Difference-frequency mixing in AgGaS(2) by use of a high-power GaAlAs tapered semiconductor amplifier at 860 nm

As much as 47 microW of cw infrared radiation and 89 microW of pulsed infrared radiation, tunable near 4.3 microm, have been generated by mixing the outputs of a high-power tapered semiconductor amplifier at 858 nm (signal wave) and a Ti:Al(2)O(3) laser at 715 nm (pump wave) in AgGaS(2). The GaAlAs tapered traveling-wave amplifier delivered as much as 1.5 W of diffraction-limited cw power into the nonlinear crystal. Output powers, conversion efficiencies, and spectral characteristics of this novel midinfrared source are discussed.