CN112072323B

CN112072323B - Terahertz switch based on metal and vanadium dioxide

Info

Publication number: CN112072323B
Application number: CN202010913766.4A
Authority: CN
Inventors: 徐弼军; 闫梦瑶; 孙志超; 吴白瑞; 程盼; 吴震东
Original assignee: Zhejiang Lover Health Science and Technology Development Co Ltd
Current assignee: Zhejiang Lover Health Science and Technology Development Co Ltd
Priority date: 2020-09-03
Filing date: 2020-09-03
Publication date: 2023-05-26
Anticipated expiration: 2040-09-03
Also published as: CN112072323A

Abstract

The invention discloses a terahertz switch based on metal and vanadium dioxide, which is characterized in that: comprises a vanadium dioxide layer and a silicon dioxide layer which are sequentially laminated from bottom to top and have square sections; the surface of silica layer is equipped with metal paster layer, metal paster layer including setting up the square ring paster on silica layer surface, be equipped with the cross paster in the silica layer surface area that square ring paster encloses. The terahertz wave absorption or reflection regulation device has excellent absorption or reflection characteristics for terahertz waves, and can regulate and control the absorption or reflection of the terahertz waves.

Description

Terahertz switch based on metal and vanadium dioxide

Technical Field

The invention relates to the technical field of microwave absorbers, in particular to a terahertz switch based on metal and vanadium dioxide.

Background

Terahertz (THz) waves are electromagnetic waves between microwaves and far infrared rays, and are one type of broadband light. In recent years, with the development of ultrafast laser technology, a stable and reliable excitation light source is generated for terahertz pulse, so that people can study terahertz. Terahertz waves have extremely remarkable advantages in the society of high-speed development today, and thus attract extensive research attention. The metamaterial electromagnetic absorber is a component capable of effectively absorbing electromagnetic waves and being utilized in the subsequent process, and the accurate control of the electromagnetic waves can be achieved by designing the surface array unit structure of the metamaterial electromagnetic absorber. The metamaterial electromagnetic absorber has a precise micron-sized structure, so that the absorber is smaller in size, easier to integrate and more superior in performance, and has stronger competitiveness than the traditional absorption equipment, and the huge application potential of the metamaterial electromagnetic absorber enables the metamaterial electromagnetic absorber to be focused by researchers worldwide. However, the metamaterial electromagnetic absorber generally has the defects of limited bandwidth or complex design and manufacturing process, and the like, and the bandwidth of an absorption band is insufficient, so that the absorption performance cannot be adjusted, which is not beneficial to practical application.

Disclosure of Invention

The invention aims to provide a terahertz switch based on metal and vanadium dioxide. The terahertz wave absorption or reflection regulation device has excellent absorption or reflection characteristics for terahertz waves, and can regulate and control the absorption or reflection of the terahertz waves.

The technical scheme of the invention is as follows: a terahertz switch based on metal and vanadium dioxide comprises a vanadium dioxide layer and a silicon dioxide layer which are sequentially laminated from bottom to top and have square sections; the surface of the silicon dioxide layer is provided with a metal patch layer, the metal patch layer comprises a square ring patch arranged on the surface of the silicon dioxide layer, and a cross patch is arranged in the surface area of the silicon dioxide layer surrounded by the square ring patch; the thickness of the silicon dioxide layer is 10 mu m, the width is 10 mu m, and the dielectric constant is 3.9; the thickness of the vanadium dioxide layer is 0.2 mu m, and the width is 10 mu m; the thickness of the square ring patch is 0.2 mu m, the outer side length of the square ring is 4.25 mu m, the inner side length is 3.25 mu m, and the width is 0.5 mu m; the thickness of the cross-shaped patch is 0.2 μm, the length is 2.4 μm, and the width is 1 μm.

According to the terahertz switch based on the metal and the vanadium dioxide, the graphene layers distributed in an array are arranged on the surface of the silicon dioxide layer between the square ring patch and the cross patch, and wavy topological boundaries are respectively arranged in the middle of the four edges of the graphene layers.

