Visible infrared ultra-wide spectrum color separator and processing method thereof

Abstract

The invention discloses a visible infrared ultra-wide spectrum color separator and a processing method thereof. The visible infrared ultra-wide spectrum color separator comprises a substrate, an ultra-wide spectrum color separation film and an infrared anti-reflection film, wherein the ultra-wide spectrum color separation film and the infrared anti-reflection film are arranged on the two sides of the substrate respectively; wherein the ultra-wide spectrum color separation film is used for reflecting visible light, and the infrared anti-reflection film is used for transmitting infrared light. According to the visible infrared ultra-wide spectrum color separator with the structure and the processing method of the visible infrared ultra-wide spectrum color separator, an all-dielectric film interference technology is adopted, and a light path for transmitting visible light and reflecting infrared light is changed into a light path for reflecting visible light and transmitting infrared light, so that a spectrum transition area is reduced, visible and near-infrared color separation is increased, and the color separation efficiency is improved. Moreover, the design scheme that the all-dielectric film layer is free of the metal film layer also reduces the sensitivity of the film system, and reduces the abnormal rate of preparation.

Description

Technical Field

[0001] The invention relates to the technical field of color separation devices, and in particular to a visible infrared ultra-wide spectrum color separator and a processing method thereof. Background Art

[0002] In the spatial multi-spectral remote sensing system, it is necessary to distribute the optical signals of different wavelengths to different optical paths and match them to different detectors. Each detector then performs photoelectric conversion and signal processing for non-specific spectral wavelengths. At present, the common method of spectral color separation is to use color separation devices. The applied spectrum covers visible wavelengths (0.4-0.7um), near-infrared wavelengths (0.85-1.65um), medium-wave infrared wavelengths (3-5um), and long-wave infrared wavelengths (8-12um), which can be called ultra-wide spectrum color separators.

[0003] At present, ultra-wide spectrum color separators usually adopt a color separation scheme that transmits visible light and reflects infrared light, and the color separation film mostly uses the characteristics of metal thin films that induce transmission of visible wavelengths and reflect infrared wavelengths. This color separation method can extend the infrared reflection wavelength to long-wave infrared, but its disadvantages are also obvious:

[0004] (1) The spectral transition region is wide, and the spectrum in the transition region cannot be fully utilized, so it is impossible to effectively separate visible light and near-infrared light;

[0005] (2) For visible light to pass through, the thickness of the metal film must be very thin. The thickness of the metal film at the nanometer level is difficult to accurately control, so slight differences in the thickness of the metal film will cause the visible light transmittance to deteriorate. Summary of the invention

[0006] The purpose of the present invention is to provide a visible infrared ultra-wide spectrum color splitter and a processing method thereof, so as to solve the problems that the spectral transition zone of the above-mentioned ultra-wide spectrum color splitter is wide, the spectrum in the transition zone cannot be fully utilized, and the thickness of the metal film used for visible light transmission is very thin and difficult to accurately control.

[0007] To achieve the above objectives, the first aspect of the present invention provides a visible-infrared ultra-wide spectrum color separator, comprising a substrate and an ultra-wide spectrum color separation film and an infrared anti-reflection film respectively arranged on both sides of the substrate; wherein the ultra-wide spectrum color separation film is used to reflect visible light, and the infrared anti-reflection film is used to transmit infrared light.

[0008] Preferably, the substrate is a material that transmits both visible light and infrared light.

[0009] Preferably, the substrate is one of multi-spectrum ZnS and CVD ZnSe.

[0010] The present invention adopts the full dielectric interference technology, and changes the optical path of transmitting visible light and reflecting infrared light in the prior art into an optical path of transmitting infrared light and reflecting visible light. The substrate only needs to be made of a material that is transparent to infrared light. In order to improve the resolution of visible and near-infrared color separation, a material that is transparent to both visible light and infrared light is selected, such as multi-spectral ZnS or CVD ZnSe.

[0011] Multi-spectral ZnS, or multi-spectral zinc sulfide, is an important infrared optical material. The transmission band of multi-spectral zinc sulfide is very wide, covering the entire band from visible light to long-wave infrared (8-12μm), and even the microwave band. This characteristic makes it the only infrared optical material that can transmit such a wide spectral range except diamond. Its transmission range can reach 0.37 to 13.5μm, and it performs well in infrared windows and thermal band (8 to 14μm) lenses, especially windows that require greater transmission and lower absorption.

