基于米氏散射模型的高斯激光束在海水中传输特性的数值仿真

Numerical Simulation of Gaussian Laser Beam Propagation Characteristics in Seawater Based on Mie Scattering Model

为进一步研究高斯激光束在水下通信与信息探测中的应用和在不同海水环境中传输过程的特性,以海水中最常见的陆源悬浮泥沙粒子为例,将米氏(Mie)散射理论与蒙特卡罗(Monte Carlo)方法相结合建立含有悬浮物海水中波长为520 nm的高斯激光传输模型,研究了特定直径和密度的粒子群对激光传输的影响。分析了不同探测距离下高斯激光传输模型的归一化接收功率随激光初始发散角的变化。研究结果表明:1)通过改变米氏散射模型中的悬浮泥沙粒子的直径和密度,从而改变仿真中设置的消光系数、散射系数和不对称因子,探测靶面的接收功率随散射体直径、密度和传输距离增加呈指数级减小;2)在一定范围内,初始发散角的变化不会影响接收面的接收功率,并且这种范围随着散射系数以及传输距离的增大而减小。所提的研究方法为进一步实际分析含复杂颗粒群(悬浮气泡、浮游藻类、悬浮泥沙)海水中高斯激光传输特性变化奠定理论基础,可为相关的工程估算提供参考。

To further study the application of Gaussian laser beams in underwater communication and information detection and the characteristics of the transmission process in different seawater environments,in this study,the mostcommon terrestrial suspended sediment particles in seawater were taken as an example.First,Mie scattering theory was combined with the Monte Carlo method to establish a 520-nm Gaussian laser transmission model in seawater containing suspended solids,and the effects of particle groups with specific diameters and densities on laser transmission were studied.Second,the variation in the normalized received power with the initial divergence angle of the laser at different detection distances was analyzed.The research results indicate the following.1)When the diameter and density of suspended sediment particles in the Mie scattering model are changed,thereby changing the extinction coefficient,scattering coefficient,and asymmetry factor set in the simulation,the received power of the detection target decreases exponentially with increases in scatterer diameter,density,and transmission distance.2)Within a certain range,the change in the initial divergence angle does not affect the power of the receiving surface,and this range decreases with increases in the scattering coefficient and transmission distance.The research method used lays a theoretical foundation for further analyzing the changes in Gaussian laser transmission characteristics in seawater containing complex particle groups(suspended bubbles,planktonic algae,and suspended sediment)and provides reference for related engineering estimates.