In the terahertz switch based on metal and vanadium dioxide, the four corners of the graphene layer are respectively provided with a transmission hole lattice, and the transmission hole lattice at each corner is in a regular triangle matrix shape; and an array grid is formed among the four transmission hole lattices.

Compared with the prior art, the terahertz switch has the advantages that the vanadium dioxide layer and the silicon dioxide layer with the square cross sections are sequentially laminated from bottom to top, the metal patch layer is arranged on the silicon dioxide layer and comprises the square ring patch arranged on the surface of the silicon dioxide layer, the cross patch is arranged in the surface area of the silicon dioxide layer surrounded by the square ring patch, the terahertz switch has the polarization insensitivity characteristic due to the perfect symmetrical structure of the metal patch layer, and the vanadium dioxide is used as an ideal material of a thermal control system, so that the vanadium dioxide can be subjected to reversible phase change from an insulating phase to a metal phase through changing the temperature condition, and excellent absorption characteristic and reflection characteristic can be kept for terahertz within a wide incident angle range. In addition, a graphene layer distributed in an array is arranged on the surface of the silicon dioxide layer between the square ring patch and the cross patch, and wavy topological boundaries are respectively arranged in the middle of the edge of the graphene layer; transmission hole lattices are respectively arranged at four corners of the graphene layer, and each transmission hole lattice at each corner is in a regular triangle matrix shape; and an array grid is formed among the four transmission hole lattices. The two polarization states based on the in-phase and the opposite-phase of the terahertz wave are mutually overlapped to obtain a spin state through the combination, so that topological phase change can be generated in the structure of the gold layer, and better robustness is obtained.

Drawings

FIG. 1 is a schematic diagram of the structure of the present invention;

FIG. 2 is a schematic top view of the present invention;

FIG. 3 is a graph of absorbance versus frequency;

FIG. 4 is a surface layer structure of the silica layer in example 2;

fig. 5 is a schematic structural diagram of a graphene layer.

Reference numerals

1. A vanadium dioxide layer; 2. a silicon dioxide layer; 3. a metal patch layer; 4. square ring patch; 5. a cross-shaped patch; 6. a graphene layer; 7. a topology boundary; 8. the lattice of holes is transmitted.

Detailed Description

The invention is further illustrated by the following figures and examples, which are not intended to be limiting.

Example 1: a terahertz switch based on metal and vanadium dioxide is shown in fig. 1-2, and comprises a vanadium dioxide layer 1 and a silicon dioxide layer 2 which are sequentially laminated from bottom to top and have square sections; the surface of the silicon dioxide layer 2 is provided with a metal patch layer 3, and the metal patch layer 3 can be made of gold or copper; the metal patch layer 3 comprises a square ring patch 4 arranged on the surface of the silicon dioxide layer, and a cross patch 5 is arranged in the surface area of the silicon dioxide layer 2 surrounded by the square ring patch 4. The thickness of the silicon dioxide layer 2 is 10 μm, the width is 10 μm, and the dielectric constant is 3.9. The thickness of the vanadium dioxide layer 1 is 0.2 μm and the width is 10 μm. The square ring patch 4 has a thickness of 0.2 μm, an outer side length of 4.25 μm, an inner side length of 3.25 μm, and a width of 0.5 μm. The cross-shaped patch 5 has a thickness of 0.2 μm, a length of 2.4 μm and a width of 1 μm.

The applicant prefers a process of arranging a metal patch layer on a silicon dioxide layer, specifically, fluoridation treatment is carried out on the silicon dioxide, ozone gas is used for catalytic oxidation under a sealed environment, an isolation medium is formed on the surface through an atomic layer deposition technology, and the treated silicon dioxide is cut into a specified shape to obtain the silicon dioxide layer. And placing the metal patch layer on the surface of the silicon dioxide layer, attaching an isolation medium of the silicon dioxide layer to the metal patch layer, and heating and annealing under the environment of 80% of nitrogen and 20% of oxygen to combine the metal patch layer and the silicon dioxide layer. The invention can make the combination between the metal patch layer and the silicon dioxide layer more compact and stable through the process, reduces the warpage of the metal patch layer, greatly reduces the stress between the metal patch layer and the silicon dioxide layer, and can also ensure the resonance performance of sensitive devices such as terahertz absorbers.

