Silver Thiogallate (AgGaS2) crystal has a high non-linear coefficient, high damage threshold, and a wide transmission range. It also has low optical absorption and scattering, low wavefront distortion. Among commercially available crystals, AgGaS2 has the highest figure of merit for non-linear interactions in the near and deep infrared.
Silver Selenogallate (AgGaSe2) has band edges at 0.73 and 18 μm. Its useful transmission range lying within 0.916 μm and wide phase matching provide excellent potential for OPO applications when pumped by variety of currently available lasers. Tuning within 2.512 μm was obtained when pumped by Ho:YLF laser at 2.05 μm. It has also been shown as an excellent crystal for non-linear three-wave interactions.