基于明暗场融合的大口径光学元件表面损伤检测关键技术研究

With the needs of scientific research and equipment manufacturing, the effective aperture of the optical element is growing larger and larger. However, the optical processing will leave all kinds of defects inevitably on the surface of the optical element. These defects may cause a serious impact on the performance of the fine optical system. But the precise detection of the defects in a large area is challenging. For recent years, the measurement of detects on the surface of the larger aperture optical element is a hot and difficult subject in this area. The research target of this project is to solve the bottleneck problem and to make breakthrough on key technologies for the measurement of the defects on the surface of the large aperture optical element. A prototype system is designed contains bright and dark field imaging systems for the detect measurement. In order to improve the real-time performance of the defect image capture, processing and display, the adaptability of a variety of optical element, the accuracy of calibration, the following key techniques are studied by this project: 1) structure design of the defect detection instrumentation and intelligent control strategy; 2) scanning trajectory planning method and image data matching and integration between bright and dark field imaging systems; 3) flaws recognition and classification algorithm under complex condition; 4) calibration algorithm based on the fusion of bright and dark field imaging systems; The results of the project will improve the capability in optical element processing and manufacturing, high power laser system, semiconductor processing in our country. It also has great strategic meaning for the development of science and technology and national defense.

随着科学研究和装备制造的需要，光学系统的有效口径越来越大，但由于加工过程不可避免的会留下各类损伤，这些损伤会对精密光学系统的性能产生严重影响，然而大范围下高精度损伤检测极其困难，近年来大口径光学元件表面损伤检测一直是研究的热点与难点。本项目以解决大口径光学元件表面损伤检测中的瓶颈问题与突破关键技术为目标，提出一种基于明暗场融合的大口径损伤检测原理样机，为提高系统在大数据量下损伤图像采集、处理、显示的实时性、多种元件检测的适应性与损伤标定的准确性，重点围绕以下几项关键技术开展研究：1)损伤检测装置结构设计与智能控制策略；2）损伤扫描路径规划方法与明暗场图像的数据匹配与融合；3）复杂条件下损伤分割与识别方法；4）明暗场融合下的损伤标定方法。本项目的研究成果对提高我国在光学元件加工与制造、大功率激光系统、半导体加工等领域的水平具有重要的意义，对我国科技和国防事业的发展具有重大的战略意义。

本项目以解决大口径光学元件表面损伤检测中的共性问题与突破关键技术为目标，提出一种基于明暗场融合的大口径损伤检测原理样机，并针对当前光学元件损伤检测中存在的瓶颈问题开展研究工作。通过项目攻关，研发了一套大口径光学玻璃检测装置，掌握了一系列关键技术，包括提出基于自准值激光粗对准与明场自动聚焦精对准的光学元件姿态调整与扫描路径规划方法，实现了平面光学元件和曲面元件表面暗场图像的采集；提出了一种基于SURF特征的图像拼接算法，实现了暗场图像的精确拼接；提出了基于暗场图像的明场定位方法，实现了缺陷的准确定位与测量；提出了基于Garbo滤波与LSD方法相结合的微弱划伤缺陷检测算法。.通过项目攻关，研发了一套大口径光学玻璃检测装置，掌握了一系列关键技术，首次解决了神光装置中的大口径光学元件的检测难题。装置已在中物院激光聚变中心、上海光机所等单位得到实际应用，填补了国内空白。该装置是国内第1套成功应用于神光装置的同类仪器，每年为神光系统装置节约成本近亿元。研制的国内首批19套远距离高精度在线缺陷检测装置，在神光系统运行至今，在700mm的观测距离实现30微米精度的损伤在线监测，为大量光学元件的稳定运行和维护及神光装置后期的集中控制系统实现奠定了坚实的基础。发表学术论文11篇，包括IEEE Transactions on Instrumentation and Measurement, IEEE Transactions on Components, Packaging, and Manufacturing Technology, Optics Communications等高水平SCI期刊4篇，并获得IEEE International Conference on Automation Science and Engineering 2018的最佳学生论文提名奖，发表学位论文3篇，培养博士生2名，硕士研究生3名，申请发明专利14项，获北京市科技进步奖3等奖一项。获得成果转化应用经费20万，并在3C领域的手机盖板玻璃缺陷检测上也得到重要应用。