High power triple clad fiber combiner and its application for the power scaling of 2.1 µm Ho3+-doped fiber lasers pumped at 1.9 µm

In this contribution, we show for the first time to our knowledge the realization of a high power 1.94 µm triple clad fiber combiner with low insertion losses, thanks to the implementation in the component of a low-index glass capillary. Moreover, in this contribution we discuss the power scalability of a 2.1 µm Ho3+-doped fiber laser architecture integrating the above mentioned triple clad fiber combiner and pumped at 1.94 µm using Tm3+-doped fiber lasers developed at ISL.