高功率双包层光纤激光器热效应及功率极限

Thermal effect and power limit in high power double-clad fiber laser

基于稳态热传导方程,对高功率双包层光纤激光器的热效应进行了研究,分析了光纤尺寸、冷却条件、泵浦功率等因素对光纤温度场的影响。对给定参数的光纤,给出了理论功率极限。指出对于目前常用双包层光纤激光器,最大输出功率主要受各外包层材料的熔点和非线性效应限制,从而可以确定功率限制的瓶颈所在,提出有效的改进方案,如减弱或消除线性效应、提高外包层的耐热能及改进制冷方案。

According to the steady-state heat conduction equation, the temperature distribution in the high power double-clad fiber laser（DCFL） has been analyzed. The influence of fiber size, cooling-boundary condition and pump power on temperature distribution are discussed based on the analytic solution. The theoretical maximum output power with given parameters is obtained. The maximum power of a commonly used DCFL is limited by the melting point of the material and the non-linear effect. The bottlenecks can be easily determined so as to come up with effective improved shemes, such as weakening or eliminating the linear effect, raising the heat-resistant of outer-clad and improving the cooling method.