TE/TM decomposition of electromagnetic sources in a nonreciprocal anisotropic medium

The principle of source decomposition for electromagnetic problems is considered in the most general homogeneous anisotropic medium in which electromagnetic fields can be decomposed in two partial fields characterised by either TE or TM polarisation with respect to two given complex vectors. It is shown that, for each of the decomposed fields, the original medium can be replaced by a simpler equivalent medium, allowing one to apply existing analytic Green functions corresponding to each of the equivalent media. The problem of decomposing a given electromagnetic source into two parts corresponding to the TE and TM fields is solved in the case when the two complex vectors are coplanar. As an example, an electric current dipole is decomposed into two current sheets in the plane of the complex vectors. The source decomposition principle can be applied for solving field problems involving a homogeneous anisotropic space of the present type, for which no known analytic form for the Green dyadic exists