~2μm Laser Performance in Double-clad Yb3+/Tm3+ co-doped boro-bismuth glass fiber

In this paper, the Tm3+/Yb3+ co-doped double-clad Bi2O3-B2O3-BaF2 glass fiber with a core diameter of 11 μm is prepared by the rod-in-tube method, the ~2 μm performance of Bi2O3-B2O3-BaF2 glass and double-clad fiber is investigated. The results indicate that Yb3+ doping significantly enhances the pumping efficiency at 978 nm, and when the Yb3⁺ doping concentration is 1.0 mol%, the highest ~2μm fluorescence intensity is observed.With a 980 nm laser diode pumped, a slope efficiency of 13.61%, and a central wavelength of 1810 nm was acquired in a 90 cm-long Tm³⁺/Yb³⁺ co-doped double-clad Bi₂O₃-B₂O₃-BaF₂ glass fiber. It is indicated that the Tm3+/Yb3+ co-doped double cladding Bi₂O₃-B₂O₃-BaF₂ laser fiber has a great application prospect in mid-infrared broadband fiber amplifiers.