LiMII(IO3)(3) (M-II=Zn and Cd): Two Promising Nonlinear Optical Crystals Derived from a Tunable Structure Model of alpha-LiIO3

摘要

Excellent nonlinear optical materials simultaneously meet the requirements of large SHG response, phase-matching capability, wide transparency windows, considerable energy band-gap, good thermal stability and structure stability. Herein, two new promising nonlinear optical (NLO) crystals LiMII(IO3)(3) (M-II=Zn and Cd) are rationally designed by the aliovalent substitution strategy from the commercialized alpha-LiIO3 with the perfect parallel alignment of IO3 groups. Compared with parent alpha-LiIO3 and related A(2)(I)M(IV)(IO3)(6), the title compounds exhibit more stable covalent 3D structure, and overcome the racemic twinning problem of A(2)(I)M(IV)(IO3)(6). More importantly, both compounds inherit NLO-favorable structure merits of alpha-LiIO3 and show larger SHG response (approximate to 14x and approximate to 12xKDP), shorter absorption edge (294 and 297 nm) with wider energy band-gap (4.21 and 4.18 eV), good thermal stability (460 and 430 degrees C), phase-matching behaviors, wider optical transparency window and good structure stability, achieving an excellent balance of NLO properties.