Properties of Faraday chiral media: Green dyadics and negative refraction

Selected properties of generalized Faraday chiral media are thoroughly studied in this paper where Green's dyadics are formulated for unbounded and layered structures, and the possibility of negative refractive index, the backward eigenwaves, and quantum vacuum are also investigated. After a general representation of the Green's dyadics is obtained, the scattering coefficients of the Green's dyadics are determined from the boundary conditions at each interface and are expressed in a greatly compact form of recurrence matrices. In the formulation of the Green's dyadics and their scattering coefficients, three cases are considered, i.e., the current source is immersed in (i) the intermediate, (ii) the first, and (iii) the last regions, respectively. We present here layered dyadic Green's functions for generalized Faraday chiral media. This kind of Faraday chiral media can also be manipulated to achieve negative refraction and possible backward wave propagation is presented as well. As compared to the existing results, the present work mainly contributes: (1) the exact representation of the dyadic Green's functions, with irrotational part extracted out, for the gyrotropic Faraday chiral medium in multilayered geometry; (2) the general DGFs and scattering coefficients which can be reduced to either layered chiroferrite, chiroplasma or other simpler cases; and (3) negative refractive index and backward waves achieved with less restriction and more advantages compared to chiral media.