[0012] CVD ZnSe is zinc selenide prepared by chemical vapor deposition and is an important infrared optical material. Chemical properties: CVD ZnSe is a chemically inert material with high purity and strong environmental adaptability. Physical properties: It has low light transmission loss and good light transmittance, especially in the infrared spectrum. Preparation method: It is prepared by chemical vapor deposition, which can control the grain size, purity and optical properties of the material, making CVD ZnSe an ideal material for high-performance infrared optical components.

[0013] The multi-spectrum ZnS and CVD ZnSe in the present invention are both purchased directly, for example, from II-IV Company in the United States.

[0014] Preferably, the ultra-wide spectrum dichroic film has R>99%@0.4-0.7um, T>97%@0.85-1.65um&@3-5um&@8-12um at an incident angle of 45 degrees.

[0015] R>99%@0.4-0.7um, which means that within the spectral range of 0.4um to 0.7um (i.e. 400nm to 700nm, roughly corresponding to the blue to red range of visible light), the reflectivity of the dichroic film is greater than 99%, which means that most (more than 99%) of the incident light will be reflected back within this band.

[0016] T>97%@0.85-1.65um&@3-5um&@8-12um, which means that in three different spectral ranges (0.85-1.65um, 3-5um, 8-12um), the transmittance of the dichroic film is greater than 97%, and these bands correspond to different parts of infrared light. 0.85-1.65um: may be part of near-infrared light. 3-5um: part of mid-infrared light. 8-12um: part of far-infrared light.

[0017] 45-degree incidence means that when measuring these reflectances and transmittances, the angle between the incident light and the dichroic film surface is 45 degrees, which is an important condition because the performance of optical films may change with changes in the angle of incidence.

[0018] Preferably, the ultra-wide spectrum color separation film includes multiple layers of ZnS film material, and YbF3 film material or YF3 film material is arranged between two adjacent layers of ZnS film material. The ratio of the total thickness of the ZnS film material, the total thickness of the YbF3 film material and the total thickness of the YF3 film material is (1~1.5):(1~1.5):(1~1.5).

[0019] Preferably, the outer layer of the ultra-wide spectrum color separation film can be set to YbF3 film material or YF3 film material.

[0020] Preferably, the ratio of the total thickness of the ZnS film material, the total thickness of the YbF3 film material and the total thickness of the YF3 film material is (1-1.3): (1-1.3): (1-1.3).

[0021] The ultra-wide spectrum color separation film of the present invention selects ZnS as a high refractive index film material, and YbF3 (ytterbium fluoride) and YF3 (yttrium fluoride) are used in combination as low refractive index film materials.

[0022] Preferably, the ultra-wide spectrum color separation film includes at least 10 layers of ZnS film material.

[0023] Preferably, the ultra-wide spectrum color separation film includes at least 15 layers of ZnS film material.

[0024] Preferably, the ultra-wide spectrum color separation film includes at least 20 layers of ZnS film material.

[0025] Preferably, the ultra-wide spectrum color separation film includes at least 25 layers of ZnS film material.

[0026] Preferably, the ultra-wide spectrum color separation film includes at least 29 layers of ZnS film material.

[0027] Preferably, YbF3 film or YF3 film is arranged between two adjacent layers of ZnS film, and YbF3 film and YF3 film appear alternately between two adjacent layers of ZnS film, forming a cyclic layered structure of ZnS film-YbF3 film-ZnS film-YF3 film-ZnS film, which together constitute an ultra-wide spectrum color separation film.

[0028] Preferably, the thickness of each layer of ZnS film material is 15-140 nm, the thickness of each layer of YbF3 film material is 30-500 nm, and the thickness of each layer of YF3 film material is 5-320 nm.

[0029] Preferably, the infrared anti-reflection film has an R value of <1.5% @0.85-1.65um & @3-5um & @8-12um at an incident angle of 45 degrees.

[0030] R<1.5%@0.85-1.65um&@3-5um&@8-12um: This means that in three different infrared spectrum ranges (0.85-1.65um, 3-5um, 8-12um), the reflectivity of the infrared anti-reflection film is less than 1.5%, which means that most (more than 98.5%) of the infrared light will be transmitted. These bands correspond to different parts of the infrared light, including near infrared, mid-infrared and far infrared.

