CN109932774B - Infrared narrow-band filter film and infrared recognition system - Google Patents
Infrared narrow-band filter film and infrared recognition system Download PDFInfo
- Publication number
- CN109932774B CN109932774B CN201711378597.3A CN201711378597A CN109932774B CN 109932774 B CN109932774 B CN 109932774B CN 201711378597 A CN201711378597 A CN 201711378597A CN 109932774 B CN109932774 B CN 109932774B
- Authority
- CN
- China
- Prior art keywords
- layer
- infrared
- narrowband filter
- film
- refractive index
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Landscapes
- Optical Filters (AREA)
Abstract
The invention provides an infrared narrow-band filter film and an infrared identification system. The infrared narrow-band filter film comprises: a substrate layer; the visible light cut-off film system is used for absorbing or reflecting visible light within the range of 380 nm-780 nm; the infrared window film system is provided with one or more narrow-band light-transmitting windows in the range of 700-1400 nm, and the peak width of the narrow-band light-transmitting window is in the range of 5-50 nm when the transmittance of the narrow-band light-transmitting window is greater than or equal to 50%; the visible light cut-off film system and the infrared window film system are oppositely arranged on two surfaces of the base material layer or are superposed on one surface of the base material layer. The visible light cut-off film system and the infrared window film system are arranged at the same time, so that the infrared narrow band can penetrate on the basis of effectively cutting off the visible light, the interference of the visible light is avoided, the infrared light is utilized to realize higher discrimination, the visual level effect is improved, the accuracy of organism identification can be greatly improved, and the accuracy of final infrared image camera image acquisition is improved.
Description
Technical Field
The invention relates to the field of optical films, in particular to an infrared narrow-band filter film and an infrared recognition system.
Background
Face recognition is also called face recognition, or the like, and face recognition uses a general-purpose camera as a recognition information acquisition device. The face image of the identification object is acquired in a non-contact mode, and the computer system is compared with the database image after acquiring the image to complete the identification process. The face recognition is a recognition mode based on biological characteristics, and compared with traditional recognition modes such as fingerprint recognition and the like, the face recognition has the characteristics of real time, accuracy, high precision, easiness in use, high stability, difficulty in counterfeiting, high cost performance, non-intrusion and the like, and is easily accepted by users. The regional characteristic analysis algorithm widely adopted in the face recognition technology integrates the computer image processing technology and the biological statistical principle, extracts the human image characteristic points from the video by using the computer image processing technology, and analyzes and establishes a mathematical model, namely a face characteristic template, by using the biological statistical principle. Carrying out feature analysis by using the established human face feature template and the face image of the tested person, and giving a similar value according to the analysis result; from this value it can be determined whether the persons are the same person.
The FaceID adopted by the latest iPhone is an image recognition technology based on three-dimensional imaging, which needs a specific active light irradiation system and a camera, generates a head portrait three-dimensional modeling, and matches the head portrait with each subsequent recognition. The faceID adopts a face structured light mode, mainly aims to adapt to the complexity and safety requirements of human face five sense organs, and codes a projection pattern by using a specific illumination instrument so as to accelerate the confirmation of the corresponding relation between object surface points and image pixel points. The infrared image camera is mainly used for collecting projected codes to finish face decoding, an image with three-dimensional depth information is generated and compared with the recorded face depth information, and successful unlocking of face recognition is finished when certain accuracy is achieved.
However, when the user uses a tool such as a wig, beard attachment, mask, etc., products such as FaceID and Kinect cannot perform face recognition. Therefore, it is necessary to improve the accuracy of image acquisition of the infrared image camera to improve the accuracy of face recognition.
Disclosure of Invention
The invention mainly aims to provide an infrared narrow-band filter film and an infrared recognition system, and aims to solve the problem of low image acquisition accuracy of an infrared image camera in the prior art.
In order to achieve the above object, according to one aspect of the present invention, there is provided an infrared narrow band filter comprising: a substrate layer; the visible light cut-off film system is used for absorbing or reflecting visible light within the range of 380 nm-780 nm; the infrared window film system is provided with one or more narrow-band light-transmitting windows in the range of 700-1400 nm, and the peak width of the narrow-band light-transmitting window is in the range of 5-50 nm when the transmittance of the narrow-band light-transmitting window is greater than or equal to 50%; the visible light cut-off film system and the infrared window film system are oppositely arranged on two surfaces of the base material layer or are superposed on one surface of the base material layer.
Further, the visible light cut-off film system is arranged on one or two opposite surfaces of the base material layer, and the infrared window film system is laminated on the surface of the visible light cut-off film system; the visible light cut-off film system and the infrared window film system are oppositely arranged on the surface of the base material layer; or the infrared window film system is arranged on one or two opposite surfaces of the base material layer, and the visible light cut-off film system is laminated on the surface of the infrared window film system.
Furthermore, the visible light cut-off film comprises one or more absorption units, the absorption units are arranged on one or two opposite surfaces of the substrate layer, each absorption unit comprises a high-refractive-index material layer and a matching material layer arranged in contact with the high-refractive-index material layer, the refractive index of the high-refractive-index material layer is 3-5.5, and a structural water layer is formed between the high-refractive-index material layer and the matching material layer at a contact interface.
Furthermore, the high-refractive-index material layer is an alpha-hydrogenated amorphous silicon layer, the matching material layer is an oxide layer, the oxide layer is a metal oxide layer or a nonmetal oxide layer, and the change of the refractive index of the alpha-hydrogenated amorphous silicon layer in the wavelength range of 380-780 nm is less than or equal to 0.8; preferably, the refractive index of the matching material layer is 1.0-2.7.
Further, the surface Si-H bond of the alpha-hydrogenated amorphous silicon layer is bonded to the oxide layer to form a structural water layer, and preferably, the surface Si-H bond and the oxide layer together form 1 to 10 structural water layers in the visible light cut-off film system.
Further, the physical thickness of the water layers with the structures is 0.1-2 nm.
Further, the mole percentage of hydrogen atoms in the alpha-hydrogenated amorphous silicon layer is 5 to 25%, and the oxide layer is preferably selected from SiO2Layer, Ti3O5Layer of Al2O3Layer, SiO layer, TiO2Layer, Ti2O3Layer, Ta2O5Layer, HfO2Layer, MgO layer, ZrO2Layer, CeO2Layer, CaO layer, Y2O3Layer, ZnO layer, Nb2O5Any one or more of the layers.
Further, the physical thickness of the high refractive index material layer is 1 to 1000nm, preferably 1 to 500nm, and more preferably 1 to 200 nm; the physical thickness of the matching material layer is 1-1000 nm, preferably 1-500 nm, and more preferably 1-200 nm.
Further, the substrate layer is a silicon layer, a glass layer, a PET layer, a COP layer, a COC layer, a CPI layer, a PMMA layer, a PEN layer, a PC layer, or a TAC layer, and preferably, the physical thickness of the visible light cut film system is less than 500 μm; preferably less than 400 μm; more preferably less than 300 μm; more preferably less than 200 μm; further preferably less than 100 μm; still more preferably less than 50 μm; or the physical thickness of the visible light cut-off film system is preferably 50 to 250 μm.
