Kong Weiwen, Sun Yongmei, Gao Yaoxian, Ji Yuefeng
The State Key Laboratory of Information Photonics and Optical Communications, School of Information and Communication Engineering, Beijing University of Posts and Telecommunications, Beijing 100876, China.
Nanophotonics. 2023 Apr 24;12(11):1979-1994. doi: 10.1515/nanoph-2023-0047. eCollection 2023 May.
In this paper, the influence of classical signals on quantum key distribution (QKD) is studied over multi-core fiber (MCF) when optical amplifiers exist. Firstly, the long-distance simultaneous transmission architectures of QKD and classical signals are proposed based on advanced asymmetric sending or not sending QKD (SNS-QKD) and classical Bennett-Brassard 1984-QKD (BB84-QKD), and the segment length between optical amplifiers can be adjusted according to requirement. Then, theoretical models of spontaneous Raman scattering noise and four-wave mixing noise are established based on the proposed architectures. Next, the calculation models of the secure key rate under the influence of noises from classical signals are derived. Finally, the experimental results show that the theoretical models match well with the experimental photons, and the maximum difference between experimental and simulated noise photons is less than 2.6 dB. Simulation results show that the performance of asymmetric SNS-QKD is better than that of BB84-QKD architecture when classical signals and quantum signals are transmitted in different cores of MCF.
本文研究了存在光放大器时，经典信号对多芯光纤（MCF）上量子密钥分发（QKD）的影响。首先，基于先进的非对称发送或不发送QKD（SNS-QKD）和经典的1984年贝内特-布拉萨德量子密钥分发（BB84-QKD），提出了QKD和经典信号的长距离同时传输架构，并且光放大器之间的段长可根据需要进行调整。然后，基于所提出的架构建立了自发拉曼散射噪声和四波混频噪声的理论模型。接下来，推导了经典信号噪声影响下的安全密钥率计算模型。最后，实验结果表明理论模型与实验光子匹配良好，实验噪声光子与模拟噪声光子之间的最大差异小于2.6 dB。仿真结果表明，当经典信号和量子信号在MCF的不同芯中传输时，非对称SNS-QKD的性能优于BB84-QKD架构。
