An infrared filter and its preparation method and its application in marine gas remote sensing detector

Abstract

The invention discloses an infrared filter and a preparation method thereof and an application in a marine gas remote sensing detector. The infrared filter is composed of a Si substrate and a coating layer on its surface; wherein the coating layer is composed of multiple layers of SiO coating layers and Si coating layers alternately superimposed. By alternately coating SiO coating layers and Si coating layers on the surface of the Si substrate by ion sputtering, an infrared filter with three channels of 2.8μm band, 2.35μm band and 1.59μm band is obtained. The infrared filter can realize one or more gas detections, and other infrared filters do not need to be replaced during the detection process, which greatly reduces the volume and weight of the remote sensing detection device and reduces the cost. The infrared filter can realize a half-height width of 100nm, a peak transmittance of more than 95%, and a cut-off zone transmittance of less than 0.1%, which greatly improves the detection signal-to-noise ratio and improves the measurement accuracy.

Description

Technical Field

[0001] The present invention relates to an infrared filter and a preparation method and application thereof, in particular to a three-channel infrared filter with 2.8 μm, 2.35 μm and 1.59 μm bands, and also to a preparation method of the infrared filter and application of the infrared filter in a marine gas remote sensing detector, belonging to the field of remote sensing detection technology. Background Art

[0002] In the chemical process, biological process, geological process and radioactive nuclide decay process in the ocean, some gases are also produced, such as carbon monoxide, methane, hydrogen, hydrogen sulfide, nitrous oxide, helium and radon. Carbon dioxide and other gases in the atmosphere continuously enter the seawater through the interface; various seawater dissolved gases also continuously cross the interface and enter the atmosphere: forming an exchange of gas components between the sea and the air. According to the different sources of gases in seawater, the differences in composition and the characteristics of distribution, the physical processes, chemical processes, biological processes and geological processes occurring in the ocean can be studied. As a high-tech means of ocean exploration, important countries in the world attach great importance to the application of satellite ocean remote sensing. In order to obtain spectral information of different spectral bands, filters are usually used for spectral selection. With the continuous development of my country's space technology, optical thin film technology has also made continuous breakthroughs and has achieved remarkable achievements in the field of ocean satellite exploration. Traditional marine gas remote sensing detection devices add one or more infrared filters to detect one or more gases. If other gases need to be detected, the infrared filters need to be replaced, which increases the volume and weight of the remote sensing detection device and increases the material cost. Summary of the invention

[0003] In view of the defects of the infrared filter used in the marine gas remote sensing detection device in the prior art, the first purpose of the present invention is to provide an infrared filter with three channels of 2.8μm band, 2.35μm band and 1.59μm band, which can be used to detect one or more gases without replacing other infrared filters, greatly reducing the volume and weight of the remote sensing detection device and reducing costs. The infrared filter can achieve a half-height width of 100nm, a peak transmittance of more than 95%, and a cut-off zone transmittance of less than 0.1%, greatly improving the detection signal-to-noise ratio and improving measurement accuracy.

[0004] The second object of the present invention is to provide a method for preparing an infrared filter, which is simple to operate, easy to implement, and conducive to large-scale production.

[0005] The third object of the present invention is to provide an application of an infrared filter in a marine gas remote sensing detector. The infrared filter has three channels of 2.8μm band, 2.35μm band and 1.59μm band. Using it in a marine gas remote sensing detector can realize the simultaneous detection of one or more gases. There is no need to replace other infrared filters during the detection process, which greatly reduces the volume and weight of the remote sensing detection device and reduces the cost. The infrared filter can achieve a half-height width of 100nm, a peak transmittance of more than 95%, and a cut-off zone transmittance of less than 0.1%, which greatly improves the detection signal-to-noise ratio and the measurement accuracy. It can be used for long-term detection of dissolved gases in the ocean, especially accurate measurement of CO, methane, and hydrogen sulfide.

[0006] In order to achieve the above technical objectives, the present invention provides an infrared filter, which is composed of a Si substrate and a coating layer on its surface; the coating layer is composed of multiple layers of SiO coating layers and Si coating layers alternately stacked.

[0007] As a preferred solution, the total thickness of the coating layer is 39517±10 nm.

[0008] As a more preferred solution, the total thickness of the Si coating layer in the coating layer is 14570±10 nm, and the total thickness of the SiO coating layer is 24947±10 nm.

