Research Of The Beacon Launching Technology Based On BOE In Satellite Optical Communication System

The satellite optical communication is a cutting edge communication form byemploying light as transmission medium and taking free space as information channel.The satellite optical communication has its remarkable advantages of high transmissionrate, excellent privacy, and can apply to complicated environments, which make it aneffective high speed communication method.Laser Diode is preferred in satellite optical communication system, owing to itssmall size, compact structure and narrow linewidth. However, LD is notorious for itslow beam quality. Hence shaping the output beam of LD is more than necessary. Thecollimating system is extremely important in that it directly affects the reliability ofcommunication.This dissertation is aimed at collimating the generally used beacon laser,810nmLD with fiber end, by the Binary Optical Element (BOE). Firstly, we analyze the outputmodel of LD, followed by building up the collimation optical model according to thedesigning requirements. Secondly, we utilize Matlab to solve the phase information ofBOE, and simulate the influence of quantization order, etching error and off-focus oncollimation results and efficiency respectively. Then Zemax is introduced to test theresults of Matlab. And finally, experiments are executed to testify the simulation. Thedetailed work includes:1) According to the designing requirements, we choose GS algorithm to build up theinput-to-output transformation on BOE, on the basis of BOE.2) Utilize Matlab to simulate the output optical field of BOE, and compare the realisticoutput with the ideal output. And the off-focus effect should also be analyzed.3) Employ Matlab to simulate the effect of quantization order and writing erroron thecharacteristics of output beam.4) Zemax is applied to carry out further reliability test of the results of Matlab.Collimating system is an essencial part in satellite optical communication system,our work included in this dissertation offers crucial theory and experimental basis forthe of collimating system, hence laying the foundation for optimization of theperformance of satellite optical communication system.