“…Photoelectric functional crystals, which are widely used as core optical devices in solid state lasers, are of great significance for the development of modern laser technology. [1][2][3] Nonlinear optical (NLO) materials, typically KBe 2 BO 3 F 2 (KBBF), 4 b-BaB 2 O 4 (b-BBO), 5 a-LiIO 3 , 6 BaGa 4 S/Se 7 (BGS/BGSe), 7,8 etc., can effectively realize frequency conversion and broaden the working wavelength using optical parameter oscillators, optical parameter amplification, frequency doubling, difference frequency generation, and so on, which make them widely useful in civil and military fields. With the development of modern laser technology, more stringent requirements of NLO crystals are proposed.…”