Tunable bistability in hybrid Brillouin-erbium single-frequency fiber laser with saturable absorber

We demonstrate optical bistability with flexible tunability based on a single-frequency hybrid Brillouin-erbium fiber laser with a saturable absorber. An unpumped erbium-doped fiber is used as the saturable absorber to play the role of a dynamic ultranarrow self-tracking filter and suppress the multiple-longitudinal-mode operation. By properly adjusting the power of two pumps (980 nm pump and Brillouin pump), the bistable region can be conveniently tuned from 23 mW to similar to 1 W. The smallest bistable region (23 mW) appears under a fixed Brillouin pump power (1.104 W). The result shows that the proposed fiber laser performs a single-longitudinal-mode status with excellent stability of the output wavelength and optical power. (C) 2016 Optical Society of America