Broadly tunable 40 GHz Brillouin frequency spacing multiwavelength Brillouin–Erbium fiber laser for DWDM

In this paper, we propose and experimentally demonstrate quadruple Brillouin-shift wavelength spacing (˜0.33 nm, ˜40 GHz) utilizing multiwavelength Brillouin–Erbium fiber laser (MBEFL) cavity. High Brillouin pump (BP) power, Pre-amplification technique, and capturing the residual pump power using wave selective coupler (WSC) are used to enhance laser comb tunability. The proposed structure has a tuning range of 60 nm (1530 nm–1590 nm) in the absence of self lasing cavity modes. Four stable Brillouin Stokes with high output power are achieved at 20mW and 225mW of BP and 1480 nm pump power respectively. In addition, multi-output ports with quadruple channel spacing is presented. This wide channel spacing make the proposed structure has strong potential to be used in dense wavelength division multiplexing (DWDM) communication systems.