研究了三种常见天气降雨、降雪和雾霾对采用不同波长信号的自由空间量子通信系统的安全密钥率的影响。利用建立的基于连续变量高斯调制的量子密钥分发传输模型,分析了在个体攻击和集体攻击情况下Bob分别采用零差检测和外差检测时,不同天气条件和不同信号光波长对安全密钥率的影响。随后仿真得到了不同天气情况和等级、不同波长量子信号、不同攻击类型和不同检测方式条件下安全密钥率随传输距离的变化关系,并对结果进行了分析。研究结果可以为实际的自由空间量子通信系统的设计提供一定的参考。

This paper investigates the effects of three weather conditions, such as rain, snow, and haze, on security key rate of a free-space quantum communication system using different signal wavelengths. For the cases of collective and individual attacks, analysis is conducted on why and how different weather conditions and signal wavelengths affect the security key rate based on a continuous-variable quantum key distribution model with Gaussian modulation. In the analysis, two different conditions are considered: one in which Bob uses a homodyne detector and the other in which a heterodyne detector is used. The relationship between the security key rate and transmission distance is simulated under various conditions, including different weather conditions and levels, different quantum signal wavelengths, different attack types, and different detection modes. The results of this paper can serve as an instructive reference for future practical free-space quantum communication system designs.