Frequency doubling of 2.06-µm Ho-doped apatite laser output in Ag3AsS3

The 2.06-μm output of a holmium-doped silicon oxyapatite laser was successfully frequency doubled by means of a proustite single crystal. Frequency doubling to 1.03 μm permitted the use of an
S1
photomultiplier for the accurate determination of the laser wavelength, linewidth, and temporal behavior. The experiment also demonstrated that intracavity second-harmonic generation provided better amplitude correlation between the fundamental and second harmonic than did extracavity generation.