400-740 nm high-transmittance 900-1100 nm waveband cut-off coating process

Abstract

The invention relates to a 400-740 nm high-transmittance 900-1100 nm waveband cut-off coating process. The coating process comprises the following steps: cleaning a substrate; two Nb2O5 targets, two Si targets and an RF ion source are selected; the substrate is fixed on the lower surface of the rotating table, and the process cavity is vacuumized; cleaning the surface of the substrate by an RF ion source; the magnetron sputtering equipment grabs Nb2O5 / SiO2 data, Ar gas is introduced into the Nb2O5 target position provided with the medium-frequency power supply, oxygen is introduced into the RF ion source, and the process cavity is maintained to exhaust and plate Nb2O5, Ar gas is introduced into the Si target position provided with the medium-frequency power supply, oxygen is introduced into the RF ion source, and the process cavity is maintained to exhaust and plate SiO2; the rotating table drives the substrate to rotate, rotation of a target corresponding to a plated film layer is started based on film system data, meanwhile, a corresponding medium-frequency power source and a corresponding RF ion source are started, Ar gas and oxygen are correspondingly controlled, and exhaust of a process cavity is maintained; and taking out the sample after the whole film system is plated according to the film system data.

Description

Technical Field

[0001] The present disclosure relates to the field of optical coating technology, and more specifically to a coating technology with high transmittance of 400-740nm and cutoff of 900-1100nm wavelength band. Background Art

[0002] With the continuous development of optical technology, the performance requirements for optical devices are also constantly increasing, especially to achieve a good anti-reflection effect in the visible light band and a certain cut-off effect in the near-infrared band. Optical films with high transmittance in the 400-740nm band and a certain cut-off effect in the 900-1100nm band can effectively improve the shooting performance of vehicle-mounted cameras.

[0003] With the continuous development and rise of new energy vehicles and autonomous driving, the demand for automotive camera lenses has been further released. Conventional coating technology cannot meet the requirements of film hardness and weather resistance. An optical film that can meet both optical performance and can be used in harsh natural environments has important practical significance and prospects. Summary of the invention

[0004] In view of the problems existing in the background technology, an object of the present disclosure is to provide a coating process with high transmittance of 400-740nm and cutoff of 900-1100nm band, which can achieve both good anti-reflection effect in the visible light band and certain cutoff effect in the near-infrared band.

[0005] Another object of the present disclosure is to provide a coating process with high transmittance of 400-740nm and cutoff of 900-1100nm band, and the prepared film system can meet both the optical performance and the use in harsh / complex natural environments.

[0006] Another object of the present disclosure is to provide a coating process with high transmittance of 400-740nm and cutoff of 900-1100nm band, which can be widely used in lens lenses of vehicles, security, cameras, etc., and can effectively improve shooting performance and service life of lenses.

[0007] Thus, a coating process with high transmittance of 400-740nm and cutoff of 900-1100nm wavelength includes the following steps: S1, cleaning the surface of the substrate; S2, selecting two Nb2O5 targets, two Si targets, and an RF ion source for the process chamber of the magnetron sputtering equipment, wherein all the targets and the RF ion source are lower than the rotating table at the top of the process chamber; S3, fixing the substrate on the lower surface of the rotating table, and evacuating the process chamber to a vacuum of less than 9.0×10 -5Pa; S4, use RF ion source to clean the surface of the substrate; S5, magnetron sputtering equipment captures Nb2O5 / SiO2 data, introduces Ar gas into the Nb2O5 target position equipped with medium frequency power supply, introduces oxygen into the RF ion source and maintains exhaust in the process chamber to plate Nb2O5, introduces Ar gas into the Si target position equipped with medium frequency power supply, introduces oxygen into the RF ion source and maintains exhaust in the process chamber to plate SiO2; S6, the rotating table drives the substrate to rotate, and based on the Nb2O5 / SiO2 film system data, two Nb2O5 targets and two S The target corresponding to the coated film layer in the i target rotates, and the medium frequency power supplies and RF ion sources corresponding to the two Nb2O5 targets and the two Si targets are turned on at the same time, the introduction of Ar gas and the introduction of oxygen are controlled accordingly, and the process chamber is exhausted to maintain the flow pressure in the process chamber; S7, after the entire film system is coated according to the film system data, the prepared sample is taken out; after the end of step S7, the substrate after the entire film system is coated has an average transmittance of ≥95% in the wavelength range of 400-740nm and an average transmittance of ≤15% in the wavelength range of 900-1100nm at an incident angle of 0°.

