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.

固态激光器提供了一种有吸引力的方法来提高激光器的性能，这得益于低温下增益介质的热光和光谱特性的显着改善。我们已经系统地研究了Nd：YAlO ₃的结构，热学和光谱性质（Nd：YAP）在77-300 K的温度范围内。我们发现a切Nd：YAP晶体的热膨胀系数在180 K附近约为零。零热膨胀可能导致可忽略不计的热效应，并且抑制高平均功率激光器中的光学畸变，这为产生高功率和高光束质量的激光器提供了很大的帮助。低温下导热系数的增加和热膨胀的减小导致抗热震性参数明显大于室温下的抗热震性。此外，还确定了Nd：YAP晶体在77–300 K的温度范围内的详细热学和光谱特性。Nd：YAP晶体的所有结果，特别是零热膨胀的出现，为低温冷却大功率激光器的设计提供了重要信息。