[0031] 45 degree incidence means that when measuring these reflectivities, the incident light is at an angle of 45 degrees to the surface of the IR anti-reflection coating. This is an important condition because the properties of optical films (including reflectivity) may change with changes in the angle of incidence.

[0032] Preferably, the infrared anti-reflection film comprises multiple layers of ZnS film material, a YF3 film material is arranged between two adjacent layers of ZnS film material, and the ratio of the total thickness of the ZnS film material to the total thickness of the YF3 film material is 1:(2.5-4.0).

[0033] The infrared anti-reflection film of the present invention selects ZnS as the high-refractive-index film material and YF3 as the low-refractive-index film material.

[0034] Preferably, the infrared anti-reflection film includes at least 5 layers of ZnS film material.

[0035] Preferably, the infrared anti-reflection film includes at least 7 layers of ZnS film material.

[0036] Preferably, the infrared anti-reflection film includes at least 10 layers of ZnS film material.

[0037] Preferably, a YF3 film material is arranged between two adjacent layers of ZnS film material to form a cyclic layered structure of ZnS film material-YF3 film material-ZnS film material, which together constitute an infrared anti-reflection film.

[0038] Preferably, the thickness of each layer of ZnS film material is 25-125 nm, and the thickness of each layer of YF3 film material is 60-700 nm.

[0039] A second aspect of the present invention provides a method for processing a visible infrared ultra-wide spectrum color separator, comprising the following steps:

[0040] (1) Substrate pretreatment

[0041] Wipe the surface of one side of the substrate clean with a dust-free cloth dipped in isopropyl alcohol, then load the substrate onto a flat planetary clamp and place it into a vacuum chamber;

[0042] (2) Vacuuming before plating

[0043] The vacuum degree of the vacuum chamber was reduced to 5×10 -2 Pa, turn on the constant temperature and heat to 120℃, then keep the constant temperature;

[0044] (3) Pre-etching before plating

[0045] When the vacuum degree is less than 3×10 -3 Pa, turn on the ion source to etch and clean for 10 min;

[0046] (4) Evaporation of infrared anti-reflection film

[0047] According to the film layer design, the corresponding film materials are evaporated in sequence. The ion source is kept working during the evaporation process to achieve ion-assisted deposition. The ZnS film material is evaporated by an electron gun, the evaporation rate is controlled to be 0.8nm / s, and the ion source working parameters of ZnS are an anode voltage of 150V and an anode current of 2A; the YF3 film material is evaporated by a molybdenum boat resistance evaporation, the evaporation rate is controlled to be 0.4nm / s, and the ion source working parameters of YF3 are an anode voltage of 120V and an anode current of 1.5A;

[0048] (5) Post-annealing treatment

[0049] After the infrared anti-reflection film is deposited, the ion source is turned off, and the heating temperature is continued to be increased to 150°C, and the constant temperature is maintained for 1 hour, and then the heater is turned off and the temperature is slowly lowered for post-annealing treatment;

[0050] (6) Quality inspection of infrared anti-reflection film

[0051] The vacuum chamber is inflated, and the substrate with the infrared anti-reflection film evaporated is taken out for spectrum testing and surface quality inspection;

[0052] (7) pre-treating the other side of the substrate, evacuating the substrate before plating, and pre-etching the substrate before plating according to steps (1) to (3);

[0053] (8) Vapor deposition of ultra-wide spectrum color separation film

[0054] According to the film layer design, the corresponding film materials are evaporated in sequence. The ion source is kept working during the evaporation process to achieve ion-assisted deposition. The ZnS film material is evaporated by an electron gun, the evaporation rate is controlled to be 0.8nm / s, and the ion source working parameters of ZnS are an anode voltage of 150V and an anode current of 2A; the YbF3 film material and the YF3 film material are both evaporated by molybdenum boat resistance evaporation, the evaporation rate is controlled to be 0.4nm / s, and the ion source working parameters of YbF3 and YF3 are an anode voltage of 120V and an anode current of 1.5A;

[0055] (9) performing post-annealing treatment and quality inspection on the ultra-wide spectrum dichroic film according to steps (5) to (6);

[0056] (10) After the test is qualified, a visible infrared ultra-wide spectrum color separator is obtained, and the R of the visible infrared ultra-wide spectrum color separator is greater than 99% @ 0.4-0.7um, and T is greater than 95% @ 0.85-1.65um & @ 3-5um & @ 8-12um.

