Glide-Symmetric All-Metal Holey Metasurfaces for Low-Dispersive Artificial Materials: Modeling and Properties

Abstract

We study the wave propagation between two glidesymmetric metallic plates drilled with periodic rectangular holes. A mode-matching method is proposed in order to derive efficiently the dispersive properties of these periodic structures. The method takes advantage of the higher symmetry of the structure reducing the computational cost by enforcing boundary conditions on the field on only one of the two surfaces. Physical insight on specific symmetry properties of Floquet harmonics in glide-symmetric structures is also gained. The code is validated with commercial software assessing its accuracy when varying the most influential/critical parameters. We confirm the potential of glide-symmetric structures to tune the effective refractive index. Specifically, we demonstrate that glide-symmetric structures with rectangular shapes can be employed to synthesize anisotropic refractive indexes with a large band of operation, which makes such metasurface structures applicable for realization of UWB planar lenses.

Modeling of Glide-Symmetric Dielectric Structures

“…The analysis of guiding dielectric structures having higher symmetries is based on Floquet mode decomposition and MM approach [26][27][28][29]. The electric and magnetic fields in each section of the structure are represented as a sum of suitable modes with unknown complex amplitude, i.e., we used the preknowledge about the electromagnetic (EM) field configuration and symmetry properties to reduce the number of unknowns, to precisely describe the EM field present in the structure, and to give a physical insight about the presence of higher symmetry properties.…”

“…This expression should have the double sign ± in front of the exponential term. However, the double sign ± does not define two different sets of modes or introduce any ambiguity because the solutions of the two problems actually coincide: the Floquet harmonic 0 becomes the harmonic −1 when switching the sign from plus to minus (see Reference [28] for details).…”

One-Plane Glide-Symmetric Holey Structures for Stop-Band and Refraction Index Reconfiguration

“…Periodic glide-symmetric structures are obtained by translating and mirroring a unit cell with respect to the glide plane [11]. The theoretical analysis of some of these structures with glide symmetry was carried out using the Floquet theorem [12][13][14], which provides an effective tool for the analysis of periodic structures. Glide symmetries were successfully used to reduce the dispersion of periodic structures [15][16][17][18], to increase the equivalent refractive index [19][20][21][22], or to increase the band and attenuation of electromagnetic bandgaps [10,[23][24][25].…”

Independent Control of Copolarized Amplitude and Phase Responses via Anisotropic Metasurfaces

“…[ 12,13 ] Besides these common metallic structures with dielectric substrates, also worth of mention are all‐dielectric [ 14,15 ] and all‐metallic alternatives. [ 16,17 ] The availability of broad libraries of meta‐atom responses, together with the generalized Snell's laws, provides an effective design tool to manipulate EM wavefronts in a powerful and versatile fashion by only considering the scattering responses and desired amplitude or phase distributions on the metasurface equivalent aperture. The reader can refer to refs.…”