Effect of Fiber Bragg Grating Reflectivity in Linear Cavity Brillouin/Erbium Fiber Laser

A multiwavelength generation was demonstrated using a Brillouin/Erbium fiber laser (BEFL) with stimulated Brillouin scattering (SBS) effect. BEFL utilizes single-mode fiber (SMF) and erbium-doped fiber as nonlinear and linear gain medium [1-4]. The linear gain of the EDF provides high gain to amplify the Stokes signal produced through SBS in the SMF. We demonstrate a linear cavity BEFL utilizing a fiber Bragg grating (FBG) to act as a cavity loop mirror. The effect of FBG reflectivity ranging from 5 nm to 40 nm in brillouin erbium fiber laser cavity is studied. The bandwidth of the oscillating modes is determined by the FBG bandwidth. 19 stable output channels with 0.088 nm line spacing were obtained for the 40 nm setup. 23 Stokes were achieved when the FBG bandwidth was reduced to 10 nm. Though more Stokes were generated at smaller FBG bandwidth, there is a trade-off for the tuning range.