Open AccessBroadband terahertz absorber with a flexible, reconfigurable performance based on hybrid-patterned vanadium dioxide metasurfaces
Author(s) -
Jin Huang,
Jie Li,
Yang Yue,
Yating Zhang,
Jianquan Yao
Publication year - 2020
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.394359
Subject(s) - terahertz radiation , materials science , optics , absorptance , optoelectronics , absorption (acoustics) , cloaking , perfect conductor , terahertz gap , impedance matching , attenuation coefficient , polarization (electrochemistry) , amplitude modulation , bandwidth (computing) , electrical impedance , metamaterial , frequency modulation , physics , scattering , telecommunications , far infrared laser , laser , terahertz metamaterials , computer science , chemistry , quantum mechanics , reflectivity
An actively tunable broadband terahertz absorber is numerically demonstrated, which consists of four identical vanadium dioxide (VO 2 ) square loops and a metal ground plane separated by a dielectric spacer. Simulation results show that an excellent absorption bandwidth of 90% terahertz absorptance reaches as wide as 2.45 THz from 1.85 to 4.3 THz under normal incidence. By changing the conductivity of VO 2 , an approximately perfect amplitude modulation is realized with the absorptance dynamically tuned from 4% to 100%. This absorption performance is greatly improved compared with previously reported VO 2 -based absorbers. The physical mechanisms of a single absorption band and the perfect absorption are elucidated by the wave-interference theory and the impedance matching theory, respectively. Field distributions are further discussed to explore the physical origin of this absorber. In addition, it also has the advantages of polarization insensitivity and wide-angle absorption. The proposed absorber may have many promising applications in the terahertz range such as modulator, sensor, cloaking and optic-electro switches.