[0057] R>99%@0.4-0.7um: This means that within the spectral range of 0.4um to 0.7um (i.e. 400nm to 700nm, corresponding to the blue to red range of visible light), the reflectivity of the color separator is greater than 99%. This means that when visible light (blue to red) shines on the color separator, more than 99% of the light will be reflected back, and only a very small part of the light will be absorbed or transmitted.

[0058] T>95%@0.85-1.65um&@3-5um&@8-12um: This means that in three different infrared spectral ranges (0.85-1.65um, 3-5um, 8-12um), the transmittance of the color separator is greater than 95%. These bands correspond to near-infrared, mid-infrared and far-infrared light respectively. When infrared light shines on the color separator, more than 95% of the infrared light will pass through the color separator, and only a very small part of the infrared light will be reflected or absorbed.

[0059] Combining these performance indicators, the following conclusions can be drawn: the visible infrared ultra-wide spectrum color separator prepared by the present invention has extremely high reflectivity in the visible light range (0.4-0.7um), and can effectively reflect visible light back, while almost no visible light is transmitted or absorbed. At the same time, in multiple infrared spectral ranges (0.85-1.65um, 3-5um, 8-12um), the color separator has extremely high transmittance, which can allow a large amount of infrared light to pass through the color separator, while almost no infrared light is reflected or absorbed. Therefore, the color separator designed and prepared by the present invention can solve the problems in the prior art of using a color separation scheme that transmits visible light and reflects infrared, such as a wide spectral transition zone, the spectrum of the transition zone cannot be fully utilized, and the thickness of the metal film used for visible light transmission is difficult to control.

[0060] Therefore, the present invention adopts a visible infrared ultra-wide spectrum color separator and a processing method thereof of the above structure, which has the following beneficial effects:

[0061] (1) The present invention adopts the all-dielectric film interference technology to change the optical path of visible-transmitting and infrared-reflecting to that of visible-reflecting and infrared-transmitting. This not only reduces the spectral transition region and increases the visible and near-infrared color separation, but also the design of the all-dielectric film layer without a metal film layer also reduces the sensitivity of the film system and reduces the abnormality rate of preparation.

[0062] (2) The ultra-wide spectrum color separation film and infrared anti-reflection film of the present invention respectively use three and two low refractive index film materials, which not only avoids the problem of excessive total thickness of a single film material, but also effectively reduces the film layer stress and improves the reliability of the color separation film through matching of different film materials.

[0063] (3) The color separator of the present invention not only realizes efficient color separation of the visible infrared ultra-wide spectrum, but also realizes fine color separation of the two adjacent spectrums of visible and near-infrared, and further realizes complete color separation of visible light and infrared light. The R of the visible infrared ultra-wide spectrum color separator is greater than 99% @ 0.4-0.7um, and T is greater than 95% @ 0.85-1.65um & @ 3-5um & @ 8-12um.

[0064] (4) The dichroic film of the present invention adopts the technical solution of all-dielectric film to ensure that the film thickness is accurately controllable, and effectively ensure the performance indicators of the dichroic film. Among them, the ultra-wide spectrum dichroic film has R>99%@0.4-0.7um and T>97%@0.85-1.65um&@3-5um&@8-12um at an incident angle of 45 degrees, and the infrared anti-reflection film has R<1.5%@0.85-1.65um&@3-5um&@8-12um at an incident angle of 45 degrees.

[0065] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] Figure 1 This is a structural diagram of the visible infrared ultra-wide spectrum color separator;

[0067] Figure 2 The spectrum of the ultra-wide spectrum dichroic film prepared in Example 1;

[0068] Figure 3 This is the spectrum of the infrared anti-reflection film prepared in Example 1.

[0069] In the figure: 1. substrate; 2. ultra-wide spectrum color separation film; 3. infrared anti-reflection film. DETAILED DESCRIPTION

[0070] The present invention will be further described below. It should be noted that this embodiment is based on the technical solution and provides a detailed implementation method and a specific operation process, but the present invention is not limited to this embodiment.

