激光差动共焦曲率半径快速测量方法

Laser differential confocal radius measurement with high precision and high efficiency

针对大批量球面光学元件曲率半径的快速、高精度、非接触测量难题,提出一种基于差动共焦技术的批量元件曲率半径快速测量方法。先将一已知曲率半径的样件S在其共焦位置进行扫描定焦,获取其差动共焦曲线和线性段方程;依次装卡同批次被测元件S_(l)-S_(n)并无扫描地获得其离焦量;根据样件曲率半径和被测件离焦量换算出被测样品曲率半径。仿真和实验表明,精度可达12.2ppm,同时测量速度比传统式差动共焦曲率半径扫描系统提高59倍。方法仅需1次扫描和N次快速装卡即可实现N件球面元件曲率半径的快速、高精度、非接触式检测,为大批量球面元件的高效率、高精度加工检测提供全新途径。

To meet the need for rapid, high-precision measurement of the radius of curvature for large quantities of spherical optics, a radius measurement method based on differential confocal detection is proposed in this study. Firstly, scan a templet whose radius is known on its confocal position axially to obtain the fitted linear function;Secondly, replace the templet to the test sample in sequence, capture the differential confocal intensity without scan, map the single intensity to defocus with the linear function;Finally, calculate the radius under test by defocus and radius of template. Simulation and experiments show that the measurement accuracy is 12.2 ppm, and the measurement efficiency is 59 times higher than the traditional differential confocal scanning measurement. The measurement proposed only needs scanning once and replacing S_(n) N times to realize fast, high-precision, radius detection of N pieces of spherical surface. The proposed measurement provides a new way for high-efficiency and high-precision measurement of large quantities of spherical lenses.