Dual-Functional Coding Metasurfaces Made of Anisotropic All-Dielectric Resonators

Abstract

Digital coding metasurfaces, composed of only two types of unit cells with opposite phase responses (0 and π) that can map to the usual binary elements “0” and “1”, are capable of generating coded pulsed sequences of electromagnetic waves. In this paper, we present a generic extensible strategy for designing dual-functional anisotropic coding metasurfaces based on all-dielectric resonators. The polarization-dependent beam manipulations are achieved via encoding the metasurfaces with different coding sequences in the two orthogonal polarizations of the electromagnetic wave propagating through the surface. As proof of concept, we show it is possible to achieve line focusing and point focusing in a single coding metasurface when illuminated by the x- or y-polarized electromagnetic waves. We also present anisotropic coding metasurfaces for realizing multi-beam generation and polarization-selected mirror/diffuse reflection. The near-field distributions and far-field scattering patterns extracted from full-wave simulations are presented to show the multiple functions of the metasurfaces and good conformance with theoretical predictions.

Keywords

• All-dielectric
• anisotropic
• coding metasurface
• electromagnetic wave manipulation