Direct and inverse scattering problems for spherical Electromagnetic   waves in chiral media
  We study the direct and inverse scattering problems when the incident electromagnetic field is a time harmonic point- generated wave in a chiral medium and the scatterer is a perfectly conducting sphere. The exact Green s function and the electric far-field patterns of the scattering problem are constructed. For a small sphere, a closed-form approximation of the scattered wave field at the source of the incident spherical wave is obtained. These near-field results lead to the solution of an inverse problem. We also treat the same inverse problem using far-field results via the leading order term in the low-frequency asymptotic expansion of the scattering cross-section. 
Nikolaos Berketis, Christodoulos Athanasiadis