Optical Damage to LiNbO3 from GaAs Laser Radiation

We have observed optical damage to LiNbO
3
at room temperature from focused cw GaAs laser radiation at a wavelength of 8450 Å. Visible damage was apparent after a 20-sec exposure corresponding to an energy flux of about 1.2 × 10
⁵
J/cm
²
and was observed by changes in the diffraction pattern of the crystal. This is believed to be the first report of such damage in the potentially useful wavelength range of 0.8 to 0.9 µm. No damage was observed at a wavelength of 9030 Å in a similar but pulsed-laser experiment.