MEAN-FIELD APPROXIMATION OF MIE SCATTERING BY FRACTAL AGGREGATES OF IDENTICAL SPHERES

We apply the recent exact theory of multiple electromagnetic scatterin g by sphere aggregates to statistically isotropic finite fractal clust ers of identical spheres. In the mean field approximation the usual Mi e expansion of the scattered wave is shown to be still valid, with ren ormalized Mie coefficients as the multipolar terms. We give an efficie nt method of computing these coefficients, and we compare this mean-fi eld approach with exact results for silica aggregates of fractal dimen sion 2. (C) 1997 Optical Society of America.