Research On Steady Optical Beam Optimization Design Method Based On Genetic Algorithm

Since the emergence of lasers,beam quality has been a key performance indicator in the optical field,directly determining the quality of optical signal transmission and application.However,during the process of beam transmission,factors such as self-diffraction and nonlinear distortion effects cause the degradation of beam quality,making it difficult to achieve efficient and stable optical signal transmission.This presents a great challenge for high-precision applications such as optical communication and laser radar.Therefore,researchers are constantly exploring various methods and techniques to reduce the deterioration of beam quality caused by self-diffraction and uneven distribution of the transmission medium.The main focus is on optimization design of optical components,adaptive optical systems,transmission medium control technology,and non-diffracting beams.In this thesis,based on genetic algorithms,steady optical beams constructed with multiple ring beams nested with a Gaussian beam were optimized,and the transmission characteristics of the steady optical field before and after optimization in free space were analyzed by simulation and experiment to explore the improvement of beam quality.The research in this thesis is mainly divided into three parts:1.The transmission formula of the ring beam through the paraxial optical system was derived using the generalized diffraction integral theory.The mechanism of coherent elimination of transverse wave vectors by ring beams was theoretically deduced,and the feasibility of this mechanism was verified through theoretical analysis and numerical simulations.Simulation results demonstrate that within a certain distance,during the interference process of two ring beams,the overall spot shape of the beam remains unchanged,indicating stable transmission of the beam in this region,consistent with the theory.2.A steady optical beam optimization design method based on genetic algorithms was proposed.The beam quality problem was modeled as a multi-objective optimization problem,and the optimization of beam waist radius and far-field divergence angle were jointly optimized rather than the traditional single objective problem of beam quality evaluation.Genetic operators relevant to genetic algorithms were deeply considered,and the genetic operator best suited for steady optical beam optimization was selected.This method solves the problem that steady optical beams generated by traditional methods cannot achieve optimal transmission performance and actually finds some optimal solutions for generating steady optical beams with the best propagation performance.Simulation results show that under the same initial beam aperture size,the optimized steady optical beam has a 49.3%reduction in the product of beam parameters when the beam waist radius is reduced by 10.0%and the divergence angle is reduced by 43.4%.3.The experimental verification of the transmission characteristics of steady optical fields through spatial light modulators,analyzing the rationality of the design scheme.The experimental results are consistent with the simulation results,verifying the effectiveness of the optimization design scheme.Compared with the steady optical beam design method without optimization proposed in this thesis,the optimization method proposed in this thesis increases the beam quality of the steady optical beam by more than 33%,further expanding the application scenarios of steady optical beams.In summary,the optimization method proposed in this thesis has the characteristics of high efficiency and stability,which has a significant effect on improving the quality and performance of optical applications.Simulation and experimental results show that the beam quality of steady optical beams optimized by this method is significantly improved compared to before optimization,and the beam quality of steady optical beams generated by optimization methods has been greatly improved,providing more efficient and stable light sources for applications in optical communication,laser processing,and other fields.