Yb3+:YAG片状激光器的温度效应及金刚石窗口冷却设计

 基于准三能级速率方程分析了Yb³⁺:YAG 片状激光器的温度效应，结果表明随着激光介质的温度由300 K升高到400 K，激光器的储能提取效率由43%下降到26%。提出了利用热传导性能及优异的金刚石窗口对激光片的两端面进行冷却设计。模拟结果表明对掺杂11.6 %厚度为1.2 mm的激光片在泵浦功率密度为15 kW/cm²，重复频率为10 Hz的条件下，要将最高温度控制在可接受的范围内（比如320 K），周围冷却水的对流换热系数不应小于2 kW/(m²·K）。模拟结果还表明，在相同的热功率密度和冷却条件下，减小激光片的厚度同时增加抽运光的传输次数可以明显的降低激光片的温度。

Temperature effect of Yb3+:YAG slab laser and diamond window cooling design

The temperature-related laser performances of the Yb3 :YAGslablaser have beeninvestigatedbased on quasi-three level rate equation model,whichinclude the energy storage and extraction efficiency.Theresults showthat the extractable energy storage efficiency decreases significantly from43 %to 26 % with the in-crease of the temperature in the lasing slab from 300 to 400 K.We also have demonstrated the feasibility ofdouble-face cooling of lasing slab with a diamond window whose thermal conductivityis so high that a very thinplate suffices to efficiently remove the heat generated in the lasing slab.Si mulation results show that with apump intensity of 15 kW/cm2and repetition rate of 10 Hz,to keep the maxi mumtemperature of the lasing slabbelowa reasonable value,e.g.,less than 320 K,the heat exchange coefficient of water should not be less than2 000 W/(m2.K).The results also showthat under the same cooling condition reducing the thickness of thelasing slab and si multaneously increasing the number of pump passes can effectively reduce the temperature oflasing slab.