OPTICAL-PROPERTIES OF SPHERES CONTAINING A SPHERICAL ECCENTRIC INCLUSION

The formalism presented a few years ago by Fikioris and Uzunoglu [J. Opt. Soc. Am. 69,1359 (1979)] to describe the electromagnetic scattering by homogeneous spheres containing an eccentric spherical inclusion is reformulated. The resulting approach is an extension of our previous formalism [Aerosol Sci. Technol. 3, 227 (1984)] designed to deal with the dependent scattering by aggregated spheres and is put in a form readily extensible to the case of spheres containing more than one inclusion. A comparison of our results with those of Fikioris and Uzunoglu is made, and the differences are explained in terms of the approximations that they used. Specific results for dielectric spheres containing either a metallic inclusion or a dielectric inclusion with parameters quite incompatible with the approximation scheme of Fikioris and Uzunoglu are also presented. These scatterers have a response that depends on the direction of incidence and, in general, also on the polarization, thus making them distinguishable from spheres with a centered inclusion as well as from homogeneous spheres.