Laser Damage Of Optical Coatings From Uv To Deep Uv At 193nm.

Scanning electron microscope observations of damaged coatings from 355nm to 193nm are reported. From these results it appears that oxide based coating are strongly limited at 193nm while they performed very well at the other wavelength. Damages occurs at the coating surface for oxides while they concern both surface and substrate interfaces with fluoride base coatings. While fluorides have a better threshold than oxide at 193nm they are limited by localized defects. The ability to overcome this limitation with ion beam sputtering fluoride material at 193nm is discussed starting from results at 355nm.