All-fibre Brillouin amplifiers in single mode fibres and fibre ring resonators

With rapid development of the coherent fibre communications systems, there has been a considerable interest in all-fibre optical amplification. Due to inherent index and mode-matching, the all-fibre geometry offers the advantage of low insertion loss and direct splicing into an all-fibre system. The uses of gain in the nonlinear Raman and Brillouin scattering processes for amplification have received much attention in recent years. In this paper, the authors report the results of numerical solutions of the SBS (stimulated Brillouin scattering) equations using the 4th order Runge Kutta algorithm which yielded stable and accurate solutions. For amplification, the pump laser is operated at a power below threshold to ensure linear gain, as above threshold, the output power is no longer linearly dependent on the input power