Phase-matching properties of LiIn(SxSe1-x) for THG of a CO2 laser at 10.5910 μm

This paper reports on the phase-matching properties of LiIn(SxSe1-x)2 for type-2 sum-frequency generation (SFG) between the fundamental and second-harmonic of a CO2 laser at 10.5910 μm. The calculations based on the Sellmeier and thermo-optic dispersion formulas of the present authors [Appl. Opt. 53, 7998 (2014) / 53, 1063 (2014)] for LiInS2 and LiInSe2 revealed that LiIn(S0.8Se0.2) is nearly 90° phase-matchable for this process along the y (= a) axis with Δθext·l1/2 = 33.4 deg·cm1/2, Δφext·e1/2 = 13.9 deg·cm1/2, and ΔΤ·e = 117°C·cm at 20°C.