Further, the infrared window film comprises a plurality of refractive index dual units, each refractive index dual unit comprises a high-folding layer and a low-folding layer matched with the high-folding layer, and the refractive index dual unit forms a film system structure of alpha (alpha)1Hβ1Lα2Hβ2L...αnHβnL) wherein H represents a high-fold layer, L represents a low-fold layer, n is a positive integer, n is greater than 2 and less than or equal to 60, and the optical thickness coefficients of the high-fold layer and the low-fold layer in the same film stack are alpha1，α2，...，αnAnd beta1，β2，...，βnThe same gradient rule on the same cosine waveform or sine waveform is respectively and independently satisfied, and the gradient rule of each film stack of the same infrared window film system is the same; for the ith refractive index dual unit αiHβiL，1≤i≤n,αiDenotes the optical thickness coefficient, beta, of the i-th high-refractive layer in the direction perpendicular to the base material layeriThe optical thickness coefficient of the i-th low-refractive layer in the direction perpendicular to the base material layer is shown.
Further, in the same film stack, for the ith refractive index dual unit αiHβiL, optical thickness of high refractive layer is alphai*Lambda/4, optical thickness of low refractive layer betai*Lambda/4, refractive index of high refractive layer is NHThe physical thickness of the high refractive layer is DHThen N is presentH*DH＝αi*Lambda/4; refractive index of the low refractive layer is NLThe physical thickness of the low-folding layer is DLThen N is presentL*DL＝βi*Lambda/4; wherein alpha is1，α2，...，αnAnd beta1，β2，...，βnThe gradient-changing method is characterized in that the gradient-changing method independently satisfies the same gradient rule on the upper left half chord, the lower left half chord, the upper right half chord and the lower right half chord of the same sine waveform or cosine waveform in the range of 0-2 pi.
Furthermore, the infrared window film system takes 455nm as the monitoring wavelength, alphai，βiThe value range of (A) is as follows: alpha is more than or equal to 0.01i≤3.2，0.01≤βi3.2 or less, preferably 0.05 or less alphai≤2.8，0.05≤βiLess than or equal to 2.8; preferably, 0.1. ltoreq. alpha.i≤2.8，0.1≤βiLess than or equal to 2.8; more preferably, 0.2. ltoreq. alpha.i≤2.7，0.2≤βi≤2.7。
Furthermore, the number of the refractive index dual units of the film stack accounts for 60-99% of the total number of the refractive index dual units of the infrared window film system.
Further, the physical thickness of the high refractive layer is 1 to 400nm, preferably 10 to 150nm, and the physical thickness of the low refractive layer is preferably 1 to 400nm, preferably 10 to 150 nm.
Further, the refractive index of the high refractive layer is 1.5 to 5.0, preferably 1.65 to 3.0, and the refractive index of the low refractive layer is 1.1 to 1.5, preferably 1.25 to 1.48.
Further, the refractive index materials forming the high and low refractive layers are each independently selected from MgF2、CaF2Transition metal fluoride, ZnO, TiO2、TiN、In2O3、SnO3、Cr2O3、ZrO2、Ta2O5、LaB6、NbO、Nb2O3、Nb2O5、SiO2、SiC、Si3N4、Al2O3And a fluorine-containing resin or a hollow silica-containing resin.
Further, the total number of layers of the high fold layer and the low fold layer is 10 to 150, preferably 12 to 60.
According to another aspect of the present invention, an infrared identification system is provided, which includes one or more light sources, an infrared image receiver, and a filter film disposed on a surface of the infrared image receiver, where the filter film is any one of the above infrared narrowband filter films, and the light source is an infrared or near infrared light source with a center wavelength within a light transmission band of an infrared window film system of the infrared narrowband filter film in a range of 700 to 1400 nm.
By applying the technical scheme of the invention, the infrared narrow-band filter film simultaneously comprises the visible light cut-off film system and the infrared window film system, so that the infrared narrow band can penetrate on the basis of effectively cutting off the visible light, the interference of the visible light is avoided, the high discrimination is realized by utilizing the infrared light, the visual hierarchy effect is improved, the accuracy of organism identification can be improved, and the accuracy of the final infrared image camera image acquisition is further improved.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:
fig. 1 is a schematic structural diagram of an infrared narrowband filter according to an embodiment of the present invention;
FIG. 2 is a schematic structural diagram of an infrared narrowband filter according to another embodiment of the present invention;
FIG. 3 is a spectrum test chart of an infrared narrowband filter according to embodiment 1 of the present invention;
FIG. 4 shows a spectrum test chart of an infrared narrowband filter film according to embodiment 2 of the invention; and
fig. 5 shows a spectral test chart of the infrared narrowband filter film according to comparative example 1 of the present invention.
Wherein the figures include the following reference numerals:
1. a substrate layer; 2. a visible light cut-off film system; 3. an infrared window film system;
20. an absorption unit; 21. a high refractive index material layer; 22. a matching material layer; 23. a structured water layer;
31. a high-folding layer; 32. and (5) low-fold layer.
Detailed Description
It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.
As analyzed by the background art of the present application, the accuracy of image acquisition of an infrared image camera in the prior art is insufficient, and the applicant finds, through research, that the above-mentioned insufficiency is due to interference caused by insufficient cut-off rate of a filter of the infrared image camera on visible light to a great extent, and on the other hand, the accuracy of image acquisition of the infrared image camera is finally caused by low discrimination of infrared light and poor visual effect due to too wide bandwidth of transmitted infrared light.
In an exemplary embodiment of the present application, an infrared narrowband filter is provided, as shown in fig. 1, the infrared narrowband filter includes a substrate layer 1, a visible light cut-off film system 2 and an infrared window film system 3, the visible light cut-off film system 2 is used for absorbing or reflecting visible light in a range of 380nm to 780 nm; the infrared window film system 3 is provided with one or more narrow-band light-transmitting windows in the range of 700-1400 nm, the peak width of the narrow-band light-transmitting window in the transmittance of more than or equal to 50% is in the range of 5-50 nm, and the visible light cut-off film system and the infrared window film system are oppositely arranged on two surfaces of the base material layer 1 or are superposed on one surface of the base material layer 1.
Because the infrared narrow-band filter film simultaneously comprises the visible light cut-off film system and the infrared window film system, the infrared narrow band can penetrate through the visible light on the basis of effectively cutting off the visible light, the interference of the visible light is avoided, the infrared light is utilized to realize higher discrimination, the visual gradation effect is improved, the accuracy of organism identification can be improved, and the accuracy of final infrared image camera image acquisition is further improved.
The visible light cut-off film system 2 and the infrared window film system 3 are arranged in various ways relative to the substrate layer 1, for example, the visible light cut-off film system 2 is arranged on one or two opposite surfaces of the substrate layer 1, and the infrared window film system 3 is laminated on the surface of the visible light cut-off film system 2; the visible light cut-off film system 2 and the infrared window film system 3 are oppositely arranged on the surface of the base material layer 1; or the infrared window film system 3 is arranged on one or two opposite surfaces of the substrate layer 1, and the visible light cut-off film system 2 is laminated on the surface of the infrared window film system 3. Preferably, in order to improve the matching relationship between the visible light cut-off film system and the infrared window film system, the visible light cut-off film system is preferably disposed on one or two opposite surfaces of the base material layer 1, and the infrared window film system 3 is preferably laminated on the surface of the visible light cut-off film system.
In an embodiment of the present application, the visible light cut-off film system 2 includes one or more absorption units 20, the absorption units 20 are disposed on one or two opposite surfaces of the substrate layer 1, each absorption unit 20 includes a high refractive index material layer 21 and a matching material layer 22 disposed in contact therewith, a refractive index of the high refractive index material layer is 3 to 5.5, and a structural water layer 23 is formed at a contact interface between the high refractive index material layer 21 and the matching material layer 22.
