Effects of substrate cleaning methods on laser-induced damage performance of three-wavelength antireflection coatings

The effects of different cleaning conditions on substrate laser-induced damage threshold (LIDT), surface roughness, as well as coating LIDT and damage morphologies were systematically compared. The results reveal a direct correlation between the removal of absorptive defects on the substrate and the improvement of coating damage resistance.

Optimized laser ablation and ion beam etching effectively eliminate the vulnerable absorptive defects beneath the substrate surface, significantly enhancing the LIDT of the triple-wavelength AR coatings at the key wavelengths. This work provides a feasible technical route and theoretical basis for fabricating high-performance AR coatings for high-power laser systems.