研究了掺钬光纤激光极限输出功率，综合考虑热效应、光纤损伤、抽运亮度以及非线性效应的影响，计算了硅基掺钬光纤激光两种常规的抽运方式(掺镱激光抽运和掺铥激光抽运)在连续运转情况下的极限功率。计算结果表明，在现有工艺条件下，两种抽运方式的极限功率分别是29.9 kW和70.2 kW。功率的受限因素主要包括抽运亮度、热透镜效应和受激拉曼散射(SRS)，其中进一步提高抽运亮度是当前实现掺钬光纤激光高功率输出的主要有效途径。考虑了相应的单频激光输出以及受单模条件限制时的极限功率和受限因素。对两种抽运方案比较可得，掺铥激光抽运方案更具高功率输出优势。

We study the power limit of holmium-doped fiber lasers with the consideration of thermal effects, optical damage effect, brightness of pump source and nonlinear effects. Power limits and physical limits of holmium-doped silica fiber lasers in both pump regions (pumped with ytterbium-doped or thulium-doped laser source) are calculated. It is found that using both of the two pump regions, separately, based on current technical conditions, power limits of broad bandwidth holmium-doped fiber lasers are 29.9 kW and 70.2 kW, respectively. Limits to power now are, in fact, brightness of the pump sources, thermal lens effect and stimulated Raman scattering (SRS), and thus to improve the brightness of the pump sources is an effective method to promote high output power of holmium-doped fiber lasers. The situations of fiber lasers with single-frequency and strict single-mode operation are considered. At the same time, fiber laser pumped with a thulium-doped laser source has an advantage for achieving higher output power.