[0008] The beneficial effects of the present disclosure are as follows.

[0009] In the coating process with high transmittance of 400-740nm and cutoff of 900-1100nm band according to the present disclosure, through steps S1 to S7, it can be achieved that the substrate after the entire film system is plated has an average transmittance of ≥95% in the wavelength range of 400-740nm and an average transmittance of ≤15% in the wavelength range of 900-1100nm at an incident angle of 0°, that is, it can achieve a good anti-reflection effect in the visible light band and a certain cutoff effect in the near-infrared band. In addition, as verified by the test process, the substrate after the entire film system is plated is subjected to pencil hardness and Mohs hardness tests, and the film system reaches a pencil hardness of 9H and a Mohs hardness of 3.5. The substrate after the entire film system is subjected to a 48-hour salt spray test, and the film system does not fall off and crack. The substrate after the entire film system is plated is subjected to a hundred-grid test with 3M tape after salt spray, and the film system does not fall off. That is to say, the film system prepared by the coating process with high transmittance of 400-740nm and cutoff of 900-1100nm band disclosed in the present invention can meet both the optical performance and the requirements for use in harsh / complex natural environments.

[0010] In the coating process with high transmittance of 400-740nm and cutoff of 900-1100nm band according to the present disclosure, two kinds of Nb2O5 / SiO2 films are obtained by using two kinds of target materials, Nb2O5 target and Si target, and the method of medium frequency magnetron sputtering plus RF ion source and then oxidation has the characteristics of high precision and high controllability, which can realize precise control of the coating layer and ensure the stability and reliability of the process; it has higher film forming energy and film forming rate, can improve the stacking density and compactness of the film layer, can effectively increase the refractive index of high refractive index materials, and reduce material absorption.

[0011] The substrate with a film system prepared by the coating process with high transmittance of 400-740nm and cutoff of 900-1100nm band disclosed in the present invention can be widely used in lens lenses for vehicles, security, cameras, etc., and can effectively improve the shooting performance and the service life of the lens.

[0012] In the coating process with high transmittance of 400-740nm and cutoff of 900-1100nm band according to the present disclosure, by adopting magnetron sputtering technology, there is no need to use harmful chemicals and highly dangerous flammable and explosive gases, which effectively protects the health of operators and is environmentally friendly; at the same time, the coating process is highly efficient and energy-saving, which is conducive to reducing production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic structural diagram of the magnetron sputtering equipment used in the coating process with high transmittance of 400-740nm and cutoff of 900-1100nm band according to the present disclosure.

[0014] Figure 2 It is a flow chart of the coating process with high transmittance of 400-740nm and cutoff of 900-1100nm band according to the present disclosure.

[0015] Figure 3 and Figure 4 yes Figure 2 The spectral data of the single-layer film in the data captured by the magnetron sputtering device in the flowchart, wherein at least four single-layer films with a thickness of 1 / 4 wavelength of two types of Nb2O5 / SiO2 film layers are respectively deposited on the cleaned BK7 optical glass according to steps S1 to S5, and then the spectral data of the material of the single-layer film is tested by a spectrophotometer.

[0016] Figure 5 is based on Figure 2 The flow chart shows the test data of the transmittance of the substrate at an incident angle of 0° in the 380-1250nm band after the entire film system is plated on the BK7 substrate. DETAILED DESCRIPTION

[0017] The accompanying drawings show embodiments of the present disclosure, and it will be understood that the disclosed embodiments are merely examples of the present disclosure, and the present disclosure can be implemented in various forms. Therefore, the specific details disclosed herein should not be interpreted as limiting, but merely as the basis for the claims and as a representative basis for teaching ordinary technicians in the field to implement the present disclosure in various ways.

[0018] [400-740nm high transmittance and 900-1100nm cut-off coating process]

[0019] Reference Figures 1 to 5According to the present disclosure, the coating process with high transmittance of 400-740nm and cut-off of 900-1100nm wavelength band includes the following steps:

[0020] S1, cleaning the surface of the substrate;

[0021] S2, two Nb2O5 targets, two Si targets, and an RF ion source are selected for the process chamber of the magnetron sputtering equipment, and all the targets and the RF ion source are lower than the rotating table at the top of the process chamber;

[0022] S3, fix the substrate on the lower surface of the rotating table, and evacuate the process chamber to a vacuum of less than 9.0×10 -5 Pa;

[0023] S4, cleaning the surface of the substrate using an RF ion source;

