Q-switched laser damage of infrared nonlinear materials

Q
-switched laser-damage thresholds have been determined for six materials (proustite-Ag
3
AsS
3
, pyrargyrite-Ag
3
SbS
3
, cinnabar-HgS, silver thiogallate-AgGaS
2
, tellurium-Te, and gallium arsenide-GaAs) of interest for nonlinear optics in the medium infrared. Four TEM
00
mode lasers were employed with outputs at wavelengths of 694 nm, 1.06, 2.098, and 10.6 μm. Damage has been found to be confined to the surface of the crystals and occurs for radiation intensities between 3 and 75 MW/cm
²
. Particular care is needed in the cutting and polishing of tellurium crystals if a high-damage threshold is to be achieved.