千瓦级浸入式直接液冷Nd:YAG多薄片激光谐振腔

Kilowatt-Level Immersed and Direct-Liquid-Cooling Nd:YAG Multi-Disk Laser Resonator

介绍了一种工作在准连续状态下的直接液体冷却的侧面抽运Nd:YAG多薄片激光谐振腔,装置中选用20片Nd:YAG薄片作为增益介质,由激光二极管阵列在其侧面进行抽运,流动的硅氧烷溶液作为冷却液在其端面进行冷却,振荡激光以布儒斯特角穿过多层薄片和冷却液实现增益。设计了层流冷却流场并通过数值模拟验证了其对来流不均匀性的耗散能力。根据之前报道的层流冷却能力测量实验建立数值模型,模拟了流场的冷却效果,实验结果证明了模型的置信性,进而基于模型对激光器中薄片的热安全性进行了评估。在抽运能量为49.9J时,获得了15.7J的最大脉冲能量输出,对应光-光效率和斜率效率分别为31.4%和39.2%;在抽运脉宽为250μs,重复频率为100Hz,平均抽运功率为5kW时,获得了1440 W的平均输出功率。

A direct-liquid-cooling side-pumped Nd： YAG multi-disk laser resonator works in quasi-continuous state is presented, in which twenty Nd： YAG thin disks side-pumped by laser diode arrays are directly cooled by flowing siloxane solution at the end surfaces, while oscillating laser propagates through multiple thin disks and cooling flow layers in Brewster angle. The laminar flow cooling flow field is designed to cool the thin disk. The dissipation capability of the inhomogeneity of the incoming flow is verified by numerical simulation. According to the experiment reported before, a numerical model based on laminar flow is built to measure the cooling ability of the flow field. The experimental result verifies the reliability of numerical model, the thermal safety of the thin disk in laser device is evaluated based on the model. The maximum pulse energy output of 15.7 J is obtained at the pump energy of 49.9 J, corresponding to an optical-optical efficiency of 31.4% and a slope efficiency of 39.2%. The average output power of 1440 W is achieved at the pump pulse width of 250 μs, repetition frequency of 100 Hz, and average pumping energy of 5 kW.