Temperature tuned 90° phase-matched CO2 laser doubling in AgGa1-xInxS2 crystal

90° phase-matched type-I second harmonic generation (SHG) of CO2 laser radiation at 10.591μm is demonstrated at 203°C in mixed chalcopyrite AgGa1-xInxS2 crystal with x = 0.14 ± 0.01. In addition, temperature-tuned difference frequency generation (DFG) at 4.02μm is obtained by mixing the idler output of a Nd:YAG third harmonic pumped β-BBO optical parametric oscillator and its fundamental source at 1.0642μm. The Sellmeier and thermo-optic dispersion formulas that reproduce well these experimental results are presented.