Optical filter

Abstract

The utility model provides an optical filter which comprises six filter plates, each filter plate is composed of sixteen structural units, each structural unit is provided with a plurality of protruding portions, the protruding portions can be round, oval, rectangular or triangular, the structural units are connected through transition plates, and the transition plates are connected with the filter plates. The transition plate is formed by sequentially overlapping four layers of materials, namely a silicon oxide layer, a germanium layer, a titanium oxide layer and a silicon oxide layer, the optical response of the optical filter can be effectively improved by designing the shape of the protruding part and the multi-layer structure of the transition plate, the stable filtering performance of the optical filter can be kept under different wavelengths and incident angles, and the optical filter can be applied to the optical filter. Therefore, the application requirements in a complex environment are met.

Description

TECHNICAL FIELD

[0001] The utility model relates to an optical filter. BACKGROUND

[0002] The optical filter is a key element widely used in spectrum detection and signal processing, can be selectively transmitted or reflected to different wavelengths of light, and is widely used in gas detection, environmental monitoring, biomedical diagnosis and other fields. The traditional filter mainly relies on multi-layer dielectric coating technology, and the filtering effect of specific wavelength is realized through the optical thickness control of different layers.

[0003] The optical filter of the prior art is very sensitive to the angle of incident light, and the filtering effect is significantly reduced under non-perpendicular incidence. The filter structure is designed as a simple regular arrangement, which cannot meet the demand of combining randomness and periodicity, and limits the multi-dimensional regulation and control ability of optical properties in actual environment.

[0004] Therefore, how to solve the unstable filtering performance of the optical filter in the actual complex environment is a problem to be solved. UTILITY MODEL CONTENT

[0005] The utility model aims at solving the above prior art, providing an optical filter, through the shape of the protruding part and the setting of the transition plate, the filter can be more stable in the filtering performance of the actual complex optical environment, and the utility model aims at achieving the following:

[0006] The utility model provides an optical filter, including filter board, the filter board is equipped with six, every filter board all includes sixteen structure units, every structure unit all is equipped with a plurality of protruding parts, the shape of protruding part is one of circular, oval, rectangle or triangle, the structure unit all is equipped with transition plate, the transition plate includes silicon oxide layer, germanium layer, titanium oxide layer and silicon oxide layer that overlap from top to bottom in turn.

[0007] Further, the filter board is arranged in two rows and three columns.

[0008] Further, the structure units are arranged in four by four.

[0009] Further, the diameter or side length of each protruding part ranges from 1 to 10 microns.

[0010] Further, the thickness of the silicon oxide layer is 50 nm, the thickness of the germanium layer is 100 nm, the thickness of the titanium oxide layer is 30 nm, and the thickness of the silicon oxide layer is 50 nm.

[0011] Further, the silicon oxide layer has a refractive index of 1.45, the germanium layer has a refractive index of 4.0, the titanium oxide layer has a refractive index of 2.5, and the silicon oxide layer has a refractive index of 1.45.

[0012] Further, the filter plate is arranged on a ZnSe substrate, and the thickness of the ZnSe substrate is 50 nm.

[0013] Further, the transition plate is provided with a nonlinear gradient pattern.

[0014] Further, the nonlinear gradient pattern is an exponential or Gaussian type of geometric shape.

[0015] Compared with the prior art, the optical filter has the advantages that: the filter can have more obvious optical response to light of different wavelengths, different shapes of the protruding portions can produce different interference or diffraction effects on the incident light, thereby adjusting the propagation path of the light and improving the filtering effect; the transition plate effectively controls the refractive index change of the light through the multilayer film structure, provides smooth optical transition, optimizes the spectral response, and further improves the filtering effect. BRIEF DESCRIPTION OF DRAWINGS

[0016] Fig. 1 is a structural diagram of a structural unit of an optical filter;

[0017] Fig. 2 is a structural diagram of a transition plate and a filter plate of an optical filter;

[0018] In the figure: 1, filter plate, 2, structural unit, 3, protruding portion, 4, transition plate, 5, substrate. DETAILED DESCRIPTION

[0019] 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 a limitation on the protection scope of the utility model.

[0020] Please refer to Figs. 1-2 The embodiment of the utility model provides an optical filter, which comprises a filter plate 1, the filter plate 1 is provided with six, each filter plate 1 comprises sixteen structural units 2, each structural unit 2 is provided with a plurality of protruding portions 3, the shape of the protruding portion 3 is one of circular, oval, rectangular or triangular, the transition plate 4 is arranged between each structural unit 2, the transition plate 4 comprises silicon oxide layer, germanium layer, titanium oxide layer and silicon oxide layer that are overlapped from top to bottom in turn, the shape of the protruding portion 3 and the setting of the transition plate 4 make the filtering performance of the filter more stable in actual complex optical environment.

