Research On Wavefront Distortion Correction Of Stimulated Brillouin Scattering

During the transmission of the laser,the turbulence effect will distort the phase of the beam,resulting in the decrease of the beam quality at the receiving end and the increase of the error rate of the system.In order to solve the instability of optical communication system caused by wavefront distortion,it is proposed to compensate the wavefront distortion by using Stimulated Brillouin Scattering(SBS)Phase Conjugation Mirror(PCM).The phase conjugation characteristic of SBS has great application value in improving the laser phase distribution and the energy concentration of the spot.This paper mainly investigates the wavefront distortion correction ability of SBS-PCM system and the basic physical properties of SBS,and carries out some relevant experimental verification.The main work is as follows:1.The Gaussian beam is selected as the research object and combined with the theory of turbulent phase screen to study the distortion of the beam propagating through atmospheric turbulence.The effect of SBS phase conjugation mirror to compensate for wavefront distortion is simulated and analyzed with turbulence intensity,sampling aperture and transmission distance.2.Based on the basic theory of phase conjugation of SBS,the SBS experimental research scheme of repeated frequency 1Hz is designed.The energy reflectivity of SBS single cell system are measured with the pumping energy,len focal and mirror cell spacing.3.According to the theory of SBS phase conjugation mirror compensating distortion,the distortion compensation capability of SBS phase conjugation mirror system and ordinary mirror system is analyzed and compared with the surrounding energy diameter and phase conjugation fidelity.Research and analysis show that:(1)After correction,the center energy of the light spot with different distortion is strong,and the large sampling aperture phase conjugation mirror shows obvious advantages when the turbulence is strong;(2)Selecting the appropriate lens focal and mirror-cell spacing is of great significance to obtain the best results for the energy reflectivity of the system;(3)The SBS-PCM system generates back phase conjugate scattered light,which return along the original optical path can effectively compensate the distortion caused in the optical path,and the ordinary mirror system does not compensate for the distortion.