Static imaging of dynamic fluctuations in multiple light scattering media

Multiple light scattering experiments in backscattering geometry are performed on highly viscous and solid turbid media which contain macroscopic inclusions of a low viscosity colloidal suspension. We demonstrate that the intensity probability distribution P(I) of the multiple scattering speckle patterns can be used to image an inclusion even if its photon transport mean free path matches the value of the surrounding medium. The main difference between solid and liquid samples is discussed. (C) 1998 Elsevier Science B.V.