Geometrical Optics in Inhomogeneous Chiral Media for Applications in Polarization Rotating Microwave Lenses

Geometrical optics approximation for waves in inhomogeneous chiral media is introduced based on the concept of normalized wave fields, which are certain complex combinations of the electric and magnetic fields, uncoupled for sufficiently slowly varying media. For small values of the chirality parameter, the geometrical optics rays can be calculated as for a chiral media and the main effect of the chirality is rotation of polarization along the ray. Thus, adding chirality to inhomogeneous lens antennas, their polarization properties can be improved. As an example, it is demonstrated how the inherent cross polarization of the Maxwell fish-eye lens is compensated through a suitable chirality distribution.