[0071] Example 1

[0072] This embodiment provides a visible infrared ultra-wide spectrum color splitter, comprising a substrate and an ultra-wide spectrum color splitting film and an infrared anti-reflection film respectively arranged on both sides of the substrate; wherein the ultra-wide spectrum color splitting film is used to reflect visible light, and the infrared anti-reflection film is used to transmit infrared light. The substrate is multi-spectrum ZnS.

[0073] The ultra-wide spectrum color separation film uses ZnS as the high refractive index film material, and YbF3 and YF3 as the low refractive index film materials. The specific film structure is shown in Table 1.

[0074] Table 1 Film structure of the ultra-wide spectrum color separation film of Example 1

[0075]

[0076]

[0077] It can be seen from Table 1 that the total thickness of the ZnS film is 1857nm (29 layers), the total thickness of the YbF3 film is 1953nm (15 layers), and the total thickness of the YF3 film is 1559nm (15 layers). The total thickness of the three film materials is relatively close, and the film stress is optimized.

[0078] The above ultra-wide spectrum color separation film was tested for spectrum. Figure 2 It can be seen that R = 99.6% @ 0.4-0.7um, T = 98.2% @ 0.85-1.65um & T = 97.5% @ 3-5um & T = 97.7% @ 8-12um, indicating that the ultra-wide spectrum color separation film prepared by the present invention can reflect visible light and transmit infrared light.

[0079] The infrared anti-reflection film uses ZnS as the high refractive index film material and YF3 as the low refractive index film material. The specific film layer structure is shown in Table 2.

[0080] Table 2 Film structure of infrared anti-reflection film of Example 1

[0081]

[0082]

[0083] It can be seen from Table 2 that the total thickness of the ZnS film is 469 nm (7 layers) and the total thickness of the YF3 film is 1790 nm (8 layers).

[0084] The above infrared anti-reflection film was tested by spectrum. Figure 3 It can be seen that at 45 degrees of incidence, R = 1.04% @ 0.85-1.65um & R = 1.32% @ 3-5um & R = 1.17% @ 8-12um, indicating that the infrared anti-reflection film prepared by the present invention can transmit infrared light to reduce the reflection loss on the back side and increase the infrared light transmittance.

[0085] The equipment involved in the processing include: domestic infrared vacuum coating equipment, which is equipped with Hall-type ion source, ultra-low temperature deep cold trap, constant temperature heating system, crystal film thickness monitoring device, planar planetary fixture, rotating 6-steric evaporation boat, electron gun, etc.

[0086] This embodiment also provides a method for processing a visible infrared ultra-wide spectrum color separator, comprising the following steps:

[0087] (1) Substrate pretreatment

[0088] Wipe the surface of one side of the substrate (S1 side) clean with a dust-free cloth dipped in isopropyl alcohol, then load the substrate on a flat planetary clamp and place it in a vacuum chamber;

[0089] (2) Vacuuming before plating

[0090] The vacuum degree of the vacuum chamber was reduced to 5×10 -2 Pa, turn on the constant temperature and heat to 120℃, then keep the constant temperature;

[0091] (3) Pre-etching before plating

[0092] When the vacuum degree is less than 3×10 -3 When the temperature is 0.0447°C, the ion source is turned on for etching and cleaning for 10 min; the anode voltage of the ion source is 200 V, and the anode current is 4 A; the analytical surface is further cleaned to improve the bonding of the film layer;

[0093] (4) Evaporation of infrared anti-reflection film

[0094] According to the film layer design, the corresponding film materials are evaporated in sequence. The ion source is kept working during the evaporation process to achieve ion-assisted deposition. The ZnS film material is evaporated by an electron gun, the evaporation rate is controlled to be 0.8nm / s, and the ion source working parameters of ZnS are an anode voltage of 150V and an anode current of 2A; the YF3 film material is evaporated by a molybdenum boat resistance evaporation, the evaporation rate is controlled to be 0.4nm / s, and the ion source working parameters of YF3 are an anode voltage of 120V and an anode current of 1.5A;

[0095] (5) Post-annealing treatment

[0096] After the infrared anti-reflection film is deposited, the ion source is turned off, and the heating temperature is continued to be increased to 150°C, and the constant temperature is maintained for 1 hour, and then the heater is turned off and the temperature is slowly lowered for post-annealing treatment;

