A Broadband Dipolar Resonance in THz Metamaterials

TL;DR

This paper reports the design, fabrication, and characterization of a THz metamaterial exhibiting a broadband dipolar resonance due to hybridized LC resonances, with potential applications in terahertz devices.

Contribution

It introduces a novel broadband dipolar resonance in THz metamaterials achieved through hybridization of LC resonances, validated by simulations and experiments.

Findings

Broadband dipolar resonance observed at 1.12 THz with 0.47 THz bandwidth

Resonance width depends on the separation between resonators

Experimental extinction ratio of 15 dB in the stopband

Abstract

We demonstrate a THz metamaterial with broadband dipole resonance originating due to the hybridization of LC resonances. The structure optimized by finite element method simulations is fabricated by electron beam lithography and characterized by terahertz time-domain spectroscopy. Numerically, we found that when two LC metamaterial resonators are brought together, an electric dipole resonance arises in addition to the LC resonances. We observed a strong dependence of the width of these resonances on the separation between the resonators. This dependence can be explained based on series and parallel RLC circuit analogies. The broadband dipole resonance appears when both the resonators are fused together. The metamaterial has a stopband with FWHM of 0.47 THz centered at 1.12 THz. The experimentally measured band features are in reasonable agreement with the simulated ones. The experimental power extinction ratio of THz in the stopbands is found to be 15 dB.