Open AccessTunable electromagnetically induced transparency based on graphene metamaterials
Author(s) -
Binggang Xiao,
Shengjun Tong,
Alexander Fyffe,
Zhimin Shi
Publication year - 2020
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.382485
Subject(s) - electromagnetically induced transparency , graphene , metamaterial , materials science , refractive index , optoelectronics , terahertz radiation , optics , resonance (particle physics) , fabrication , nanotechnology , physics , medicine , alternative medicine , particle physics , pathology
In this paper we propose a graphene-based metasurface structure that can exhibit tunable electromagnetically-induced-transparency-like (EIT) spectral response at mid-infrared frequencies. The metasurface structure is composed of two subwavelength mono-layer graphene nano-disks coupled with a mono-layer graphene nano-strip. We show that the coupling of the nano-disks' dipole resonance with the quadrupole resonance of the nano-strip can create two split resonances with a transparency window in between at any desired center frequency within a wide frequency range. We show that such an EIT-like response can also be dynamically shifted in frequency by adjusting the Fermi-level of the graphene through external voltage control, which provides convenient post-fabrication tunability. In addition, the performance of such a metastructure for sensing the refractive index of the surrounding medium is analyzed. The simulation results show that its sensitivity can reach 3016.7 nm/(RIU) with a FOM exceeding 12.0. Lastly, we present an analysis of the slow light characteristics of the proposed device, where the group index can reach as large as 200. Our design provides a new miniaturized sensing platform that can facilitate the development of biochemical molecules testing, etc.