Cascaded Random Fiber Laser Based on Hybrid Brillouin-Erbium Fiber Gains

We demonstrate a stable, cascaded random fiber laser with a half-open cavity, which is based on hybrid Brillouin-erbium fiber gains and uses Rayleigh scattering as random distributed feedback. Up to four cascaded stimulated Brillouin stokes lines with frequency spacing of about 11 GHz have been generated. The peak power difference between the first and fourth stokes lines is 2.808 dB. The number of output stokes lines can be controlled by the 980 nm pump power. Peak power discrepancy between the odd and even stokes lines is avoided using the scheme of half-open cavity. The optimized Brillouin pump power is reduced to 1–2 mW and the multiwavelength output is flattened due to the employment of erbium-doped fiber.