Superluminous three-wave solitary Brillouin structures

Self-similar deformation of three-wave stimulated Brillouin scattering (SBS) dissipative structures ("Brillouin quasi-solitons") yields superluminous behaviors. The authors discuss the relevancy of the various velocities involved in the nonlinear propagation of such complex structures, both in the ideal semi-infinite case and in a real-world Brillouin fiber ring laser experiment. Optical and acoustical group velocities greater than c are shown to occur during pulse propagation in SBS soliton lasers.