Research On Laser Spot Multi Parameter Measurement System

The character of laser spot are of bon connotation to the evaluation of laser connotation and practical application.At present,the related detection technologies both here and overseas mostly focus on the detection of single parameter,such as spot energy distribution or spot size,and lack of multi parameter detection system.In this paper,a laser spot multi parameter measurement system based on CCD camera is designed for five parameters: spot center,beam width,spot offset,spot area and spot energy distribution.The chief things of this essay as shown belows.(1)Through the analysis of CCD camera imaging characteristics and spot imaging error,the diffuse transmission method is designed to sample the spot,which reduces the influence of the angle between CCD camera and scattering screen.According to the characteristics of the collected facula,the majors techniques of the above five facula parameters computing methods are studied.(2)By way of settle the trouble of mass quality of collected facula and affecting the calculation results of parameters,a set of image processing flow is designed.Because the traditional Zernike moment sub-pixel edge investigation methods has low positioning accuracy and can not meet the requirements of the system,the conventional methods is improved,and the best step threshold is determined by the maximum interclass variance method.Compared with the traditional algorithm,the elapsed time of the improved algorithm is shorter 35.294%,and the maximum calculation error is reduced from0.501 pixels to 0.338 pixels.(3)Starting from the performance requirements of laser spot multi parameter measurement system,the software system is enforced by using object-oriented programming language and multi thread techniques.The key technologies such as multi thread programming,data processing and code stream data conversion are described,and the nozzle design scheme of the software system is given.Through the actual investigat of 650 nm laser,the various magnitude calculation of laser spot is completed,and the magnitude calculation results are given,which testify the feasibility of this system.The repetitiveness of the same position extraction and the robustness of the system to the change of spot calculation range testifies that the system has good stability and accuracy.