Visible light filter and fluorescence detection device
By designing visible light filters with metal-dielectric-metal structures and circular nanodisk microstructures, the complexity and high cost of traditional coated filters have been solved, achieving high transmittance and narrowband filtering effects, and supporting multi-passband integration.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-06
- Publication Date
- 2026-04-10
AI Technical Summary
In the existing technology, traditional coated filters have complex structures and high costs, making it difficult to integrate multiple filters on the same substrate, and it is also difficult to achieve high cutoff and narrow bandwidth filtering effects.
A visible light filter is designed using a periodically arranged metal-dielectric-metal structure combined with a circular nanodisk microstructure. By adjusting the thickness of the metal and dielectric layers and the distribution of the microstructure, narrowband filtering and multi-passband filtering effects can be achieved.
It achieves high transmittance and narrowband filtering in the visible light band, reduces filter thickness, simplifies structure, reduces cost, and supports multi-passband integration.
Smart Images
Figure CN224109674U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the field of fluorescence detection, and particularly relates to a visible light filter and a fluorescence detection device BACKGROUND
[0002] With the deepening of the field of biology research, gene detection technology has been greatly developed. As a fast and accurate detection method, fluorescence detection is widely used. In the actual detection process, in order to distinguish the excitation light from the fluorescence, a filter with high cutoff and narrow bandwidth is needed.
[0003] Such a filter is usually realized by coating. In order to realize such a band-pass filtering characteristic, a stack of hundreds of film systems is usually needed, which has a complex structure and high cost. Different thicknesses and numbers of layers are needed for different passbands, and it is difficult to integrate multiple filters on the same substrate. CONTENT OF THE INVENTION
[0004] The application provides a visible light filter and a fluorescence detection device to at least solve the above technical problems in the prior art.
[0005] The application provides a visible light filter, which comprises a substrate and a structure layer arranged on the substrate. The structure layer is composed of a plurality of unit structures arranged periodically. The period size of the unit structure is 200 nm. Any unit structure comprises a first metal layer, a dielectric layer and a second dielectric layer. The dielectric layer is internally provided with a microstructure. The thickness of the dielectric layer is greater than the thickness of the microstructure. The microstructure is a circular nanodisk. The radial size of the microstructure ranges from 50 nm to 180 nm and is distributed along the central plane of the dielectric layer.
[0006] In an implementable manner, the radius r of the circular nanodisk is 20-90nm.
[0007] In an implementable manner, the radius r of the circular nanodisk is any one of 34nm, 64nm or 83nm.
[0008] In an implementable manner, the circular nanodisk comprises a combined structure of two different radii r1 and r2, and the radii r1 and r2 are 20-90nm.
[0009] In an implementable manner, the radii r1 and r2 of the circular nanodisk are any one of 34nm, 64nm or 83nm, and r1 and r2 are different values.
[0010] In an implementable manner, the first metal layer is tightly attached to the substrate, and the thickness thereof is in the range of 1-50nm; the thickness of the second metal layer is in the range of 1-50nm.
[0011] In an embodiment, the thickness of the dielectric layer is in the range of 80-300 nm, and the thickness of the microstructure is in the range of 20-100 nm.
[0012] In an embodiment, the thickness of the metal layer is 35 nm, the thickness of the dielectric layer is 100 nm, and the thickness of the microstructure is 50 nm.
[0013] Another aspect of the embodiments of the present application provides a fluorescence detection device, which comprises any of the visible light filters described above.
[0014] In an embodiment, the fluorescence detection device further comprises a detector, an excitation light generating device, and a reaction tube, the visible light filter is installed in front of the detector, and the visible light filter is used to filter the light of non-target wavelength in the incident light and simultaneously focus the light of target wavelength on the detector. BRIEF DESCRIPTION OF DRAWINGS
[0015] Figure 1 is a schematic diagram of the principle of the visible light filter in Embodiment 1 of the present application;
[0016] Figure 2 is a schematic diagram of the structure of the visible light filter in Embodiment 1 of the present application;
[0017] Figure 3 is a top view of the microstructure in Embodiment 1 of the present application;
[0018] Figure 4 is a schematic diagram of the transmittance curve of the visible light filter in Embodiment 1 of the present application;
[0019] Figure 5 is a schematic diagram of the principle of the visible light filter in Embodiment 2 of the present application;
[0020] Figure 6 is a schematic diagram of the structure of the visible light filter in Embodiment 2 of the present application;
[0021] Figure 7 is a top view of the microstructure in Embodiment 2 of the present application;
[0022] Figure 8 is a schematic diagram of the transmittance curve of the visible light filter in Embodiment 2 of the present application;
[0023] BRIEF DESCRIPTION OF DRAWINGS
[0024] (1, 3) substrate; (2, 4) structure layer; (21, 41) first metal layer; (22, 42) dielectric layer; (23, 43) microstructure; (24, 44) second metal layer. DETAILED DESCRIPTION
[0025] The application will be described in further detail below with reference to the drawings.
[0026] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.
[0027] Traditional filters are usually achieved by coating, but the coating method requires a large number of film layers and a complex structure, and the cost is high. In addition, different thicknesses and numbers of layers are required for different passbands, and it is difficult to integrate multiple filters on the same substrate.
[0028] The purpose of the present application is to provide a metasurface filter structure that can realize band-pass filtering of visible light. The metal-dielectric-metal structure design realizes narrow-band filtering of visible light, which reduces the thickness compared with the traditional coating scheme. The introduction of the intermediate high-refractive-index dielectric block realizes the modulation of the filter passband without changing the film layer thickness. At the same time, by combining different types of microstructures, multiple passbands in the visible light can be realized.
[0029] The embodiment of the present application provides a visible light filter, which comprises a substrate and a structure layer arranged on the substrate. The structure layer is composed of a plurality of unit structures arranged periodically, the period size of the unit structure is 200nm, any unit structure comprises a first metal layer, a dielectric layer and a second dielectric layer, the dielectric layer is internally provided with a microstructure, and the thickness of the dielectric layer is greater than the thickness of the microstructure. The microstructure is a circular nanodisk, the radial size of the microstructure ranges from 50nm to 180nm, and the microstructure is distributed along the center plane of the dielectric layer.
[0030] The radius r of the circular nanodisk is 20-90nm. Among them, the radius r of the circular nanodisk is any one of 34nm, 64nm or 83nm. The circular nanodisk can also be a combined structure of two different radii r1 and r2, and the radii r1 and r2 range from 20nm to 90nm. The radii r1 and r2 of the circular nanodisk are any one of 34nm, 64nm or 83nm, and r1 and r2 are different values.
[0031] The first metal layer is tightly attached to the substrate, and the thickness thereof is in the range of 1-50nm. The thickness of the second metal layer is in the range of 1-50nm. The thickness of the dielectric layer is in the range of 80-300nm, and the thickness of the microstructure is in the range of 20-100nm. The thickness of the metal layer is 35nm, the thickness of the dielectric layer is 100nm, and the thickness of the microstructure is 50nm.
[0032] Example 1
[0033] This embodiment provides a visible light filter with a single passband, comprising a substrate 1 and a structural layer 2, the effect of which is as follows: Figure 1 As shown, when a wide wavelength of light is incident, light in a certain middle band will pass through. The filter is made of... Figure 2 The structure shown is periodically assembled, with a period size of 200 nm. The substrate 1 is made of glass. The structural layer 2 is a metal-dielectric-metal structure, including a first metal layer 21, a dielectric layer 22, and a second metal layer 24. A microstructure 23 is located within the dielectric layer 22. The first metal layer 21 and the second metal layer 24 are made of silver, the dielectric layer 22 is made of silicon oxide, and the microstructure 23 is made of silicon. To ensure high transmittance and a narrow passband for the filter, the first metal layer 21 and the second metal layer are 35 nm thick, the dielectric layer 22 is 100 nm thick, and the microstructure 23 is 50 nm thick and positioned in the middle of the dielectric layer 22. The microstructure 23 is shaped like a circular nanodisc, and its top view is shown below. Figure 3 As shown, its radius r varies from 25 to 90 nm. Figure 4 Transmittance curves for three different microstructure radii are presented, with center wavelengths of 450 nm, 532 nm and 632 nm, and corresponding microstructure radii of 34 nm, 64 nm and 83 nm, respectively.
[0034] Example 2
[0035] This embodiment provides a visible light filter with dual passbands, comprising a substrate 3 and a structural layer 4, the effects of which are as follows: Figure 5 As shown, when a wide wavelength of light is incident, light in a certain intermediate band will pass through. The filter is made of... Figure 6 The structure shown is periodically assembled, with a period size of 200 nm. The substrate 3 is made of glass. The structural layer 4 is a metal-dielectric-metal structure, including a first metal layer 41, a dielectric layer 42, and a second metal layer 44. A microstructure 43 is located within the dielectric layer 42. The first metal layer 41 and the second metal layer 44 are made of silver, the dielectric layer 42 is made of silicon oxide, and the microstructure 43 is made of silicon. To ensure high transmittance and a narrow passband for the filter, the first metal layer 41 and the second metal layer 44 are 35 nm thick, the dielectric layer 42 is 100 nm thick, and the microstructure 43 is 50 nm thick and positioned in the middle of the dielectric layer 42. The microstructure 43 is shaped like a circular nanodisc, and its top view is shown below. Figure 7 As shown, the nanodisk radii r1 and r2 can be obtained through optimization. The optimization evaluation function can be expressed by the following formula:
[0036]
[0037] Wherein, Tdes(λi) is the required transmittance, and Treal(λi) is the actual transmittance value obtained by simulation calculation. Figure 8 The transmittance curves of three different microstructure radii are given, and the central wavelengths are 450 nm and 632 nm respectively.
[0038] The application further discloses a fluorescence detection device, which comprises the above visible light filter, a detector, an excitation light generating device and a reaction tube.
[0039] The above is only a specific embodiment of the present disclosure, but the protection scope of the present disclosure is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present disclosure, which should be covered within the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be subject to the protection scope of the claims.
Claims
1. A visible light filter, characterized by: The substrate and a structure layer arranged on the substrate; The structure layer is composed of a plurality of unit structures arranged periodically, the period size of the unit structure is 200 nm, any unit structure comprises a first metal layer, a dielectric layer and a second dielectric layer, the dielectric layer is internally provided with a microstructure, and the thickness of the dielectric layer is greater than the thickness of the microstructure; The microstructure is a circular nanodisc, the radial size of the microstructure ranges from 50 nm to 180 nm, and the microstructure is distributed along the central plane of the dielectric layer.
2. The visible light filter of claim 1, wherein: The radius r of the circular nanodisc ranges from 20 nm to 90 nm.
3. A visible light filter according to claim 2, wherein: The radius r of the circular nanodisc is any one of 34 nm, 64 nm or 83 nm.
4. The visible light filter of claim 1, wherein: The circular nanodisc comprises a combined structure of two different radii r1 and r2, and the radii r1 and r2 range from 20 nm to 90 nm.
5. A visible light filter according to claim 4, wherein: The radii r1 and r2 of the circular nanodisc are any one of 34 nm, 64 nm or 83 nm, and r1 and r2 are different values.
6. The visible light filter of claim 1, wherein: The first metal layer is tightly attached to the substrate, and the thickness of the first metal layer ranges from 1 nm to 50 nm; the thickness of the second metal layer ranges from 1 nm to 50 nm.
7. A visible light filter according to claim 6, wherein: The thickness of the dielectric layer ranges from 80 nm to 300 nm, and the thickness of the microstructure ranges from 20 nm to 100 nm.
8. A visible light filter according to claim 7, wherein: The thickness of the metal layer is 35 nm, the thickness of the dielectric layer is 100 nm, and the thickness of the microstructure is 50 nm.
9. A fluorescence detection device characterized by: The visible light filter comprises any one of claims 1-8.
10. The fluorescence detection device of claim 9, comprising a detector, an excitation light generating device and a reaction tube, characterized in that: The visible light filter is arranged in front of the detector, and the visible light filter is used for filtering non-target wavelength light in incident light and simultaneously focusing target wavelength light on the detector.