All-fiber high-power supercontinuum laser source over 3.5  µm based on a germania-core fiber

In this Letter, a high-power all-fiber mid-infrared (MIR) supercontinuum (SC) laser source based on 9 cm long germania-core fiber (GCF) pumped by a high-power thulium-doped fiber amplifier is presented. As the pump power was set as 60 W, we obtained a 21.34 W broadband SC source extending from 1742 to 3512 nm with a slope efficiency of 32.5%. The 10 dB spectral bandwidth was over 1000 nm, spanning 1.97 to 3.04 µm. Furthermore, the numerical simulation of SC generation in GCF was in good agreement with the experimental results. As far as we know, this is the highest average output power over 3.5 µm in GCF based on a MIR SC laser source.