The terahertz switch in example 1 was tested by changing the conductivity of vanadium dioxide by changing the temperature conditions to change the reversible phase of vanadium dioxide from the insulating phase to the metal phase, and an absorption efficiency change diagram under different conductivities as shown in fig. 3 was obtained, and it can be seen from fig. 3 that the effective impedance of the terahertz switch and the effective impedance of the free space are gradually matched in the frequency range of 2-4THz with the continuous increase of the conductivity (300-300000S/m) due to the characteristics of titanium dioxide, and the terahertz switch of the invention obtains the highest absorption rate and the widest absorption bandwidth when the titanium dioxide is in the metal state (conductivity is 30000S/m) and shows the full absorption state. When titanium dioxide is in an insulating state (conductivity of 300S/m), the absorption efficiency is almost zero, and at this time, a total reflection state is exhibited. Thus, the present invention can maintain excellent absorption characteristics and reflection characteristics for terahertz in a wide range of incidence angles.

Example 2: on the basis of the embodiment 1, as shown in fig. 4-5, a graphene layer 6 distributed in an array is arranged on the surface of the silicon dioxide layer 2 between the square ring patch 4 and the cross patch 5, and wavy topological boundaries 7 are respectively arranged in the middle of four edges of the graphene layer 6; transmission hole lattices 8 are respectively arranged at four corners of the graphene layer 6, and the transmission hole lattice 8 at each corner is in a regular triangle matrix shape; and an array grid is formed among the four transmission hole lattices 8. The two polarization states based on the in-phase and the opposite-phase of the terahertz wave are mutually overlapped to obtain a spin state through the combination, so that topological phase change can be generated in the structure of the gold layer, and better robustness is obtained. The applicant has conducted a comparison of the selector of example 2 and the selector of example 1 for testing the terahertz absorption rate, and tested that the absorption rate of example 2 can be further improved than that of example 1.

In conclusion, the terahertz wave absorption and reflection control device has excellent absorption characteristics or reflection characteristics for terahertz waves, and can realize the regulation and control of terahertz wave absorption or reflection.

Claims

1. A terahertz switch based on metal and vanadium dioxide is characterized in that: comprises a vanadium dioxide layer (1) and a silicon dioxide layer (2) which are sequentially laminated from bottom to top and have square sections; the surface of the silicon dioxide layer (2) is provided with a metal patch layer (3), the metal patch layer (3) comprises square ring patches (4) arranged on the surface of the silicon dioxide layer, and a cross patch (5) is arranged in the surface area of the silicon dioxide layer (2) surrounded by the square ring patches (4); the thickness of the silicon dioxide layer (2) is 10 mu m, the width is 10 mu m, and the dielectric constant is 3.9; the thickness of the vanadium dioxide layer (1) is 0.2 μm, and the width is 10 μm; the thickness of the square ring patch (4) is 0.2 mu m, the outer side length of the square ring is 4.25 mu m, the inner side length is 3.25 mu m, and the width is 0.5 mu m; the thickness of the cross-shaped patch (5) is 0.2 mu m, the length is 2.4 mu m, and the width is 1 mu m; the surface of the silicon dioxide layer (2) between the square ring patch (4) and the cross patch (5) is provided with graphene layers (6) distributed in an array, and the middle parts of four edges of the graphene layers (6) are respectively provided with wavy topological boundaries (7); transmission hole lattices (8) are respectively arranged at four corners of the graphene layer (6), and the transmission hole lattice (8) at each corner is in a regular triangle matrix shape; and an array grid is formed among the four transmission hole lattices (8).