Ultra wideband tunable terahertz metamaterial absorber based on single-layer graphene strip

Abstract

In this paper, a terahertz absorber based on monolayer graphene is proposed. Compared with other absorber structures, the structure is very simple, which is conducive to the realization of the actual processing technology; in addition, the pattern of the absorber presents a certain combination of regularity, and certain research has been carried out, which provides a certain reference for the subsequent research related work. In particular, the pattern creatively proposes a structure based on the combination of patterns, which has a certain regularity and is more valuable for research than other absorbers. The absorber is capable of three-peak broadband absorption in the terahertz band and high absorption (absorption >0.9) over 3.39 THz in the frequency range of 1.53–4.92 THz. The feasibility of the combined modes is verified by structural delineation, and it is shown that the graphene-based designed and prepared absorber has good performance. In addition, the absorption mechanism of the absorber is illustrated by analysing individual modes and combinations. Furthermore, by tuning the Fermi energy level, the absorber exhibits absorption specificity, with the best absorption effect when = 0.7 eV. This finding suggests that the absorber may have better applications in the detection field. In addition, experimentally, we found that the absorber can maintain the stability of its absorption efficiency when the incidence angle of the electromagnetic wave changes slightly. By varying the physical parameters of the absorber, it is found that the absorber has excellent tolerance. The absorption performance remains stable when the physical parameters of the absorber are changed slightly. Finally, we investigated the effect of the physical parameters of the dielectric layer on the absorber and obtained the best overall performance at H = 18 um. Overall, the absorber shows good absorption, stability, and tolerance in the terahertz band, and this broadband absorber should have wide applications in terahertz absorption as well as in novel optical devices. Due to the good performance of this absorber, it has potential applications in smart switches, stealth fighters, etc., in addition to applications in the field of energy absorption and new optical devices.