Tunable multiband directional electromagnetic scattering from spoof Mie resonant structure

TL;DR

This paper presents a design for a spoof Mie resonant structure that achieves tunable multiband directional electromagnetic scattering by supporting multiple dipole modes, with potential applications across microwave to terahertz frequencies.

Contribution

The study introduces a quasiperiodic spoof Mie resonant structure enabling multi-band directional scattering through multiple electric and magnetic dipole excitations, a novel approach in the field.

Findings

Directional scattering controlled by wavelength and geometry.

Multi-band scattering achieved with quasiperiodic structure.

Enhanced directionality due to electric quadrupole contribution.

Abstract

We demonstrate that directional electromagnetic scattering can be realized from a artificial Mie resonant strcuture which supports electric and magnetic dipole modes simultaneously. The directivity of the far-field radiation pattern can be switched by changing the incident light wavelength as well as tailoring the geometric parameters of the structure. Particularly, the electric quadrupole at higher frequency contribute significantly to the scattered fields, leading to enhancement of the directionality. In addition, we further design a quasiperiodic spoof Mie resonant structure by alternately inserting two materials into the slits. The results show that multi-band directional light scattering are realized by exciting multiple electric and magnetic dipole modes with different frequencies in the quasiperiodic structure. The presented design concept is general from microwave to terahertz region and can be applied for various advanced optical devices, such as antenna, metamaterial and metsurface.