In-situ optical coatings on subsurface damage-removed substrate

The development of high power lasers requires highly damage-resistant optical coatings. Present multilayer dielectric coatings, do not have sufficient laser-induced damage thresholds (LIDTs) to pulsed lasers, particularly in the short wavelength region. LIDT strongly depends on the absorption coefficient of optical coatings and the impurities on the optical substrate. The absorption coefficient of optical coatings can be minimized by optimizing the deposition conditions. However, the impurities on the optical substrate cannot be completely removed by standard optical cleaning techniques. In this paper, the significant improvement of LIDT of optical coatings on subsurface-damage removed fused silica glass due to ion beam etching is presented.