Open AccessTerahertz electric field modulated mode coupling in graphene-metal hybrid metamaterials
Author(s) -
Shaoxian Li,
Priyo S. Nugraha,
Xiaoqiang Su,
Xieyu Chen,
Quanlong Yang,
Márta Unferdorben,
Ferenc Kovács,
Sándor KunságiMáté,
Meng Li,
Xueqian Zhang,
Chunmei Ouyang,
Yanfeng Li,
J. A. Fülöp,
Jiaguang Han,
Weili Zhang
Publication year - 2019
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.27.002317
Subject(s) - terahertz radiation , materials science , graphene , metamaterial , electric field , split ring resonator , optoelectronics , coupling (piping) , resonator , optics , modulation (music) , electromagnetic field , physics , nanotechnology , quantum mechanics , acoustics , metallurgy
Taking advantage of the tunable conductivity of graphene under high terahertz (THz) electric field, a graphene-metal hybrid metamaterial consisting of an array of three adjoined orthogonally oriented split-ring resonators (SRRs) is proposed and experimentally demonstrated to show a maximum modulation depth of 23% in transmission when the THz peak field reaches 305 kV/cm. The transmission of the sample is dominated by the antisymmetric and symmetric resonant modes originating from the strong magneto-inductive and conductive coupling among the three SRRs, respectively. Numerical simulations and model calculations based on a coupled oscillator theory were performed to explain the modulation process. It is found that the graphene coating impairs the resonances by increasing the damping of the modes and decreasing the coupling between the SRRs whereas the strong THz field restores the resonances by decreasing the conductivity of graphene.