偏振光子的水下传输特性分析

提出了利用蒙特卡罗法对偏振光子在表层叶绿素浓度不同的4个海域中的水下传输特性进行研究。首先建立了水下量子信道垂直传输模型，基于此模型分析了在4个海域中叶绿素浓度、海水对光信号的吸收系数和散射系数随海水深度的变化规律。随后仿真分析了4个海域中偏振光子的散射、衰减和偏振度特性随传输距离的变化趋势，给出了不同传输距离时计算接收总光子数的公式。仿真结果表明，海水对光信号的吸收和散射作用主要受叶绿素影响；随着不同海域的表层叶绿素浓度增大，光子的散射次数增加，最远接收距离减小，光子偏振度略微降低但基本保持不变。研究结果可以为星-潜量子通信系统的性能分析和建立提供一定的参考。

Analysis on Underwater Transmission Characteristics of Polarized Photons

The Monte Carlo method is used to study the underwater transmission characteristics of polarized photons in four sea areas with different surface chlorophyll concentrations. First, a vertical transmission model of underwater quantum is established. Based on the model, the variations of chlorophyll concentration, absorption coefficient and scattering coefficient of light signal with seawater depth in the four sea areas are studied. In addition, analysis of the variation of polarization photon's scattering, attenuation and polarization characteristics with the transmission distance in four sea areas is carried out. The expression of calculating the number of received photons at different transmission distances is derived. The simulation results show that the absorption and scattering of optical signals in seawater channel are mainly affected by chlorophyll. With the increase of chlorophyll concentration in the surface layer of different sea areas, the scattering numbers of photons increase, whereas the farthest receiving distance decreases. The degree of polarization is also slightly reduced but basically remains unchanged. The research can shed some light on the performance analysis and the establishment of the satellite-submersible quantum communication system.