Superstructure surface optical filter based on ZnSe substrate

Abstract

The utility model relates to a super-structure surface optical filter based on a ZnSe substrate, comprising a substrate, the material of the substrate is zinc selenide, the front surface of the substrate is provided with a germanium layer, the germanium layer is provided with a micron structure unit, the micron structure unit is formed by etching the germanium layer, the back surface of the substrate is provided with an infrared anti-reflection AR film, and the infrared anti-reflection AR film is provided with a ZnSe layer. An aluminum film is arranged on the upper surface of the micron structure unit, the thickness of the aluminum film is 18-22 nm, a color layer is arranged on the upper surface of the aluminum film, and the problem that the efficiency of the optical filter is low under the complex conditions of high temperature, poisonous and harmful gas and the like is solved by adding the aluminum film and the color layer.

Description

Technical Field

[0001] The utility model relates to a metasurface filter based on a ZnSe substrate. Background Art

[0002] With the rapid development of optical technology, filters, as a key optical component, are widely used in optical systems. Traditional filters often achieve selective reflection or transmission of specific wavelengths through a multi-layer dielectric thin film design, but they still have limitations in terms of filtering performance, bandwidth control, and angular stability. For example, when faced with broadband spectra or complex light environments, traditional filters struggle to simultaneously meet the requirements of precise light wave selection and high light transmittance. Their performance degrades significantly, especially when used in harsh environments, and they are unable to effectively cope with the effects of high temperatures, corrosive gases, and other extreme conditions.

[0003] In recent years, metasurface technology has gradually emerged. Metasurface is a new type of optical element that regulates optical response by precisely designing subwavelength-scale micro-nanostructures. Compared with traditional filters, metasurfaces can provide better transmission and reflection control over a wide spectrum range, and at the same time have higher flexibility. Structures with specific optical properties can be designed according to different application requirements, especially with unique advantages in regulating light amplitude, phase and polarization. This makes the application prospects of metasurface filters in optical systems broader, especially in the fields of optical detection and monitoring in complex and harsh environments, such as mines, petrochemicals, remote sensing, military, medicine, etc.

[0004] At present, in response to the needs of optical detection in special environments, there is an urgent need for a filter that can selectively transmit or reflect light of specific wavelengths under complex conditions such as high temperature and toxic and harmful gases. Utility Model Content

[0005] The purpose of this utility model is to address the deficiencies of the above-mentioned prior art and provide a metasurface filter based on a ZnSe substrate. By adding an aluminum film and a color layer, the problem of low filter efficiency under complex conditions such as high temperature and toxic and harmful gases is solved. The following is a specific solution:

[0006] A metasurface filter based on a ZnSe substrate comprises a substrate made of zinc selenide; a germanium layer is provided on the front of the substrate; micron-structured units are provided on the germanium layer; the micron-structured units are formed by etching the germanium layer; an infrared anti-reflection (AR) film is provided on the back of the substrate; an aluminum film is provided on the upper surface of the micron-structured units; the aluminum film has a thickness of 18-22 nm; and a color layer is provided on the upper surface of the aluminum film.

[0007] Furthermore, the substrate is a 2-inch wafer and is 0.7 mm thick.

[0008] Further, the thickness of the germanium layer is 4.5 μm.

[0009] Further, the depth of the etching is 3 μm.

[0010] Further, the wave band of the infrared anti-reflection AR film is 8-12 μm, and the reflectivity of the infrared anti-reflection AR film in the wave band is less than 3%.

[0011] Further, the thickness of the aluminum film is 20 nm.

[0012] Further, the color of the color layer is silver.

[0013] Beneficial effects: by setting the aluminum film and the color layer, the FP resonance is avoided to interfere with the structural color, so that the light filtering effect of the product is better under the complex conditions such as high temperature and toxic and harmful gas. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 is a three-dimensional structural schematic view of a super-structured surface filter based on a ZnSe substrate;

[0015] Figure 2 is Figure 1 a partial perspective enlarged view of

[0016] In the figure: 100, germanium layer, 200, micron structure unit, 210, aluminum film, 220, color layer, 300, infrared anti-reflection AR film. DETAILED DESCRIPTION

[0017] In order to deepen the understanding of the utility model, the utility model will be further described in combination with examples and drawings below, and the examples are only used to explain the utility model, and do not constitute the limitation to the protection scope of the utility model.

[0018] Please refer to Figures 1-2 , a super-structured surface filter based on a ZnSe substrate, including a substrate, the material of the substrate is zinc selenide, the front surface of the substrate is provided with a germanium layer 100, the micron structure unit 200 is arranged on the germanium layer 100, the micron structure unit 200 is formed by etching the germanium layer 100, the back surface of the substrate is provided with an infrared anti-reflection AR film 300, the upper surface of the micron structure unit 200 is provided with an aluminum film 210, the thickness of the aluminum film 210 is 18-22 nm, and the upper surface of the aluminum film is provided with a color layer 220.

[0019] The substrate is a 2-inch wafer, the substrate is 0.7 mm thick; the thickness of the germanium layer 100 is 4.5 μm; the etching depth is 3 μm; the wave band of the infrared anti-reflection AR film 300 is 8-12 μm, the reflectivity of the infrared anti-reflection AR film 300 in this wave band is less than 3%; the thickness of the aluminum film 210 is 20 nm; the color of the color layer 220 is silver.

[0020] The preparation process comprises the following steps:

[0021] The Si imprinting template is prepared by using an electron beam lithography and dry etching process, the imprinting template is exactly complementary to the finally formed periodic structure; the periodic array of nanostructures is generated after the imprinting template on the surface of the imprinting glue is demolded, the color of the pattern after demolding is very weak due to the very low refractive index contrast between the imprinting glue polymer and air, therefore a 20-nm-thick metal Al film is deposited on the surface of the imprinting glue polymer; finally, in order to avoid the interference of FP resonance on the structural color, a protective layer is deposited on the surface of the structure, and different colors are obtained, and the color is preferably silver in this embodiment.

[0022] Finally, it should be explained that the above embodiments are only used to illustrate the technical solutions of the present application but not limit the present application, although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced equivalently without departing from the purpose and scope of the technical solutions of the present application, and all of them should be covered in the scope of the claims of the present application.

Claims

1. A metasurface filter based on a ZnSe substrate, characterized in that, The application relates to a substrate, wherein the substrate is made of zinc selenide, the front surface of the substrate is provided with a germanium layer, the germanium layer is provided with a microstructure unit, the microstructure unit is formed by etching the germanium layer, the back surface of the substrate is provided with an infrared antireflection (AR) film, the upper surface of the microstructure unit is provided with an aluminum film, the thickness of the aluminum film is 18-22 nm, and the upper surface of the aluminum film is provided with a color layer.

2. The ZnSe-based metasurface optical filter of claim 1, wherein, The substrate is a 2-inch wafer, and the thickness of the substrate is 0.7 mm.

3. The ZnSe-based metasurface optical filter of claim 1, wherein, The thickness of the germanium layer is 4.5 microns.

4. The ZnSe-based metasurface optical filter of claim 1, wherein, The etching depth is 3 microns.

5. The ZnSe-based metasurface optical filter of claim 1, wherein, The infrared antireflection (AR) film has a wave band of 8-12 microns, and the reflectivity of the infrared antireflection (AR) film in the wave band is less than 3%.

6. The ZnSe-based metasurface optical filter of claim 1, wherein, The thickness of the aluminum film is 20 nm.

7. The ZnSe-based metasurface optical filter of claim 1, wherein, The color of the color layer is silver.

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