Laser Near-field Spot Shaping Based On Deformable Mirror

In recent years,with the continuous development of laser technology,lasers are increasingly used in industrial processing,information transmission and other fields.However,the structure of the laser itself will affect the quality of the laser beam output by the laser,and the laser output by the laser the beam is generally a specific Gaussian light intensity distribution.These reasons make the laser beam output by the laser have certain limitations in practical use.Therefore,in the actual application process,it is often necessary to shape the laser beam output by the laser to achieve the purpose of improving the beam quality or changing the intensity distribution of the laser beam.In this paper,an electromagnetically driven deformable mirror is used to research the laser beam shaping.The genetic algorithm is applied to the research of laser beam intensity distribution shaping.The algorithm is used to obtain the optimal phase screen to shape the intensity distribution of the laser beam.Through specific experiments,the effect of the phase screen obtained by the algorithm in practical application is analyzed.Experiments of shaping gaussian beams into super-gaussian beams,flat-top beams and hollow beams were carried out using deformable mirrors.This article mainly studies the following contents:1.Starting from the laser beam diffraction theory,analyze the method of laser beam shaping and establish a mathematical model of the laser beam shaping system based on deformable mirrors.Through the research and analysis of the genetic algorithm principle,algorithm structure and operation steps.The research and analysis of Zernike polynomials are carried out.Based on this,based on relevant experimental verification and actual departure,a genetic algorithm combining Zernike polynomial mode coefficients is proposed.numerical simulations are performed to simulate and calculate the shaping of super-gaussian beams,flat-top beams,and hollow beams,and analyze the calculation results.2.Analyze and research the beam shaping technology based on the deformable mirror,and use the Hartmann-Shack wavefront sensor to analyze the beam quality of the laser beam output by the laser.The optical path of the laser beam intensity distribution shaping experiment based on the deformable mirror was designed by the deformable mirror instead of the phase screen,and the laser beam intensity distribution shaping experiment system based on the deformable mirror was established,and the genetic algorithm combined with the Zernike polynomial was experimentally verified.3.The phase screen obtained by the genetic algorithm combined with Zernike polynomials is converted into the voltage parameters of each unit of the deforming mirror,and the deforming mirror is controlled to realize the shaping of the super-gaussian beam,flat-top beam and hollow beam,and use the beam quality analyzer to analyze the light intensity distribution of the laser beam after shaping.The genetic algorithm combined with Zernike polynomials is used to solve the phase screen required for laser beam shaping,which realizes the purpose of using deformable mirrors to improve the quality of laser beams,and can shape the laser beam intensity distribution according to requirements.