大气激光通信中的光斑特性模拟和验证

根据空-地大气激光通信信道的特性,基于惠更斯-菲涅耳原理,应用夫琅禾费圆孔衍射的算法,对光波强度和光斑图像在光束截面内的分布进行分析及计算,研究了传输距离、发射孔径、激光波长以及湍流结构常数等对光斑形状及光强分布的影响。利用对数正态分布建立了大气湍流信道模型,通过对不同传输距离条件下光斑上不同点的光强分布进行计算统计和仿真分析,实验和仿真结果表明：光斑的光强分布图样服从贝塞尔分布。因此,在相同的大气湍流条件下,选择较长波长激光和较大孔径的发射器,可以有效降低光强闪烁引起的衰减,从而提高大气激光的通信质量。

Simulation and Verification of Laser Spot Characteristics in Atmospheric Laser Communication

This paper shows the analysis and the calculation of the intensity of light and the distribution of the laser spot image on a beam section.It also includes the result of the study of how transmission range,transmitting aperture,wavelength and magnitude of turbulence would influence the shape of laser spot and the intensity distribution.All the studies are according to the characters of space-earth atmospherical laser communication channels,the results are based on Huygens-Fresnel principle and calculated with the method of calculating Fraunhofer circular hole diffraction.This paper carried out an atmospheric turbulence channel model using lognormal distribution.By comparing with the result of experiments and the simulation of intensity distribution in different transmission ranges,a conclusion was drawn that the distribution of the image of laser spot obeys Bessel distribution.Thus,by selecting a transmitter which has a longer wavelength and a larger transmitting aperture could dramatically reduce the attenuation caused by flashing.And this will directly result in improving the quality of communication.