefei 230026, China
Quantum key distribution (QKD) provides a solution for communication of unconditional security. However, the quantum channel disturbance in the field severely increases the quantum bit-error rate, degrading the performance of a QKD system. Here we present a setup comprising silica planar light wave circuits (PLCs), which is robust against the channel polarization disturbance. Our PLCs are based on the asymmetric Mach–Zehnder interferometer (AMZI), integrated with a tunable power splitter and thermo-optic phase modulators. The polarization characteristics of the AMZI PLC are investigated by a novel pulse self-interfering method to determine the operation temperature of implementing polarization insensitivity. Over a 20 km fiber channel with 30 Hz polarization scrambling, our time-bin phase-encoding QKD setup is characterized with an interference fringe visibility of 98.72%. The extinction ratio for the phase states is kept between 18 and 21 dB for 6 h without active phase correction.
Photonics Research
2021, 9(2): 02000222
中国科学院半导体研究所光电系统实验室, 北京 100083
基于光纤中高相干光源（相干长度大于100 km）的瑞利散射光的统计特性，采用随机相向量模型，推导了光纤中瑞利散射光的功率分布和相位分布，指出瑞利散射光功率的概率密度函数(PDF)符合修正的莱斯分布，而瑞利散射光的相位分布近似为高斯分布。采用高灵敏度的光电探测器对不同长度的光纤的瑞利散射光功率进行了测试，实验结果与理论吻合，同时发现不同长度光纤的瑞利散射光功率的最大值随平均值线性增加。
统计光学 瑞利散射 概率密度函数 高相干光源
