Open AccessIndependently tunable multi-band and ultra-wide-band absorbers based on multilayer metal-graphene metamaterials
Author(s) -
Yan Liu,
Renbin Zhong,
Jiebiao Huang,
Yilin Lv,
Han Chen,
Shenggang Liu
Publication year - 2019
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.27.007393
Subject(s) - materials science , graphene , metamaterial , optoelectronics , terahertz radiation , absorption (acoustics) , metamaterial absorber , optics , electronic band structure , cloaking , stacking , strips , nanotechnology , tunable metamaterials , physics , nuclear magnetic resonance , quantum mechanics , composite material
Dynamically and independently tunable absorbers based on multilayer metal-graphene metamaterials are proposed to achieve multi-band and ultra-wide-band absorbing properties at mid-infrared frequencies. Dual-band, triple-band and even more bands absorption can be arbitrarily customized by etching the appropriate number of tandem gold strips in each meta-molecule, as well as stacking multiple metal-graphene layers. Through tuning the Fermi energy level of the graphene in each metal-graphene layer separately, the multiple absorption resonances can be dynamically and independently adjusted. With side-by-side arrangement of the gold strips in each supercell, the proposed structure is rendered to be a promising candidate for ultra-wide-band absorber. The extreme bandwidth exceeding 80% absorption up to 7.5THz can be achieved with a dual-layered structure, and the average peak absorption is 88.5% in the wide-band range for lossless insulating interlayer. For a triple-layered structure, the average peak absorption is 84.7% from 27.5 THz to 38.4 THz with a minimum of 60%. The absorption windows can be even further broadened with more metal-graphene layers. All these results will benefit the integrated microstructure research with simple structure and flexible tunability, and the multilayer structure has potential applications in information processing fields such as filtering, sensing, cloaking objects and other multispectral devices.