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 employed to reduce the fusion-splicing loss induced at the interface between 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 similar to 0.29 dB is obtained. An improvement on splicing loss of up to 0.46 dB is obtained as compared 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.