中红外2 μm Tm:YLF激光热效应分析

Research on Thermal Effects of Mid-Infrared 2 μm Tm:YLF Laser

摘要: 基于2 μm Tm:YLF激光器的实际工作条件建立了各向异性激光晶体的稳态热模型，通过解析法得到了Tm晶体内温度场分布的解析表达式；模拟并分析了泵浦功率，光斑半径，晶体端面尺寸对Tm晶体内温度场分布的影响。最终得到了在不同条件下晶体内部温度分布，结果表明：掺杂浓度的增加加剧了晶体的温升，增加了晶体热畸变不均匀性，产生更明显的热效应；而晶体长度的适度增加降低了晶体的温升，缓解了晶体热畸变不均匀性，削弱了晶体的热效应。本论文所得结论可以为LD抽运Tm:YLF激光器的腔型及散热系统设计提供理论支持。

Abstract: The theoretical model of thermal-steady-state anisotropic 2μmTm:YLF crystal was built based on the practical operation condition. Analytical solution was used to get the analytical expression of the distribution of temperature in Tm crystal and thermal focal length. Then, the influence of pump power, waist radius and crystal face size to the distribution of temperature and thermal focal length was simulated. The results show that the temperature rise and nonuniformity of thermal distortion are intensified by the increase of doping density which leads to a worse thermal effect. The temperature rise and nonuniformity of thermal distortion are weakened by the modest increase of crystal length which leads to a good thermal condition. The results in this paper provide theoretical basis for cavity design and cooling system of dual-pumped Tm:YLF laser.