A Dual-Band Tunable Metamaterial Near-Unity Absorber Composed of Periodic Cross and Disk Graphene Arrays

A three-dimensional dual-band perfect absorber in the THz range (3&#x2013;10&#x00A0;THz) is theoretically investigated. The absorber is composed of periodically placed cross- and disk-shaped graphene arrays on the top of a gold layer separated by a thick SiO<inline-formula><tex-math...

Full description

Saved in:
Bibliographic Details
Main Authors: Jianguo Zhang, Jinping Tian, Lu Li
Format: Article
Language:English
Published: IEEE 2018-01-01
Series:IEEE Photonics Journal
Subjects:
Online Access:https://ieeexplore.ieee.org/document/8315442/
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:A three-dimensional dual-band perfect absorber in the THz range (3&#x2013;10&#x00A0;THz) is theoretically investigated. The absorber is composed of periodically placed cross- and disk-shaped graphene arrays on the top of a gold layer separated by a thick SiO<inline-formula><tex-math notation="LaTeX">$_{2}$</tex-math></inline-formula> dielectric spacer. The simulated results show two absorption peaks with near-unity absorbance (<inline-formula> <tex-math notation="LaTeX">$99.923\%$</tex-math></inline-formula> and <inline-formula><tex-math notation="LaTeX"> $99.601\%$</tex-math></inline-formula>) at wavelengths 43.747&#x00A0;<inline-formula><tex-math notation="LaTeX">$\mu$ </tex-math></inline-formula>m and 69.94&#x00A0;<inline-formula><tex-math notation="LaTeX">$\mu$</tex-math> </inline-formula>m, respectively. Also, the absorber is insensitive to the polarization of the incident light and has a good tolerance to the incident angle whether it is TE or TM waves. Moreover, the peak wavelengths of the absorber can be flexibly modulated by varying the Fermi level <inline-formula><tex-math notation="LaTeX">$\mu _{C}$</tex-math> </inline-formula> of graphene while no need to refabricate the structure. This paper provides a new perspective for the design of graphene-based tunable multiband perfect THz absorbers, but not limited to THz absorbers, and may also be used in other THz graphene-based photonic devices.
ISSN:1943-0655