Dynamically Tunable Resonant Strength in Electromagnetically Induced Transparency (EIT) Analogue by Hybrid Metal-Graphene Metamaterials

Abstract

In this paper, a novel method to realize a dynamically tunable analogue of EIT for the resonance strength rather than the resonance frequency is proposed in the terahertz spectrum. The introduced method is composed of a metal EIT-like structure, in which a distinct EIT phenomenon resulting from the near field coupling between bright and dark mode resonators can be obtained, as well as an integrated monolayer graphene ribbon under the dark mode resonator that can continuously adjust the resonance strength of transparency peak by changing the Fermi level of the graphene. Comparing structures that need to be modulated individually for each unit cell of the metamaterials, the proposed modulation mechanism was convenient for achieving synchronous operations for all unit cells. This work demonstrates a new platform of modulating the EIT analogue and paves the way to design terahertz functional devices which meet the needs of optical networks and terahertz communications.

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

“…Recently, EIT metamaterial has attracted intense research interest due to its easy production, small volume, and extreme scalability because the electromagnetic properties of metamaterial are primarily determined by the configuration of the metamaterial unit cell. − Metamaterial can provide a desirable electromagnetic response by specifically tailoring the configuration of the unit cell in a subwavelength scale or nanoscale feature size. , So far, the EIT effect has been achieved through various designs with combinations of different structures spanning various spectra, such as bar, split-ring resonator (SRR), closed circular/square ring, and other complex asymmetric configurations. − However, most designs have limited applications associated with the passive properties of the metamaterial structures, which means that once the structure is fabricated, the optical characteristics are fixed. Within these two decades, there has been a variety of approaches enabling active control in order to obtain richer functionality and flexibility of metamaterial.…”

A frequency-adjustable electromagnetic induced transparency with terahertz metasurface based on vanadium dioxide

“…One is the bright-dark mode in which the bright mode and the dark mode are coupled 14 , and the other is the bright-bright mode in which the bright mode and the bright mode are coupled 15 . Most of the previously designed typical adjustable EIT metasurfaces mainly modulate the transparency of the transparent window [16][17][18] .…”

Broadband Filter and Adjustable Extinction Ratio Modulator Based on Metal-Graphene Hybrid Metamaterials

“…In past decade, graphene with unique properties, particularly the conductivity of graphene, can be easily regulated by changing the Fermi level [ 22 , 23 ], and has attracted considerable attention to the active control of the EIT-like response. Our group proposed an active modulation of the amplitude of the EIT-like transmission window in terahertz-band metamaterials by changing the Fermi level of graphene [ 24 ]. A lot of similar work [ 25 , 26 , 27 ] has been done on the amplitude modulation of the transmission window.…”