基于诱骗态MDI-QKD协议,提出了一种使用波分复用技术(WDM)的MDI-QKD协议。通信双方Alice 和Bob同时发送不同波长的多路信号,通过光复用器将多路信号合并,由单根光纤进行长距离传输。 第三方Charlie通过光解复用器将多路合成信号分开,分别对每一路进行贝尔态测量。理论分析结果 表明协议的密钥生成率与传输距离、复用路数及平均光子数目有关;数值仿真结果表明在不增加系 统传输设备的前提下,该协议极大提高了系统的密钥生成率。当传输距离为150 km, 单路的密钥生成率为0.17 Mbps, 20路、40路复用的密钥生成率分别可达3.34 Mbps、6.68 Mbps。

Based on the decoy state measurement-device-independent quantum key distribution (MDI-QKD) protocol, a MDI-QKD protocol using wavelength division multiplexing (WDM) technique is proposed. Both sides of communications, Alice and Bob, transmit multiple-channel signals with different wavelengths at the same time. The multi-channel signals are merged with optical multiplexer, and then a single fiber is adopted for long distance transmission. The third party, Charlie, separates the multi-channel synthetic signal with optical demultiplexer, and Bell-state measurement is performed for each sub-channel signal. Theoretical analysis results show that the key generation rate relates to the transmission distance, number of multiplexing and mean photon numbers. Numerical simulation results show that the proposed protocol greatly improves the system key generation rate. When the transmission distance is 150 km, the single-channel key generation rate is 0.17 Mbps. The key generation rates with 20 channels, 40 channels multiplexing are 3.34 Mbps, 6.68 Mbps respectively.