3-microm cw laser operations in erbium-doped YSGG, GGG, and YAG

We have demonstrated cw laser operation at wavelengths near 3 microm from monolithic, Er-doped YSGG, GGG, and YAG lasers by direct upper-state pumping in the 0.97-microm wavelength region with either a Ti:sapphire laser or InGaAs diode lasers. We have obtained slope efficiencies as high as 31% and, with diode-laser pumping, output powers of 0.5 W. In addition, we have demonstrated tunable single-frequency operations from Er:YAG.