量子密钥分配系统中非线性偏振耦合的研究

摘要

Because of the effect of nonlinear polarization of transmission fiber , coupling ratio between local oscillator and quantum signal in a quantum key distribution system is decreased , signal jitters which leads to polarization multiplexing is increased, and security and stability of the system are decreased .To enhance technical performance of polarization encodement of quantum optics , after theoretical analysis and numerical simulation , operational experiment scheme was proposed to solve the polarization jitters caused by nonlinear polarization coupling of fiber .The results show that signal stability of polarization multiplexing enhances and transmission capacity of quantum key distribution increases to 61%by using feedback of spectral test results to control fiber nonlinear polarization coupling ratio between local oscillator and quantum signal .The research is helpful for practical application of polarization coding technology in quantum key distribution .%受传输光纤非线性偏振影响，量子密钥分配系统本振光与信号光耦合率下降，使形成偏振复用信号的抖动增强，系统的稳定性和安全性下降。为了提高量子光学中偏振编码技术的性能，经过理论分析和数值模拟，给出可操作性的实验方案，解决了光纤非线性偏振耦合导致的偏振抖动问题。结果表明，在同等条件下，以分光检测结果反馈控制本振光和信号光的非线性偏振耦合率，可增强偏振复用信号的稳定性，将系统传输容量提高61％。该结果有利于偏振编码技术在量子密钥分配系统的实际应用。