光学 精密工程, 2016, 24 (1): 1, 网络出版: 2016-03-22
微缩投影系统的垂轴放大率测量
Measurement of transversal magnification for reduced projection system
成像系统 微缩投影系统 垂轴放大率测量 点衍射干涉仪 离焦 imaging system reduced projection system transversal magnification measurement point diffraction interferometer defocus
摘要
考虑有限距光学系统的成像质量与系统垂轴放大率相关, 本文提出了基于系统波像差检测的垂轴放大率测量方案。以给定的光学系统中像平面位置与物平面位置满足高斯公式和牛顿公式的原理为出发点, 通过系统波像差中离焦量的变化监控物点移动微小量后像点的移动距离。然后, 对牛顿公式或高斯公式微分导出轴向放大率, 最终求出系统垂轴放大率。建立了垂轴放大率测量模型, 给出物点的微小位移量和初始离焦量的选取标准, 并系统地分析了光学元件形位公差和像点定位精度对垂轴放大率测量结果的影响。搭建了基于点衍射干涉仪的微缩投影系统波像差检测平台, 测量了系统的垂轴放大率。 实验显示, 系统垂轴放大率的测量值与理论值的偏差优于0.24%, 验证了提出的垂轴放大率测量方法的可行性和理论分析的准确性。
Abstract
As the imaging performance of an optical system is related to its transversal magnification, this paper proposes a transversal magnification measurement scheme based on wavefront error metrology for the optical system. On the basis of that the locations of image plane and object plane satisfy the Newtons and Gausss formulas in a given optical system, the defocus in wavefront error was used to monitor the movement of image point. According to the minor movement of object point, the longitudinal magnification could be calculated by the differential of Newtons and Gausss formulas, and the transversal magnification was obtained finally. In order to validate the scheme, a model of transversal magnification measurement was established, and the criterions of the object point shift and the initial defocus were summarized. Then, the influences of geometric tolerance and positioning accuracy of the image point on transversal magnification were analyzed. Finally, an experimental platform based on a point diffraction interferometer was established for measuring the wavefront error of a reduced projection system, and the transversal magnification of the system was measured. It shows that the difference between theoretical and measured results is lower than 0.24%, which verifies the feasibility and veracity of this scheme.
谢耀, 王丽萍, 郭本银, 王君, 苗亮, 王辉, 周烽. 微缩投影系统的垂轴放大率测量[J]. 光学 精密工程, 2016, 24(1): 1. XIE Yao, WANG Li-ping, GUO Ben-yin, WANG Jun, MIAO Liang, WANG Hui, ZHOU Feng. Measurement of transversal magnification for reduced projection system[J]. Optics and Precision Engineering, 2016, 24(1): 1.