Graphene-based terahertz broadband tunable absorber

Abstract

The invention discloses a graphene based terahertz broadband adjustable wave absorption device, and relates to a wave absorption device. The graphene based terahertz broadband adjustable wave absorption device is of a three-layer structure which comprises a periodic mesh-shaped graphene layer, a dielectric layer and a metal layer from top to bottom, and is characterized in that the horizontal period of a unit structure of the periodic mesh-shaped graphene layer is Px, the longitudinal period of the unit structure is Py, the graphene width has a characteristic of continuous gradual change modulation, the edge of the periodic mesh-shaped graphene layer has a sine curve, a cosine curve, a parabolic curve, an elliptic curve or other curves capable of realizing graphene width gradual change modulation, the maximum width Wmax is consistent with the horizontal period Px, and the minimum width Wmin ranges between 0 and the horizontal period Px; the dielectric layer is made of an insulator such as silicon dioxide, and the thickness td of the dielectric layer is associated with the wave absorption frequency band; and the metal layer is made of a good conductor such as gold or silver, and the thickness tm of the metal layer is greater than the skin depth of incident waves. The graphene based terahertz broadband adjustable wave absorption device can realize broadband strong absorption for terahertz waves, the absorption rate of incident broadband terahertz waves is adjusted on a large scale, and the structure is simple.

Description

technical field [0001] The invention relates to a wave absorber, in particular to a graphene-based terahertz broadband adjustable wave absorber. Background technique [0002] Terahertz waves (Terahertz waves) generally refer to electromagnetic waves with frequencies ranging from 0.1THz to 10THz and wavelengths ranging from 3 to 0.03mm. It has important application prospects and is one of the hotspots in the field of terahertz technology research. Graphene is a honeycomb two-dimensional material composed of a single layer of hexagonal original cell carbon atoms. It has a unique two-dimensional structure and zero-gap electronic energy band, excellent mechanical, electrical, optical properties and good electrical conductivity. Tunable characteristics, capable of supporting surface plasmon resonance in the terahertz to mid-infrared band, is a new material for terahertz surface plasmon absorbers with adjustable performance and great potential. Generally, a surface plasmon absor...

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Problems solved by technology

However, at present, most graphene-based wave absorbers use periodic independent strips, disks, squares, cross-shaped or other shapes of graphene arrays, and their structural scales are relatively single, resulting in a narrow bandwidth for perfect absorption of incident electromagnetic waves. And their periodic structural units are independent of each other, requiring a relatively complex static bias voltage structure to adjust the wave-absorbing characteristics, which greatly limits their practical application in the terahertz field. The new terahertz wave broadband absorber has received extensive attention

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