[0024] S5, magnetron sputtering equipment captures Nb2O5 / SiO2 data, introduces Ar gas into the Nb2O5 target position equipped with a medium frequency power supply, introduces oxygen into the RF ion source and maintains exhaust in the process chamber to plate Nb2O5, and introduces Ar gas into the Si target position equipped with a medium frequency power supply, introduces oxygen into the RF ion source and maintains exhaust in the process chamber to plate SiO2;

[0025] S6, the rotating table drives the substrate to rotate, and based on the Nb2O5 / SiO2 film system data, the rotation of the targets corresponding to the plated film layers among the two Nb2O5 targets and the two Si targets is started, and at the same time, the intermediate frequency power supplies and RF ion sources corresponding to the two Nb2O5 targets and the two Si targets are started, and the introduction of Ar gas and oxygen gas is controlled accordingly, and the process chamber is exhausted to maintain the flow pressure of the process chamber;

[0026] S7, after the entire film system is plated according to the film system data, the prepared sample is taken out;

[0027] After step S7 is finished, the substrate after the entire film system is plated has an average transmittance of ≥95% in the wavelength range of 400-740nm and an average transmittance of ≤15% in the wavelength range of 900-1100nm at an incident angle of 0°.

[0028] In the coating process with high transmittance of 400-740nm and cutoff of 900-1100nm band according to the present disclosure, through steps S1 to S7, it can be achieved that the substrate after the entire film system is plated has an average transmittance of ≥95% in the wavelength range of 400-740nm and an average transmittance of ≤15% in the wavelength range of 900-1100nm at an incident angle of 0°, that is, it can achieve a good anti-reflection effect in the visible light band and a certain cutoff effect in the near-infrared band. In addition, as verified by the subsequent test process, the substrate after the entire film system is plated is subjected to pencil hardness and Mohs hardness tests, and the film system reaches a pencil hardness of 9H and a Mohs hardness of 3.5. The substrate after the entire film system is subjected to a 48-hour salt spray test, and the film system does not fall off and does not crack. The substrate after the entire film system is plated is subjected to a hundred-grid test with 3M tape after salt spray, and the film system does not fall off. That is to say, the film system prepared by the coating process with high transmittance of 400-740nm and cutoff of 900-1100nm band disclosed in the present invention can meet both the optical performance and the requirements for use in harsh / complex natural environments.

[0029] In the coating process with high transmittance of 400-740nm and cutoff of 900-1100nm band according to the present disclosure, two kinds of Nb2O5 / SiO2 films are obtained by using two kinds of target materials, Nb2O5 target and Si target, and the method of medium frequency magnetron sputtering plus RF ion source and then oxidation has the characteristics of high precision and high controllability, which can realize precise control of the coating layer and ensure the stability and reliability of the process; it has higher film forming energy and film forming rate, can improve the stacking density and compactness of the film layer, can effectively increase the refractive index of high refractive index materials, and reduce material absorption.

[0030] The substrate with a film system prepared by the coating process with high transmittance of 400-740nm and cutoff of 900-1100nm band disclosed in the present invention can be widely used in lens lenses for vehicles, security, cameras, etc., and can effectively improve the shooting performance and the service life of the lens.

[0031] In the coating process with high transmittance of 400-740nm and cutoff of 900-1100nm band according to the present disclosure, by adopting magnetron sputtering technology, there is no need to use harmful chemicals and highly dangerous flammable and explosive gases, which effectively protects the health of operators and is environmentally friendly; at the same time, the coating process is highly efficient and energy-saving, which is conducive to reducing production costs.

[0032] In step S1, for example, the sample substrate is BK7 optical glass, which is also used to collect single-layer film data. In step S1, for example, the substrate is cleaned using ultrasound. Specifically, in step S1, the substrate is cleaned in pure water using ultrasonic vibration, with an ultrasonic frequency of 50 KHz, a temperature of 45° C., and a power of 400 W.

[0033] In step S2, for example, the purity of the Nb2O5 target and the Si target is 5N.

[0034] In step S3, for example, the process chamber is evacuated to a vacuum of 5.0×10 -5 Pa.

[0035] In step S4, for example, the process parameters for RF ion source cleaning are: 100 sccm Ar gas is introduced into the RF ion source, the cleaning time is 3 minutes, the RF ion source power is set to 4 KW, the forward power is 3.994 KW, and the reverse power is 6W.

