T-matrix method for electromagnetic scattering by a general anisotropic particle

Abstract

A general T-matrix solution for electromagnetic or light scattering by an anisotropic particle with an arbitrary permittivity tensor is constructed based on the extended boundary condition method (EBCM). By using the inverse Fourier transform, a system of quasi-spherical vector wave functions (qSVWFs) are obtained for an expansion representation of electromagnetic fields inside a general anisotropic medium. Special cases for gyroelectric anisotropic medium, biaxial anisotropic medium as well as uniaxial anisotropic medium are discussed. By virtue of the obtained series of qSVWFs, T-matrix formula are constructed to find solutions for characterizing electromagnetic or light scattering from an arbitrary shaped homogeneous anisotropic particle, and a home-made FORTRAN program is written. To validate the presented theoretical treatments as well as the home-made program, numerical results concerning radar cross section (RCS) or differential scattering cross sections (DSCSs) for various parameters are calculated by using the present method and are compared with those computed using other methods. Very good agreements are achieved, which partially confirms the correctness of the theoretical derivations and home-made program. Some new numerical results are also presented to analyze the influences of anisotropy components in permittivity tensor upon the scattering properties, which also provide a reference data for other methods.