光纤激光器中包层功率剥离器散热性能的优化

Optimization of thermal performance of cladding power stripper in fiber laser

光纤激光器系统中的包层功率剥离器在去除残余抽运光和高阶激光时,由于光热转换会产生大量的热能,所以将热能高效的耗散成为当前的研究热点.本文对国内外现有的五种剥离器进行了仿真研究与对比,发现用高折胶法制作剥离器时,改变填胶孔的形状,可以有效地增大热源与传热介质间的表面积-体积比,从而降低剥离器工作时的温度峰谷值;还发现将高折胶法和酸腐蚀法结合制备粗细不均匀的两段式光纤包层结构,可以提升剥离器的热分布均匀性.根据上述发现,提出了一种新颖的剥离器结构并进行了热效应研究.结果表明:包层功率为150 W时,该剥离器的温度峰值为298 K,温度谷值为293 K,温差为5 K;相比于上述五种剥离器,其温度峰值最多降低了11.3%,温度谷值最多降低了8.4%,温差最多降低了87.5%,证明了该剥离器能有效抑制温升及具有热分布均匀性.

In the process of eliminating the residual pump light and high-order laser light,the cladding power stripper(CPS)generates abundant heat,which can affect the performance of the fiber laser system due to the photothermal conversion.Hence the efficient dissipation of thermal energy becomes a current research focus.In this paper,the five kinds of existing CPSs are simulated and compared with the results in the literature.It is found that the surface-volume ratio between the heat source and the heat transfer medium can be effectively increased by changing the shape of the polymer filling hole when the CPS is made by the high refractive index polymer method,thus reducing the temperature peak and valley value of the CPS.Besides,the heat distribution uniformity of CPS can be improved by combining the high refractive index polymer method with the acid corrosion method to prepare the two-section fiber cladding structure with uneven thickness.According to the above results,a novel CPS structure is proposed and its thermal effect is studied.The results show that when the cladding light power is 150 W,the temperature peak value of the CPS is 298 K,the temperature valley value is 293 K,and the temperature difference is 5 K.Comparing with the above five CPSs,the peak temperature is reduced by up to 11.3%,and the valley temperature is reduced by up to 8.4%,the temperature difference is reduced by up to 87.5%,which proves that the novel CPS structure can effectively suppress the temperature rising and have excellent heat distribution uniformity.