[0097] (6) Quality inspection of infrared anti-reflection film

[0098] The vacuum chamber is inflated, and the substrate with the infrared anti-reflection film evaporated is taken out for spectrum testing and surface quality inspection;

[0099] The above ultra-wide spectrum color separation film was tested for spectrum. Figure 2 It can be seen that R = 99.6% @ 0.4-0.7um, T = 98.2% @ 0.85-1.65um & T = 97.5% @ 3-5um & T = 97.7% @ 8-12um, indicating that the ultra-wide spectrum color separation film prepared by the present invention can reflect visible light and transmit infrared light;

[0100] After the test is qualified, the ultra-wide spectrum color separation film is evaporated on the other side of the substrate;

[0101] (7) pre-treating the other side of the substrate, evacuating the substrate before plating, and pre-etching the substrate before plating according to steps (1) to (3);

[0102] Specifically, wipe the other side (S2 side) of the substrate clean with a dust-free cloth dipped in isopropyl alcohol, then load the substrate onto a flat planetary clamp and place it into a vacuum chamber;

[0103] The vacuum degree of the vacuum chamber was reduced to 5×10 -2 Pa, turn on the constant temperature and heat to 120℃, then keep the constant temperature;

[0104] When the vacuum degree is less than 3×10 -3 When the temperature is 0.0447°C, the ion source is turned on for etching and cleaning for 10 min; the anode voltage of the ion source is 200 V, and the anode current is 4 A; the analytical surface is further cleaned to improve the bonding of the film layer;

[0105] (8) Vapor deposition of ultra-wide spectrum color separation film

[0106] According to the film layer design, the corresponding film materials are evaporated in sequence. The ion source is kept working during the evaporation process to achieve ion-assisted deposition. The ZnS film material is evaporated by an electron gun, the evaporation rate is controlled to be 0.8nm / s, and the ion source working parameters of ZnS are an anode voltage of 150V and an anode current of 2A; the YbF3 film material and the YF3 film material are both evaporated by molybdenum boat resistance evaporation, the evaporation rate is controlled to be 0.4nm / s, and the ion source working parameters of YbF3 and YF3 are an anode voltage of 120V and an anode current of 1.5A;

[0107] (9) performing post-annealing treatment and quality inspection on the ultra-wide spectrum dichroic film according to steps (5) to (6);

[0108] Specifically:

[0109] After the ultra-wide spectrum film color separation film is deposited, the ion source is turned off, and the heating temperature is continued to be increased to 150°C, and the constant temperature is maintained for 1 hour, and then the heater is turned off and the temperature is slowly lowered for post-annealing treatment;

[0110] The vacuum chamber is inflated, and the substrate with the infrared anti-reflection film evaporated is taken out for spectrum testing and surface quality inspection;

[0111] The above infrared anti-reflection film was tested by spectrum. Figure 3 It can be seen that at 45 degrees of incidence, R = 1.04% @ 0.85-1.65um & R = 1.32% @ 3-5um & R = 1.17% @ 8-12um, indicating that the infrared anti-reflection film prepared by the present invention can transmit infrared light to reduce the reflection loss on the back side and increase the infrared light transmittance;

[0112] (10) After the test is qualified, a visible infrared ultra-wide spectrum color separator is obtained, and the R of the visible infrared ultra-wide spectrum color separator is greater than 99% @ 0.4-0.7um, and T is greater than 95% @ 0.85-1.65um & @ 3-5um & @ 8-12um.

[0113] Example 2

[0114] The difference from Example 1 is: the film structure of the ultra-wide spectrum dichroic film and the film structure of the infrared anti-reflection film. The film structures of the ultra-wide spectrum dichroic film and the infrared anti-reflection film of this embodiment are shown in Table 3 and Table 4.

[0115] Table 3 Film structure of the ultra-wide spectrum color separation film of Example 2

[0116]

[0117]

[0118] It can be seen from Table 3 that the total thickness of the ZnS film is 1048nm (18 layers), the total thickness of the YbF3 film is 1000nm (9 layers), and the total thickness of the YF3 film is 1022nm (9 layers). The total thickness of the three film materials is relatively close, and the film stress is optimized.

