8.08 W holmium doped fluorotellurite fiber laser at 2067 nm

We reported a multi-watt ∼2.1 µm laser output from a 30 cm long Ho³⁺-doped fluorotellurite microstructured fiber (FTMF) pumped by a homemade 1980 nm Tm³⁺-doped silica fiber laser. When the pump power was increased to 61.8 mW, lasing at 2067 nm was achieved from the Ho³⁺-doped FTMT, and an unsaturated maximum output power of ∼8.08 W was obtained for a pump power of ∼10.56 W. The corresponding slope efficiency was about 77.21%. During our experiments, no obvious damage was observed on the end face of the Ho³⁺-doped FTMF. Our results indicated that Ho³⁺-doped fluorotellurite fibers had the potential for constructing high power fiber lasers at 2.1 µm. (letter)