Open AccessBroadband wave absorption in single-layered and nonstructured graphene based on far-field interaction effect
Author(s) -
Fei Gao,
Zhihong Zhu,
Wei Xu,
Jianfa Zhang,
Chucai Guo,
Ken Liu,
Xiaodong Yuan,
Shiqiao Qin
Publication year - 2017
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.25.009579
Subject(s) - graphene , terahertz radiation , materials science , optics , dielectric , absorption (acoustics) , optoelectronics , broadband , plasmon , surface plasmon polariton , near and far field , resonance (particle physics) , surface plasmon , physics , nanotechnology , atomic physics
We present a wave absorption design consisting of periodical arrays of dielectric bricks on the dielectric substrate, which is coated with single-layered and nonstructured graphene, supported by a thick piece of metal. The design is demonstrated to broadband near-perfect absorption with 0.82 terahertz (THz) bandwidth of over 90% absorption and with central frequency of 1.68 THz. The broadband absorption mechanism originates from two contributions. Firstly, the periodical arrays of dielectric bricks on the nonstructured graphene can provide both a set of graphene plasmon resonances with large relative frequency interval and relative radiation rate γ/ω in the THz range. Secondly, the linewidth of each resonance can be broadened by the far-field interaction between neighboring resonators to overlap and spread over a wide frequency region in the THz range. The design in this paper is simple, and consequently facilitates the fabrication and promotes the application of broadband graphene absorbers.