The high-refractive-index material layer 21 has a refractive index of 3-5.5, so that the high-refractive-index material layer has good absorptivity for ultraviolet light and visible light; the structure water layer 23 is formed on the contact interface of the matching material layer and the matching material layer 22 in a matching mode, the refractive index of the structure water layer 23 is approximately 1.3 similar to that of water, so that the structure water layer can form film interference with the high-refractive-index material layer on visible light, good absorption characteristics can be achieved for the visible light according to the properties of the high-refractive-index material layer, an ideal cut-off effect is achieved for ultraviolet light and visible light, the ideal transmittance of infrared light can be achieved, the requirements of various infrared light transmission devices can be met, and good visual effects can be achieved.
Preferably, the high refractive index material layer 21 is an α -hydrogenated amorphous silicon layer, the matching material layer 22 is an oxide layer, the oxide layer is a metal oxide layer or a nonmetal oxide layer, and the change of the refractive index of the α -hydrogenated amorphous silicon layer in the wavelength range of 380-780 nm is less than or equal to 0.8; preferably, the refractive index of the matching material layer 22 is 1.0-2.7.
The alpha-hydrogenated amorphous silicon layer has a prominent absorption effect on ultraviolet light and visible light and an ideal transmission effect on infrared light, and meanwhile, the absorption effect of the alpha-hydrogenated amorphous silicon layer on the visible light is more stable by controlling the refractive index change of the alpha-hydrogenated amorphous silicon layer in a wavelength range of 380-780 nm to be less than or equal to 0.8; furthermore, the difference between the refractive index of the formed structural water layer and the refractive index of the metal or nonmetal oxide layer is small, so that the thin film interference between the high-low refractive structure formed between the alpha-hydrogenated amorphous silicon layer and the metal or nonmetal oxide layer is exerted more stably, and the visible light is cut off more stably. Through tests, the average value of the visible light transmittance of the visible light cut-off film in the wavelength range of 380-780 nm is less than 20%, and the average value of the infrared light transmittance in the wavelength range of 800-1400 nm is more than or equal to 80%, so that the total reflection cut-off and absorption of visible light are basically realized, and further the ideal transmittance of infrared light is realized.
The inventor believes through long-term research that the possible mechanism lies in: the alpha-hydrogenated amorphous silicon layer is formed by sputtering, evaporation coating or PECVD (plasma enhanced chemical vapor deposition) and micropores in the microstructure are formed on the surface of the hydrogenated amorphous silicon layer, and dangling bonds are arranged in the micropores; when the dangling bond requirement of the hydrogenated amorphous silicon is low, the dangling bond density is controlled to be 1018cm-3When the hydrogenated amorphous silicon layer and the oxide layer are arranged in contact, the hydrogenated micropores form bonds or adsorbs oxygen atoms in the oxide layer formed by a subsequent process, so that the structure of the micropores is stabilized, and the micropores have more stable absorption performance in ultraviolet and visible light regions.
Preferably, the surface Si-H bond of the above-described alpha-hydrogenated amorphous silicon layer is combined with the oxide layer to form a structured water layer 23 (i.e., a structured water layer
A structural layer, wherein M is a positive valence element of the oxide layer). The surface of the alpha-hydrogenated amorphous silicon layer has certain roughness, the surface is provided with a plurality of micropores, more silicon-hydrogen bonds exist in the micropores, hydrogen atoms on the surface are more active and are easy to escape from the film layer, further, the absorption effects of the alpha-hydrogenated amorphous silicon layers with different hydrogen contents and different thicknesses on visible light are different, in order to avoid the change of the absorption effect of the visible light caused by the escape of the hydrogen atoms, after the oxide layer is arranged on the surface of the alpha-hydrogenated amorphous film, the oxygen atoms in the oxide layer can capture the hydrogen atoms on the surface of the hydrogenated amorphous silicon layer, so that the hydrogen atoms are stable, and bound water H is formed2O "structure, avoiding the above problems due to hydrogen atom escape.
In order to further enhance the effect of the visible light cut-off film of the present invention in cutting off visible light, it is preferable that the visible light cut-off film system 2 collectively form 1 to 10 layers of the water layer 23. By arranging the water layers 23 with the multilayer structure, the functions of the water layers 23 with the structures are mutually overlapped, so that the absorption effect of visible light is further enhanced, and the cut-off rate is more than 90%.
To ensure each structural water layer
The physical thickness of each of the structural water layers 23 is preferably 0.1 to 2 nm.
The refractive index of the α -hydrogenated amorphous silicon layer is closely related to the content of micropores, Si, and H in the surface of the film layer, and in order to increase the optical admittance of the α -hydrogenated amorphous silicon layer as much as possible, the molar percentage content of hydrogen atoms in the α -hydrogenated amorphous silicon layer is preferably 5 to 25%. The refractive index material forming the matching material layer 22 may be selected from the prior art, and preferably, the oxide layer is selected from SiO2Layer, Ti3O5Layer of Al2O3Layer, SiO layer, TiO2Layer, Ti2O3Layer, Ta2O5Layer, HfO2Layer, MgO layer, ZrO2Layer, CeO2Layer, CaO layer, Y2O3Layer, ZnO layer, Nb2O5Any one or more of the layers. According to the infrared absorption test and the Raman test, hydrogen atoms in the alpha-hydrogenated amorphous silicon layer have different bonding characteristics and are easier to bond with oxygen atoms, and the bonding characteristics can be effectively controlled through a deposition mode and deposition conditions. Through an infrared absorption test and a Raman test, the inventor surprisingly discovers that the bonding mode of the alpha-hydrogenated amorphous silicon layer H obtained by the invention is mainly SiH and SiH2、(SiH2)nChain polymers, and SiH3Substantially no occurrence. According to the nuclear magnetic resonance technology test, the inventor finds that: the alpha-hydrogenated amorphous silicon layer has a significant amount of H or H in surface pores thereof2These H or H2Has no mobility, is confined in the interior of the small-sized micropores, and is bonded or not bonded to oxygen atoms in the oxide layer, stabilizing the structure in which the α -hydrogenated amorphous silicon layer and the oxide layer are combined. The alpha-hydrogenated amorphous silicon layer protected and packaged by the oxide-free layer is not resistant to hydrolysis, the alpha-hydrogenated amorphous silicon layer is disintegrated after contacting water, and the alpha-hydrogenated amorphous silicon layer and the oxide layer are resistant to water and oil, so that the alpha-hydrogenated amorphous silicon layer and the oxide layer can successfully pass high-temperature and high-humidity experiments (the quality and the characteristics are not changed after the alpha-hydrogenated amorphous silicon layer and the oxide layer are finished for 1000 hours at constant temperature of 85 ℃).
On the basis of satisfying the better absorption effect of visible light, in order to further save cost and control the thickness of the visible light cut-off film, the physical thickness of the high refractive index material layer 21 is preferably 1 to 1000nm, preferably 1 to 500nm, more preferably 1 to 200nm, and the smaller the thickness of the alpha-hydrogenated amorphous silicon layer is, the more difficult micropores are generated therein, and the larger the refractive index thereof is. The physical thickness of the matching material layer 22 is 1-1000 nm, preferably 1-500 nm, and more preferably 1-200 nm.
The material for the substrate layer 1 of the present application can be selected from materials commonly used in substrates for manufacturing visible light cut-off films in the prior art, preferably, the substrate layer 1 is a silicon layer, a glass layer, a PET layer, a COP layer, a COC layer, a CPI layer, a PMMA layer, a PEN layer, a PC layer or a TAC layer, and preferably, the physical thickness of the visible light cut-off film system 2 is less than 500 μm; preferably less than 400 μm; more preferably less than 300 μm; more preferably less than 200 μm; further preferably less than 100 μm; still more preferably less than 50 μm; or the physical thickness of the visible light cut-off film system 2 is preferably 50 to 250 μm.
