基于模分复用的量子密钥分发系统性能分析

Performance Analysis of Quantum Key Distribution System Based on Mode Division Multiplexing

模分复用技术可实现量子信号与经典光信号的共纤同传。针对量子模分复用同传系统构建同时存在非线性效应和模式耦合的量子密钥生成率模型,通过仿真计算量子密钥生成率与通信距离的关系。仿真结果表明:该系统的最大安全通信距离过短,且与传统量子密钥分发系统的性能相比存在较大差距。因此在此基础上提出基于双诱骗态的量子模分复用同传方案,以增大复用同传的最大安全通信距离。同时为了充分利用光纤信道的资源,对空闲模式信道进行多路量子信号复用传输,进一步改善量子模分复用同传系统的通信性能,缩小与传统的量子密钥分发系统的差距。

Mode division multiplexing technology can achieve the co-fiber-transmission technology of quantum signals and classical optical signals.A quantum key generation rate model with simultaneous nonlinear effects and mode coupling is constructed for a quantum mode division multiplexing simultaneous-transmission system.The relationship between the quantum key generation rate and the communication distance is studied by simulation calculations.Simulation results show that the maximum safe communication distance of the system is too short,and there is a big gap compared with the performance of traditional quantum key distribution systems.Accordingly,a quantum mode division multiplexing simultaneous-transmission scheme based on double decoy states is proposed to increase the maximum safe communication distance of multiplexing simultaneous transmissions.Moreover,to make full use of fiber channel resources,multiplex quantum signal multiplexing transmission is performed on an idle mode channel,which improved the communication performance of the quantum mode division multiplexing simultancous-transmission system and narrowed the gap with the traditional quantum key distribution systems.