A new approach to the generalized optical cross-section theorem in electromagnetics

This work is concerned with electromagnetic scattering in general nonhomogeneous, lossy, anisotropic media. A new approach to the generalized optical cross-section theorem (for two incident fields) and of its particular manifestation, the ordinary optical theorem (for a single incident field), is developed that is relevant to electromagnetic direct and inverse problems. The derived results are based on cross-flux concepts and Green´s function theory, and apply in arbitrary background media (where the scatterers are embedded), under arbitrary incident fields, and in arbitrary representational domains (plane wave, multipole field, Green´s function, and so on).