In addition, the application also provides a preparation method of the visible light cut-off film system, and the preparation method comprises the following steps: step S1, disposing the high refractive index material layer 21 on the base material layer 1; step S2, disposing a matching material layer 22 on the high refractive index material layer 21; and optionally repeating step S3 one or more times, disposing the high refractive index material layer 21 on the matching material layer 22, and disposing the matching material layer 22 on the high refractive index material layer 21.
Preferably, the high refractive index material layer 21 is an α -hydrogenated amorphous silicon layer, the matching material layer 22 is an oxide layer, and the oxide layer is a metal oxide layer or a non-metal oxide layer, and both the α -hydrogenated amorphous silicon layer and the oxide layer of the present application can be fabricated by methods commonly used in the art. To enable stable contact between them
The structure, preferably, the α -hydrogenated amorphous silicon layer and the oxide layer are disposed using a chemical vapor deposition method (CVD), an electron beam physical vapor deposition method (EBPVD), a Laser Chemical Vapor Deposition (LCVD), a Plasma Enhanced Chemical Vapor Deposition (PECVD), or a vacuum magnetron sputtering method. The alpha-hydrogenated amorphous silicon layer and the oxide layer formed by the method have good film uniformity and contact surface activity, and further stable can be formed
And (5) structure.
In a preferred embodiment of the present application, the process of disposing the α -hydrogenated amorphous silicon layer using the vacuum magnetron sputtering method includes: forming an alpha-hydrogenated amorphous silicon layer in a vacuum chamber filled with argon and hydrogen by taking silicon as a target material; the process of setting the oxide layer by the vacuum magnetron sputtering method comprises the following steps: metal and/or nonmetal is used as a target material, an oxide layer is formed in a vacuum chamber into which argon and oxygen are introduced, the metal is any one or more of Al, Ti, Ta, Hf, Mg, Zr, Ce, Ca, Y, Zn and Nb, and the nonmetal is Si, so thatIs high at the contact surface
The efficiency of the structure, and therefore, a desired visible light cut-off efficiency can be achieved by a smaller number of layers of the hydrogenated amorphous silicon layer and the oxide layer.
In one embodiment, the above process for preparing an α -hydrogenated amorphous silicon layer by using a plasma enhanced chemical vapor deposition method includes: with SiH4、H2The precursor gas forms plasma state at the substrate surface temperature of 100-300 ℃ and the radio frequency of 10-15 MHz and reacts to form the alpha-hydrogenated amorphous silicon layer.
In another embodiment, the process of preparing the α -hydrogenated amorphous silicon layer by the vacuum magnetron sputtering method includes: silicon is selected as a target material, argon and H are used2Is a working gas in the range of 0.01 to 100 x 10-5And under the vacuum degree of Pa, regulating the surface temperature of the substrate to be within the range of 25-300 ℃ with the radio frequency sputtering power within the range of 100-400W, and carrying out sputtering coating at the working air pressure of 0.1-10 Pa to obtain the alpha-hydrogenated amorphous silicon layer.
In the above embodiment, the content of H in the formed α -hydrogenated amorphous silicon layer can be controlled by adjusting the working pressure and the ratio of hydrogen in the process of forming the α -hydrogenated amorphous silicon layer, and the adjustment of the working pressure and the ratio of hydrogen can be realized by the prior art, which is not described herein again.
In addition, in an embodiment where the oxide layer is a silicon oxide layer, the process of preparing the silicon oxide layer by using the plasma enhanced chemical vapor deposition method includes: with SiH4、O2The precursor gas forms plasma state at the substrate surface temperature of 100-300 ℃ and the radio frequency of 10-15 MHz and reacts to form a silicon oxide layer.
Further, in another embodiment, the process of preparing the oxide layer by using the vacuum magnetron sputtering method comprises: selecting metal and/or nonmetal as target material, and argon and O2Is a working gas in the range of 0.01 to 100 x 10-5The temperature of the substrate is adjusted to be 25-300 ℃ under the vacuum degree of Pa and the radio frequency sputtering power is within the range of 100-400WIn the range of (1), carrying out sputtering coating at the working air pressure of 0.1-10 Pa to obtain an oxide layer; the metal is any one or more of Al, Ti, Ta, Hf, Mg, Zr, Ce, Ca, Y, Zn and Nb, and the nonmetal is Si.
In addition, in order to further ensure the narrow-band transmission effect of the infrared light, it is preferable that the infrared window film system 3 includes a plurality of refractive index dual units, each refractive index dual unit includes a high-folding layer 31 and a low-folding layer 32 matching with the high-folding layer, and the refractive index dual unit forming film system structure is | (α)1Hβ1Lα2Hβ2L...αnHβnL) wherein H represents a high-refractive layer 31, L represents a low-refractive layer 32, n is a positive integer, n is greater than 2 and less than or equal to 60, and the optical thickness coefficients α of the high-refractive layer and the low-refractive layer in the same film stack1，α2，...，αnAnd beta1，β2，...，βnThe same gradient rule on the same cosine waveform or sine waveform is respectively and independently satisfied, and the gradient rule of each film stack of the same infrared window film system 3 is the same; for the ith refractive index dual unit αiHβiL，1≤i≤n,αiDenotes an optical thickness coefficient, β, of the i-th high-folding layer 31 in the direction perpendicular to the base material layer 1iThe optical thickness coefficient of the i-th low-refractive layer 32 in the direction perpendicular to the base material layer 1 is shown.
It should be noted that the sine waveform and the cosine waveform in the present application are variation trends (limited to the variation trend, and the specific numerical values are not limited by quadrants and positive and negative values) of the standard sine waveform and the cosine waveform in the coordinate system, that is, the sine waveform includes an upper half chord and a lower half chord that are symmetrically arranged, the upper half chord includes an upper left half chord and an upper right half chord, and the lower half chord includes a lower left half chord and a lower right half chord; the cosine waveform comprises a left half chord and a right half chord which are symmetrically arranged, the left half chord is a decreasing chord, the right half chord is an increasing chord, the left half chord comprises a left upper half chord and a left lower half chord, and the right half chord comprises a right upper half chord and a right lower half chord.
Since the cosine and sine waveforms are only phase differences. For convenience of description, only the cosine waveform will be described below. At present, in order to realize narrow-band transmission, the prior art is dedicated to increasing the number of high-fold layers and low-fold layers in a reflective film system and the selection of refractive materials, and the inventor of the present application unexpectedly finds that when the thickness variation of the high-fold layers and the low-fold layers has direct correlation to the bandwidth of a reflection peak, based on the fact that the inventor of the present application deeply studies the thickness variation rule of the high-fold layers and the low-fold layers, and finds that a cosine film stack formed by the gradual variation of the optical thickness coefficients of the high-fold layers 31 and the low-fold layers 32 following the rule of cosine waveforms can have deep reflection cutoff effect on spectral light in the spectral wavelength range, and the narrow-band transmission can be realized through the control of the cosine film stack. The action principle of the method is that:
according to the Fabry-Perot interference principle, when the frequency of the incident light satisfies the resonance condition, the transmission spectrum has a high peak value, which corresponds to a high transmittance. Assuming an interference intensity distribution:
in the formula I0Is the incident light intensity; r is the energy reflectivity of the reflecting surface; δ is a phase difference between two adjacent coherent light beams, and R + T is 1(R is surface reflectance of the film system, and T is transmittance) depending on an incident light tilt angle. The distance between the adjacent high-fold layers and the distance between the adjacent low-fold layers are equal to the distance of the spacing layer, according to the Fabry-Perot interference principle, the interference reaches the maximum when the distance of the spacing layer is a multiple of lambda/4, and according to the cosine wave characteristic of the wave particle binary transmission of light, the period of the cosine is gradually increased, so the structure passing through the film system is the | (. alpha.) (1Hβ1Lα2Hβ2L...αnHβnL) -because the optical thickness coefficients (i.e., alpha and beta) of the high-fold layer 31 and the low-fold layer 32 of the film stack follow the regular gradient of the cosine waveform, that is, the distance between the adjacent high-fold layers and the distance between the adjacent low-fold layers show the regular gradient of the cosine waveform, the interference effect of a specific wavelength is enhanced, and the band range of the interference formed corresponding to the corresponding refractive index tends to be narrowed, that is, the film stackThe light wavelength range in which the transmittance is sharply changed is narrowed to a great extent, so that a narrow-band transmission effect is achieved, and the visible light is cut off based on the visible light cut-off film system 2, so that the interference mainly occurs in the infrared spectrum, and the infrared light is finally transmitted in a stable narrow band.
