Generalized Brewster Effect using Bianisotropic Metasurfaces

Abstract: We show that a properly designed bianisotropic metasurface placed at the interface between two arbitrary different media, or coating a dielectric medium exposed to the air, provides Brewster (reflectionless) transmission at arbitrary angles and for both the TM and TE polarizations. We present a rigorous derivation of the corresponding surface susceptibility tensors based on the Generalized Sheet Transition Conditions (GSTCs), and demonstrate the system with planar microwave metasurfaces designed for polarization-independent and azimuth-independent operations. Moreover, we reveal that such a system leads to the concept of effective refractive media with engineerable impedance. The proposed bianisotropic metasurfaces provide deeply subwavelength matching solutions for initially mismatched media, and alternatively lead to the possibility of on-demand manipulation of the conventional Fresnel coefficients. The reported generalized Brewster effect represents a fundamental advance in optical technology, where it may both improve the performance of conventional components and enable the development of novel devices.