Structure, thermal and spectroscopic properties of Nd:YAlO3 perovskite crystal between 77 to 300 K for the design of cryogenic cooled solid state laser

Abstract

The solid-state lasers provide an attractive approach to enhance the laser performance benefitting from significant improvements in both thermo-optic and spectroscopic properties of the gain mediums under cryogenic temperature. We have systematically investigated the structure, thermal and spectral properties of Nd:YAlO3 (Nd:YAP) in the temperature range of 77–300 K. We found that the thermal expansion coefficient of a-cut Nd:YAP crystal is about zero around 180 K. The zero-thermal-expansion could lead to negligible thermal effect and suppress optical distortion in high average power lasers, which provides great help for high power and high beam quality laser generation. The increase in thermal conductivity and reduced thermal expansion at cryogenic temperature lead to thermal shock resistance parameter significantly larger than that at room temperature. Furthermore, the detailed thermal and spectral properties of Nd:YAP crystal in the temperature range across 77–300 K were determined. All results of the Nd:YAP crystal, in particular, the emergence of zero-thermal-expansion, provide important information for the design of cryogenic cooled high-power lasers.