高精度激光光束质量测量系统设计与实验研究

发布时间：2018-03-02 12:23

本文选题：光束质量　切入点：M2因子　出处：《华中科技大学》2015年硕士论文　论文类型：学位论文

【摘要】：随着激光技术在各个领域的应用不断拓展,如何有效的检测和评价激光光束质量成为了激光技术研究的一个关键问题。从衍射极限因子M2因子在上世纪90年代被提出后,它就成为了一种有效而常用的衡量激光光束质量的方法了,如何能够快速有效的测量M2因子也成为了一个人们研究的热点。本文基于CMOS相机设计并完成了一套高精度激光光束质量测量系统,该系统首先通过图像处理法获取光束偏转角度,再自动由电动微调装置控制反射镜改变光束传输方向从而完成光路的高精度调整,实现光束垂直入射相机光敏面的目的,在此基础上系统可以实现M2因子的自动测量。论文的主要研究成果如下:1.研究了现有激光光束质量评价方法,围绕激光光束M2因子测量制定了激光光束质量测量的总体方案。基于重心法和二阶矩法设计了计算激光光斑中心与尺寸的图像处理方法。根据光束质量测量中光路调整的要求,设计了基于图像处理的光路高精度调整方法。2.设计并完成了激光光束质量测量系统的软硬件。其中软件包括系统设置、步进电机控制、图像预处理和参数计算等模块,硬件包括系统光路、单片机控制、图像采集、精密电动微调及其驱动和定位等模块,并进行了软硬件联合调试。3.对所研制的激光光束质量测量系统进行了一系列实验测试。结果表明:(1)本系统可以高效率的完成光路调整,调整后的光束偏移角度不超过设定偏转阈值0.05°;(2)不同焦距透镜对光束质量测量影响较小;(3)选取不同波长进行测量对比时,本系统光束质量测量结果与商用系统基本一致,但重复精度更高,并且重复测量偏差可以达到1.0%以下。
[Abstract]:With the continuous development of laser technology in various fields, how to effectively detect and evaluate laser beam quality has become a key issue in laser technology. After the diffraction limit factor M2 factor was proposed in -10s, It has become an effective and commonly used way to measure the quality of laser beams. How to measure M2 factor quickly and effectively has become a hot topic. A high precision laser beam quality measurement system based on CMOS camera is designed and completed in this paper. The system firstly acquires the beam deflection angle by image processing method, and then automatically controls the reflector to change the direction of beam transmission by the electric fine-tuning device, thus accomplishing the high-precision adjustment of the light path, thus realizing the objective of the Guang Min plane of the camera with the vertical incidence of the beam. On this basis, the system can realize the automatic measurement of M2 factor. The main research results of this paper are as follows: 1. The existing methods of laser beam quality evaluation are studied. The overall scheme of laser beam quality measurement is established around the M2 factor measurement of laser beam. An image processing method for calculating the center and size of laser spot is designed based on the center of gravity method and the second order moment method. According to the requirements of light path adjustment in beam quality measurement, The high precision adjustment method of optical path based on image processing is designed. The hardware and software of laser beam quality measurement system are designed and completed. The software includes system setup, step motor control, image preprocessing and parameter calculation, etc. The hardware includes system optical path, single-chip microcomputer control, image acquisition, precision electric fine-tuning, driving and positioning modules, etc. A series of experimental tests on the laser beam quality measurement system have been carried out. The results show that the system can efficiently adjust the optical path. When the adjusted deviation angle of the beam does not exceed the set deflection threshold of 0.05 掳/ 2) the influence of different focal lens on the measurement of beam quality is smaller than that of different wavelengths, the results of beam quality measurement of the system are basically consistent with those of the commercial system. But the repetition accuracy is higher, and the error of repeated measurement can reach below 1.0%.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN24

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