SnP$_2$S$_6$: A Promising Infrared Nonlinear Optical Crystal with Strong Non-Resonant Second Harmonic Generation and Phase-matchability
Abstract
High-power infrared laser systems with broadband tunability are of great importance due to their wide range of applications in spectroscopy and free-space communications. These systems require nonlinear optical (NLO) crystals for wavelength up/down conversion using sum/difference frequency generation, respectively. NLO crystals need to satisfy many competing criteria, including large nonlinear optical susceptibility, large laser induced damage threshold (LIDT), wide transparency range and phase-matchability. Here, we report bulk single crystals of SnP_2S_6 with a large non-resonant SHG coefficient of d33= 53 pm/V at 1550nm and a large LIDT of 350 GW/cm^2 for femtosecond laser pulses. It also exhibits a broad transparency range from 0.54 {\mu}m to 8.5{\mu}m (bandgap of ~2.3 eV) and can be both Type I and Type II phase-matched. The complete linear and SHG tensors are measured as well as predicted by first principles calculations, and they are in excellent agreement. A proximate double-resonance condition in the electronic band structure for both the fundamental and the SHG light is shown to enhance the non-resonant SHG response. Therefore, SnP2S6 is an outstanding candidate for infrared laser applications.
Keywords
Cite
@article{arxiv.2204.04298,
title = {SnP$_2$S$_6$: A Promising Infrared Nonlinear Optical Crystal with Strong Non-Resonant Second Harmonic Generation and Phase-matchability},
author = {Jingyang He and Seng Huat Lee and Francesco Naccarato and Guillaume Brunin and Rui Zu and Yuanxi Wang and Leixin Miao and Huaiyu Wang and Nasim Alem and Geoffroy Hautier and Gian-Marco Rignanese and Zhiqiang Mao and Venkatraman Gopalan},
journal= {arXiv preprint arXiv:2204.04298},
year = {2022}
}