数值模拟分析了大功率光子晶体光纤(PCF)激光器的温度场和热应力场。通过引入等效热传导率对光子晶体光纤结构进行简化,建立了光子晶体光纤激光器的三维温度场模型。利用有限元方法数值模拟得到了自然对流换热时光子晶体光纤中的温度场及光纤端面的热应力场,并对强制对流换热时光子晶体光纤的冷却效果进行了数值模拟分析。结果表明,对于选取的PCF,通过采取强制对流换热措施可以承受1000 W的抽运功率而不会产生热效应损伤,如果需要通过提高抽运功率以获得更大功率的激光运转,则需要改变光纤的结构。

Temperature and thermal stress of high-power photonic crystal fiber (PCF) lasers were numerically simulated and analyzed. Equivalent thermal conductivity was introduced to simplify the structure of photonic crystal fiber,and then three dimensional temperature field model of photonic crystal fiber laser was established. By using the finite element method,the distributions of the temperature in fiber and the thermal stress in end-surface of fiber were numerically simulated and analyzed with natural and forced convection heat transfer,respectively. The results show that the selected PCF can support the pumped power of 1000 W under forced convection heat transfer,but improving the parameters of fiber is required to further enhance the output power by supporting higher pump power.