Open AccessDesign of a polarization-insensitive and broadband terahertz absorber using metamaterials
Author(s) -
Taobo Zou,
Fangrong Hu,
Jing Xiao,
Longhui Zhang,
Fang Liu,
Tao Chen,
Junhao Niu,
Xiang Xiong
Publication year - 2014
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.63.178103
Subject(s) - metamaterial absorber , terahertz radiation , materials science , metamaterial , full width at half maximum , optics , polarization (electrochemistry) , electric field , absorption (acoustics) , electromagnetic radiation , optoelectronics , dipole , physics , chemistry , tunable metamaterials , quantum mechanics
A polarization-insensitive and broadband terahertz (THz) absorber based on metamaterial (MM) is presented. The absorber consists of two layers of metal and a single layer of medium. Each periodic cell of the upper metallic layer consists of five different sizes of metal patches which form a square array of 55. In the array, the size of each metal patch is different from that of its adjacent one, and each size of the metal patch generates a single resonance absorption peak. The broadband absorption is actually produced by the overlapping of five adjacent resonance absorption peaks. By studying the distribution of the surface current and the z-component of electric field, it is easy to know that the energy of the incident THz wave is absorbed by two factors: one is the electric dipole oscillation caused by the electric field in the y direction, and the other is the magnetic polariton caused by the magnetic field in the z direction. And the ohmic loss of metal layers plays a major role on the absorption of the absorber. Simulation results show that the bandwidth achieves 1.2 THz for the absorption beyond 80%, and the maximum absorption is up to 98.7%. It's full width at half maximum (FWHM) is 1.6 THz, and the thickness of the broadband absorber is only about one twentieth of the center wavelength. In addition, the absorber is insensitive to the polarization and has a wide-angle feature, and the potential applications of the absorber are electromagnetic stealth, THz thermal radiation detectors, and THz communication.