Scattering by an arbitrarily shaped rotationally uniaxial anisotropic object: Electromagnetic fields and dyadic Green's functions

Abstract

The electromagnetic scattering by a three-dimensional arbitrarily shaped rotationally uniaxial anisotropic object is studied. Electromagnetic fields in a uniaxial medium are solved for first using the method of separation of variables, and then expressed in a very compact form by introducing the modified spherical vector wave functions. The equivalence theorem and the T-matrix method are applied in the analysis of the scattering problem. The scattered fields and the dyadic Green's functions both external and internal to the scatterer are derived in terms of spherical vector wave functions and matrix-form coefficients. Through making use of the dyadic Green's functions obtained, numerical results are provided for an incident field excited by an infinitesimal dipole. The scatterers are assumed to be prolate and oblate dielectric spheroids with the rotational z-axis. The angular scattering intensities in far-zone are plotted for all these cases. And some conclusions are also drawn eventually from numerical discussions.