基于虚拟双目相位偏折的自由曲面透明光学元件绝对面形测试技术研究

Optical elements with free-form surfaces are able to achieve the compactness and the high transmittance of a optical system while having effectively corrected the system aberration. Hence there is a very important significance to apply these elements into the design and implementation of photoelectric systems. Processing and testing are two important and inseparable parts of the manufacture of optical elements. Furthermore, processing results often directly depend on the level of testing accuracy. At present, it is still lack of an absolute-shape measurement technology being able to accomplish a on-site testing with a large dynamic range, high-precision and high-performance under a simple system structure in the manufacture of (transparent) optical elements with free-form surfaces. For these requirements, an absolute-shape on-site measurement technique with a virtual-stereo phase deflectometry for the elements is proposed in this proposal. It is based on phase deflectometry, stereo vision and virtual imaging technologies. Investigation of several key issues, including system modeling and full-chain simulating, flexible system calibration with a global optimization, error correction for absolute-phase retrieval, optimization for point-matching of virtual-stereo,etc., are also carried out. A technical basis is accordingly provided to further promote the manufacture and application of related optical elements in China.

自由曲面光学元件能够在有效地校正系统像差的同时，实现光学系统的紧凑化和高透过率。因而，将其应用到光电系统的设计和实现中具有十分重要的意义。加工与检测作为光学元件制造过程中重要而密不可分的两部分，检测精度的高低往往直接决定了加工成型效果的优劣。目前，在自由曲面（透明）光学元件的制作过程中，尚缺乏一种绝对面形测量技术：能够实现在简单系统结构下的大动态范围、高精度、高效能在位检测。针对这一需求，本申请以相位偏折术、立体视觉和虚拟成像技术为基础，提出一种应用于自由曲面透明光学元件的虚拟双目相位偏折绝对面形在位测量技术。对包括系统建模与全链路仿真、柔性的全局优化系统标定、绝对相位恢复误差的校正、虚拟双目点匹配的优化等在内的关键问题展开研究。从而为进一步地推动我国相关元件的制造及应用提供技术基础。

自由曲面（透明）光学元件能够在有效提升光学系统性能的同时，实现系统结构的轻量化和紧凑化，在现代光电系统中具有十分重要的应用价值。该类光学元件表面的三维形貌分布与其性能之间有着紧密联系，对其面形的高精度检测是其加工成型的关键。然而目前，对于自由曲面（透明）光学元件，尚缺乏一种简单有效的测量技术：能够实现在低复杂度系统结构下的大动态范围、高精度、高效能绝对面形检测。针对这一现状，本项目以相位偏折术为基础，结合基于双棱镜的虚拟成像结构，提出了一种可应用于自由曲面（透明）光学元件的虚拟双目相位偏折绝对面形量技术，并设计、加工和构建了相应的实验系统装置。对包括所提虚拟双目相位偏折术的测量原理、基于梯度的面形积分重构、绝对相位的快速恢复、相位恢复误差的抑制校正、柔性的全局优化系统标定、虚拟双目点匹配的优化等在内的关键问题展开了研究，提出了基于混合迭代补偿的面形积分重构、基于频率色彩的复合通道条纹编码、Gamma预标定校正、基于非线性迭代优化的双频移相、基于正弦条纹和棋盘格的系统标定、基于区域生长的虚拟双目点匹配等核心算法，并通过相关仿真和实验测试验证了所提方法的可行性与有效性。通过项目研究所掌握的虚拟双目相位偏折绝对面形测量原理与系列关键技术，能够为我国相关光学元件的加工与检测过程中遇到的类似问题，提供有益的参考或解决方案。