Advances in multi-wavelength Brillouin fiber lasers: An outlook across different spectral regions

In recent years, Brillouin fiber lasers have become a promising optical source technology for academic and industrial purposes. Among the promising laser solutions that have emerged with low threshold, high efficiency, small linewidth, and low resonator loss, multi-wavelength architecture has attracted the most attention recently. However, the development of configurations with an increased number of Stokes channels that present high flatness and reasonable optical-to-signal ratio (OSNR) is a challenge that this fiber laser technology still faces, and the development of solutions for this is an open problem. From this perspective, this paper presents a review focused on recent progress in multi-wavelength Brillouin fiber laser (MBFL) devices. Specifically, microwave generation and temperature sensing applications are discussed. Key results in the spectral regions of 1.0 mu m, 1.3 mu m, 1.5 mu m, 1.6 mu m, and 2.0 mu m are reported, as well as future perspectives are addressed in this review for the advancements in multi-wavelength fiber laser sources.