Analysis And Elimination Of Error Of Laser Wavefront Detection By PD Method

In order to explore the characteristics of the laser,the laser wavefront detection is one of the methods.The laser wavefront detection based on PD method is a simple system,which can detect continuous and discontinuous changes in wavefront distortion.However,it will be disturbed by many factors in the process of wavefront detection,resulting errors in the detection results.Therefore,it is of great significance to analyze and eliminate the adaptability of laser wavefront detection by PD method.In this paper,the main error factors in wavefront detection are analyzed adaptively and the corresponding error elimination methods are given.The main contents are as follows.?1?The laser wavefront detection theory of PD method is studied,which can determine the basic mathematical model.The unconstrained optimization method is used to solve the unknown wavefront image.?2?The adaptability of PD laser wavefront detection is analyzed and eliminated.For the problem of defocus error,the objective function is optimized,and the defocus is solved directly according to the knowledge of geometric optics.In order to solve the problem of image noise error,the image is pre-processed by subtracting the image noise baseline,and the iterative parameters are added to optimize the objective function.For the image registration error problem,the image is first coarsely registered,and then the method of combining surface fitting and gradient based on least square is used to accurately register the image.And the sampling condition of Q_min?2 is given to solve image sampling problem.?3?The simulation experiment of wavefront detection is carried out to verify the feasibility of the algorithm in this paper.The experimental data show that the optimal objective function method combined with the calculated defocusing method is the best method to eliminate the defocusing error.The average RMS value is optimized by0.06?compared with the wavefront residual with no error processing.For the image noise error,the optimal objective function method combined with the image pre-processed has the best effect to eliminate the image noise error.The RMS value is optimized by 0.23?on average compared with the wavefront residual without error.For the image registration error,the combination of surface fitting method and gradient method can eliminate the registration error best.The average RMS value is optimized by 1.00?compared with the unprocessed wavefront residual.The precision of integrated wavefront detection reaches0.03?,which provides technical support for the engineering application of laser wavefront detection.