高速连续变量量子密钥分发系统同步技术研究

Study of Synchronous Technology in High-Speed Continuous Variable Quantum Key Distribution System

在高速连续变量量子密钥分发系统中,位帧同步技术是确保准确获取量子信号所携带有效信息的核心技术之一。结合平衡零差探测器测量相干态的正则分量数据,提出了一种简单高效的位帧同步理论方案。基于此理论方案,在重复频率为25MHz的高斯调制相干态连续变量量子密钥分发系统上进行了实验测试和性能分析。结果表明,所提出的位帧同步方案能有效克服量子信号在密钥分发中受到的环境因素影响,有效实现通信双方同步。

In high-speed continuous-variable quantum key distribution system, frame synchronous technology is one of the most important technologies to ensure accurate access to effective information carried by quantum signals. A simple and efficient frame synchronization theoretical method based on the measurement results of the quadratures of coherent states with balanced homodyne detector is proposed. This synchronous method in the continuous-variable quantum key distribution system is experimentally realized with repetition frequency of 25 MHz based on Gaussian modulation coherent states, and the performance of the proposed synchronous method is analyzed in detail. The results show that the proposed frame synchronization method can effectively overcome the disturbance from the environmental factor in the key distribution of quantum signals, and thus realizes efficient frame synchronization between the two communicators.