Development of low-loss sapphire mirrors

摘要

We report on the successful development of low-loss sapphire mirrors for use at a 1-mu m wavelength. Methods for polishing and coating are described. The analysis of each process shows a roughness of better than 0.1 nm, a coating scattering of 1 ppm, and a surface scattering of 13 ppm. The mirrors have been characterized in a Fabry-Perot cavity, having a finesse of 100,000. Mode doublets result from the birefringence of the coatings. (C) 1997 Optical Society of America