CN113161760B - An all-dielectric multiband terahertz metamaterial absorber with randomly distributed cells - Google Patents

Abstract

The invention discloses an all-dielectric multi-band terahertz metamaterial absorber with randomly distributed units, which comprises a substrate layer and a structural layer, wherein the substrate layer and the structural layer are made of integrated highly-doped silicon materials, a plurality of grids are uniformly divided on the structural layer, and a plurality of etching units are arranged in the grids. The absorption spectrum has the characteristics of being capable of keeping stable absorption spectrum characteristics under different unit arrangements, high in absorption rate, multiple in absorption frequency points and high in quality factor.

Description

An all-dielectric multiband terahertz metamaterial absorber with randomly distributed cells

technical field

The invention belongs to the technical field of metamaterial absorbers, and relates to an all-dielectric multi-band terahertz metamaterial absorber with randomly distributed units.

Background technique

Terahertz metamaterials are artificial materials that work at terahertz frequencies and have extraordinary electromagnetic properties. According to the classification of material properties, they can generally be divided into metal metamaterials, all-dielectric metamaterials, and carbon-based metamaterials. Resonance occurs under the incidence of terahertz waves in the frequency or frequency range, which has broad application prospects and application value in sensing, detection, imaging, communication and other application fields, attracting a lot of attention and triggering a research upsurge.

In the current state of the art, metamaterial absorbers are usually designed to have a periodic structure, and the overall structure of the absorber device is continuously formed from the absorption unit structure to the surrounding area. The size of the absorption unit structure is much smaller than the incident wavelength. Therefore, After the incident wave touches the metamaterial, it will cause resonance of the unit structure, and a resonance peak or resonance valley will appear in the transmission or reflection spectrum or absorption spectrum.

However, strict periodicity increases the difficulty of product manufacturing, and also limits the generation of surface plasmon modes of different orders, and the coupling of modes can improve the quality factor of resonance under certain conditions, which is useful for sensing, detection, etc. The field of application is crucial.

Therefore, how to realize a unit structure that does not require periodic arrangement, and has more abundant and diverse absorption modes, can maintain stable absorption spectral characteristics under different unit arrangements, and has the characteristics of high absorption rate, many absorption frequency points, and high quality factor. of metamaterial absorbers.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide an all-dielectric multi-band terahertz metamaterial absorber with random distribution of cells, which has absorption spectrum characteristics that can maintain stable under different cell arrangements, and has high absorption rate, many absorption frequency points, and high quality factor. specialty.

The technical scheme adopted in the present invention is that an all-dielectric multi-band terahertz metamaterial absorber with randomly distributed units includes a substrate layer and a structural layer, a highly doped silicon material in which the substrate layer and the structural layer are integrated, and the structural layer is a high-doped silicon material. A number of grids are evenly divided, and a number of etching units are arranged in the grids.

The feature of the present invention also lies in:

The etching unit is one or more of square etching holes, rectangular etching holes, circular etching holes, equilateral triangle etching holes, irregular triangle etching holes, and elliptical etching holes. A number of etching units are arranged without overlapping or closely contacting.

At least a part of the etching pattern of the etching unit in any grid is divided into adjacent grids.

The thickness of the substrate layer is greater than 110 μm, and the thickness of the substrate layer is less than 300 μm.

The ratio of the thickness of the structural layer to the thickness of the substrate layer is greater than 1/6 and less than 1/2.

The ratio of the etching area of the etching unit to the grid area is greater than 1/20, and the ratio of the etching area of the etching unit to the grid area is less than 1/2.

The etched units are randomly distributed in the grid, and the etched units do not have periodicity in the grid.

There are no less than 10 grids.

The etched cells within the grid are all the same.

The geometrical characteristics of the etched cells within any grid are the same.

The beneficial effects of the present invention are as follows: an all-dielectric multi-band terahertz metamaterial absorber with randomly distributed units of the present invention has absorption spectrum characteristics that can keep stable under different unit arrangements, and has high absorptivity and many absorption frequency points. Features of high quality factor. The absorption modes are more abundant and diverse, and can maintain stable absorption spectral characteristics under different random conditions.

Description of drawings

1 is a schematic structural diagram of an all-dielectric multi-band terahertz metamaterial absorber with randomly distributed units of the present invention;

2 is a schematic diagram of grid division of an all-dielectric multi-band terahertz metamaterial absorber with randomly distributed units of the present invention;

3 is a schematic diagram of an etching structure in a grid of an all-dielectric multi-band terahertz metamaterial absorber with randomly distributed cells according to the present invention;

4 is a schematic diagram of the structure of an all-dielectric multi-band terahertz metamaterial absorber etching unit with randomly distributed units of the present invention;

FIG. 5 is the absorption spectrum of an all-dielectric multi-band terahertz metamaterial absorber with random distribution of cells in different random situations.

In the figure, 1. Structural layer, 2. Substrate layer, 3. Grid, 4. Etching unit, 5. Square etching hole, 6. Rectangular etching hole, 7. Circular etching hole, 8. Regular triangle Etching hole, 9. Irregular triangular etching hole, 10. Oval etching hole.

