High-speed switching of mid-infrared wavelength generated by difference-frequency mixing in AgGaS/sub 2/and In-doped AgGaS/sub 2/

1-ms wavelength-switching in a mid-infrared range was achieved by difference-frequency mixing in an In-doped AgGaS/sub 2/ crystal. Tuning range was shifted to a longer wavelength region maintaining noncritical phase-matching with increase of indium concentration.