[0021] Optionally, in the coal mine gas detection system, the optical filter of the embodiment is used as the core component of the sensor; the filter can selectively transmit the characteristic absorption spectrum of the gas through a specific wavelength, thereby accurately identifying the concentration of the gas; for example, when detecting methane gas, the characteristic absorption wavelength of methane is located in the infrared region of 3.3 μm, and by using the filter in the sensor system, other interference signals can be accurately filtered out, and only the wavelength matched with the methane absorption spectrum is retained, thereby improving the detection accuracy. In addition, in the city air quality monitoring station, the optical filter of the embodiment is used to screen the characteristic absorption spectrum of nitrogen oxides in the atmosphere; the characteristic absorption peak of nitrogen oxides appears near the wavelength of 5.3 μm, while the absorption peak of carbon dioxide appears near 4.3 μm; by designing different filters, selective transmission is performed according to the wavelength range of the target gas, so that the sensor can accurately distinguish the concentration of different gases, and by monitoring the concentration changes of these key gases, the air quality can be effectively evaluated, real-time data can be provided, and decision-making and early warning can be supported.

[0022] In the embodiment, the filter is composed of six filter plates 1, each filter plate 1 is composed of a plurality of structure units 2 for screening and transmitting light of different wavelengths; the protrusions 3 on each structure unit 2 have multiple shape options, and these shape options are selected to adjust the refraction, reflection or transmission characteristics of light; a transition plate 4 is arranged between each structure unit 2, which is composed of different material layers overlapped to guide and adjust the optical performance. Through the design of these structures, the filter can have more obvious optical response to light of different wavelengths, and different shapes of the protrusions 3 can produce different interference or diffraction effects with incident light, thereby adjusting the propagation path of light and improving the filtering effect; the transition plate 4 effectively controls the refractive index change of light through the multi-layer film structure, provides smooth optical transition, optimizes the spectral response, and further improves the filtering effect.

[0023] Further, the filter plates 1 are arranged in two rows and three columns, through this arrangement, the filter plates 1 can obtain uniform light distribution in the entire optical system, avoiding the phenomenon of local light intensity unevenness, thereby improving the optical performance of the filter, especially at a non-perpendicular incidence angle, maintaining a relatively stable filtering effect.

[0024] Further, the structure units 2 are arranged in a four-by-four manner, through this arrangement, the filter can effectively improve the adjustment ability to incident light and realize more accurate wavelength selective transmission or reflection.

[0025] Further, the diameter or side length of each protrusion 3 ranges from 1 μm to 10 μm, which ensures that the protrusions 3 neither cause excessive light loss nor produce effective optical response at different wavelengths.

[0026] Further, the thickness of the silicon oxide layer is 50nm, the thickness of the germanium layer is 100nm, the thickness of the titanium oxide layer is 30nm, and the thickness of the silicon oxide layer is 50nm, so as to better the optical refraction characteristics, reduce the reflection loss, and improve the transmittance.

[0027] Further, the refractive index of the silicon oxide layer is 1.45, the refractive index of the germanium layer is 4.0, the refractive index of the titanium oxide layer is 2.5, and the refractive index of the silicon oxide layer is 1.45, so as to further improve the stability of the optical filter in multi-angle or wide-band applications.

[0028] Further, the filter plate 1 is arranged on the ZnSe substrate 5, and the thickness of the ZnSe substrate 5 is 50nm.

[0029] Optionally, the transition plate 4 is provided with a nonlinear gradient pattern.

[0030] Further, the nonlinear gradient pattern is an exponential or Gaussian type of geometric shape.

[0031] In the embodiment, the forming mode of the pattern can form an exponential or Gaussian type of gradient through photolithography, etching and other technologies, so that the optical performance of the transition plate 4 is more fine, and through the design, the optical response of the transition plate 4 can present a gradient change under different wavelengths of light or angles of incidence, so as to enhance the adaptability and angle stability of the optical filter to light, reduce the reflection loss, and improve the filtering effect under different angles.

[0032] Finally, it should be pointed out that the above embodiments are only used to illustrate the technical solutions of the present application and are not limited, 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 by equivalents without departing from the purpose and scope of the technical solutions of the present application, and all should be covered in the scope of the claims of the present application.

Claims

1. An optical filter, characterized by, The filter plate is provided with six filter plates, each of which comprises sixteen structural units, each of which is provided with a plurality of protrusions, the shape of the protrusions is one of circular, oval, rectangular or triangular, and transition plates are arranged between the structural units, the transition plates comprise silicon oxide layers, germanium layers, titanium oxide layers and silicon oxide layers which are overlapped from top to bottom.

2. An optical filter according to claim 1, wherein The filter plate is arranged in two rows and three columns.

3. An optical filter according to claim 1, wherein The structural units are arranged in a four-by-four manner.

4. An optical filter according to claim 1, wherein The diameter or side length of each protrusion ranges from 1 to 10 microns.

5. The optical filter of claim 1, wherein, The thickness of the silicon oxide layer is 50 nm, the thickness of the germanium layer is 100 nm, the thickness of the titanium oxide layer is 30 nm, and the thickness of the silicon oxide layer is 50 nm.

6. An optical filter according to claim 5, wherein The refractive index of the silicon oxide layer is 1.45, the refractive index of the germanium layer is 4.0, the refractive index of the titanium oxide layer is 2.5, and the refractive index of the silicon oxide layer is 1.

45.

7. The optical filter of claim 1, wherein, The filter plate is provided on a ZnSe substrate, and the thickness of the ZnSe substrate is 50 nm.

8. An optical filter according to any one of claims 1 to 7, wherein The transition plate is provided with a nonlinear gradient pattern.

9. An optical filter according to claim 8, wherein, The nonlinear gradient pattern is an exponential or Gaussian type of geometric shape.

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