基于傅里叶变换的激光数字散斑测量平板玻璃的楔角

摘要

采用基于傅里叶变换的激光数字散斑测量了平板玻璃的微小楔角。通过在光路中借助毛玻璃的散射特性，采用高分辨率CCD直接记录激光散斑图像，对散斑图像进行快速傅里叶变换获得散斑结构的高信噪比的杨氏双缝干涉条纹，分析干涉条纹获得光强分布曲线，采用移动平均法消除光强曲线噪声后计算出干涉条纹间距，从而计算出平板玻璃的微小楔角。%A method for measuring micro wedge of glass plate using laser speckle based on FFT was proposed .This method used a high resolution CCD to record the laser speckle images of glass plate originated from the frosted glass placed in the optical path .The Young double slit with speckle patterns and high signal noise ratio was obtained by fast FFT .The light intensity distribution curve could be gotten by analyzing the interference fringes .The fringe spacing could be obtained after the noise was smoothed out ,and then the micro wedge could be calculated .The experimental result was in accordance with that of auto-collimating method .