Effect of etching morphology of artificial defect on laser-induced damage properties under 355  nm laser irradiation

Structural defects and absorptive impurities generated in the process of grinding and polishing optical substrates before coating significantly lower the resistance of optical elements to laser. Thus, artificial defects that contain indentations and absorptive particles are fabricated in this study. Chemical etching is used to examine the morphology and depth of artificial defects with different sizes and types under various etching times. Moreover, the transverse and longitudinal sizes, as well as the morphology, of defects are determined to analyze the damage properties of artificial defects under 355 nm of laser irradiation. Finally, the differences in the artificial defects induced by various materials are discussed along with their influences on damage properties.