  In conventional approaches to the homogenization of random particulate
composites, the component phase particles are often treated mathematically as
vanishingly small, point-like entities. The electromagnetic responses of these
component phase particles are provided by depolarization dyadics which derive
from the singularity of the corresponding dyadic Green functions. Through
neglecting the spatial extent of the depolarization region, important
information may be lost, particularly relating to coherent scattering losses.
We present an extension to the strong-property-fluctuation theory in which
depolarization regions of nonzero volume and ellipsoidal geometry are
accommodated. Therein, both the size and spatial distribution of the component
phase particles are taken into account. The analysis is developed within the
most general linear setting of bianisotropic homogenized composite mediums
(HCMs). Numerical studies of the constitutive parameters are presented for
representative examples of HCM; both Lorentz-reciprocal and
Lorentz-nonreciprocal HCMs are considered. These studies reveal that estimates
of the HCM constitutive parameters in relation to volume fraction, particle
eccentricity, particle orientation and correlation length are all significantly
influenced by the size of the component phase particles.

Optics