Evidence of phase singularities and dynamic patterns in stimulated Brillouin scattering

We report first experimental evidence of static and dynamical phase singularities and pattern formations in the transverse field of multimode Stokes emission from stimulated Brillouin scattering. We find that nucleation and motion of the phase singularities, in the presence of feedback, results in symmetry breaking and dynamics of the patterns. They are also shown to mediate the spatio-temporal chaos we observe in the more complex patterns.