[0119] Table 4 Film structure of infrared anti-reflection film of Example 2

[0120]

[0121]

[0122] It can be seen from Table 4 that the total thickness of the ZnS film is 753 nm (10 layers), and the total thickness of the YF3 film is 2104 nm (11 layers).

[0123] Comparative Example 1

[0124] The difference from Example 1 is: the film layer structure of the ultra-wide spectrum dichroic film. The film layer structure in this comparative example is shown in Table 5.

[0125] Table 5 Film structure of the ultra-wide spectrum color separation film of Comparative Example 1

[0126] Number of film layers Material Type Film thickness / nm 1 ZnS 928.5 2 <![CDATA[YbF3]]> 1953 3 ZnS 77.70 4 <![CDATA[YF3]]> 928.5

[0127] It can be seen from Table 5 that the total thickness of the ZnS film layer, the total thickness of the YbF3 film layer and the total thickness of the YF3 film layer in Comparative Example 1 are the same as those in Example 1, but the ultra-wide spectrum dichroic film in Comparative Example 1 only contains two layers of ZnS film material, one layer of YbF3 film material and one layer of YF3 film material, and the thickness of the film layer of each material type is also significantly higher than the ZnS film layer, YbF3 film layer and YF3 film layer in Example 1, which will increase the stress of the film layer and deteriorate the reliability and environmental resistance of the dichroic film.

[0128] Comparative Example 2

[0129] The difference from Example 1 is: the film layer structure of the infrared anti-reflection film. The film layer structure in this comparative example is shown in Table 6.

[0130] Table 6 Film structure of infrared anti-reflection film of comparative example 2

[0131] Number of film layers Material Type Film thickness / nm 1 ZnS 469 2 <![CDATA[YF3]]> 1790

[0132] It can be seen from Table 6 that the total thickness of the ZnS film layer and the total thickness of the YF3 film layer in Comparative Example 2 are the same as those in Example 1, but the infrared anti-reflection film in Comparative Example 2 only includes one layer of ZnS film material and one layer of YF3 film material, and the thickness of the film layer of each material type is also significantly higher than that of the ZnS film layer and the YF3 film layer in Example 1, which will increase the stress of the film layer and deteriorate the reliability and environmental resistance of the infrared anti-reflection film.

[0133] The visible infrared ultra-wide spectrum color splitters prepared in Example 1-2 and Comparative Example 1-2 were subjected to spectral testing, and the test results are shown in Table 7.

[0134] Table 7 Spectral test results of the visible infrared ultra-wide spectrum color splitter prepared in Comparative Examples 1-2

[0135] R@0.4-0.7um T@0.85-1.65um T@3-5um T@8-12um Example 1 >99％ >95％ >95％ >95％ Example 2 >95％ >93％ >93％ >93％ Comparative Example 1 >62％ >70％ >72％ >69％ Comparative Example 2 >75％ >65％ >60％ >62％

[0136] Therefore, the present invention adopts a visible-infrared ultra-wide spectrum color separator of the above structure and a processing method thereof, and adopts the technology of full dielectric film interference to change the optical path of visible-transmitting and anti-infrared into anti-visible-transmitting and infrared-transmitting. It not only reduces the spectral transition zone and increases the visible and near-infrared color separation, but also the design of full dielectric film layer without metal film layer also reduces the sensitivity of the film system and reduces the abnormal rate of preparation.

[0137] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A visible infrared ultra-wide spectrum color separator, characterized in that: It comprises a substrate and an ultra-wide spectrum color separation film and an infrared anti-reflection film respectively arranged on both sides of the substrate; wherein the ultra-wide spectrum color separation film is used for reflecting visible light, and the infrared anti-reflection film is used for transmitting infrared light.

2. The visible infrared ultra-wide spectrum color separator according to claim 1, characterized in that: The substrate is a material that transmits both visible light and infrared light.

3. The visible infrared ultra-wide spectrum color separator according to claim 2, characterized in that: The substrate is one of multi-spectrum ZnS and CVD ZnSe.

4. The visible infrared ultra-wide spectrum color separator according to claim 1, characterized in that: The ultra-wide spectrum dichroic film has R>99%@0.4-0.7um and T>97%@0.85-1.65um&@3-5um&@8-12um at an incident angle of 45 degrees.

