Analog electromagnetically induced transparency for circularly polarized wave using three-dimensional chiral metamaterials.

Hai Lin,Song Han,Yangjie Liu,Helin Yang,Dong Yang

doi:10.1364/oe.24.030068

Abstract

In this paper, we theoretically and experimentally demonstrate a three-dimensional metamaterial that can motivate electromagnetic induced transparency (EIT) by using circular polarized wave as stimulations. The unit cell consists of a pair of metallic strips printed on both sides of the printed circuit board (PCB), where a conductive cylinder junction is used to connect the metal strips by drilling a hole inside the substrate. When a right circularly polarized wave is incident, destructive interference is excited between meta-atoms of the 3D structure, the transmission spectrum demonstrates a sharp transparency window. A coupled oscillator model and an electrical equivalent circuit model are applied to quantitatively and qualitatively analyze the coupling mechanism in the EIT-like metamaterial. Analysis in detail shows the EIT window's amplitude and frequency are modulated by changing the degree of symmetry breaking. The proposed metamaterial may achieve potential applications in developing chiral slow light devices.

Highlights

Metamaterials are artificial materials that have fascinating properties [1]
Electromagnetic induced transparency (EIT) has been considered as a possible means to realize slow light for future sensing and communication devices [14]
On the other hand, when 11.7GHz LCP wave incidents, the loop currents runs parallel to each other, their strength are comparable as shown in Fig.3(c), which means both twisted asymmetry U-shape resonator works at quasi-bright mode, typical EIT response vanished in this case

Summary

Introduction

Metamaterials are artificial materials that have fascinating properties [1]. Through carefully designing the structures and geometries of subwavelength unit cells, metamaterials have the ability to manipulate the propagation behavior of EM waves, including its amplitude, phase [2, 3], polarization [4, 5] and linear/angular momentum [6]. "Asymmetric electromagnetic wave transmission of linear polarization via polarization conversion through chiral metamaterial structures," PHYS REV B 85, 195131 (2012). "Tunable electromagnetically induced transparency in coupled three-dimensional split-ring-resonator metamaterials," SCI REP-UK 6, 20801 (2016).

Results

Conclusion