自相关在双向剪切激光准直检校中的应用

对基于双向剪切干涉的激光准直检校方法进行了研究.采用CCD对干涉条纹进行采集,提出了用自相关比较条纹宽度的方法,解决了人眼直接观察会引入主观判断误差且不适用于非可见光的问题.理论分析和实验表明：条纹灰度分布的自相关函数会以条纹宽度值为周期出现峰值；比较两半场条纹自相关函数峰值出现的位置即能得知入射激光的准直与否.

Application of Autocorrelation in Double-shearing Interference Method for Checking and Calibrating of Laser Collimation

A laser collimation check and calibration method based on double-shearing interference theory has been studied. CCD is used to grasp the interference fringes, and a method of autocorrelation is presented to compare the width of fringes. This method can solve the problem that a subjective error would be introduced if observed with naked eyes which is not applicable for invisible light. Theoretical analysis and experiment results show that autocorrelation function of the fringes has peaks which occur periodically, and the period equals to the width of fringes. By comparing peaks of the two autocorrelation functions in the two half-fields, it is easy to know whether the incident laser is collimated or not.