Resonance modes in stereometamaterial of square split ring resonators connected by sharing the gap

TL;DR

This paper introduces a 3D stereometamaterial composed of connected square split ring resonators sharing gaps, revealing three distinct resonance modes with potential for multiband filtering in the near-infrared range.

Contribution

It proposes and numerically analyzes a novel connected SRR stereometamaterial structure exhibiting multiple resonance modes with unique electromagnetic properties.

Findings

Identified three resonance modes: magnetic toroidal dipole, magnetic dipole, and mixed electric-magnetic modes.

The modes are derived from different order modes of individual SRRs.

All modes are excitable in an array, enabling multiband filtering.

Abstract

Stereometamaerials can fully utilize the 3D degrees of freedom to exploit the coupling and hybridization between multiple split ring resonators (SRRs), enabling more extraordinary resonances and properties over their planar counterparts. Here we propose and numerically study a kind of structure based on connected SRRs sharing their gap in a rotational fashion. It is shown that there are three typical resonance modes in such cage-like SRR (C-SRR) stereometamaterial in the communication and near infrared range. In the order of increasing energy, these modes can be essentially ascribed to magnetic torodial dipole, magnetic dipole, and a mixture of electric-dipole and magnetic toroidal dipole. We show that the latter two are derived from the second-order mode in the corresponding individual SRR, while the first one from the fundamental one. The highest energy mode remains relatively "dark" in an individual C-SRR due to the high-order feature and the rotational symmetry. However, they are all easily excitable in a C-SRR array, offering multiband filtering functionality.