Simulation And Experiment Of The Relationship Between The Size Change Of High Reflector Defect And The Distribution Of Laser Scattering Field

High reflector is one of the core components of laser gyro.The surface defect of high reflector has a great influence on the linearity and stability of laser gyro output.Therefore,the detection of surface defect is the key in the development and production of high reflector.Based on the theory of light scattering,the laser scattering field distribution characteristics and intensity of defects of different types and sizes on the high reflector surface applied to the laser gyro are studied,and builds an integrated scattering measurement system to detect and verify the defects of known types and sizes.The research content includes the following aspects:In this paper,the types,causes and detection mechanism of the surface defect of high reflector is studied,the influence factors of the laser scattering light field and the calculation and characterization method of the scattering field intensity are analyzed.Based on the numerical calculation method of electromagnetic field,finite element method(FEM),a high reflector model with many kinds of defects is designed by using the multiphysical field numerical simulation software,and the simulation experiment is carried out.The process of scattering light produced by defects is simulated,and the influence of various types of defects with different sizes on the laser scattering field distribution and intensity is analyzed.Based on the principle of correlation detection and Lab VIEW data acquisition and processing program,the integrated scattering measurement system is built with integrating sphere as the core,lock-in amplifier and photomultiplier tube,which realizes the acquisition and processing of weak scattered light signal in the complex noise background.This system is used to detect the scratch defects with known size of rectangular section on the surface of high reflector samples.The scattering rate of the defects on the surface of high reflector samples changes with the size through calculation,and the results are compared with the simulation results.The conclusions are basically the same.The influence of defects of different types and sizes of high reflector surface on the distribution and intensity value of laser scattering field is revealed by simulation analysis and experimental measurement.