Improving the Quantum Efficiency of Erbium-Doped Fiber Laser by Using a Low-Loss Tipped Fiber Splicing Process

Abstract—A tipped single-mode fiber (SMF) structure is em-ployed to reduce the fusion-splicing loss induced at the interface be-tween SMFs and Erbium-doped fibers (EDFs). By fusing the EDF and the tipped SMF with lens-like end face at once, the optimized fusion-splicing loss of as low as 0 2 0 29 dB is obtained. An improvement on splicing loss of up to 0.46 dB is obtained as com-pared to the conventional EDF/SMF fusion geometry. The effects of tapered angle and radius of curvature at the end face of tipped fiber on the optimization of fusion-splicing loss are compared. The erbium-doped fiber laser with maximum quantum efficiency of 2.75 % is reported by using the proposed splicing technology. Index Terms—Erbium-doped fiber laser (EDFL), fusion-splicing loss, quantum efficiency, single-mode fiber (SMF), tipped fiber. I