光学与光电技术, 2016, 14 (3): 42, 网络出版: 2016-07-26
基于空间直线预标定检测光学元件面形的研究
Surface Measurement of Optical Element Based on the Pre-Calibrating Camera
光学检测 斜率 偏折术 空间直线法 预标定 optical measurement slope deflection spatial straight line method pre calibration
摘要
基于斜率检测的相位偏折术能够快速、简单、准确地测量光学元件面形和透射光学元件畸变波前。借助点光源显微测量系统对参考点坐标的准确测量提出了空间直线预标定的方法,利用它得到了相机中CCD面阵上每个像素对应每条光线的方向向量,通过每条光线的方向向量和被测面方程,追迹得到了被测面的世界坐标,从而求出被测面上各点斜率,采用波前重建算法,实现了光学元件面形的准确重建。实验结果显示,拟合面形去掉Zernike多项式前4项的RMS数据与干涉仪的测量结果最大相差仅约10 nm,并且实验中重建的面形与利用张正友提出的标定方法坐标计算重建的面形几乎相同。因此,空间直线预标定法切实可行,可以实现高精度的反射光学元件面形测量,且测量系统简单,具有应用价值。
Abstract
The phase measurement deflectometry based on slope detection can be used to quickly, simply and accurately measure the distorted wavefront of optical components. In this paper, the method of pre-calibrating space line is put forward by means of a point-source microscopic measurement system. The direction vector which is determined by the correction of each pixel on CCD plane array and the pinhole in front of the camera is obtained by using this method. The world coordinates of the measured suface is calculated by using each of the light directions and the slope can be obtained eventually. With the algorithm of wavefront reconstruction, the shape of optical component surface can be reconstructed exactly. The experimental result shows that the maximum RMS difference between the fitting surface and the interferometer measurement result is only 10 nm when the first 4 items of the Zernike polynomials is removed. Also, the experimental result is almost the same as the reconstruction result by using the calibration method proposed by Zhang Zhengyou. Therefore, the method proposed in this paper is feasible and it can achieve the high-accuracy measurement on surface of reflecting optics . Furthermore, the measurement system is simple and has high value in practice.
杨丽杰, 李大海, 鄂可伟, 章涛, 王雪敏. 基于空间直线预标定检测光学元件面形的研究[J]. 光学与光电技术, 2016, 14(3): 42. YANG Li-jie, LI Da-hai, E Ke-wei, ZHANG Tao, WANG Xue-min. Surface Measurement of Optical Element Based on the Pre-Calibrating Camera[J]. OPTICS & OPTOELECTRONIC TECHNOLOGY, 2016, 14(3): 42.