All-fiber core-pumped Ho-doped laser with 95 W output power and high efficiency

We report a core-pumped, all-fiber, monolithic holmium-doped silica fiber laser (HDFL) pumped at 1940 nm by a high-power Tm-doped fiber laser. The system delivers up to 95 W of continuous-wave output power at 2109 nm, representing one of the highest reported powers for a core-pumped holmium fiber laser. A slope efficiency of 84% with respect to launched pump power is achieved, making a 10% improvement over previously published papers. These results confirm the effectiveness of core pumping using advanced Tm-doped fiber architectures and highlight the potential of compact, efficient Ho-doped fiber sources for high-power applications in the 2.1 µm spectral region. All experiments were further supported by numerical modelling together with a simulation of possible further power-scaling up to 250 W.