In Atmosphere Laser Communication Research Of Adaptive Optics System

The adaptive optics system studied in this paper is used for ground-to-groundatmosphere laser communication. AS a carrier of information transmission, the laser isinfluenced easily by atmospheric turbulence in the process of ground-to-groundatmosphere channel transmission. The laser is affected by atmospheric absorption,atmosphere scatters, atmospheric bending in the process of transmission, which willleads to changes of laser wave-front phase, flare drift, changes of laser intensity, laserbeam jitter, beam expansion and so on. All the phenomenon will affect the The qualityof the laser communication badly, including reducement of communications code rate,the bit error rate increase significantly, even Frame lost and Communicationinterruption. The purpose of the adaptive optics system studied in this paper is to revisewave-front phase distortion, to compensate phase error and to improve the quality oflaser communication system.This paper includes two parts: the first part is about the research of wave-frontprocessor, the second part is about the research of PZT driver. The wave-frontprocessor consists of A/D module, wave-front slope computation module, wave-frontreversion module, wave-front control module and D/A transmission module. Eachmodule is analysed and compared in this paper. Some hardware circuit is designed inthis part. In the part of PZT driver, some performance index is studied, including thesystem control bandwidth, voltage amplification factor, steady state ripple wave,system linear error and so on. The whole hardware circuit is designed perfectly, at thesame time, some simulation is studied in this module.Theoretical analysis, system simulation, experimental research is combined inthis paper to study the adaptive optics system. When it comes to each module, firstly,some speculative knowledge was analysed and studied, secondly, related hardwarecircuit module is established, at last, some confirmatory experiment is carry out in thewhole system.In the last part of the paper, some confirmatory experiment is carry out in the whole system. In the case of turned on and turned off the adaptive optics system, thesystem optical output power gain, the system communication code rate and thecommunication bit error rate of receiving end is analyzed. The results show that whenthe adaptive optics system is turned on, the adaptive optics system can revisewave-front aberration which is arosed by atmospheric turbulence and relieve lightintensity flicker and solve the laser beam excursion and light spot expanding. At thesame time, the system heighten the optical output power and improve the quality of thecommunication system perfectly.