Experimental observation of hybrid TE-TM polarized surface waves supported by hyperbolic metasurface

Hyperbolic metasurfaces have gained significant attention due to their extraordinary electromagnetic properties to control propagating plane waves, but the excitation and propagation of the surface plasmon-polaritons at hyperbolic metasurfaces, called hyperbolic plasmons, have been experimentally observed just recently. However, the advantages of the hyperbolic plasmons, such as hybrid TE-TM polarization discussed below, are not yet fully revealed and analyzed. In this paper we focus on the numerical and experimental characterization of surface waves in the frequency range from 2 to 8 GHz supported by a hyperbolic metasurface composed of anisotropic metallic Jerusalem crosses printed on a thin dielectric substrate. We show different shapes of equal frequency contours, which correspond to a plethora of excitation and propagation regimes of surface waves. The principal novelty of this work consists in the experimental demonstration of the surface waves with a hybrid, i.e. mixed TE-TM, polarization. Surface waves with a hybrid polarization are the promising tool in a number of applications and phenomena including polarization converters, plasmonic sensors, plasmon steering over a surface, optical forces, spin-orbit photonics, and highlight the impact for the on-chip and planar networks.