The change of the optical thickness coefficients of the high-refractive-index layer 31 and the low-refractive-index layer 32 can realize the narrow-band transmission effect by only following the same gradient rule on the sine waveform or the cosine waveform, and in a preferred embodiment of the present application, for the ith refractive-index dual unit α in the same film stackiHβiL, the optical thickness of the high-refractive layer 31 is alphai*Lambda/4, optical thickness of the low-refractive layer 32 is betai*λ/4, refractive index of the high refractive layer 31 is NHThe physical thickness of the high fold layer 31 is DHThen N is presentH*DH＝αi*Lambda/4; the refractive index of the low refractive layer 32 is NLThe physical thickness of the low-folding layer 32 is DLThen N is presentL*DL＝βi*Lambda/4; wherein alpha is1，α2，...，αnAnd beta1，β2，...，βnThe gradient-changing method is characterized in that the gradient-changing method independently satisfies the same gradient rule on the upper left half chord, the lower left half chord, the upper right half chord and the lower right half chord of the same sine waveform or cosine waveform in the range of 0-2 pi. The optical thickness coefficients follow the waveform change rule of four half-chords of the same sine wave in the range, and the difference value of the obtained optical thickness is in a narrower range, so that the narrow-band effect can be better exerted; and the common half-wave hole in the design of the optical film can not appear (in the actual preparation of the optical filter, a reflection peak is often appeared in a band-pass region, namely, a half-wave hole is generally called as the half-wave hole, and is also called as the half-wave falling of the optical filter).
In order to obtain a physical thickness which is easier to realize and to control the total physical thickness of the infrared window film system 3, it is preferable that α is measured when the infrared window film system 3 is monitored at a wavelength of 455nmi，βiThe value range of (A) is as follows: alpha is more than or equal to 0.01i≤3.2，0.01≤βi3.2 or less, preferably 0.05 or less alphai≤2.8，0.05≤βiLess than or equal to 2.8; preferably, 0.1. ltoreq. alpha.i≤2.8，0.1≤βiLess than or equal to 2.8; more preferably, 0.2. ltoreq. alpha.i≤2.7，0.2≤βi≤2.7。
In the design of the infrared window film system of the present application, in order to make the infrared window film system 3, the visible light cut-off film system 2 and the substrate layer 1 have better hardness, adhesiveness, etc., generally, a transitional high-low layer is set in advance before the film stack is set, or in order to improve the adaptability of the adjacent film stacks, a transition layer is also set, and in order to ensure the narrow-band effect of the film stack, the number of the refractive index dual units of the film stack preferably accounts for 60-99% of the total number of the refractive index dual units of the infrared window film system 3.
In consideration of the requirements of the structure of the optical filter and the like applied to the infrared narrow band filter film of the present application, the physical thickness of the high refractive layer 31 is preferably 1 to 400nm, preferably 10 to 150nm, and the physical thickness of the low refractive layer 32 is preferably 1 to 400nm, preferably 10 to 150 nm.
The refractive index of the high refractive layer 31 and the low refractive layer 32 can be referred to the refractive index of the material for manufacturing the transmission film in the prior art, preferably, the refractive index of the high refractive layer 31 is 1.5 to 5.0, preferably 1.65 to 3.0, and the refractive index of the low refractive layer 32 is 1.1 to 1.5, preferably 1.25 to 1.48.
The refractive index materials forming the high fold 31 and the low fold 32 having the above refractive index may be selected from those commonly used in the art, and preferably, the refractive index materials forming the high fold 31 and the low fold 32 are each independently selected from MgF2、CaF2Transition metal fluoride, ZnO, TiO2、TiN、In2O3、SnO3、Cr2O3、ZrO2、Ta2O5、LaB6、NbO、Nb2O3、Nb2O5、SiO2、SiC、Si3N4、Al2O3And a fluorine-containing resin or a hollow silica-containing resin.
In order to increase the transmittance to a target wavelength, the total number of layers of the high-refractive-index layer 31 and the low-refractive-index layer 32 is preferably 10 to 150, and more preferably 12 to 60.
The above-mentioned method for manufacturing the infrared window film system can refer to the method for manufacturing the reflective film system or the transmissive film system in the prior art, and the thickness of each high-fold layer and each low-fold layer is controlled by programming, and the specific control method can refer to the prior art, and is not described herein again.
In another exemplary embodiment of the present application, an infrared identification system is provided, which includes one or more light sources, an infrared image receiver, and a filter disposed on a surface of the infrared image receiver, where the filter is any one of the above infrared narrowband filters, and the light source is an infrared or near-infrared light source with a center wavelength in a light transmission band of an infrared window film system of the multi-infrared narrowband filter in a range of 700 to 1400 nm.
The infrared or near-infrared light source is used as a light source to be matched with the multiband cut-off filter film, so that the external visible light is cut off, the influence of the visible light on the infrared recognition system is avoided, meanwhile, the multiband cut-off filter film is used for realizing the narrowband transmission effect on the infrared light, the recognition accuracy of the infrared recognition system is improved, and the accuracy of final image acquisition of the infrared recognition system is improved.
The advantageous effects of the present application will be further described below with reference to examples and comparative examples.
Example 1
The structure of the infrared narrow-band filter film of the embodiment is as shown in fig. 1, that is, the substrate layer, the visible light cut-off film system and the infrared window film system are sequentially stacked. The structure of each membrane system is as follows:
the structure of the visible light cut-off film system is Sub |1.376L1.795H | Sub |5.003H0.236L | Air, wherein: sub is a base material layer, and Air is Air; h is an alpha-hydrogenated amorphous silicon layer with a refractive index of 4.306; l is a silicon dioxide layer with a refractive index of 1.470, as can be seen in fig. 1.
Preparing the visible light cut-off film by adopting a vacuum magnetron sputtering method:
(1) forming a hydrogenated amorphous silicon layer on a substrate
The glass substrate layer is strictly cleaned before use: soaking in standard washing solution (saturated solution of potassium permanganate in sulfuric acid) for 24 h; then, sequentially ultrasonically cleaning the mixture for 15min by using toluene, acetone and ethanol respectively, and repeatedly washing the mixture by using deionized water during the ultrasonic cleaning; and finally, placing the cleaned substrate in analytically pure ethanol and keeping the substrate away from light for later use.
