Tunable erbium-doped fiber laser based on random distributed feedback

Abstract

A tunable erbium-doped fiber (EDF) laser based on random distributed feedback through backward Rayleigh scattering in a 20-km-long single-mode fiber and a tunable fiber Fabry-Perot interferometer filter is demonstrated. It has a broad wavelength tuning range up to 40 nm (from 1525 to 1565 nm) with a narrow linewidth of ∼0.04 nm. Due to the half-opened laser cavity design and the efficient gain from the pumped EDF, the measured threshold power is only 13 mW, and the pump efficiency is up to 14%.