title: Instabilities of waves in nonlinear disordered media
abstract: We develop a self-consistent theory of temporal fluctuations of a speckle pattern resulting from the multiple scattering of a coherent wave in a weakly nonlinear disordered medium. The speckle pattern is shown to become unstable if the nonlinearity exceeds a threshold value. The instability is due to a feedback provided by the multiple scattering and manifests itself in spontaneous fluctuations of the scattered intensity. The development of instability is independent of the sign of nonlinearity.
authors.affiliation: Laboratoire de Physique et Modelisation des Milieux Condenses, Universite Joseph Fourier, Maison des Magisteres-CNRS, BP 166, 38042 Grenoble Cedex 9, France.
authors.initials: SE
authors.lastname: Skipetrov
authors.initials: R
authors.lastname: Maynard