Ultra-Broadband Electromagnetically Induced Transparency in Metamaterial Based on Conductive Coupling

Tiantian Zheng,Zhongyin Xiao,Mingming Chen,Xiaoyu Wang,Xiang Miao

doi:10.1007/s11468-021-01561-z

Abstract

This paper proposes a structure composed of a horizontal metal strip resonator (SR) and four C-shaped ring resonators (CRR) to obtain a broadband electromagnetic induction transparency (EIT)–like effect. The SR and CRRs are divided into bright mode and dark mode according to whether they can be directly excited by the incident electromagnetic wave. The three-level $$\Lambda$$ -type system and electric field are used to explain the mechanism of the EIT-like effect. Meanwhile, by decreasing the distance between the SR and CRRs, a transparency window with a relative bandwidth of 91.93% and a width of 1.4 THz is observed. It is found that when the bright and dark modes are directly contacted, the EIT window increases rapidly through conductive coupling, which can be explained by the surface current. Our work provides a new method for a wide band EIT-like effect, which has a certain value in the fields of slow light, filters, and non-linear optics.

Highlights

EIT is a phenomenon of quantum interference in a three-level system, which can weaken the absorption at the resonance frequency, resulting in a sharp transparency window[1]
Our work provides a new method for wide band EIT-like effect, which has certain value in the field of slow light, filter and non-linear optics
The response of C-shape ring resonators (CRRs) to incident electromagnetic wave is almost a straight line, which is not excited by incident electromagnetic waves and works as dark mode[14]

Summary

Introduction

EIT is a phenomenon of quantum interference in a three-level system, which can weaken the absorption at the resonance frequency, resulting in a sharp transparency window[1]. The SR and CRRs are classified into bright mode and dark mode depending on whether they can be directly excited by the incident electromagnetic wave. It is found that when the bright and dark mode are directly contacted, the EIT window increases rapidly via conductive coupling, which can be explained by the surface current.

Results

Conclusion