title: Intensity-modulating graphene metamaterial for multiband terahertz absorption.
abstract: In this paper, we design a tunable strength multiband absorber consisting of a graphene metamaterial structure and a thick dielectric interlayer deposited on a metal ground plane. We investigate the tunable conductivity properties of the graphene metamaterial and demonstrate multiband absorbers with three absorption bands using a polyimide interlayer in the 0-2.25 THz range by numerical simulation. The results show that the mix absorptivity reached 99.8% at 1.99 THz, and the absorptive strength can be tuned with the modulation depth up to 84.2%. We present a theoretical interpretation based on a standing wave field, which shows that the field energy is localized inside the thicker spacer and then dissipated, effectively trapping the light in the metamaterial absorbers with negligible near-field interactions. The standing wave field theory developed here explains all the features of the multiband metamaterial absorbers and provides a profound understanding of the underlying physics.
authors.forename: Run-Mei
authors.initials: RM
authors.lastname: Gao
authors.forename: Zong-Cheng
authors.initials: ZC
authors.lastname: Xu
authors.forename: Chun-Feng
authors.initials: CF
authors.lastname: Ding
authors.forename: Jian-Quan
authors.initials: JQ
authors.lastname: Yao