Tunable Erbium-Doped Fiber Laser Assisted by a fs-laser Introduced Random Fiber Grating

A tunable erbium-doped fiber (EDF) laser assisted by a random fiber grating introduced by an fs-laser and a tunable fiber Bragg grating is demonstrated. The tuning range is up to 4.45 nm（ 1548.04 -1552.49 nm）. Due to the half-opened laser cavity design and the efficient gain from the pumped EDF, the measured threshold pump power is 18 mW, and the slope efficiency is up to 13.2%.