详细讨论了直接液体冷却薄片激光器的设计。包括增益模块中晶体和冷却液的选取, 以及流道结构的设计, 分析了增益模块中两类组合方式各自的优缺点。组合方式一中, 需要严格控制激光的入射角以及晶体的切割角, 给出了具体的计算和分析。组合方式二无需特别选取角度, 然而所选的冷却液的折射率要与晶体的折射率尽可能一致。在抽运方式选取方面, 分析了采用端面抽运和侧面抽运对激光器储能以及像差等方面的影响。最终, 理论分析了采用10片Nd∶YLF作为增益介质, 折射率匹配液作为冷却液, 在抽运功率为5 kW时, 激光器输出功率大于1 kW, 光-光效率大于20%, 理论分析和实验结果基本一致。

The design of the direct-liquid-cooled thin-disk laser is detailedly discussed. It includes the choosing of crystal and coolant in the gain module as well as the design of the channel structure. Moreover, the advantages and disadvantages of two kinds of combination modes are analyzed. In the first mode, the incident angle of the beam and the cutting angle of the crystal should be controlled strictly. The theory calculations and analysis are given. In the second mode, the angles do not need to be specially selected, while the refractive index of the coolant should be close to that of the crystal. In the aspect of pump mode selection, the energy storage and aberration effects both in end-pumped and side-pumped lasers are analyzed. Theoretically, with the use of 10 pieces of Nd∶YLF thin-disks as the gain media and the refractive index matched liquid as the coolant, an average output power larger than 1 kW is achieved at the pump power of 5 kW, corresponding to an optical-optical efficiency larger than 20%. The theoretical analysis is basically consistent with the experimental results.