Laser mirror damage in germanium at 10.6 μm

Abstract

Damage in the germanium output mirror of a TEA CO2 laser shows a periodicity of 10.6 μm, the laser wavelength. A mechanism is proposed in which scattered and cavity radiation interfere. An interference mechanism is confirmed by experiments outside of the laser cavity. Periodic damage is obtained in thin films irradiated at angles other than the normal where the fringe spacing is modified.