掺镱双包层高功率光纤激光器热效应的理论研究

 针对高功率掺镱双包层光纤激光器（DCFL）的热效应，由热传导方程并借助速率方程模型导出温度分布的解析解，研究了泵浦方式和泵浦吸收系数对DCFL腔内温度的影响。结果表明：温度沿径向的变化与轴向相比可以忽略；采用传统端面泵浦会导致DCFL局部温度过高，实际中应使用两端对称泵浦方式；而减小泵浦吸收系数虽可改善温度特性但会降低系统的输出功率。进一步分析得出，综合采用分段泵浦方式和不均匀泵浦吸收系数可实现温度分布和输出功率的最佳匹配。

Thermal effects in Yb-doped double-clad high power fiber lasers

Temperature distribution in Yb-doped double-clad high power fiber lasers (DCFL) was analyzed by the thermal conductive equations, and pump way and pump absorption coefficients which may influence cavity temperature were discussed based on this analytic solution. Results indicate that the temperature variation in radius can be neglected compared to that in axial direction; local temperature will be very high if merely adopted traditional end pump, then symmetrical two-end pump should be used in practice; temperature characteristics improves by reducing pump absorption coefficient, whereas output power decreases together. In conclusion an approach under distributed pump and with nonuniform pump absorption coefficients is proposed to get the best match of temperature distribution and output power.