Theoretical Prediction-Assisted Synthesis and Characterization of Infrared Nonlinear Optical Material NaSrBS_3

摘要

NaSrBS_3, the first noncentrosymmetric alkali and alkaline earth metal mixedthioborate with the isolated [BS_3] as the building units, has been synthesizedsuccessfully under the guidance of theoretical prediction. Comprehensivecharacterizations reveal that NaSrBS_3 exhibits wide bandgap (3.94 eV), largebirefringence (0.185 at 1064 nm), a high laser-induced damage threshold (9 ×AGS), and a suitable phase-matching second-harmonic generation (SHG)response (0.3 × AGS). Structure-properties analyses illustrate that the [BS_3]units determine the bandgap and contribute the most to the birefringence andSHG response. This work is the first successful case of “prediction tosynthesis” involving infrared (IR) nonlinear optical (NLO) crystals in thethioborate system and provides an avenue to SHG materials design.