Detailed ways

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

An all-dielectric multi-band terahertz metamaterial absorber with randomly distributed units of the present invention includes a substrate layer 2 and a structural layer 1. As shown in FIG. 1, the substrate layer 2 and the structural layer 1 are a highly doped silicon material, A plurality of grids 3 are evenly divided on the structural layer 1 , and a plurality of etching units 4 are arranged in the grids 3 . The etching unit 4 is one or more of a square etching hole 5, a rectangular etching hole 6, a circular etching hole 7, a regular triangular etching hole 8, an irregular triangular etching hole 9, and an elliptical etching hole 10. In any of the grids 3, a number of etching units 4 are arranged without overlapping and not closely contacting. At least a part of the etching pattern of the etching unit 4 in any grid 3 is divided into adjacent grids 3 . The thickness of the substrate layer 2 is greater than 110 μm, and the thickness of the substrate layer 2 is less than 300 μm. The ratio of the thickness of the structural layer 1 to the thickness of the substrate layer 2 is greater than 1/6 and less than 1/2. The ratio of the etching area of the etching unit 4 to the area of the grid 3 is greater than 1/20, and the ratio of the etching area of the etching unit 4 to the area of the grid 3 is less than 1/2. The etching units 4 are randomly distributed in the grid 3 , and the etching units 4 have no periodicity in the grid 3 . Grid 3 is not less than 10. The etching units 4 in the grid 3 are all the same. The geometric features of the etching units 4 in any grid 3 are the same.

As shown in FIG. 2 , the present invention provides an all-dielectric multi-band terahertz metamaterial absorber with randomly distributed cells, wherein the structural layer 1 has a uniformly divided grid 3 distribution, that is, the etched structures in different grid distributions are composed The structure layer 1 is not etched, and the grid only defines the range of the etched structure. In the divided grid distribution, each grid has the same size, and the ratio of the length in the x-direction to the length in the y-direction is greater than 1/2 and less than 2, and the ratio of the length in the y-direction to the length in the x-direction is greater than 1/2 and less than 2.

As shown in FIG. 3 , the present invention provides an all-dielectric multi-band terahertz metamaterial absorber with randomly distributed units. The etched unit structure is randomly distributed in each grid of the structural layer, and the random units in the grid use the same The geometrical dimensions and geometrical features of the etched unit structures do not overlap and adhere to each other, and at least a part of the etched pattern of the etched unit structure is divided into grids.

As shown in FIG. 4 , the present invention provides an all-dielectric multi-band terahertz metamaterial absorber with randomly distributed cells. The area of the etched unit structure is less than 1/20 of the grid area, and the etched unit structure includes a circular Etching holes 7, square etching holes 5, regular triangular etching holes 8, and other derived rectangular etching holes 6, elliptical etching holes 10, irregular triangular etching holes 9, etc., as well as other uniform patterns.

As shown in FIG. 5 , an all-dielectric multi-band terahertz metamaterial absorber with randomly distributed units of the present invention adopts five different random unit distributions, and the absorption spectrum in the terahertz frequency band is 0.8THz, 1.5THz, The absorption peaks near 2.2THz have the characteristics of high absorption rate and high quality factor, and the corresponding spectra of different random modes are similar, which ensures the stability of the absorption characteristics and also increases the richness of the resonance modes.

The invention is an all-dielectric multi-band terahertz metamaterial absorber with random distribution of cells, which can maintain stable absorption spectrum characteristics under different cell arrangements, and has the characteristics of high absorption rate, many absorption frequency points and high quality factor. The absorption modes are more abundant and diverse, and can maintain stable absorption spectral characteristics under different random conditions.

Claims (2)

1. An all-dielectric multi-band terahertz metamaterial absorber with randomly distributed units comprises a substrate layer (2) and a structural layer (1), and is characterized in that the substrate layer (2) and the structural layer (1) are made of a highly doped silicon material, a plurality of grids (3) are uniformly divided on the structural layer (1), a plurality of etching units (4) are arranged in the grids (3), the thickness of the substrate layer (2) is larger than 110 micrometers, the thickness of the substrate layer (2) is smaller than 300 micrometers, the ratio of the thickness of the structural layer (1) to the thickness of the substrate layer (2) is larger than 1/6 and smaller than 1/2, the ratio of the etching area of each etching unit (4) to the area of the grid (3) is larger than 1/20, the ratio of the etching area of each etching unit (4) to the area of the grid (3) is smaller than 1/2, and the etching units (4) are randomly distributed in the grid (3), the etching units (4) do not have periodicity in the grids (3), the number of the grids (3) is not less than 10, the etching units (4) in the grids (3) are all the same, the geometric characteristics of the etching units (4) in any grid (3) are all the same, at least one part of etching patterns of the etching units (4) in any grid (3) are divided into adjacent grids (3), and a plurality of etching units (4) are arranged in any grid (3) in a non-overlapping and non-tight mode.

2. The all-dielectric multi-band terahertz metamaterial absorber with randomly distributed units as claimed in claim 1, wherein the etching units (4) are one or more of square etching holes (5), rectangular etching holes (6), circular etching holes (7), regular triangle etching holes (8), irregular triangle etching holes (9) and oval etching holes (10).

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