CN110707437B

CN110707437B - Terahertz dual-band absorber based on plastic cone frustum structure

Info

Publication number: CN110707437B
Application number: CN201911020624.9A
Authority: CN
Inventors: 李九生; 张丽娜
Original assignee: China Jiliang University
Current assignee: China Jiliang University
Priority date: 2019-10-25
Filing date: 2019-10-25
Publication date: 2021-01-26
Anticipated expiration: 2039-10-25
Also published as: CN110707437A

Abstract

The invention discloses a dual-band absorber based on a plastic cone frustum structure. The device comprises an NxN plastic cone frustum unit structures, wherein N is a natural number; the plastic cone frustum unit structure sequentially comprises a bottommost metal film, a rectangular plastic medium matrix, a plastic cone frustum and a top metal layer from top to bottom; the absorber achieves the best absorption effect by changing the height of the plastic cone frustum and the period of the adjacent plastic cone frustum. Simulation results show that the absorber has two absorption frequency points, and the absorption rate reaches more than 90%. The dual-band absorber based on the plastic cone frustum structure has the advantages of simple structure, low cost, excellent performance and the like, and meets the requirements of terahertz communication.

Description

Terahertz dual-band absorber based on plastic cone frustum structure

Technical Field

The invention relates to a terahertz absorber, in particular to a terahertz dual-band absorber based on a plastic cone frustum structure.

Background

Terahertz generally refers to electromagnetic waves with the frequency of 0.1-10 THz, and the corresponding wavelength is 0.03-3 mm. In recent years, terahertz waves, which have become well developed as a link between millimeter waves and infrared light in the electromagnetic spectrum, are undoubtedly a new field of research, and have great value in all aspects. For a long time, due to the lack of an effective terahertz wave generation and detection method, the electromagnetic radiation property of the band is poorly understood compared with the traditional microwave technology and optical technology, so that the band becomes a terahertz gap in the electromagnetic spectrum. With the breakthrough of terahertz radiation sources and detection technologies, the unique and superior characteristics of terahertz are discovered and have great application prospects in material science, gas detection, biological and medical detection, communication and the like. It can be said that terahertz technology science is not only an important fundamental problem in scientific technology development, but also an important requirement for new-generation information industry and basic science development. The terahertz system mainly comprises a radiation source, a detection device and various functional devices.

In recent years, terahertz absorbers have wide application values in the fields of optical communication, biomedicine, high-precision imaging and the like. However, most of domestic and foreign terahertz absorbers have the characteristics of complex structure, high processing cost and the like, so that the application of the absorbers is restricted. Therefore, it is important to design a device with simple structure, remarkable absorption effect and low processing cost. Aiming at the problems of the terahertz absorber, the invention provides the terahertz dual-band absorber based on the plastic cone frustum structure, the absorption rate of the terahertz dual-band absorber reaches over 90 percent, and the terahertz dual-band absorber has the characteristics of compact structure, excellent performance, low processing cost and the like.

Disclosure of Invention

The invention aims to solve the problems in the prior art and provides a terahertz dual-band absorber based on a plastic cone frustum structure. The technical scheme of the invention is as follows: it is characterized in that the device comprises an NxN plastic cone frustum unit structures, wherein N is a natural number; the plastic cone frustum unit structure sequentially comprises a bottommost layer metal film, a rectangular plastic medium matrix, a plastic cone frustum and a top metal layer from bottom to top; the bottom surfaces of the bottommost metal film and the rectangular plastic medium substrate are squares with equal side length; the absorber achieves the best absorption effect by changing the height of the plastic cone frustum and the period between the adjacent plastic cone frustums. Simulation results show that the absorber has two absorption frequency points, and the absorption rate reaches more than 90%.

The specific parameters of each part in the scheme can adopt the following preferable modes:

the height of the plastic cone frustum is 170-190 microns. The period between the adjacent plastic cone frustum unit structures is 120-140 mu m. The bottom surface of the rectangular plastic medium substrate is square, and the side length of the rectangular plastic medium substrate is 120-140 microns.

The dual-band absorber based on the plastic cone frustum structure provided by the invention has the characteristics of absorption rate of more than 90%, compact structure, excellent performance, low processing cost and the like.

Drawings

FIG. 1 is a three-dimensional schematic diagram of a unit structure of a terahertz dual-band absorber with a plastic cone frustum structure;

FIG. 2 is a top view of a terahertz dual-band absorber array structure with NxN plastic truncated cone structures;

fig. 3 is a terahertz dual-band absorber performance curve of a plastic frustum structure when the period between adjacent plastic frustum unit structures is L =120 μm and L =140 μm;

fig. 4 is an absorption performance curve of the terahertz dual-band absorber of the plastic cone structure when the plastic cone height H =170 μm and H =190 μm;

FIG. 5 is a performance curve of a terahertz dual-band absorber with a plastic cone frustum structure.

Detailed Description

As shown in fig. 1, a dual-band terahertz absorber unit based on a plastic truncated cone structure comprises an N × N plastic truncated cone unit structures 1, where N is a natural number; the plastic cone frustum unit structure 1 sequentially comprises a bottommost metal film 2, a cuboid plastic medium matrix 3, a plastic cone frustum 4 and a top metal layer 5 from bottom to top; the bottom surfaces of the bottommost metal film 2 and the rectangular plastic medium substrate 3 are squares with equal side length; by varying the height of the plastic cone 4 and the period between adjacent plastic cones 4, excellent absorption properties of the absorber can be achieved.

The height of the plastic cone frustum 4 is 170-190 microns. The period between the unit structures of the adjacent plastic cone frustums 4 is 120-140 mu m; the bottom surface of the rectangular plastic medium matrix 3 is square, and the side length of the rectangular plastic medium matrix is 120-140 micrometers.

The following will explain specific effects of the absorber by way of example.

Example 1

In this embodiment, the shapes of the dual-band terahertz absorber structure based on the plastic truncated cone structure and the parts are as described above, and therefore are not described again. The specific parameters of each part are as follows: the bottom surface of the rectangular plastic medium matrix is square, the side length of the rectangular plastic medium matrix is 140 micrometers, and the height of the rectangular plastic medium matrix is 110 micrometers; the thickness of the metal film on the bottommost layer and the thickness of the metal layer on the top layer are both 1 micrometer; the height H of the plastic cone frustum is 190 μm, and the interval L between adjacent plastic cone frustum periodic units is 140 μm. Fig. 5 is a performance curve of the terahertz dual-band absorber with a plastic truncated cone structure. At 2.7THz, the absorption of the absorber reaches 96%; at 3.3THz, the absorption of the absorber reached 98%. All performance indexes of the terahertz dual-band absorber based on the plastic cone frustum structure are obtained by simulation of CST software.

Claims

1. A terahertz dual-band absorber based on a plastic cone frustum structure is characterized by comprising N multiplied by N plastic cone frustum unit structures (1), wherein N is a natural number; the plastic cone frustum unit structure (1) sequentially comprises a bottommost metal film (2), a cuboid plastic medium substrate (3), a plastic cone frustum (4) and a top metal layer (5) from bottom to top; the bottom surfaces of the bottommost metal film (2) and the rectangular plastic medium substrate (3) are squares with equal side length; the height of the plastic cone frustum (4) and the period between the adjacent plastic cone frustums (4) are changed, so that the absorber achieves the optimal absorption effect.

2. The terahertz dual-band absorber based on the plastic cone frustum structure as claimed in claim 1, wherein the height of the plastic cone frustum (4) is 170-190 μm.

3. The terahertz dual-band absorber based on the plastic cone frustum structure as claimed in claim 1, characterized in that the period between the adjacent plastic cone frustum (4) unit structures is 120 μm to 140 μm; the bottom surface of the rectangular plastic medium matrix (3) is square, and the side length of the rectangular plastic medium matrix is 120-140 micrometers.