Research on Spatial Spreading Effect of Blue-Green Laser Propagation through Seawater and Atmosphere

Based on the semi-analytic Monte Carlo method, this paper uses a modified Henyey Greenstein function to represent the scattering phase function of sea and atmosphere, calculates the multipath spatial effect of uplink of Airborne Laser Submarine Communication (ALSC). The results show the spatial spreading is decided by the divergence angle of transmitter, the depth of submarine, working zone, the wind speed upper sea surface and the atmosphere climatic condition. The spatial spreading of uplink is changing severely following with the depth of submarine increasing. Because of the refraction from sea to atmosphere, the light spot on the optic receiving plane is larger than that on the sea surface. The light spot impacts on the signal receiving and capturing strongly.