Metasurfing: Addressing Waves on Impenetrable Metasurfaces

TLDR

Metasurfaces are thin metamaterials employed from microwave to optical frequencies for novel antennas and devices, and their modulation effects mimic volumetric metamaterial transformation optics by redirecting wave propagation. The study proposes using variable‑impedance metasurfaces to transform surface or guided waves into desired wavefield configurations. Metasurfing is achieved by synthesizing inhomogeneous metasurface reactance to locally modify the dispersion equation and wave vector at a fixed operating frequency. Metasurfing delivers significant technological simplicity and is validated by several proof‑of‑concept examples.

Abstract

Metasurfaces constitute a class of thin metamaterials, which are used from microwave to optical frequencies to create new antennas and microwave devices. Here, we propose the use of variable-impedance metasurfaces for transforming surface or guided waves into different wavefield configurations with desirable properties. We will shortly refer to this metasurface-driven wavefield transformation as “metasurfing.” Metasurfing can be obtained by an appropriate synthesis of inhomogeneous metasurface reactance that allows a local modification of the dispersion equation and, at constant operating frequency, of the local wave vector. Metasurfing can be obtained by an appropriate synthesis of inhomogeneous metasurface reactance that allows a local modification of the dispersion equation and, at constant operating frequency, of the local wave vector. The general effects of metasurface modulation are similar to those obtained in solid (volumetric) inhomogeneous metamaterial as predicted by the transformation optics-namely, readdressing the propagation path of an incident wave. However, significant technological simplicity is gained. Several examples are shown as a proof of concept.