Electromagnetic field and source decomposition in a class of linear media

The classical TE/TM decomposition of electromagnetic fields and sources valid for isotropic and uniaxially anisotropic linear media is generalized to a class of linear bi-anisotropic media. It is shown that any field in the medium belonging to this class can be split into two individual parts with certain restrictions on their polarizations (the a-field and the b-field). Because of these restrictions, the fields are blind to certain parameter values of the medium. Thus, the original medium can be replaced by simpler effective media for the decomposed fields and, for these media, Green dyadics can be constructed in analytical form