5. The visible infrared ultra-wide spectrum color separator according to claim 4, characterized in that: The ultra-wide spectrum color separation film includes multiple layers of ZnS film material, and YbF3 film material or YF3 film material is arranged between two adjacent layers of ZnS film material. The ratio of the total thickness of the ZnS film material, the total thickness of the YbF3 film material and the total thickness of the YF3 film material is (1~1.5):(1~1.5):(1~1.5).

6. The visible infrared ultra-wide spectrum color separator according to claim 5, characterized in that: The thickness of each layer of ZnS film material is 15~140nm, the thickness of each layer of YbF3 film material is 30~500nm, and the thickness of each layer of YF3 film material is 5~320nm.

7. The visible infrared ultra-wide spectrum color separator according to claim 1, characterized in that: The infrared anti-reflection film has an R<1.5%@0.85-1.65um&@3-5um&@8-12um at an incident angle of 45 degrees.

8. The visible infrared ultra-wide spectrum color separator according to claim 7, characterized in that: The infrared anti-reflection film comprises multiple layers of ZnS film material, and YF3 film material is arranged between two adjacent layers of ZnS film material. The ratio of the total thickness of the ZnS film material to the total thickness of the YF3 film material is 1: (2.5-4.0).

9. The visible infrared ultra-wide spectrum color separator according to claim 8, characterized in that: The thickness of each layer of ZnS film material is 25~125nm, and the thickness of each layer of YF3 film material is 60~700nm.

10. The method for processing a visible infrared ultra-wide spectrum color separator according to any one of claims 1 to 9, characterized in that: The following steps are involved: (1) Substrate pretreatment Wipe the surface of one side of the substrate clean with a dust-free cloth dipped in isopropyl alcohol, then load the substrate onto a flat planetary clamp and place it into a vacuum chamber; (2) Vacuuming before plating The vacuum degree of the vacuum chamber was reduced to 5×10 -2 Pa, turn on the constant temperature and heat to 120℃, then keep the constant temperature; (3) Pre-etching before plating When the vacuum degree is less than 3×10 -3 Pa, turn on the ion source to etch and clean for 10 min; (4) Evaporation of infrared anti-reflection film According to the film layer design, the corresponding film materials are evaporated in sequence. The ion source is kept working during the evaporation process to achieve ion-assisted deposition. The ZnS film material is evaporated by an electron gun, the evaporation rate is controlled to be 0.8nm / s, and the ion source working parameters of ZnS are an anode voltage of 150V and an anode current of 2A; the YF3 film material is evaporated by a molybdenum boat resistance evaporation, the evaporation rate is controlled to be 0.4nm / s, and the ion source working parameters of YF3 are an anode voltage of 120V and an anode current of 1.5A; (5) Post-annealing treatment After the infrared anti-reflection film is deposited, the ion source is turned off, and the heating temperature is continued to be increased to 150°C, and the constant temperature is maintained for 1 hour, and then the heater is turned off and the temperature is slowly lowered for post-annealing treatment; (6) Quality inspection of infrared anti-reflection film The vacuum chamber is inflated, and the substrate with the infrared anti-reflection film evaporated is taken out for spectrum testing and surface quality inspection; (7) Pre-treating the other side of the substrate, vacuuming before plating, and pre-etching before plating according to steps (1) to (3); (8) Vapor deposition of ultra-wide spectrum color separation film According to the film layer design, the corresponding film materials are evaporated in sequence. The ion source is kept working during the evaporation process to achieve ion-assisted deposition. The ZnS film material is evaporated by an electron gun, the evaporation rate is controlled to be 0.8nm / s, and the ion source working parameters of ZnS are an anode voltage of 150V and an anode current of 2A; the YbF3 film material and the YF3 film material are both evaporated by molybdenum boat resistance evaporation, the evaporation rate is controlled to be 0.4nm / s, and the ion source working parameters of YbF3 and YF3 are an anode voltage of 120V and an anode current of 1.5A; (9) performing post-annealing treatment and quality inspection on the ultra-wide spectrum dichroic film according to steps (5) to (6); (10) After passing the test, a visible infrared ultra-wide spectrum color separator is obtained, and the R of the visible infrared ultra-wide spectrum color separator is greater than 99% @ 0.4-0.7um, and T is greater than 95% @ 0.85-1.65um & @ 3-5um & @ 8-12um.

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