CN112817073A - Infrared wave absorbing device based on principle of non-reflection filter - Google Patents

Abstract

The invention relates to an infrared wave absorber based on the principle of a non-reflection filter, comprising several wave absorbing units arranged in sequence, and each wave absorbing unit includes a conductive reflection layer, a dielectric layer and a Structural unit layer, the micro-structural unit layer is formed by four identical isosceles right-angled triangle units after quadruple rotation around the center point of the micro-structural unit layer, each isosceles right-angled triangle unit is composed of a large isosceles right-angled triangle and It consists of a small isosceles right triangle. In each isosceles right triangle unit, the hypotenuses of the large isosceles right triangle and the small isosceles right triangle are close and parallel. The absorber has a simple structure and a thin thickness, has four absorption peaks in the mid-infrared band of 4.1-4.7 μm, and has a high absorption rate. It has great application potential in the fields of military, environmental monitoring and imaging systems.

Description

An infrared wave absorber based on the principle of non-reflection filter

technical field

The invention belongs to the technical field of infrared metamaterials, and in particular relates to an infrared wave absorber based on the principle of a non-reflection filter.

Background technique

Metamaterials refer to a class of composite materials with artificially designed structures. They are called metamaterials because they have some extraordinary electromagnetic properties that natural materials do not possess. Electromagnetic metamaterials can control the phase, amplitude and polarization state of electromagnetic waves with specific artificial structures, thereby realizing various extraordinary physical phenomena, and can achieve special functions such as negative refractive index, electromagnetic stealth, and perfect absorption by perfect lenses. A metamaterial absorber is a device that can convert the electromagnetic wave energy incident on its surface into other energy and lose it through special mechanisms and materials.

Mid-infrared radiation is usually defined as electromagnetic waves with wavelengths in the range of 2.5-25 μm, which can not only be used for the detection of molecular content and identification of molecular types, but also to realize molecular imaging, which can be used in military, environmental monitoring, medical treatment, and basic research. field has a wide range of applications. Therefore, it is of great significance to study metamaterial absorbers in the mid-infrared band. Existing infrared absorbers usually only have a single absorption frequency band, and due to their complex metasurface structure and morphology, it is not conducive to large-scale processing and production.

SUMMARY OF THE INVENTION

The purpose of the present invention is to solve the deficiencies of the prior art, and to provide an infrared wave absorber based on the principle of a non-reflection filter, which has a simple structure, a thin thickness, four absorption peaks in the 4.1-4.7 μm band, and a high absorption rate. and polarization sensitive.

Technical solutions

An infrared wave absorber based on the principle of a non-reflection filter, comprising a number of wave absorption units arranged in sequence, each wave absorption unit including a conductive reflection layer, a dielectric layer and a microstructure unit layer that are sequentially laminated from bottom to top , the microstructure unit layer is formed by four identical isosceles right triangle units after quadruple rotation around the center point of the microstructure unit layer, each isosceles right triangle unit consists of a large isosceles right triangle and a small isosceles right triangle In each isosceles right triangle unit, the hypotenuse of the large isosceles right triangle and the small isosceles right triangle are close to and parallel; the material of the microstructure unit layer is selected from metal, graphene or ITO. Any one; the material of the conductive reflective layer is one of metal or ITO.

Further, in the isosceles right triangle unit, the length of the right angle of the large isosceles right triangle is 1.000 μm, the length of the right angle of the small isosceles right triangle is 0.707 μm, and the hypotenuses of the large isosceles right triangle and the small isosceles right triangle are apart from each other. 0.200μm.

Further, the dielectric layer is a polyimide film with a dielectric constant of 2.88 and a loss tangent of 0.0032.

Further, the thickness of the dielectric layer is 3.00 μm.

Further, the thicknesses of the conductive reflective layer and the microstructure unit layer are both 0.100 μm.

Beneficial effects of the present invention: The present invention provides an infrared wave absorber based on the principle of a non-reflection filter, which includes several wave absorbing units arranged in sequence, and each wave absorbing unit includes a Conductive reflective layer, dielectric layer and micro-structure unit layer. The micro-structure unit layer has a unique structure and can obtain 4 absorption peaks in the 4.1-4.7μm band. The material of the bottom conductive reflective layer is metal or ITO with strong electromagnetic wave reflection. , it can ensure that no electromagnetic wave is transmitted, and the electromagnetic wave entering the wave absorber is completely lost under the action of dielectric loss and ohmic loss. The infrared wave absorber of the invention has a simple structure, a thin thickness, is conducive to integration and has flexibility. The infrared band has four absorption peaks and high absorption rate, and has a wide range of applications in military, environmental monitoring, medical treatment and basic research.

Description of drawings

Fig. 1 is the three-dimensional structure schematic diagram of the wave absorbing unit of the infrared wave absorber based on the principle of the non-reflection filter in Embodiment 1;

Fig. 2 is the front view of the wave absorbing unit of the infrared wave absorber based on the principle of non-reflection filter of embodiment 1;

Fig. 3 is the array diagram of the infrared wave absorber based on the non-reflection filter principle of embodiment 1;

Fig. 4 is the absorption characteristic curve diagram of the infrared wave absorber based on the principle of non-reflection filter in the 4.1-4.7 μm waveband of Example 1;

In the figure, 1-microstructure unit layer; 2-dielectric layer; 3-conductive reflective layer.

Detailed ways

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

Example 1

As shown in Figure 1-3, an infrared wave absorber based on the principle of non-reflection filter includes several wave absorbing units arranged in sequence, and each wave absorbing unit includes a conductive reflective layer 3, The dielectric layer 2 and the microstructure unit layer 1, the microstructure unit layer 1 is formed by four identical isosceles right triangle units after quadruple rotation around the center point of the microstructure unit layer, each isosceles right triangle unit is formed by a A large isosceles right triangle and a small isosceles right triangle. In each isosceles right triangle unit, the hypotenuses of the large isosceles right triangle and the small isosceles right triangle are close to and parallel. In this embodiment, the large isosceles right triangle The length of the right angle of the triangle is 1.000 μm, the length of the right angle of the small isosceles right triangle is 0.707 μm, and the hypotenuse of the large isosceles right triangle and the small isosceles right triangle in the same unit is 0.200 μm apart.

In this embodiment, the dielectric layer is a polyimide film with a dielectric constant of 2.88 and a loss tangent of 0.0032, with a thickness of 3.000 μm; the conductive reflective layer and the microstructure unit layer have a conductivity of 5.8×10 ⁷ S/ m, both of which are made of metallic copper with a thickness of 0.100 μm. The corresponding lattice constant of the infrared absorber based on the principle of non-reflection filter is L=5.000μm, and the rest of the parameter structure is X1=1μm, X2=0.707μm, W1=0.707μm, W2=0.200μm, etc. The line width of the right isosceles triangle and the small isosceles right triangle is W=0.100 μm, and the length of the base angle near the center point of the large isosceles right triangle and the small isosceles right triangle is 2.236 μm.

The infrared wave absorber based on the principle of non-reflection filter of Example 1 was simulated and tested by CST microwave studio. As can be seen from Figure 4, the absorption characteristic curve of the infrared wave absorber based on the principle of the non-reflection filter of the present invention is 94.00% and 97.09% respectively at the wavelengths of 4.17 μm, 4.29 μm, 4.41 μm and 4.61 μm. , 92.75% and 98.42%

The preparation method of the above-mentioned infrared wave absorber based on the principle of non-reflection filter: firstly, a conductive reflective layer with a thickness of 0.100 μm is coated on both sides of the dielectric layer by means of coating, and then chemically etched on the side where the microstructure unit layer is located. The structure of the microstructure unit layer is etched in a manner to obtain a wave absorbing unit, and a plurality of wave absorbing units are arranged in sequence to obtain an infrared wave absorber.

Claims (5)

1. An infrared wave absorbing device based on a reflection-free filter principle comprises a plurality of wave absorbing units which are sequentially arranged, wherein each wave absorbing unit comprises a conductive reflecting layer, a dielectric layer and a micro-structure unit layer which are sequentially attached from bottom to top; the material of the microstructure unit layer is selected from any one of metal, graphene or ITO; the material of the conductive reflecting layer is one of metal or ITO.

2. An infrared absorber based on the principle of a reflectionless filter as set forth in claim 1, wherein in said isosceles right triangle unit, the length of the right angle side of the large isosceles right triangle is 1.000 μm, the length of the right angle side of the small isosceles right triangle is 0.707 μm, and the distance between the hypotenuses of the large isosceles right triangle and the small isosceles right triangle is 0.200 μm.

3. The infrared absorber based on the principle of the reflectionless filter of claim 1, wherein the dielectric layer is a polyimide film having a dielectric constant of 2.88 and a loss tangent of 0.0032.

4. An infrared absorber based on the principle of a reflectionless filter as set forth in claim 1, wherein the dielectric layer has a thickness of 3.00 μm.

5. The infrared absorber based on the principle of the reflectionless filter of claim 1, 2, 3, or 4, wherein the thickness of the conductive reflective layer and the microstructure unit layers are each 0.100 μm.

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