High-power solid-state lasers with good beam quality are attracting great attention on account of their important applications in industry and military. However, the thermal effects generated in the laser host materials seriously limit power scaling and degrade the beam quality. Thermal lensing and thermally induced wavefront deformation are the main causes of the beam quality deterioration. Here we investigate the performance of a zero thermal expansion (ZTE) solid-state laser gain material. In a proof-of-principle experiment, an ${a}$-cut rod ${\rm Nd}\!:\!{{\rm YAlO}_3}$ (Nd:YAP) perovskite crystal is chosen to be the gain medium for ZTE around 180 K. The laser performance spanning the temperature range from 80 to 290 K is studied. The maximum output power and minimum threshold pump power were obtained at a temperature of 180 K. Moreover, the measured thermal focal power and peak-to-valley value of the wavefront distortion also reach a minimum at this temperature, an additional benefit from the crystal’s ZTE coefficient. We envisage that these results will open a new route towards the development of high-power and high-beam-quality lasers through the use of ZTE gain materials.

中文翻译：

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基于零热膨胀的低波前畸变低温Nd：YAlO ₃低温激光器的出色性能

具有良好光束质量的高功率固态激光器由于其在工业和军事上的重要应用而引起了极大的关注。但是，激光主体材料中产生的热效应严重限制了功率缩放，并降低了光束质量。热透镜和热引起的波前变形是光束质量下降的主要原因。在这里，我们研究零热膨胀（ZTE）固态激光增益材料的性能。在原理验证实验中，切割了$ {a} $美元的棒$ {\ rm Nd} \！：\！{{\ rm YAlO} _3} $选择（Nd：YAP）钙钛矿晶体作为中兴通讯在180 K附近的增益介质。研究了在80至290 K的温度范围内的激光性能。在180 K的温度下可获得最大输出功率和最小阈值泵浦功率。此外，在该温度下，测得的热聚焦功率和波前畸变的峰谷值也达到最小值，这是晶体的附加优势。中兴系数。我们预计，这些结果将为通过使用中兴通讯增益材料开发高功率和高光束质量的激光器开辟一条新途径。