Analysis of Stimulated Brillouin Scattering in combined multi-mode optical fiber by numerical solution

Based on numerical solution of the theoretical mode for the SBS process in a novel multimode fiber, the power distributions of coupled light and sound wave in an internally tapered fiber and during pulse persistence have been shown in this paper. Compare with a common fiber PCM, it's found that the energy threshold of SBS procedure in tapered fiber can decrease greatly to a few micro-joule while maximum SBS reflectivity can theoretically arrive to 98% and the dynamic-range is expended largely. In addition, the phenomenon of the power modulation of Stokes wave is explained, and a very narrow Stokes pulse with high peak power can be achieved with the optimizing fiber parameters.