[0009] As a more preferred solution, the thickness of the single Si coating layer in the coating layer is 29-741 nm, and the thickness of the single SiO coating layer is 1-822 nm.

[0010] As a most preferred solution, the coating layer is composed of the following Si coating layers and SiO coating layers alternately stacked: SiO coating layer, thickness 430±3nm; Si coating layer, thickness 253±3nm; SiO coating layer, thickness 462±3nm; Si coating layer, thickness 310±3nm; SiO coating layer, thickness 113±3nm; Si coating layer, thickness 311±3nm; SiO coating layer, thickness 73±3nm; Si coating layer, thickness 738±3nm; SiO coating layer, thickness 358±3nm; Si coating layer, thickness 510±3nm; SiO coating layer, thickness 429±3nm; Si coating layer, thickness 308±3nm; Si O coating layer, thickness is 819±3nm; Si coating layer, thickness is 126±3nm; SiO coating layer, thickness is 535±3nm; Si coating layer, thickness is 238±3nm; SiO coating layer, thickness is 366±3nm; Si coating layer, thickness is 474±3nm; SiO coating layer, thickness is 246±3nm; Si coating layer, thickness is 239±3nm; SiO coating layer, thickness is 375±3nm; Si coating layer, thickness is 277±3nm; SiO coating layer, thickness is 459±3nm; Si coating layer, thickness is 77±3nm; SiO coating layer, thickness is 381±3nm; Si coating layer, thickness is 356±3nm; SiO coating layer, The thickness is 550±3nm; the Si coating layer is 262±3nm; the SiO coating layer is 400±3nm; the Si coating layer is 183±3nm; the SiO coating layer is 255±3nm; the Si coating layer is 145±3nm; the SiO coating layer is 272±3nm; the Si coating layer is 368±3nm; the SiO coating layer is 294±3nm; the Si coating layer is 159±3nm; the SiO coating layer is 352±3nm; the Si coating layer is 471±3nm; the SiO coating layer is 316±3nm; the Si coating layer is 128±3nm; the SiO coating layer is 9 8±3nm; Si coating layer, thickness is 242±3nm; SiO coating layer, thickness is 625±3nm; Si coating layer, thickness is 165±3nm; SiO coating layer, thickness is 183±3nm; Si coating layer, thickness is 315±3nm; SiO coating layer, thickness is 436±3nm; Si coating layer, thickness is 129±3nm; SiO coating layer, thickness is 221±3nm; Si coating layer, thickness is 226±3nm; SiO coating layer, thickness is 401±3nm; Si coating layer, thickness is 220±3nm; SiO coating layer, thickness is 1~3nm; Si coating layer, thickness is 271±3nm; SiO coating layer, thickness is 484±3nm;The thickness of Si coating layer is 241±3nm; the thickness of SiO coating layer is 470±3nm; the thickness of Si coating layer is 448±3nm; the thickness of SiO coating layer is 308±3nm; the thickness of Si coating layer is 176±3nm; the thickness of SiO coating layer is 247±3nm; the thickness of Si coating layer is 310±3nm; the thickness of SiO coating layer is 414±3nm; the thickness of Si coating layer is 140±3nm; the thickness of SiO coating layer is 252±3nm; the thickness of Si coating layer is 277±3nm; the thickness of SiO coating layer is 623±3nm; the thickness of Si coating layer is 43±3nm; the thickness of SiO coating layer is 184±3nm; the thickness of Si layer, with a thickness of 315±3nm; SiO coating layer, with a thickness of 625±3nm; Si coating layer, with a thickness of 32±3nm; SiO coating layer, with a thickness of 184±3nm; Si coating layer, with a thickness of 154±3nm; SiO coating layer, with a thickness of 491±3nm; Si coating layer, with a thickness of 305±3nm; SiO coating layer, with a thickness of 409±3nm; Si coating layer, with a thickness of 223±3nm; SiO coating layer, with a thickness of 548±3nm; Si coating layer, with a thickness of 94±3nm; SiO coating layer, with a thickness of 339±3nm; Si coating layer, with a thickness of 246±3nm; SiO coating layer, with a thickness of 465±3nm; Si coating layer, with a thickness of 156±3nm; SiO coating layer, thickness is 522±3nm; Si coating layer, thickness is 182±3nm; SiO coating layer, thickness is 794±3nm; Si coating layer, thickness is 252±3nm; SiO coating layer, thickness is 409±3nm; Si coating layer, thickness is 356±3nm; SiO coating layer, thickness is 485±3nm; Si coating layer, thickness is 265±3nm; SiO coating layer, thickness is 399±3nm; Si coating layer, thickness is 213±3nm; SiO coating layer, thickness is 662±3nm; Si coating layer, thickness is 48±3nm; SiO coating layer, thickness is 813±3nm; Si coating layer, thickness is 209± 3nm; SiO coating layer, thickness is 513±3nm; Si coating layer, thickness is 161±3nm; SiO coating layer, thickness is 591±3nm; Si coating layer, thickness is 229±3nm; SiO coating layer, thickness is 550±3nm; Si coating layer, thickness is 181±3nm; SiO coating layer, thickness is 620±3nm; Si coating layer, thickness is 186±3nm; SiO coating layer, thickness is 622±3nm; Si coating layer, thickness is 209±3nm; SiO coating layer, thickness is 670±3nm; Si coating layer, thickness is 290±3nm; SiO coating layer, thickness is 469±3nm; Si coating layer, thickness is 221±3nm;SiO coating layer, thickness is 491±3nm; Si coating layer, thickness is 473±3nm; SiO coating layer, thickness is 238±3nm; Si coating layer, thickness is 184±3nm; SiO coating layer, thickness is 577±3nm; Si coating layer, thickness is 223±3nm. ;

