Electromagnetically induced transparency based on a carbon nanotube film terahertz metasurface

Abstract

In this work, we present a study of bright-bright mode electromagnetically induced transparency based on carbon nanotube films terahertz metasurface consisting of an array of two asymmetric split rings. Under the excitation of terahertz wave, the electromagnetically induced transparency window can be obviously observed. The simulation results agree with the theoretical results. The formation mechanism of the transparent window in bright-bright mode electromagnetically induced transparency is further analyzed. Moreover, the sensing performance of the proposed terahertz metasurface is investigated and the sensitivity can reach to 320 GHz/RIU. To verify the slow light characteristics of the device, the group delay of the terahertz metasurface is calculated and the value is 2.12 ps. The proposed metasurface device and the design strategies provide opportunities for electromagnetically induced transparency applications, such as sensors, optical memories, and flexible terahertz functional devices.

High-transmission and large group delay terahertz triple-band electromagnetically induced transparency in a metal-perovskite hybrid metasurface

“…[11][12][13] EIT effect based on metasurface is created by bright-dark coupling mode and bright-bright coupling mode. 14,15 The bright-dark coupling mode consists of a bright mode and a dark mode, and the bright-bright coupling mode is composed of two different bright modes. The bright mode can be directly excited by the incident electromagnetic wave, but the dark mode cannot be excited by the incident electromagnetic wave.…”

Dynamically Tunable Electric Split-Ring Resonators Based on 300 nm Gold Films on Silica for Reconfigurable Slow-Light Application

“…Electromagnetic-induced transparency (EIT) is a quantum mechanical effect observed in the atomic three-energy level system due to the quantum destructive interference between two different excitation pathways, giving rise to a narrow transparency window within a broad transmission dip. − This concept was then extended to plasmonic metamaterial systems. − The generation of an EIT analogue in metamaterial is realized by bright-dark mode coupling and bright–bright mode coupling. − The first approach requires a bright mode resonator with a low quality ( Q ) factor and a dark mode resonator with a high Q -factor. The bright mode can be directly excited by incident light, while the dark mode is activated through near-field coupling to the bright mode indirectly.…”

“…The second approach demands that both resonators are able to interact strongly with the incident wave and usually have a large Q -factor contrast and small wavelength detuning . Nonetheless, two bright modes with comparable bandwidth and detuning frequency can also generate an EIT-like response. , The frequency and spectra shape of the EIT peak can be modulated purposefully by tuning the resonant frequency of the bright or dark mode and the coupling distance between them. − With the strong dispersion characteristic and consequent slow-light property, it means that the group velocity of the incident light is reduced within the transparency window. Such an EIT characteristic has shown enormous potential in sensors, switches, filters, slow-light devices, optical data storage, and nonlinear process enhancement.…”

Inversely-designed terahertz metadevice with ultrafast modulation of double electromagnetically induced transparency windows

“…As of late, the metasurface-based electromagnetically induced transparency (EIT) analog has drawn in impressive consideration, attributed to an assortment of promising applications in the field of quantum information storage [1][2][3] , novel optical communication [4,5] , slow-light devices [6][7][8] , and sensing [9][10][11] . Usually, in metasurfaces, the EIT effect has been obtained via the near-field coupling between bright and dark modes or superradiant and sub-radiant modes [12][13][14][15][16][17] . The common method of generating and regulating the EIT effect in metasurfaces is to utilize split-ring resonators (SRRs) by adjusting the position and distance between resonators in a unit cell [8,13,[18][19][20] .…”