“…Today, solid-state emitters are one of the promising areas for creating frequency converters, such as optical parametric generators (OPOs). Such emitters are interesting for the possibility of obtaining (converting) radiation in the range of 2-12 μm, based on the phenomenon of parametric generation ferroelectric oxides, such as LiNbO3, KTP, KTA and others, capable of converting pump radiation to the wavelength range of 3-4 μm [1][2][3][4]. In the range of 4-12 μm, crystals based on ternary compounds with a chalcopyrite type crystal lattice are used to generate radiation: AgGaS2, AgGaSe2, ZnGeP2, and also GaSe [5,6].…”