Induced transmission filter, its preparation method, and ultraviolet detection system

Abstract

The present application provides an induced transmission filter, a preparation method thereof, and an ultraviolet detection system. The induced transmission filter includes a first dielectric layer, a first metal layer, a second dielectric layer, a second metal layer, a third dielectric layer, a third metal layer, and a fourth dielectric layer sequentially stacked on a substrate; the materials of the first metal layer, the second metal layer, and the third metal layer independently include metallic aluminum; the materials of the first dielectric layer, the second dielectric layer, the third dielectric layer, and the fourth dielectric layer independently include one or more of silicon dioxide, aluminum oxide, hafnium dioxide, and magnesium fluoride; the thicknesses of the first dielectric layer, the second dielectric layer, the third dielectric layer, and the fourth dielectric layer are independently 10 nm to 100 nm; the thicknesses of the first metal layer, the second metal layer, and the third metal layer are independently 10 nm to 40 nm. While the above filter has a high pass-band transmittance in the solar-blind band, it also improves the cut-off degree on both sides of the pass band.

Description

Technical Field

[0001] The present application relates to the field of optical technologies, and in particular, to an induced transmission filter, a preparation method thereof, and an ultraviolet detection system. Background Art

[0002] Sunlight is a complex light containing multiple wavelengths. When it passes through the atmosphere and enters the Earth, the light in the solar-blind ultraviolet band (200 nm - 280 nm) will be absorbed by the ozone layer. Therefore, the solar-blind ultraviolet light from the sun can hardly reach the Earth's surface. Due to the absence of interference from the sun, the largest solar-blind ultraviolet source, solar-blind ultraviolet detection has the advantage of low background noise. When power transmission lines and electrical equipment generate abnormalities, a large amount of ultraviolet light will be generated due to corona discharge, especially the ultraviolet light in the solar-blind band. Using this characteristic, such abnormalities can be captured. Therefore, the solar-blind ultraviolet imaging technology is applied to corona discharge detection.

[0003] The solar-blind ultraviolet filter is an important component of the ultraviolet detection system, which needs to cut off other bands to the maximum extent and retain the solar-blind ultraviolet band. An excellent solar-blind ultraviolet filter can significantly improve the acquisition performance of the solar-blind ultraviolet detection system. Common filters are divided into two categories: absorption filters and interference filters. The absorption filter is transparent to the light region of the target wavelength, but has an absorption effect on other specific bands, and realizes high suppression of background light through the absorption of materials. A simple absorption filter only has a high transmittance at the center position of the transmission peak, and the transmittance gradually decreases after deviating from the center; the interference filter forms a forbidden band with a certain width for some bands through the interference reflection of multiple thin films, and forms a transmission region in some other wavelength ranges. On the basis of these two filter technologies, hybrid filters and induced transmission filters are derived. The working principle of the induced transmission filter is that by selecting an appropriate substrate-side matching film stack admittance, the potential transmittance of the entire film system can be maximized. If an appropriate antireflection film stack is designed on the incident side at the same time, the reflection of the entire film system can be reduced to almost zero, thereby inducing the maximum transmittance of the metal film.

[0004] A variety of optical medium structures used in traditional filters can be used to prepare the passband for the solar-blind band and the stop bands on both sides of the solar-blind band, but the passband transmittance in the solar-blind ultraviolet band is still not high enough, and the passband uniformity is poor, with a large difference between the peak transmittance and the average transmittance. The cut-off degree on both sides of the passband for the solar-blind band is not high, resulting in an unsatisfactory filtering effect. Summary of the Invention

[0005] Based on this, in order to ensure a high passband transmittance in the 200 nm - 280 nm band while improving the cut-off degree of the stop bands on both sides of the passband, it is necessary to provide an induced transmission filter, a preparation method thereof, and an ultraviolet detection system.

[0006] The present application provides an induced transmission filter, which includes a first dielectric layer, a first metal layer, a second dielectric layer, a second metal layer, a third dielectric layer, a third metal layer, and a fourth dielectric layer that are sequentially stacked on a substrate;

[0007] The material of the first metal layer, the material of the second metal layer, and the material of the third metal layer each independently include aluminum metal;

[0008] The material of the first dielectric layer, the material of the second dielectric layer, the material of the third dielectric layer, and the material of the fourth dielectric layer each independently include one or more of silicon dioxide, aluminum oxide, hafnium dioxide, and magnesium fluoride;

[0009] The thickness of the first dielectric layer, the thickness of the second dielectric layer, the thickness of the third dielectric layer, and the thickness of the fourth dielectric layer are each independently 10 nm to 100 nm;

[0010] The thickness of the first metal layer, the thickness of the second metal layer, and the thickness of the third metal layer are each independently 10 nm to 40 nm.

[0011] In one embodiment, the thickness of the first dielectric layer and the thickness of the fourth dielectric layer are each independently 80 nm to 100 nm.

[0012] In one embodiment, the thickness of the second dielectric layer and the thickness of the third dielectric layer are each independently 30 nm to 60 nm.

[0013] In one embodiment, the thickness of the first metal layer and the thickness of the third metal layer are each independently 10 nm to 30 nm.

[0014] In one embodiment, the thickness of the second metal layer is 20 nm to 40 nm.

[0015] In one embodiment, the substrate includes a quartz substrate.

[0016] Furthermore, the present application also provides a preparation method for preparing the induced transmission filter as described above, including the following steps:

[0017] Provide the substrate;

[0018] Prepare the first dielectric layer, the first metal layer, the second dielectric layer, the second metal layer, the third dielectric layer, the third metal layer, and the fourth dielectric layer on the substrate in sequence.

[0019] In one embodiment, the following one or two conditions are satisfied:

[0020] (1) The method for preparing the first dielectric layer, the second dielectric layer, the third dielectric layer, and the fourth dielectric layer independently includes one or both of physical vapor deposition and chemical vapor deposition;

[0021] (2) The conditions for preparing the first dielectric layer, the second dielectric layer, the third dielectric layer, and the fourth dielectric layer independently include: the preparation temperature is 20°C to 50°C, and the vacuum degree is not higher than 1×10 -3 Pa;

[0022] (3) The method for preparing the first metal layer, the second metal layer, and the third metal layer independently includes one or both of physical vapor deposition and chemical vapor deposition;

[0023] (4) The conditions for preparing the first metal layer, the second metal layer, and the third metal layer independently include: the preparation temperature is 20°C to 50°C, and the vacuum degree is not higher than 6×10 -4 Pa.

[0024] Further, the present application also provides an ultraviolet detection system, including the induced transmission filter as described above.

[0025] In one embodiment, the ultraviolet detection is a solar-blind ultraviolet detection system.

[0026] The induced transmission filter provided by the present application includes a stacked dielectric layer and metal layer. Through the structural design of the induced transmission filter, reasonable selection of the materials and thickness parameter limitations of each dielectric layer and each metal layer, the admittance matching design of the incident medium, the film stack system, and the outgoing medium is achieved, so as to obtain a high-passband transmittance in the wavelength range of 200 nm to 280 nm while improving the cut-off degree on both sides of the passband. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the following drawings are some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0028] Figure 1 It is the induced transmission filter provided by an embodiment of the present application;

[0029] Figure 2 It is the transmittance of the induced transmission filter of Example 1 under different wavelength lights.

[0030] DESCRIPTION OF REFERENCE NUMERALS

[0031] 10: Inductive transmission filter; 100: Substrate; 110: First dielectric layer; 120: First metal layer; 130: Second dielectric layer; 140: Second metal layer; 150: Third dielectric layer; 160: Third metal layer; 170: Fourth dielectric layer. Detailed implementation manners

[0032] To facilitate the understanding of the present application, the present application will be described more comprehensively below with reference to the relevant drawings. Preferred embodiments of the present application are shown in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the understanding of the disclosure of the present application more thorough and comprehensive.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs. The terms used in the specification of this application herein are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0034] The term "and / or" as used herein includes any one of two or more related listed items, as well as any and all combinations of the related listed items. The any and all combinations include any two related listed items, any more related listed items, or the combination of all related listed items. For example, "A and / or B" includes three parallel solutions: A, B, and "the combination of A and B".

[0035] In this document, unless otherwise specified, "one or more" means any one of the listed items or any combination of the listed items. Similarly, other cases such as "one or more" are understood in the same way unless otherwise specified.

[0036] In this document, words such as "further", "even further", "especially", "for example", "such as", "example", "exemplification" are used for descriptive purposes, indicating that there is an association in the covered content between the different technical solutions before and after, but should not be understood as a limitation on the previous technical solution, nor can it be understood as a limitation on the protection scope of this document. In this document, unless otherwise specified, A (such as B) means that B is a non-limiting example of A, and it can be understood that A is not limited to B.

[0037] In this text, "optionally", "optional", and "option" mean having or not having, that is, either of the two parallel options of "having" or "not having". If "optional" appears multiple times in a technical solution, without special instructions, and without contradictions or mutual constraints, each "optional" is independent. In this application, descriptions such as "optionally contain" and "optionally include" mean "contain or not contain". "Optional component X" means that component X exists or does not exist, or means containing or not containing the component X.

[0038] In this text, in "the first aspect", "the second aspect", "the third aspect", "the fourth aspect", etc., the terms "first", "second", "third", "fourth", etc. are only for descriptive purposes and cannot be understood as indicating or implying relative importance or quantity, nor can they be understood as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first", "second", "third", "fourth", etc. only serve the purpose of non-exhaustive enumeration and description and should be understood not to constitute a closed limitation on quantity.

[0039] In this text, among the technical features described in an open-ended manner, it includes a closed technical solution composed of the listed features, and also includes an open-ended technical solution containing the listed features.

[0040] In this text, regarding a numerical interval (i.e., a numerical range), without special instructions, the distribution of the optional numerical values within this numerical interval is considered continuous and includes the two numerical endpoints of this numerical interval (i.e., the minimum value and the maximum value), as well as each numerical value between these two numerical endpoints. Without special instructions, when the numerical interval only refers to the integers within this numerical interval, it includes the two endpoint integers of this numerical range, as well as each integer between the two endpoints, which is equivalent to directly listing each integer. When providing multiple numerical ranges to describe features or characteristics, these numerical ranges can be combined. In other words, unless otherwise specified, the numerical ranges disclosed in this text should be understood to include any and all sub-ranges subsumed therein. The "numerical value" in this numerical interval can be any quantitative value, such as a number, a percentage, a ratio, etc. The "numerical interval" allows for a broad inclusion of numerical interval types such as percentage intervals, ratio intervals, and ratio value intervals.

[0041] In this text, the term "room temperature" or "normal temperature" generally refers to 4°C to 35°C, such as 20°C ± 5°C. In some embodiments of this text, "room temperature" or "normal temperature" refers to 10°C to 30°C. In some embodiments of this text, "room temperature" or "normal temperature" refers to 20°C to 30°C.

[0042] In this document, for a method flow involving multiple steps, unless there are clear and different descriptions in this document, the execution of these steps has no strict order limitation, and they can be executed in an order other than the described one. Moreover, any step may include multiple sub-steps or multiple stages. These sub-steps or stages do not necessarily need to be completed at the same moment, but can be executed at different moments, and their execution order does not necessarily need to be sequential, but can be executed alternately or simultaneously with other steps or a part of the sub-steps or stages of other steps.

[0043] As Figure 1 shown, the present application provides an induced transmission filter 10, which includes a first dielectric layer 110, a first metal layer 120, a second dielectric layer 130, a second metal layer 140, a third dielectric layer 150, a third metal layer 160, and a fourth dielectric layer 170 that are sequentially stacked on a substrate 100;

[0044] The materials of the first metal layer 120, the second metal layer 140, and the third metal layer 160 each independently include aluminum metal;

[0045] The materials of the first dielectric layer 110, the second dielectric layer 130, the third dielectric layer 150, and the fourth dielectric layer 170 each independently include one or more of silicon dioxide, aluminum oxide, hafnium dioxide, and magnesium fluoride;

[0046] The thicknesses of the first dielectric layer 110, the second dielectric layer 130, the third dielectric layer 150, and the fourth dielectric layer 170 are each independently 10 nm to 100 nm;

[0047] The thicknesses of the first metal layer 120, the second metal layer 140, and the third metal layer 160 are each independently 10 nm to 40 nm.

[0048] Preferably, the materials of the first dielectric layer 110, the second dielectric layer 130, the third dielectric layer 150, and the fourth dielectric layer 170 each independently include one or more of silicon dioxide, a mixture of aluminum oxide and silicon dioxide, hafnium dioxide, and magnesium fluoride.

[0049] Further, the mass ratio of aluminum oxide to silicon dioxide in the above-mentioned mixture of aluminum oxide and silicon dioxide can be but is not limited to 1: (2 - 6). Specifically, the mass ratio of aluminum oxide to silicon dioxide can be but is not limited to 1:2, 1:3, 1:4, 1:5, or 1:6.

[0050] In a specific example, the thickness of the first dielectric layer 110 and the thickness of the fourth dielectric layer 170 are each independently 80 nm to 100 nm. It can be understood that the thickness of the first dielectric layer 110 and the thickness of the fourth dielectric layer 170 can be, but are not limited to, each independently 80 nm, 81 nm, 82 nm, 83 nm, 84 nm, 85 nm, 86 nm, 87 nm, 88 nm, 89 nm, 90 nm, 91 nm, 92 nm, 93 nm, 94 nm, 95 nm, 96 nm, 97 nm, 98 nm, 99 nm, or 100 nm.

[0051] In a specific example, the thickness of the second dielectric layer 130 and the thickness of the third dielectric layer 150 are each independently 30 nm to 60 nm. It can be understood that the thickness of the second dielectric layer 130 and the thickness of the third dielectric layer 150 can be, but are not limited to, each independently 30 nm, 31 nm, 32 nm, 33 nm, 34 nm, 35 nm, 36 nm, 37 nm, 38 nm, 39 nm, 40 nm, 41 nm, 42 nm, 43 nm, 44 nm, 45 nm, 46 nm, 47 nm, 48 nm, 49 nm, 50 nm, 51 nm, 52 nm, 53 nm, 54 nm, 55 nm, 56 nm, 57 nm, 58 nm, 59 nm, or 60 nm.

[0052] In a specific example, the thickness of the first metal layer 120 and the thickness of the third metal layer 160 are each independently 10 nm to 30 nm. It can be understood that the thickness of the first metal layer 120 and the thickness of the third metal layer 160 can be, but are not limited to, each independently 10 nm, 11 nm, 12 nm, 13 nm, 14 nm, 15 nm, 16 nm, 17 nm, 18 nm, 19 nm, 20 nm, 21 nm, 22 nm, 23 nm, 24 nm, 25 nm, 26 nm, 27 nm, 28 nm, 29 nm, or 30 nm.

[0053] In a specific example, the thickness of the second metal layer 140 is 20 nm to 40 nm. It can be understood that the thickness of the second metal layer 140 can be, but is not limited to, 20 nm, 21 nm, 22 nm, 23 nm, 24 nm, 25 nm, 26 nm, 27 nm, 28 nm, 29 nm, 30 nm, 31 nm, 32 nm, 33 nm, 34 nm, 35 nm, 36 nm, 37 nm, 38 nm, 39 nm, or 40 nm.

[0054] In a specific example, the substrate 100 includes a quartz substrate.

[0055] The induced transmission filter 10 provided in this application is composed of a dielectric layer and a metal layer. Through the structural design of the induced transmission filter 10, reasonable selection of the materials of each dielectric layer and each metal layer, and limitation of the thickness parameters, the admittance matching design of the incident medium, the film stack system, and the outgoing medium is realized, so as to obtain a high-passband transmittance in the band of 200 nm to 280 nm while improving the cut-off degree on both sides of the passband.

[0056] Furthermore, this application also provides a preparation method for the induced transmission filter 10 as described above, including the following steps:

[0057] Provide the substrate 100;

[0058] Successively prepare a first dielectric layer 110, a first metal layer 120, a second dielectric layer 130, a second metal layer 140, a third dielectric layer 150, a third metal layer 160, and a fourth dielectric layer 170 on the substrate 100.

[0059] In a specific example, the methods for preparing the first dielectric layer 110, the second dielectric layer 130, the third dielectric layer 150, and the fourth dielectric layer 170 each independently include one or two of physical vapor deposition and chemical vapor deposition. Preferably, the physical vapor deposition is electron beam evaporation.

[0060] In a specific example, the conditions for preparing the first dielectric layer 110, the second dielectric layer 130, the third dielectric layer 150, and the fourth dielectric layer 170 each independently include: the preparation temperature is 20°C to 50°C, and the vacuum degree is not higher than 1×10 -3 Pa. It can be understood that the preparation temperature can be but is not limited to 20°C, 21°C, 22°C, 23°C, 24°C, 25°C, 26°C, 27°C, 28°C, 29°C, 30°C, 31°C, 32°C, 33°C, 34°C, 35°C, 36°C, 37°C, 38°C, 39°C, 40°C, 41°C, 42°C, 43°C, 44°C, 45°C, 46°C, 47°C, 48°C, 49°C, or 50°C.

[0061] Preferably, the method for preparing the first dielectric layer 110, the second dielectric layer 130, the third dielectric layer 150, and the fourth dielectric layer 170 is electron beam evaporation, with a deposition rate of 0.1 nm / s to 0.5 nm / s and a current of 30 mA to 70 mA. Specifically, the deposition rate can be, but is not limited to, 0.1 nm / s, 0.15 nm / s, 0.2 nm / s, 0.25 nm / s, 0.3 nm / s, 0.35 nm / s, 0.4 nm / s, 0.45 nm / s, or 0.5 nm / s, and the current can be, but is not limited to, 30 mA, 35 mA, 40 mA, 45 mA, 50 mA, 55 mA, 60 mA, 65 mA, or 70 mA.

[0062] In a specific example, the method for preparing the first metal layer 120, the second metal layer 140, and the third metal layer 160 independently includes one or both of physical vapor deposition and chemical vapor deposition. Preferably, the physical vapor deposition is resistance evaporation.

[0063] In a specific example, the conditions for preparing the first metal layer 120, the second metal layer 140, and the third metal layer 160 independently include: the preparation temperature is 20°C to 50°C, and the vacuum degree is not higher than 6×10 -4 Pa. It can be understood that the preparation temperature can be, but is not limited to, 20°C, 21°C, 22°C, 23°C, 24°C, 25°C, 26°C, 27°C, 28°C, 29°C, 30°C, 31°C, 32°C, 33°C, 34°C, 35°C, 36°C, 37°C, 38°C, 39°C, 40°C, 41°C, 42°C, 43°C, 44°C, 45°C, 46°C, 47°C, 48°C, 49°C, or 50°C.

[0064] Preferably, the method for preparing the first metal layer 120, the second metal layer 140, and the third metal layer 160 is resistive evaporation, with a deposition rate of 0.5 nm / s to 3 nm / s and a current of 2 A to 5 A. Specifically, the deposition rate can be, but is not limited to, 0.5 nm / s, 0.6 nm / s, 0.7 nm / s, 0.8 nm / s, 0.9 nm / s, 1 nm / s, 1.1 nm / s, 1.2 nm / s, 1.3 nm / s, 1.4 nm / s, 1.5 nm / s, 1.6 nm / s, 1.7 nm / s, 1.8 nm / s, 1.9 nm / s, 2 nm / s, 2.1 nm / s, 2.2 nm / s, 2.3 nm / s, 2.4 nm / s, 2.5 nm / s, 2.6 nm / s, 2.7 nm / s, 2.8 nm / s, 2.9 nm / s, or 3 nm / s, and the current can be, but is not limited to, 2 A, 2.1 A, 2.2 A, 2.3 A, 2.4 A, 2.5 A, 2.6 A, 2.7 A, 2.8 A, 2.9 A, 3 A, 3.1 A, 3.2 A, 3.3 A, 3.4 A, 3.5 A, 3.6 A, 3.7 A, 3.8 A, 3.9 A, 4 A, 4.1 A, 4.2 A, 4.3 A, 4.4 A, 4.5 A, 4.6 A, 4.7 A, 4.8 A, 4.9 A, or 5 A.

[0065] Furthermore, the present application also provides an ultraviolet detection system, including the induced transmission filter 10 as described above.

[0066] It can be understood that the above ultraviolet detection is a solar-blind ultraviolet detection system.

[0067] The following further elaborates on the present application with specific embodiments. It should be understood that these embodiments are only used to illustrate the present application and not to limit the scope of the present application. For the experimental methods without specific conditions in the following embodiments, priority is given to the guidance provided in the present application, and it can also be carried out according to the experimental manuals or conventional conditions in the art, or according to the conditions recommended by the manufacturers, or referring to the experimental methods known in the art.

[0068] In the following specific embodiments, regarding the measurement parameters of the raw material components, without special instructions, there may be slight deviations within the weighing accuracy range. Regarding the temperature and time parameters, acceptable deviations caused by instrument testing accuracy or operation accuracy are allowed. "Normal temperature" refers to 25°C; "normal pressure" refers to 100 KPa or 101 Kpa. The mixture of aluminum oxide and silicon dioxide with a mass ratio of 1:4 for the dielectric layer material is purchased from Xuyi Xinyuan Optoelectronic Technology Co., Ltd.

[0069] Example 1

[0070] This embodiment provides an induced transmission filter, which includes a 90-nm-thick silicon dioxide film, a 20-nm-thick aluminum film, a 45-nm-thick silicon dioxide film, a 30-nm-thick aluminum film, a 45-nm-thick silicon dioxide film, a 20-nm-thick aluminum film, and a 90-nm-thick silicon dioxide film that are sequentially stacked on a quartz substrate.

[0071] The preparation method of the induced transmission filter in this embodiment is as follows:

[0072] First, prepare a fused ultraviolet quartz substrate. Polish the quartz substrate with diamond powder and clean it with a mixed solution of ethanol and ether. Use electron beam evaporation to grow a SiO2 film, set the vacuum degree not less than 1×10 -3 Pa, the deposition rate is 0.35 nm / s, the current is 50 mA, keep the temperature below 50 °C, and prepare a thickness of 90 nm.

[0073] Subsequently, ultrasonically clean and wipe the Al wire with alcohol to remove impurities. When preparing, set the vacuum degree not less than 6×10 -4 Pa, the deposition rate is 1.5 nm / s, the current is 3.8 A, the temperature is below 50 °C, and the thickness is 20 nm.

[0074] Use electron beam evaporation to grow a SiO2 film again, set the vacuum degree not less than 1×10 -3 Pa, the deposition rate is 0.35 nm / s, the current is 50 mA, keep the temperature below 50 °C, and prepare a thickness of 45 nm. Then, after completing the ultrasonic cleaning and alcohol wiping of the Al wire to remove impurities. When preparing, set the vacuum degree not less than 6×10 -4 Pa, the deposition rate is 1.5 nm / s, the current is 3.8 A, the temperature is below 50 °C, and the thickness is 30 nm. Repeat the above conditions and process again to generate a 45-nm SiO2 film, a 20-nm Al film, and a 90-nm SiO2 film, and finally complete the preparation of the induced transmission filter.

[0075] As Figure 2 shown, for the relationship between each wavelength band and the transmittance of the induced transmission filter provided in this embodiment, it can be seen that the peak transmittance wavelength of this induced transmission filter is 235 nm, the peak transmittance is about 20.9%, the bandwidth is about 40 nm, and the transmittances at 200 nm, 280 nm, 320 nm, and 400 nm wavelength bands are about 3.4%, 0.5%, 0.04%, and 0.0054% respectively. The cut-off degrees in the wavelength bands above 400 nm can reach 4.5 OD.

[0076] Example 2

[0077] On the basis of Example 1, only the material of the dielectric layer is changed and replaced with a mixture of aluminum oxide and silicon dioxide mixed at a mass ratio of 1:4 (hereinafter referred to as the mixture). A 90-nm-thick mixture film, a 20-nm-thick aluminum film, a 45-nm-thick mixture film, a 30-nm-thick aluminum film, a 45-nm-thick mixture film, a 20-nm-thick aluminum film, and a 90-nm-thick mixture film are sequentially stacked from the quartz substrate to the outside.

[0078] Corresponding to a peak transmittance wavelength of 233 nm, the peak transmittance is about 19.3%, the bandwidth is about 41 nm, and the transmittances at 200 nm, 280 nm, 320 nm, and 400 nm bands are about 3.2%, 0.42%, 0.037%, and 0.0052% respectively. The cut-off degrees in the bands above 400 nm can reach 4.5 OD respectively.

[0079] Example 3

[0080] On the basis of Example 1, only the thickness of the dielectric layer is changed. A 100-nm-thick silicon dioxide film, a 20-nm-thick aluminum film, a 52-nm-thick silicon dioxide film, a 30-nm-thick aluminum film, a 52-nm-thick silicon dioxide film, a 20-nm-thick aluminum film, and a 100-nm-thick silicon dioxide film are sequentially stacked from the quartz substrate to the outside.

[0081] Corresponding to a peak transmittance wavelength of 251 nm, the peak transmittance is about 20.4%, the bandwidth is about 37 nm, and the transmittances at 200 nm, 280 nm, 320 nm, and 400 nm bands are about 2.6%, 0.63%, 0.06%, and 0.0059% respectively. The cut-off degrees in the bands above 400 nm can reach 4.5 OD respectively.

[0082] Example 4

[0083] On the basis of Example 1, only the thickness of the metal layer is changed. A 90-nm-thick silicon dioxide film, a 22-nm-thick aluminum film, a 45-nm-thick silicon dioxide film, a 33-nm-thick aluminum film, a 45-nm-thick silicon dioxide film, a 22-nm-thick aluminum film, and a 90-nm-thick silicon dioxide film are sequentially stacked from the quartz substrate to the outside.

[0084] Corresponding to a peak transmittance wavelength of 239 nm, the peak transmittance is about 15.4%, the bandwidth is about 45 nm, and the transmittances at 200 nm, 280 nm, 320 nm, and 400 nm bands are about 2.2%, 0.41%, 0.031%, and 0.0049% respectively. The cut-off degrees in the bands above 400 nm can reach 4.5 OD respectively.

[0085] Comparative Example 1

[0086] Based on Example 1, only the thickness of the fourth metal layer is changed. A 90-nm-thick silicon dioxide film, a 20-nm-thick aluminum film, a 45-nm-thick silicon dioxide film, a 45-nm-thick aluminum film, a 45-nm-thick silicon dioxide film, a 20-nm-thick aluminum film, and a 90-nm-thick silicon dioxide film are sequentially stacked from the quartz substrate to the outside.

[0087] Corresponding to a peak transmittance wavelength of 241 nm, the peak transmittance is about 6.2%, the bandwidth is about 17 nm, and the transmittances at 200 nm, 280 nm, 320 nm, and 400 nm bands are about 0.9%, 0.24%, 0.017%, and 0.0027% respectively.

[0088] Comparative Example 2

[0089] Based on Example 1, only the metal layer material is changed and replaced with rhodium. A 90-nm-thick silicon dioxide film, a 20-nm-thick rhodium film, a 45-nm-thick silicon dioxide film, a 30-nm-thick aluminum film, a 45-nm-thick silicon dioxide film, a 20-nm-thick aluminum film, and a 90-nm-thick silicon dioxide film are sequentially stacked from the quartz substrate to the outside.

[0090] Corresponding to a peak transmittance wavelength of 247 nm, the peak transmittance is about 13.5%, the bandwidth is about 34 nm, and the transmittances at 200 nm, 280 nm, 320 nm, and 400 nm bands are about 2.5%, 0.32%, 0.031%, and 0.0035% respectively.

[0091] The optical properties of the induced transmission filters in the above examples and comparative examples are summarized in the following table:

[0092]

[0093] It can be understood that the above bandwidth refers to the full width at half maximum. By comparing the induced transmission filters in the above examples and comparative examples, it can be seen that the induced transmission filter provided by the embodiments of the present application can achieve a peak transmittance of more than 15% and a full width at half maximum of more than 35 nm in the range of 200 nm to 800 nm, and the transmittances on both sides of the passband are below 1%, and even the transmittances at the endpoints of the passband are below 4%. In Examples 1 and 2, with appropriate materials and thickness ranges, the peak transmittance of the induced transmission filter in the range of 200 nm to 800 nm can reach more than 19% and the full width at half maximum can be guaranteed to be 40 nm. In Example 3, while changing the thickness of the dielectric layer, the peak point of the transmittance wavelength is also changed.

[0094] Under the condition of changing the thickness of the metal layer in Comparative Example 1 and changing the material of the metal layer in Comparative Example 2, the highest peak transmittance in the range of 200 nm to 800 nm is only 13.5%, and the highest full width at half maximum is only 34 nm. Moreover, the replacement of the material in Comparative Example 2 will result in poor adhesion between materials, which will reduce the yield rate and service life of this induced transmission filter.

[0095] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0096] The above-described embodiments only represent several implementation manners of the present application. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several deformations and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims, and the specification and drawings can be used to explain the scope of the claims.

Claims

1. An induced transmission filter, characterized in that, It includes a first dielectric layer, a first metal layer, a second dielectric layer, a second metal layer, a third dielectric layer, a third metal layer, and a fourth dielectric layer that are sequentially stacked on a substrate; The materials of the first metal layer, the second metal layer, and the third metal layer each independently include metallic aluminum; the materials of the first dielectric layer, the second dielectric layer, the third dielectric layer, and the fourth dielectric layer are each independently silicon dioxide or a mixture with a mass ratio of aluminum oxide to silicon dioxide of 1:4; The thicknesses of the first dielectric layer and the fourth dielectric layer are each independently 90 nm to 100 nm; the thicknesses of the second dielectric layer and the third dielectric layer are each independently 45 nm to 52 nm; the thicknesses of the first metal layer and the third metal layer are each independently 20 nm; the thickness of the second metal layer is 30 nm; The induced transmission filter is used for solar-blind ultraviolet band detection.

2. The induced transmission filter according to claim 1, wherein The substrate includes a quartz substrate.

3. An ultraviolet detection system, characterized in that, It includes the induced transmission filter according to any one of claims 1 to 2.

4. The ultraviolet detection system according to claim 3, characterized in that, The ultraviolet detection is a solar-blind ultraviolet detection system.

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