Investigation of the optical strength of KRS-6 and KRS-5 crystals subjected to pulsed CO2 laser radiation

The influence of the composition of the atmosphere in which KRS-6 crystals were grown on their spectral transmission, light scattering, and optical strength when subjected to pulsed CO₂ laser radiation was studied. The bulk damage threshold of KRS-6 at 10.6 μ wavelength was shown to be directly related to the transmission and scattering of light in the visible part of the spectrum and the damage threshold of KRS-6 increased on reduction of the sulfur content in the specimens. A study was made of the influence on the surface damage threshold of the type of polishing abrasive used, and it was shown that the best results were obtained using diamond pastes and powders.