[0011] The preferred coating layer of the present invention is optimized by selecting the material of each coating layer, optimizing the thickness of each coating layer and the number of coating layers, and finally obtaining an infrared filter with the best performance. It not only has three channels of 2.8μm band, 2.35μm band and 1.59μm band, but also has a half-height width of 100nm, a peak transmittance of more than 95%, and a cut-off zone transmittance of less than 0.1%.

[0012] The present invention also provides a method for preparing an infrared filter, which comprises alternately coating a SiO coating layer and a Si coating layer on the surface of a Si substrate by ion sputtering coating. It is a common technique in the art to prepare coating layers by ion sputtering coating and to prepare superimposed coating layers by using different materials.

[0013] The present invention also provides an application of an infrared filter, and the infrared filter is applied as a three-channel infrared filter of a marine gas remote sensing detector.

[0014] As a preferred solution, the infrared filter is used as a three-channel infrared filter of 2.8 μm band, 2.35 μm band and 1.59 μm band for marine gas remote sensing detectors.

[0015] The infrared filter of the present invention is used for marine gas remote sensing detectors and can be used to measure dissolved gases in the ocean: CO, methane and hydrogen sulfide. Compared with the short wavelength range, CO detection has stronger resonance absorption characteristics at long wavelengths such as 2.8μm and 4.3μm. Methane detection has stronger resonance absorption characteristics at 2.35μm (the tail of the near-infrared region has not yet reached the mid-infrared region). Hydrogen sulfide detection has stronger resonance absorption at 1.59μm and 2.64μm. CO detection prefers the 2.8μm band, methane detection prefers the 2.35μm band, and hydrogen sulfide detection prefers the 1.59μm band. The infrared filter of the technical solution of the present invention has three channels of 2.8μm band, 2.35μm band and 1.59μm band, which can be used for marine gas remote sensing detectors to detect CO, methane and hydrogen sulfide.

[0016] Compared with the prior art, the technical solution of the present invention has the following beneficial technical effects:

[0017] The infrared filter provided by the present invention has three channels of 2.8μm band, 2.35μm band and 1.59μm band, and can be used for long-term detection of dissolved gases in the ocean. Placing an infrared filter can detect three dissolved gases in the ocean at the same time, saving space for remote sensing detection devices and reducing costs. It solves the technical problem in the prior art that traditional marine gas remote sensing detection devices need to add one or more infrared filters to detect one or more gases, and if other gases need to be detected, the infrared filter needs to be replaced, resulting in an increase in the volume and weight of the remote sensing detection device and the material cost.

[0018] The infrared filter provided by the present invention can achieve a half-width of 100nm, a peak transmittance of more than 95%, and a cut-off region transmittance of less than 0.1%, which greatly improves the signal-to-noise ratio and provides a basic guarantee for accurate measurement of the gas to be measured, especially accurate measurement of CO, methane and hydrogen sulfide.

[0019] The preparation method of the infrared filter provided by the invention is simple to operate, easy to implement and conducive to large-scale production. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of the infrared filter structure; 1 is the substrate, 2 is the SiO film layer, and 3 is the Si film layer.

[0021] Figure 2 Infrared spectrum transmittance test chart. DETAILED DESCRIPTION

[0022] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be interpreted as limiting the present application.

[0023] It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as those generally understood by those skilled in the art to which this application belongs. It should also be understood that terms such as those defined in general dictionaries should be understood to have meanings consistent with those in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless specifically defined as here.

[0024] Example 1

[0025] The specific structure of the infrared filter exemplified in this embodiment is as follows Figure 1As shown: a substrate with Si as raw material, a first coating layer with SiO as coating material, and a second coating layer with Si as coating material; the first coating layer and the second coating layer are alternately plated, and the total thickness of the coating layer is 39517.77nm, wherein the total thickness of the Si coating layer is 14570.16nm, and the total thickness of the SiO coating layer is 24947.61nm. The preparation method of the coating layer adopts the existing common ion sputtering coating equipment, BSV1030. According to the design of the coating layer structure (including the number of film layers, the thickness of each film layer, etc.), the first coating layer SiO film material and the second coating layer Si film material are repeatedly and alternately plated to finally obtain the desired coating layer. The coating deposition rate of the Si film layer is 1.5nm / s, and the coating deposition rate of the SiO film layer is 2.3~2.7nm / s. A 16cm RF ion source is used to bombard the target material, so that the target particles are deposited on the workpiece disc substrate; the heating system of the ion sputtering coating machine is set to 130°C, and the temperature fluctuation is ≤±5°C. The vacuum chamber pressure of the coating machine is ≤2*10 - Tor, argon gas is passed, and the oxygen pressure is set to 30 Pai. The coating time is the film thickness / deposition rate. The thickness of the SiO layer is 430.34nm, the thickness of the Si layer is 253.93nm, the thickness of the Si layer is 462.49nm, the thickness of the Si layer is 310.05nm, the thickness of the Si layer is 113.96nm, the thickness of the Si layer is 311.14nm, the thickness of the SiO layer is 73.45nm, the thickness of the Si layer is 738.01nm, the thickness of the Si layer is 358.96nm, the thickness of the Si layer is 510.02nm, the thickness of the SiO layer is 429.63nm, the thickness of the Si layer is 308.07nm, the thickness of the SiO layer is 819.3nm, the thickness of the Si layer is 126.15nm, the thickness of the SiO layer is 535.89nm, the thickness of the Si layer is The thickness of the SiO layer is 238.54nm, the thickness of the SiO layer is 366.32nm, the thickness of the Si layer is 474.55nm, the thickness of the SiO layer is 246.04nm, the thickness of the Si layer is 239.39nm, the thickness of the SiO layer is 375.82nm, the thickness of the Si layer is 277.67nm, the thickness of the SiO layer is 459.71nm, the thickness of the Si layer is 77.3nm, the thickness of the SiO layer is 381.48nm, the thickness of the Si layer is 356.05nm, the thickness of the SiO layer is 550.56nm, the thickness of the Si layer is 262.71nm, the thickness of the SiO layer is 400.93nm, the thickness of the Si layer is 183.01nm, and the thickness of the SiO layer is

[0026] 255.18nm, the thickness of the plated Si layer is 145.37nm, the thickness of the plated SiO layer is 272.62nm, the thickness of the plated Si layer is 368.47nm, the thickness of the plated SiO layer is 294.37nm, the thickness of the plated Si layer is 159.42nm, the thickness of the plated SiO layer is 352.31nm, the thickness of the plated Si layer is 471.47nm, the thickness of the plated SiO layer is 316.32nm, the thickness of the plated Si layer is 128.76nm, the thickness of the plated SiO is 98.99nm, the thickness of the plated Si layer is 242.53nm, the thickness of the plated SiO layer is 625.26nm, the thickness of the plated Si layer is 165.37nm, the thickness of the plated SiO layer is 183. 58nm, the thickness of the plated Si layer is 315.73nm, the thickness of the plated SiO layer is 436.1nm, the thickness of the plated Si layer is 129.18nm, the thickness of the plated SiO layer is 221nm, the thickness of the plated Si layer is 226.42nm, the thickness of the plated SiO layer is 401.46nm, the thickness of the plated Si layer is 220.48nm, the thickness of the plated SiO layer is 1.23nm, the thickness of the plated Si layer is 271.2nm, the thickness of the plated SiO layer is 484.65nm, the thickness of the plated Si layer is 241.63nm, the thickness of the plated SiO layer is 470.85nm, the thickness of the plated Si layer is 448.89nm, the thickness of the plated SiO layer is 308.86nm, the plated Si layer The thickness is 176.66nm, the thickness of the plated SiO layer is 247.63nm, the thickness of the plated Si layer is 310.58nm, the thickness of the plated SiO layer is 414.57nm, the thickness of the plated Si layer is 140.63nm, the thickness of the plated SiO layer is 252.3nm, the thickness of the plated Si layer is 277.29nm, the thickness of the plated SiO layer is 623.51nm, the thickness of the plated Si layer is 43.12nm, the thickness of the plated SiO layer is 184.73nm, the thickness of the plated Si layer is 315.14nm, the thickness of the plated SiO layer is 625.15nm, the thickness of the plated Si layer is 32.98nm, the thickness of the plated SiO layer is 184.31nm, and the thickness of the plated Si layer is 1 54.11nm, the thickness of the plated SiO layer is 491.91nm, the thickness of the plated Si layer is 305.71nm, the thickness of the plated SiO layer is 409.02nm, the thickness of the plated Si layer is 223.28nm, the thickness of the plated SiO layer is 548.71nm, the thickness of the plated Si layer is 94.46nm, the thickness of the plated SiO layer is 339.57nm, the thickness of the plated Si layer is 246.86nm, the thickness of the plated SiO layer is 465.64nm, the thickness of the plated Si layer is 156.92nm, the thickness of the plated SiO layer is 522.18nm, the thickness of the plated Si layer is 182.69nm, the thickness of the plated SiO layer is 794.64nm, the thickness of the plated Si layer is 252.09nm, the thickness of the plated SiO layer is 409.3nm, the thickness of the plated Si layer is 356.79nm, the thickness of the plated SiO layer is 485.07nm, the thickness of the plated Si layer is 265.42nm, the thickness of the plated SiO layer is 399.23nm, the thickness of the plated Si layer is 213.51nm, the thickness of the plated SiO layer is 662.27nm, the thickness of the plated Si layer is 48nm, the thickness of the plated SiO layer is 813.86nm, the thickness of the plated Si layer is 209.05nm, the thickness of the plated SiO layer is 513.52nm, the thickness of the plated Si layer is 161.86nm, the thickness of the plated SiO layer is 591.51nm, the thickness of the plated Si layer is 229.16nm, and the thickness of the plated SiO layer is 550.57nm , the thickness of the plated Si layer is 181.83nm, the thickness of the plated SiO layer is 620.43nm, the thickness of the plated Si layer is 186.58nm, the thickness of the plated SiO layer is 622.46nm, the thickness of the plated Si layer is 209.47nm, the thickness of the plated SiO layer is 670.95nm, the thickness of the plated Si layer is 290.96nm, the thickness of the plated SiO layer is 469.66nm, the thickness of the plated Si layer is 221.51nm, the thickness of the plated SiO layer is 491.44nm, the thickness of the plated Si layer is 473.25nm, the thickness of the plated SiO layer is 238.03nm, the thickness of the plated Si layer is 184.94nm, the thickness of the plated SiO layer is 577.79nm, and the thickness of the plated Si layer is 223.85nm. .

[0027] The prepared infrared filter has three channels: 2.8μm band, 2.35μm band, and 1.59μm band. After testing, the three-channel infrared filter of 1.59μm band, 2.35μm band, and 2.8μm band can achieve half-height width in the bands of 1500nm-1648nm, 2274nm-2384nm, and 4500nm-4660nm, respectively, with a peak transmittance of more than 99% and a cut-off area transmittance of less than 0.1%. Figure 2 shown.

[0028] Comparative Example 1

[0029] The difference from Example 1 is that Si is replaced by Ge as the second coating layer material, and the film system structure is redesigned after adjustment. It is found that a three-bandpass infrared filter cannot be achieved with Si as the substrate, SiO as the first coating layer material, and Ge as the second coating layer material. The reason is that Ge has an extremely high refractive index n=5.22 in the 1.59um band, but it is not suitable for the 2.35μm and 2.8μm bands.

[0030] Comparative Example 2

[0031] The difference from Example 1 is that Si is replaced by TiO2 as the second coating layer material, and the film system structure is redesigned after adjustment. It is found that a three-bandpass infrared filter cannot be achieved with Si as the substrate, SiO as the first coating layer material, and TiO2 as the second coating layer material. TiO2 has an extremely high transmittance T=92% in the visible light band, but it is only suitable for 2.35μm and 2.8μm bands.

[0032] Comparative Example 3

[0033] The difference from Example 1 is that the film layer design reduces the last two layers, and the material of the first coating layer is exchanged with the material of the second coating layer, that is, the first coating layer uses Si as the coating material, and the second coating layer uses SiO as the coating material; the first coating layer and the second coating layer are alternately plated. The film system structure obtained in this way is not valid, and a three-bandpass infrared filter cannot be realized.

[0034] Comparative Example 4

[0035] The difference from Example 1 is that Si is replaced by ZnS as the second coating layer material, and the film system structure is redesigned after adjustment. It is found that a three-bandpass infrared filter cannot be achieved with Si as the substrate, SiO as the first coating layer material, and ZnS as the second coating layer material. Multi-spectral polycrystalline ZnS is currently the best material for use as an infrared window, but the theoretical transmittance of ZnS is only 75% (without considering absorption).

[0036] The above specific implementations are only specific cases of the present invention and are not intended to limit the present invention in other forms. Any technician familiar with the profession may use the above disclosed technical content to change or modify it into an equivalent implementation of equivalent changes. However, any simple modification, equivalent change and modification made to the above implementation according to the technical essence of the present invention without departing from the technical principle of the present invention shall fall within the patent protection scope of the present invention.

Claims

1. An infrared filter, characterized in that: It is composed of a Si substrate and a coating layer on its surface; the coating layer is composed of multiple layers of SiO coating layers and Si coating layers alternately stacked; and the first coating layer on the surface of the Si substrate is a SiO coating layer, and the second coating layer is a Si coating layer; The total thickness of the coating layer is 39517±10nm; The thickness of the single-layer Si coating layer in the coating layer is 29-741 nm, and the thickness of the single-layer SiO coating layer is 1-822 nm.

2. An infrared filter according to claim 1, characterized in that: The total thickness of the Si coating layer in the coating layer is 14570±10 nm, and the total thickness of the SiO coating layer is 24947±10 nm.

3. An infrared filter according to any one of claims 1 to 2, characterized in that: The coating layer is composed of the following Si coating layers and SiO coating layers alternately stacked: SiO coating layer, thickness is 430±3nm; Si coating layer, thickness is 253±3nm; SiO coating layer, thickness is 462±3nm; Si coating layer, thickness is 310±3nm; SiO coating layer, thickness is 113±3nm; Si coating layer, thickness is 311±3nm; SiO coating layer, thickness is 73±3nm; Si coating layer, thickness is 738±3nm; SiO coating layer, thickness is 358±3nm; Si coating layer, thickness is 510±3nm; SiO coating layer, thickness is 429±3nm; Si coating layer, thickness is 308±3nm; SiO coating layer, thickness is 819±3nm; Si coating layer, thickness is 126±3nm; SiO coating layer, thickness is 535±3nm; Si coating layer, thickness is 238±3nm; SiO coating layer, thickness is 366±3nm; Si coating layer, thickness is 474±3nm; SiO coating layer, thickness is 246±3nm; Si coating layer, thickness is 239±3nm; SiO coating layer, thickness is 375±3nm; Si coating layer, thickness is 277±3nm; SiO coating layer, thickness is 459±3nm; Si coating layer, thickness is 77±3nm; SiO coating layer, thickness is 381±3nm; Si coating layer, thickness is 356±3nm; SiO coating layer, thickness is 550±3nm; Si coating layer, thickness is 262±3nm; SiO coating layer, thickness is 400±3nm; Si coating layer, thickness is 183±3nm; SiO coating layer, thickness is 255±3nm; Si coating layer, thickness is 145±3nm; SiO coating layer, thickness is 272±3nm; Si coating layer, thickness is 368±3nm; SiO coating layer, thickness is 294±3nm; Si coating layer, thickness is 159±3nm; SiO coating layer, thickness is 352±3nm; Si coating layer, thickness is 471±3nm; SiO coating layer, thickness is 316±3nm; Si coating layer, thickness is 128±3nm; SiO coating layer, thickness is 98±3nm; Si coating layer, thickness is 242±3nm; SiO coating layer, thickness is 625±3nm; Si coating layer, thickness is 165±3nm; SiO coating layer, thickness is 183±3nm; Si coating layer, thickness is 315±3nm; SiO coating layer, thickness is 436±3nm; Si coating layer, thickness is 129±3nm; SiO coating layer, thickness is 221±3nm; Si coating layer, thickness is 226±3nm; SiO coating layer, thickness is 401±3nm; Si coating layer, thickness is 220±3nm; SiO coating layer, thickness is 1~3nm; Si coating layer, thickness is 271±3nm; SiO coating layer, thickness is 484±3nm; Si coating layer, thickness is 241±3nm; SiO coating layer, thickness is 470±3nm; Si coating layer, thickness is 448±3nm; SiO coating layer, thickness is 308±3nm; Si coating layer, thickness is 176±3nm; SiO coating layer, thickness is 247±3nm; Si coating layer, thickness is 310±3nm; SiO coating layer, thickness is 414±3nm; Si coating layer, thickness is 140±3nm; SiO coating layer, thickness is 252±3nm; Si coating layer, thickness is 277±3nm; SiO coating layer, thickness is 623±3nm; Si coating layer, thickness is 43±3nm; SiO coating layer, thickness is 184±3nm; Si coating layer, thickness is 315±3nm; SiO coating layer, thickness is 625±3nm; Si coating layer, thickness is 32±3nm; SiO coating layer, thickness is 184±3nm; Si coating layer, thickness is 154±3nm; SiO coating layer, thickness is 491±3nm; Si coating layer, thickness is 305±3nm; SiO coating layer, thickness is 409±3nm; Si coating layer, thickness is 223±3nm; SiO coating layer, thickness is 548±3nm; Si coating layer, thickness is 94±3nm; SiO coating layer, thickness is 339±3nm; Si coating layer, thickness is 246±3nm; SiO coating layer, thickness is 465±3nm; Si coating layer, thickness is 156±3nm; SiO coating layer, thickness is 522±3nm; Si coating layer, thickness is 182±3nm; SiO coating layer, thickness is 794±3nm; Si coating layer, thickness is 252±3nm; SiO coating layer, thickness is 409±3nm; Si coating layer, thickness is 356±3nm; SiO coating layer, thickness is 485±3nm; Si coating layer, thickness is 265±3nm; SiO coating layer, thickness is 399±3nm; Si coating layer, thickness is 213±3nm; SiO coating layer, thickness is 662±3nm; Si coating layer, thickness is 48±3nm; SiO coating layer, thickness is 813±3nm; Si coating layer, thickness is 209±3nm; SiO coating layer, thickness is 513±3nm; Si coating layer, thickness is 161±3nm; SiO coating layer, thickness is 591±3nm; Si coating layer, thickness is 229±3nm; SiO coating layer, thickness is 550±3nm; Si coating layer, thickness is 181±3nm; SiO coating layer, thickness is 620±3nm; Si coating layer, thickness is 186±3nm; SiO coating layer, thickness is 622±3nm; Si coating layer, thickness is 209±3nm; SiO coating layer, thickness is 670±3nm; Si coating layer, thickness is 290±3nm; SiO coating layer, thickness is 469±3nm; Si coating layer, thickness is 221±3nm; SiO coating layer, thickness is 491±3nm; Si coating layer, thickness is 473±3nm; SiO coating layer, thickness is 238±3nm; Si coating layer, thickness is 184±3nm; The SiO coating layer has a thickness of 577±3nm; the Si coating layer has a thickness of 223±3nm.

4. The method for preparing an infrared filter according to any one of claims 1 to 3, characterized in that: The SiO coating layer and the Si coating layer are alternately coated on the surface of the Si substrate by an ion sputtering coating machine to obtain an infrared filter.

5. The use of an infrared filter according to any one of claims 1 to 3, characterized in that: Used as a three-channel infrared filter for marine gas remote sensing detectors.

6. The use of an infrared filter according to claim 5, characterized in that: As a three-channel infrared filter in the 2.8μm band, 2.35μm band and 1.59μm band, it is used in marine gas remote sensing detectors.

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