Thermo-mechanical properties of BaGa2GeS(e)6 nonlinear optical crystals

We report measurements of the thermo-mechanical properties of two recently devel-oped non-chalcopyrite, trigonal, mid-IR nonlinear optical crystals, BaGa2GeS6 and BaGa2GeSe6. These include orientation dependent hardness and Young's modulus, thermal expansion in the 200-430 K temperature range, and thermal conductivity in the 184-473 K temperature range. Covering similar wavelength ranges, these new quaternary compounds appear to be very promising alternatives to the classical ternary chalcopyrites AgGaS2 and AgGaSe2 due to the advantageous properties evinced by the thermo-mechanical data.(c) 2023 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement