光学自由曲面面形检测技术

Optical free-form surfaces testing technologies

光学自由曲面因其表面自由度较大,可以针对性地提供或矫正不同的轴上或轴外像差,同时满足现代光学系统高性能、轻量化和微型化的要求,逐渐成为现代光学工程领域的热点。自由曲面的检测技术已经成为制约其应用的最重要因素,而目前精密光学自由曲面的检测手段仍然沿用非球面检测方法。本文回顾了近年来的自由曲面检测发展历程,对目前主流的非接触式检测方法(微透镜阵列法,结构光三维检测法,相干层析术,干涉检测法)进行了重点介绍;总结了非球面检测方法运用到自由曲面检测中的技术难点,同时结合这些技术难点,展望了自由曲面检测的未来发展新趋势,主要集中在非旋转对称像差的动态补偿、分区域像差的回程误差校准及子孔径拼接技术。

With great degrees of freedom, optical free form surfaces would provide the axial aberrations and off axis ones. Meanwhile, they meet requirements of modem optical systems in high-performance, light weight and micromation, and gradually becomes the hot topic in modem optical engineering. However, their applications have been limited by testing technology of optical free form surface. Most testing methods are still follow those of aspheric surfaces yet. In this paper, we introduce the mathematic description, fabrication and testing of free-form surfaces, especially focusing on several non-contact metrology, such as micro-lenses methods, 3 D test with structured light, coherence tomography and interferometry. The technique difficult and development tendency stressing on flexible compensation for rotationally asymmetric aberration and subaperture stitching based on retrace error correction of the regional aberration are introduced as well.