Broadband terahertz metamaterial absorber based on L-shaped structures

Abstract

The invention discloses a broadband terahertz metamaterial absorber based on L-shaped structures and belongs to the technical field of metamaterials and electromagnetic function materials. The broadband terahertz metamaterial absorber comprises a metal reflection layer, a dielectric layer and a metal pattern layer, the metal reflection layer is a continuous metal thin film, thickness of the metal reflection layer is larger than skin depth of working terahertz wave, the dielectric layer is positioned between the metal reflection layer and the metal pattern layer and is a silicon dioxide thin film, the metal pattern layer is formed by periodically arranging the L-shaped unit metamaterial structures, and each L-shaped unit metamaterial structure is formed by connecting a horizontal arm and a vertical arm which are perpendicular to each other. By reasonably designing geometric size and lattice period of the L-shaped structures and thickness of the dielectric layer in the middle, the characteristic that electromagnetic waves vertically coming to the surface of a metamaterial are absorbed completely can be realized. The broadband terahertz metamaterial absorber is simple in graph pattern and needless of stacking of multiple layers of materials, has characteristics of wide frequency band and high absorptivity and can be used for an electromagnetic wave collecting and detecting device.

Description

technical field [0001] The invention belongs to the technical field of metamaterials and electromagnetic functional materials, and relates to a terahertz absorber, in particular to a broadband terahertz metamaterial absorber based on an L-shaped structure. Background technique [0002] Terahertz waves generally refer to electromagnetic waves with frequencies in the range of 0.1 THz to 10 THz (wavelengths in the range of 3 mm to 30 μm). From the perspective of frequency, this band is located between millimeter waves and infrared rays, and belongs to the far-infrared band; from the perspective of energy, it is between electrons and photons. For a long time, due to the lack of effective terahertz source and detection technology, people have little understanding of this wave, so that the phenomenon of "terahertz blank" has been formed. Terahertz technology is a very important cross-frontier field, which provides a very attractive opportunity for technological innovation, nation...

AI Technical Summary

Problems solved by technology

The first method, due to the limited number of resonant unit structures that can be tiled in the plane, limits the broadening of the absorption bandwidth

In the second method, due to the need for multiple alignments during the processing process, the process is complex and the number of stacked layers is limited, which also limits the bandwidth of the absorber.

Images