自由空间量子通信系统容易受到各种自然条件的影响从而影响密钥生成率,而大气湍流随机性的特点是设计自由空间量子通信系统考虑的首要因素。根据大气传播理论,考虑湍流和衰减因素,建立了自由空间极化编码单光子源的传播模型,分析了大气湍流和量子密钥生成率间的关系;然后利用实际参数分析了不同湍流强度对量子密钥生成率的影响。分析结果表明,湍流强度增加会使密钥生成率下降,在大气折射率结构常数大于10^-14时,密钥生成效率接近于0。
The key generation rates of free space quantum communication systems are vulnerable to the impact of variety natural conditions,so the character of random atmospheric turbulence is to be the primary factor taken into account to design free space quantum communication systems.A quantum key generation rate formula under the influence of turbulent flow was established,and the different intensity of the atmospheric turbulence with actual parameters impacting on the quantum key generation rate was researched.The results show that quantum key generation rate is close to 0 under the influence of strong atmospheric turbulence.