Using TXZ500-2 type radio frequency magnetron sputtering film plating machine, using Si target with purity of 99.999%, resistivity greater than 1000 omega cm, sputtering gas is argon with purity of 99.9%, reactive gas is hydrogen with purity of 99.9%, working gas is Ar2And H2Mixed gas of (2), H 220 percent of the total weight of the alloy powder is subjected to radio frequency sputtering operation in a vacuum chamber filled with argon and hydrogen, the radio frequency sputtering power is 340W, and the background is vacuumized to be less than 8.0 multiplied by 10-5Pa, the substrate temperature is 180 ℃, and the coating time is 90 min. In the experiment, the working gas pressure was 0.3Pa, and an α -hydrogenated amorphous silicon layer was formed. The thickness, refractive index and extinction coefficient of the film were measured by reflection using an M M-16 ellipsometer manufactured by H ORIBA, France.
(2) Forming a silicon oxide layer on the hydrogenated amorphous silicon layer
And depositing silicon dioxide layers on the hydrogenated amorphous silicon layers on the two sides in a vacuum chamber filled with argon and oxygen by taking silicon as a target. In the process of forming the silicon dioxide layer, the radio frequency sputtering power is 350W, and the background vacuum of the vacuum chamber is 8.0 multiplied by 10- 5Pa, sputtering time of 60min, and working pressure of 0.1 Pa. The thickness, refractive index and extinction coefficient of the visible light cut-off film were measured by reflection using an M M-16 ellipsometer manufactured by H ORIBA, France.
The molar percentage of hydrogen atoms in the resulting α -hydrogenated amorphous silicon layer was about 10.23%, and the portion of the α -hydrogenated amorphous silicon layer in contact with the silicon dioxide layer was formed
The structure forms a structural water layer (M is Si) and forms two structural water layers, wherein the physical thickness of the structural water layer is about 0.64 nm.
Arranging an anti-reflection layer and an infrared window film system on the visible light cut-off film system, wherein the central wavelength of incident light is set to be 532nm, the high-refraction layer is a titanium dioxide layer with the refractive index of 2.354, the low-refraction layer is a silicon dioxide layer with the refractive index of 1.46, the anti-reflection layer is composed of the titanium dioxide layer with the optical thickness of lambda/4 and the silicon dioxide layer, and the infrared window film system is structurally designed to be
Sub |0.947H 1.046L 1.019H 1.135L 1.300H 1.380L 1.518H 1.643L 1.808H 1.878L 1.962H2.219L 0.800.800H 0.861L 1.070H 1.194L 1.291H 1.429L 1.516H 1.635L 1.768H 1.877L 2.006H2.141L 0.792.792H 1.067L 1.436H 1.601L 1.678H 1.612L 1.566H 1.623L 1.675H 1.837L 1.829H1.385L | Air, wherein the total of three film stacks are:
0.947H 1.046L 1.019H 1.135L 1.300H 1.380L 1.518H 1.643L 1.808H 1.878L 1.962H 2.219L；
0.800H 0.861L 1.070H 1.194L 1.291H 1.429L 1.516H 1.635L 1.768H 1.877L 2.006H 2.141L；
0.792H 1.067L 1.436H 1.601L 1.678H 1.612L 1.566H 1.623L 1.675H 1.837L 1.829H 1.385L；
and (3) manufacturing the three-film stack of the infrared window film system corresponding to the embodiment 1 by adopting a magnetron sputtering process. And (3) deflating the vacuum chamber, cleaning the inside of the bell jar by using a dust collector, filling the molybdenum boat with the film material to be evaporated, and recording the name of the film material of each boat. And the substrate is placed on the substrate holder without tilting the substrate. The bell jar is dropped down, and the vacuum chamber is vacuumized according to the operation rules of the film coating machine. When the vacuum degree reaches 7 multiplied by 10-3And after Pa, pre-melting the film materials in the molybdenum boat in sequence to remove gas in the film materials. At this point, attention is paid to the baffle plate to prevent the substrate from being plated in the pre-melting process. When the vacuum degree meets the requirement, plating is carried out by adopting a method of controlling the optical thickness by adopting a lambda/4 extreme value method, and the control wavelength is placed at 532 nm. Titanium dioxide is plated on a visible light cut-off film system of the substrate, and the photocurrent indicated by the amplifier is reduced along with the thickening of the film layer. When the photocurrent value just begins to rise, the baffle is immediately stopped. And then, reducing the current to change the electrode, plating silicon dioxide, wherein when the silicon dioxide is plated, the photocurrent rises along with the increase of the film thickness, stopping plating the film when the extreme value is reached, and repeating the steps to plate the film. When a spacer layer with an optical thickness of lambda/2 is plated, the thickness is doubled,it should stop when the photocurrent rises and falls to the extreme value again. The latter layers are controlled as the former layers.
And after the coating is finished, stopping heating and vacuumizing according to the operating specification of the coating machine. After half an hour, the vacuum chamber of the film coating machine can be inflated to take out the coated interference filter. Then the coating machine is vacuumized according to the operating specification to keep clean, and finally the machine is stopped.
And (3) testing the infrared narrow-band filter film by using a full-wavelength light transmittance instrument, wherein the test result is shown in figure 3. As can be seen from FIG. 3, the wavelength range of infrared light transmission is 800-1000 nm, the center wavelengths thereof are 850nm and 940nm, the bandwidth is less than 50nm, the transmittance is also high, and the visible light is almost completely cut off.
Example 2
The difference from the example 1 is that the structure of the infrared window film system is designed to be
Sub |0.934H 1.018L 1.013H 1.133L 1.274H 1.402L 1.481H 1.635L 1.814H 1.894L 1.981H2.223L 0.792H 1.067L 1.057H 1.195L 1.272H 1.435L 1.519H 1.641L 1.774H 1.886L 2.012H2.134L | Air, where in total two membrane stacks, respectively:
0.934H 1.018L 1.013H 1.133L 1.274H 1.402L 1.481H 1.635L 1.814H 1.894L 1.981H 2.223L；
0.792H 1.067L 1.057H 1.195L 1.272H 1.435L 1.519H 1.641L 1.774H 1.886L 2.012H 2.134L。
and (3) testing the infrared narrow-band filter film by using a full-wavelength light transmittance instrument, wherein the test result is shown in figure 4. As can be seen from FIG. 4, the wavelength range of infrared light transmission is 900-1000 nm, the center wavelength is 950nm, the bandwidth is less than 50nm, the transmittance is relatively high, and the visible light is almost completely cut off.
Comparative example 1
The difference from the embodiment 1 is that the structure of the infrared window film system is designed to
Sub1.802H 0.646L 1.000H1.000L 1.000H 2.000L 1.000H1.000L 1.000H1.000L 1.000H1.000L 1.000.000H 1.000L 1.000H 2.000L 1.000H1.000L 1.000H1.000L 1.000H1.000L 1.000H1.000 H1.000L 1.000H 2.000L 1.000H1.000L 1.000H 1.002L 1.837H 0.956L | Air, a structured film stack.
And (3) testing the infrared narrow-band filter film by using a full-wavelength light transmittance instrument, wherein the test result is shown in figure 5. According to fig. 5, the wavelength range of infrared light transmission is 800-1200 nm, the center wavelength is 950nm, the transmittance is greater than 90%, the visible light is basically completely cut off, but the bandwidth is greater than 60 nm.
From the above description, it can be seen that the above-described embodiments of the present invention achieve the following technical effects:
because the infrared narrow-band filter film simultaneously comprises the visible light cut-off film system and the infrared window film system, the infrared narrow band can penetrate through the visible light on the basis of effectively cutting off the visible light, the interference of the visible light is avoided, the infrared light is utilized to realize higher discrimination, the visual effect is improved, and the accuracy of the final infrared image camera image acquisition is improved.
