Four-wave-mixing-assisted Brillouin fiber laser with double-Brillouin-frequency spacing

•Brillouin fiber laser with 18 channels at 0.176 nm spacing is presented.•Bandpass filter suppressed the ASE noise floor producing higher OSNR at the output.•The incorporation of bandpass filter increases number of channels from 15 to 18.

The generation of multiwavelength Brillouin fiber laser assisted by four wave mixing has been demonstrated. A maximum of 18 channels of laser Stokes lines are generated at a Brillouin Pump (BP) of 190 mW (∼22.5 dBm). The multiple peaks have a wavelength spacing of 0.176 nm (∼20 GHz). A tunable optical bandpass filter is incorporated to the design to suppress up to 6 dB of the noise floor hump exhibited at the multiwavelength laser spectrum while limiting the laser peaks attenuation thereby providing a much cleaner and better OSNR.