DIFFUSION OF CLASSICAL WAVES IN RANDOM-MEDIA WITH MICROSTRUCTURE RESONANCES

The diffusion constant of classical waves propagating in random media with microstructure resonances is obtained. Renormalizations of D that are due to expansions in transferred momentum q and frequency omega i n the Bethe-Salpeter equation are taken into account. The diffusion co nstant is estimated for scalar waves propagating in the medium with ra ndomly distributed dielectric spheres with the use of the nondiagonal off-shell transition matrix for penetrable scatterers. A detailed comp arison of different sources of renormalization is made. Differences be tween previous calculations based on the on-shell scattering matrix an d new results implementing the off-shell scattering matrix are discuss ed. (C) 1996 Optical Society of America