The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (37)
1. An infrared narrow-band filter film, comprising:
a base material layer (1);
a visible light cut-off film system (2) for absorbing or reflecting visible light in the range of 380nm to 780 nm;
an infrared window film system (3) having one or more narrow-band light-transmitting windows in the range of 700 to 1400nm, the narrow-band light-transmitting windows having a peak width in the range of 5 to 50nm at a transmittance of 50% or more;
the visible light cut-off film system and the infrared window film system are oppositely arranged on two surfaces of the substrate layer (1) or are superposed on one or two opposite surfaces of the substrate layer (1);
the visible light cut-off film system (2) comprises one or more absorption units (20), the absorption units (20) are arranged on one or two opposite surfaces of the substrate layer (1), each absorption unit (20) comprises a high-refractive-index material layer (21) and a matching material layer (22) arranged in contact with the high-refractive-index material layer, the refractive index of the high-refractive-index material layer is 3-5.5, and a structural water layer (23) is formed at a contact interface between the high-refractive-index material layer (21) and the matching material layer (22);
the high-refractive-index material layer (21) is an alpha-hydrogenated amorphous silicon layer, the matching material layer (22) is an oxide layer, the oxide layer is a metal oxide layer or a nonmetal oxide layer, and the change of the refractive index of the alpha-hydrogenated amorphous silicon layer to the wavelength range of 380-780 nm is less than or equal to 0.8; the refractive index of the matching material layer (22) is 1.0-2.7;
the surface Si-H bonds of the alpha-hydrogenated amorphous silicon layer combine with the oxide layer to form a structured water layer (23).
2. The infrared narrowband filter of claim 1, wherein 1 to 10 layers of the structural water layer (23) are formed in the visible light cut-off film system (2).
3. The infrared narrowband filter of claim 1, wherein each structured water layer (23) has a physical thickness of 0.1 to 2 nm.
4. The infrared narrowband filter of claim 1, wherein the α -hydrogenated amorphous silicon layer has a hydrogen atom content of 5 to 25 mol%.
5. The infrared narrowband filter of claim 1, wherein the oxide layer is selected from SiO2Layer, Ti3O5Layer of Al2O3Layer, SiO layer, TiO2Layer, Ti2O3Layer, Ta2O5Layer, HfO2Layer, MgO layer, ZrO2Layer, CeO2Layer, CaO layer, Y2O3Layer, ZnO layer, Nb2O5Any one or more of the layers.
6. The infrared narrowband filter of claim 1, wherein the high refractive index material layer (21) has a physical thickness of 1 to 1000 nm; the physical thickness of the matching material layer (22) is 1-1000 nm.
7. The infrared narrowband filter of claim 1, wherein the high refractive index material layer (21) has a physical thickness of 1 to 500 nm.
8. The infrared narrowband filter of claim 1, wherein the high refractive index material layer (21) has a physical thickness of 1 to 200 nm.
9. The infrared narrowband filter of claim 1, wherein the matching material layer (22) has a physical thickness of 1 to 500 nm.
10. The infrared narrowband filter of claim 1, wherein the matching material layer (22) has a physical thickness of 1 to 200 nm.
11. The infrared narrowband filter of claim 1, characterized in that the substrate layer (1) is a silicon layer, a glass layer, a PET layer, a COP layer, a COC layer, a CPI layer, a PMMA layer, a PEN layer, a PC layer or a TAC layer.
12. The infrared narrowband filter of claim 1, characterized in that the physical thickness of the visible cut-off film series (2) is less than 500 μ ι η.
13. The infrared narrowband filter of claim 1, characterized in that the physical thickness of the visible cut-off film series (2) is less than 400 μ ι η.
14. The infrared narrowband filter of claim 1, characterized in that the physical thickness of the visible cut-off film series (2) is less than 300 μ ι η.
15. The infrared narrowband filter of claim 1, characterized in that the physical thickness of the visible cut-off film series (2) is less than 200 μ ι η.
16. The infrared narrowband filter of claim 1, characterized in that the physical thickness of the visible cut-off film series (2) is less than 100 μ ι η.
17. The infrared narrowband filter of claim 1, characterized in that the physical thickness of the visible cut-off film series (2) is less than 50 μ ι η.
18. The infrared narrowband filter of claim 1, wherein the physical thickness of the visible light cut-off film (2) is between 50 μm and 250 μm.
19. The infrared narrowband filter of claim 1,
the infrared window film system (3) comprises a plurality of refractive index dual units, each refractive index dual unit comprises a high-folding layer (31) and a low-folding layer (32) matched with the high-folding layer, and the structure of the film system formed by the refractive index dual units is alpha1Hβ1Lα2Hβ2L... αnHβnL) film stack, wherein H represents a high-fold layer (31), L represents a low-fold layer (32), n is a positive integer, n is more than 2 and less than or equal to 60, and the optical thickness coefficient alpha of the high-fold layer (31) and the optical thickness coefficient alpha of the low-fold layer (32) in the same film stack1，α2，...，αnAnd beta1，β2，...，βnThe same gradient rule on the same cosine waveform or sine waveform is respectively and independently satisfied, and the gradient rule of each film stack of the same infrared window film system (3) is the same; for the ith said refractive index dual unit αiHβiL，1≤i≤n,αiRepresents an optical thickness coefficient beta of the ith high-folding layer (31) along a direction vertical to the substrate layer (1)iAnd an optical thickness coefficient of the ith low-folding layer (32) in a direction perpendicular to the base material layer (1).
20. The infrared narrowband filter of claim 19, wherein for the ith refractive index dual unit α in the same stackiHβiL, the optical thickness of the high-refraction layer (31) is alphai*λ/4, the optical thickness of the low-refractive layer (32) being βi*λ/4, the refractive index of the high refractive layer (31) is NHThe physical thickness of the high-folding layer (31) is DHThen N is presentH*DH=αi*Lambda/4; the refractive index of the low refraction layer (32) is NLThe physical thickness of the low-folded layer (32) is DLThen N is presentL*DL=βi*Lambda/4; wherein alpha is1，α2，...，αnAnd beta1，β2，...，βnThe sine wave and cosine wave form can independently satisfy the same gradient law on the upper left half chord, the lower left half chord, the upper right half chord and the lower right half chord of the same sine wave form or cosine wave form in the range of 0-2 pi.
21. The infrared narrowband filter according to claim 20, characterised in that the infrared window film series (3) is α at a monitoring wavelength of 455nmi，βiThe value range of (A) is as follows: alpha is more than or equal to 0.01i≤3.2，0.01≤βi≤3.2。
22. The infrared narrowband filter according to claim 20, characterized in that the infrared window film system (3) is α at a monitoring wavelength of 455nmi，βiThe value range of (A) is as follows: alpha is more than or equal to 0.05i≤2.8，0.05≤βi≤2.8。
23The infrared narrowband filter of claim 20, wherein the infrared window film system (3) is α at a monitoring wavelength of 455nmi，βiThe value range of (A) is as follows: alpha is more than or equal to 0.1i≤2.8，0.1≤βi≤2.8。
24. The infrared narrowband filter according to claim 20, characterized in that the infrared window film system (3) is α at a monitoring wavelength of 455nmi，βiThe value range of (A) is as follows: alpha is more than or equal to 0.2i≤2.7，0.2≤βi≤2.7。
25. The infrared narrowband filter according to any of claims 19 to 24, characterized in that the number of refractive index dual units of the stack represents 60 to 99% of the total number of refractive index dual units of the infrared window film series (3).
26. The infrared narrowband filter of any of claims 19 to 24, characterized in that the high fold layer (31) has a physical thickness of 1 to 400 nm.
27. The infrared narrowband filter of any of claims 19 to 24, characterized in that the high fold layer (31) has a physical thickness of 10 to 150 nm.
