STIMULATED BRILLOUIN-SCATTERING IN FIBERS WITH AND WITHOUT EXTERNAL FEEDBACK

We report on experimental investigations of stimulated Brillouin scatt ering (SBS) in single-mode optical fibers, taking fully into account t he influence of external feedback from the fiber ends. A threshold con dition for arbitrary external reflectivity is derived. Detailed time-s eries analysis reveals that for the limiting case of vanishing externa l reflectivity, the dynamics is purely stochastic. For finite reflecti vities, the observed dynamics is periodic provided environmental pertu rbations are suppressed. These findings settle a recent discussion abo ut whether there are deterministically chaotic features present in the dynamics of SBS in fibers.