NaCl·CH₄N₂O·H₂O: An Organic–Inorganic Hybrid Ultraviolet Nonlinear Optical Crystal with Optimized Comprehensive Properties

Abstract

Ultraviolet (UV) nonlinear optical (NLO) crystals are a vital component in laser systems to modulate frequency. Organic groups have the advantages of easy synthesis, structural diversity, and large hyperpolarizations (β), which can be combined with inorganic groups to form unique organic–inorganic hybrid NLO crystal materials. Herein, a urea-containing crystal NaCl·CH4N2O·H2O is screened out and large-size crystals have been grown by a simple aqueous solution method. Compared with most reported organic–inorganic hybrid NLO materials, it has optimized comprehensive properties including a large SHG effect of 1.53 × KDP, a moderate birefringence (0.084@1064 nm), and a short UV cutoff edge of 209 nm. First-principles studies reveal that the dominant contributor to the linear and nonlinear optical properties is the urea molecule.

Two Acentric Zn-Based l-Tartrates with Moderate Second Harmonic Generation Responses and Large Birefringence

“…Figures S8 and S9 present the IR spectra of the two title compounds. Both of them display broad absorption peaks near 3200 cm –1 associated with water molecules. , The absorption bands from 1238 to 1585 cm –1 could be assigned to the asymmetric stretching of CO and C–O bonds. , The IR spectrum of Zn-LTS shows the asymmetric and symmetric stretching vibrations of [SO 4 ] group near 1293 cm –1 . − The absorption bands in the range of 780–516 cm –1 can be assigned to the vibration of Zn–O bonds. − …”