28. The infrared narrowband filter of any of claims 19 to 24, characterized in that the low-fold layer (32) has a physical thickness of 1 to 400 nm.
29. The infrared narrowband filter of any of claims 19 to 24, characterized in that the low-fold layer (32) has a physical thickness of 10 to 150 nm.
30. The infrared narrowband filter of any of claims 19 to 24, characterized in that the refractive index of the high refractive layer (31) is 1.5 to 5.0.
31. The infrared narrowband filter according to any of claims 19 to 24, characterised in that the high refractive index of the high refractive layer (31) is between 1.65 and 3.0.
32. The infrared narrowband filter of any of claims 19 to 24, characterized in that the refractive index of the low-refractive layer (32) is between 1.1 and 1.5.
33. The infrared narrowband filter of any of claims 19 to 24, characterized in that the refractive index of the low-refractive layer (32) is between 1.25 and 1.48.
34. The infrared narrowband filter according to any of claims 19 to 24, characterised in that the refractive index materials forming the high fold (31) and the low fold (32) are each independently selected from MgF2、CaF2Transition metal fluoride, ZnO, TiO2、TiN、In2O3、SnO3、Cr2O3、ZrO2、Ta2O5、LaB6、NbO、Nb2O3、Nb2O5、SiO2、SiC、Si3N4、Al2O3And a fluorine-containing resin or a hollow silica-containing resin.
35. The infrared narrowband filter film according to any of claims 19 to 24, characterised in that the total number of layers of the high fold layer (31) and the low fold layer (32) is 10 to 150.
36. The infrared narrowband filter film according to any of claims 19 to 24, characterised in that the total number of layers of the high fold (31) and the low fold (32) is between 12 and 60.
37. An infrared identification system, comprising one or more light sources, an infrared image receiver, and a filter film arranged on the surface of the infrared image receiver, wherein the filter film is the infrared narrowband filter film described in any one of claims 1 to 36, and the light source is an infrared or near-infrared light source with a central wavelength in a light transmission waveband of an infrared window film system of the infrared narrowband filter film in the range of 700-1400 nm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711378597.3A CN109932774B (en) | 2017-12-19 | 2017-12-19 | Infrared narrow-band filter film and infrared recognition system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711378597.3A CN109932774B (en) | 2017-12-19 | 2017-12-19 | Infrared narrow-band filter film and infrared recognition system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109932774A CN109932774A (en) | 2019-06-25 |
| CN109932774B true CN109932774B (en) | 2021-08-10 |
Family
ID=66984073
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201711378597.3A Active CN109932774B (en) | 2017-12-19 | 2017-12-19 | Infrared narrow-band filter film and infrared recognition system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109932774B (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108169831A (en) * | 2018-01-18 | 2018-06-15 | 无锡奥芬光电科技有限公司 | 940nm spike filters and its alternation Film Design method |
| KR20210023565A (en) * | 2019-08-23 | 2021-03-04 | 현대자동차주식회사 | Optic filter integrated with lidar window |
| CN111638572B (en) * | 2019-11-29 | 2021-03-05 | 苏州京浜光电科技股份有限公司 | 3D structured light 940nm narrow-band filter and preparation method thereof |
| CN111552017A (en) * | 2020-05-26 | 2020-08-18 | 苏州京浜光电科技股份有限公司 | Novel preparation method of double-bandpass optical filter |
| CN113375857A (en) * | 2021-06-09 | 2021-09-10 | 江苏创芯海微科技有限公司 | Self-verifying vacuum degree sensor |
| CN114236662B (en) * | 2021-11-12 | 2024-09-17 | 光驰科技(上海)有限公司 | Dual-channel optical filter with high cut-off depth and preparation method thereof |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5394255A (en) * | 1992-01-27 | 1995-02-28 | Sekisui Kagaku Kogyo Kabushiki Kaisha | Liquid crystal display using a plurality of light adjusting sheets angled at 5 degrees or more |
| CN202735531U (en) * | 2012-08-03 | 2013-02-13 | 晋谱（福建）光电科技有限公司 | Multi-wavelength high reflector |
| CN103018812A (en) * | 2012-12-17 | 2013-04-03 | 晋谱（福建）光电科技有限公司 | Near-infrared narrow-band optical filter used for somatosensory recognition system |
| CN103217730A (en) * | 2013-04-18 | 2013-07-24 | 同济大学 | Narrow-band negative filter plate membrane system with gradually-changing optical thicknesses |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2012032454A (en) * | 2010-07-28 | 2012-02-16 | Fujifilm Corp | Infrared reflection film |
-
2017
- 2017-12-19 CN CN201711378597.3A patent/CN109932774B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5394255A (en) * | 1992-01-27 | 1995-02-28 | Sekisui Kagaku Kogyo Kabushiki Kaisha | Liquid crystal display using a plurality of light adjusting sheets angled at 5 degrees or more |
| CN202735531U (en) * | 2012-08-03 | 2013-02-13 | 晋谱（福建）光电科技有限公司 | Multi-wavelength high reflector |
| CN103018812A (en) * | 2012-12-17 | 2013-04-03 | 晋谱（福建）光电科技有限公司 | Near-infrared narrow-band optical filter used for somatosensory recognition system |
| CN103217730A (en) * | 2013-04-18 | 2013-07-24 | 同济大学 | Narrow-band negative filter plate membrane system with gradually-changing optical thicknesses |
Also Published As
| Publication number | Publication date |
|---|---|
| CN109932774A (en) | 2019-06-25 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109932774B (en) | Infrared narrow-band filter film and infrared recognition system | |
| JP7404367B2 (en) | optical filter | |
| TWI648561B (en) | Optical filter and sensor system | |
| Wang et al. | Design and sol–gel preparation of SiO2/TiO2 and SiO2/SnO2/SiO2–SnO2 multilayer antireflective coatings | |
| CN109932773B (en) | Visible light cut-off film, preparation method and application thereof | |
| CN106574985A (en) | Anti-reflection film and optical member provided with anti-reflection film | |
| Liu et al. | Reflection of Blue Light Using Bi-Layer Al2O3–TiO2 E-Beam Coating Films | |
| TW201348758A (en) | Infrared filter and lens module | |
| Bulkin et al. | Properties and applications of electron cyclotron plasma deposited SiOxNy films with graded refractive index profiles | |
| CN210506093U (en) | Antireflection film and antireflection glass | |
| US10196302B2 (en) | Method for manufacturing antireflection function-equipped lens | |
| US20210263195A1 (en) | Optical article having directional micro- or nanostructured thin film coating, and its process | |
| JP2001281409A (en) | Lens with antireflection film and endoscope | |
| CN111708106A (en) | Double-sided antireflection film without reducing transmittance of 940 nanometer waveband and preparation method thereof | |
| KR101573016B1 (en) | Colored and low-reflective optical lens with multi-layer thin coating, and its preparation method | |
| CN110927852A (en) | Infrared broadband cut-off filter and application thereof | |
| CN201749207U (en) | Near-infrared filter for face identification | |
| KR20220133763A (en) | Optical laminate, article and image display device | |
| CN220773287U (en) | High-broadband IR filter | |
| KR20200143670A (en) | Lens coating layer | |
| CN112415640A (en) | Resin lens for protecting green laser pen and preparation method thereof | |
| CN114864728B (en) | High light transmission coffee glass and coffee solar module | |
| CN214252637U (en) | Heat-insulation antireflection film | |
| TWI845438B (en) | Coated lens with both iris identification and sunglass function | |
| TWI855290B (en) | Optical filter and sensor system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |