Ultra-broadband terahertz absorber based on a multilayer graphene metamaterial

Abstract

An ultra-broadband absorber is introduced based on a multilayer graphene structure. Wave absorption of the optimized device is >90% in the bandwidth between 1.12 THz and 3.78 THz. Electric field distributions are studied to analyze the working mechanism. Because of the symmetrical structure, the designed absorber is not sensitive to the polarization state of the incident wave under small angles. The absorber has a reasonable tolerance for incident angles. The working intensity and bandwidth of the absorber are modulated with a wide range of tunability by different Fermi energy levels of graphene. This kind of ultra-broadband terahertz absorbers could have potential applications in a variety of areas, such as terahertz imaging, anti-radar stealth, and electrically adjustable modulation.