Open AccessTerahertz dual-band metamaterial absorber based on graphene/MgF_2 multilayer structures
Author(s) -
Zhaoxian Su,
Jianbo Yin,
Xiaopeng Zhao
Publication year - 2015
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.23.001679
Subject(s) - materials science , terahertz radiation , metamaterial absorber , optics , metamaterial , absorption (acoustics) , optoelectronics , permittivity , electromagnetic radiation , graphene , dielectric , physics , nanotechnology , tunable metamaterials , composite material
We design an ultra-thin terahertz metamaterial absorber based on graphene/MgF(2) multilayer stacking unit cells arrayed on an Au film plane and theoretically demonstrate a dual-band total absorption effect. Due to strong anisotropic permittivity, the graphene/MgF(2) multilayer unit cells possess a hyperbolic dispersion. The strong electric and magnetic dipole resonances between unit cells make the impedance of the absorber match to that of the free space, which induces two total absorption peaks in terahertz range. These absorption peaks are insensitive to the polarization and nearly omnidirectional for the incident angle. But the absorption intensity and frequency depend on material and geometric parameters of the multilayer structure. The absorbed electromagnetic waves are finally converted into heat and, as a result, the absorber shows a good nanosecond photothermal effect.