Two-watt mid-infrared laser emission in robust fluorozirconate fibers

To the best of our knowledge, we report here the first demonstration of 2.9 µm laser emission from in-house fabricated Ho³⁺/Pr³⁺ co-doped ZBYA glass fiber. The fiber was fabricated based on the ZBYA glass with compositions of ZrF₄-BaF₂-YF₃-AlF₃-PbF₂-HoF₃-PrF₃. Under the pump of a 1150 nm Raman fiber laser, the maximum unsaturated output power of 2.16 W was obtained in a 15 cm long gain fiber with a slope efficiency of 24%. The influence of rare-earth doping concentration on laser performance was also investigated. The result indicates that ZBYA glass fibers have potential for using as a fluorozirconate glass gain fiber for mid-infrared fiber lasers.