A stable tunable and switchable dual-wavelength single-longitudinal-mode erbium-doped fiber linear-cavity laser

A simple linear cavity erbium-doped linear-cavity laser is proposed and experimentally demonstrated, with tunable and switchable multi-wavelength SLM operation. The main mode-selection components of our system include an FBG Sagnac loop, an umpumped EDF together with a tunable FBG. The unpumped EDF together with the tunable FBG form a super narrow-band self-tracking FBG around the reflection peak of such tunable FBG, which ensures the SLM laser operation. By simple adjustment of two polarization controller, the laser can be designed to operate in a stable single-wavelength or dual-wavelength with a wavelength spacing of 0.05 nm at room temperature.