Recent Advances in the Characterization of Subsurface Damage in Optical Materials

Subsurface damage (SSD) in optical materials is easily induced during ultra-precision processes and plays a critical role in the surface performance and lifetime of optical materials. Without proper characterization of SSD in optical materials, it is difficult to fully understand its properties across various manufacturing processes and thus find effective ways to eliminate it. Despite the rapid development of SSD characterization, many unique features, principles, and applications of SSD characterization in optical materials are not known to this community. This review systematically reviewed the recent literature on characterization methods of SSD in optical materials in both destructive and non-destructive ways. The major drawbacks and limitations of all the characterization methods are presented in this paper, and future trends in the characterization of SSD in optical materials are also proposed.