Abstract

There exist some shallow scratch defects on the super-smooth optical surface. Their detection has a low efficiency with the existing technologies. So a new detection method, dark-field detection of adaptive smoothing and morphological differencing (DFD-ASMD), is proposed. On one hand, the information of shallow scratches can be kept in dark-field images. On the other hand, their weak characteristics can be separated and protected from being overly reduced during the elimination of noise and background in the image. Experiments show the detection rate of shallow scratches is around 82%, and DFD-ASMD can lay a foundation for quality control of defects on the high-quality optical surface.

© 2017 Chinese Laser Press

Surface weak scratch detection for optical elements based on a multimodal imaging system and a deep encoder–decoder network

Xiao Liang, Jingshuang Sun, Xuewei Wang, Jie Li, Lianpeng Zhang, and Jingbo Guo
J. Opt. Soc. Am. A 40(6) 1237-1248 (2023)

Automatic scratch detector for optical surface

Hong-Yan Zhang, Zi-Hao Wang, and Hai-Yan Fu
Opt. Express 27(15) 20910-20927 (2019)

Defects evaluation system for spherical optical surfaces based on microscopic scattering dark-field imaging method

Yihui Zhang, Yongying Yang, Chen Li, Fan Wu, Huiting Chai, Kai Yan, Lin Zhou, Yang Li, Dong Liu, Jian Bai, and Yibing Shen
Appl. Opt. 55(23) 6162-6171 (2016)

Optical–digital detection of dents and scratches on specular metal surfaces

Hugh W. Lippincott and Henry Stark
Appl. Opt. 21(16) 2875-2881 (1982)

Dark-field microscopic image stitching method for surface defects evaluation of large fine optics

Dong Liu, Shitong Wang, Pin Cao, Lu Li, Zhongtao Cheng, Xin Gao, and Yongying Yang
Opt. Express 21(5) 5974-5987 (2013)