Xinjiang Institute Of Physical And Chemical Technology Makes Progress in Research On Laser Damage Resistant Wide Band Gap Infrared Nonlinear Optical Materials

As a key device for laser frequency conversion, infrared nonlinear optical crystals have a wide range of applications in all-solid-state lasers. The current commercial mid- and far-infrared nonlinear optical crystals mainly include compounds such as AgGaS2, AgGaSe2 and ZnGeP2 with diamond-like structures. However, due to their respective intrinsic performance defects, such as low laser damage threshold and two-photon absorption caused by low bandgap, these materials can no longer fully meet the needs of current infrared laser technology development. There is an urgent need to develop wide bandgap infrared nonlinear optical materials with excellent performance.
With the financial support from the National Young Talents Program, the National Natural Science Foundation of China and the Natural Science Foundation of Xinjiang Autonomous Region, researchers at the Crystal Materials Research Center of Xinjiang Institute of Physical and Chemical Technology, Chinese Academy of Sciences have designed and synthesized two examples of wide bandgap infrared nonlinear optical materials, Rb2CdSi4S10 and Na3SiS3F, using [Si4S10] super tetrahedral substrates and [SiS3F] mixed anionic tetrahedral substrates. The band gaps of these two compounds are 4.23 eV and 4.75 eV, respectively, where Rb2CdSi4S10 has a moderate multiplicative effect: 0.6 × AGS; the damage threshold is about 5 × AGS. The results of theoretical calculations show that [Si4S10] super tetrahedral matrix and [SiS3F] mixed anionic tetrahedral matrix can effectively increase the band gaps of sulfur compounds. The results show that the [Si4S10] super tetrahedral substrate and [SiS3F] mixed anionic tetrahedral substrate can effectively increase the band gap of sulfur compounds, which provides a reference for the design of damage-resistant wide band gap infrared nonlinear optical materials.
The results were published in Materials Horizons (Mater. Horiz. 2023, 10, 619) and Advanced Optical Materials (Adv. Opt. Mater. 2023, DOI: 10.1002/adom. 202300736.), respectively. The results are presented in the following papers. Jiazheng Zhou, a Ph.D. student, is the first author of these two papers, and Junjie Li and Shili Pan are the corresponding authors.