[0036] In step S5, in one example, the process of acquiring the Nb2O5 / SiO2 data captured by the magnetron sputtering equipment includes the following sub-steps: Sa, respectively coating at least four single-layer films of 1 / 4 wavelength thickness of two Nb2O5 / SiO2 film layers on a cleaned BK7 substrate, and then testing the spectral data of the single-layer film materials by a spectrophotometer; Sb, using TFC to calculate the refractive index data of the two film layers in the required band through the spectral data; Sc, using TFC to simulate the average transmittance of ≥95% and ≤15% in the wavelength range of 400-740nm and 900-1100nm at an incident angle of 0° on the BK7 substrate through calculation, and obtain the Nb2O5 / SiO2 film system data; Sd, importing the obtained Nb2O5 / SiO2 film system data into the control system of the magnetron sputtering coating machine.

[0037] Specifically, in one example, in sub-step Sb, the refractive index N of Nb2O5 at a wavelength of 550nm is 2.36, and the refractive index of SiO2 is 1.455; in sub-step Sc, the Nb2O5 / SiO2 film system data is 12.36nmNb2O5 / 34.66nmSiO2 / 111.07nmNb2O5 / 169.23nmSi O2 / 101.66nmNb2O5 / 166.50nmSiO2 / 98.65nmNb2O5 / 165.25nmSiO2 / 101.67nmNb2O5 / 84.39nmSiO2, a total of ten film layers, are sequentially plated on the substrate, and the numbers with nm before Nb2O5 and SiO2 are the thickness of the film layer. The film system composed of ten film layers has the characteristics of a small number of film layers, a thin total thickness, and a simple and efficient film system, which makes mass production efficient and convenient.

[0038] In one example, in step S6, the rotation speed of the rotating table is 250 rpm; based on the Nb2O5 / SiO2 film system data, when each Nb2O5 film layer is plated: the power of the medium frequency power supply of the two Nb2O5 targets is 12 KW; the flow rate of Ar gas at the two Nb2O5 targets is 200 sccm, the flow rate of oxygen at the RF ion source is 100 sccm, the RF ion source power is set to 4 KW, the forward power is 3.992 KW, and the reverse power is 8 W; the deposition rate of the Nb2O5 film layer is The flow pressure is 2.2×10 -1 Pa; the number of deposition cycles of the first Nb2O5 film layer is 244; the number of deposition cycles of the third Nb2O5 film layer is 2195; the number of deposition cycles of the fifth Nb2O5 film layer is 2009; the number of deposition cycles of the seventh Nb2O5 film layer is 1950; the number of deposition cycles of the ninth Nb2O5 film layer is 2009.

[0039] In one example, in step S6, the rotation speed of the rotating stage is 250 rpm; based on the Nb2O5 / SiO2 film system data, when each SiO2 film layer is plated: the power of the medium frequency power supply of the two Si targets is 6 KW; the flow rate of Ar gas at the two Si targets is 200 sccm, the flow rate of oxygen at the RF ion source is 100 sccm, the RF ion source is set to 4 KW, the forward power is 3.994 KW, and the reverse power is 6 W; the deposition rate of the SiO2 film layer is The flow pressure is 2.2×10 -1 Pa; the number of deposition turns of the second SiO2 film layer is 411 turns; the number of deposition turns of the fourth SiO2 film layer is 2006 turns; the number of deposition turns of the sixth SiO2 film layer is 1973 turns; the number of deposition turns of the eighth SiO2 film layer is 1958 turns; the number of deposition turns of the tenth SiO2 film layer is 1000 turns.

[0040] In one example, after step S7 is completed, the substrate after the entire film system is plated has an average transmittance of 95.15% in the wavelength range of 400-740nm and an average transmittance of 12.7% in the wavelength range of 900-1100nm at an incident angle of 0°; the substrate after the entire film system is plated is subjected to pencil hardness and Mohs hardness tests, and the film system reaches a pencil hardness of 9H and a Mohs hardness of 3.5; the substrate after the entire film system is plated is subjected to a 48-hour salt spray test, and the film system does not fall off or crack; the substrate after the entire film system is plated is subjected to a 100-grid test with 3M tape after salt spray, and the film system does not fall off.

[0041] [test]

[0042] Example 1

[0043] Reference Figure 1 and Figure 2, Example 1 adopts the following steps:

[0044] S1, cleaning the surface of the substrate, the substrate is BK7 optical glass, and the substrate is cleaned by ultrasonic vibration in pure water, the ultrasonic frequency is 50KHz, the temperature is 45°C and the power is 400W;

[0045] S2, two Nb2O5 targets, two Si targets, and an RF ion source are selected for the process chamber of the magnetron sputtering equipment, all of which are below the rotating table at the top of the process chamber, wherein the purity of the Nb2O5 target and the Si target is 5N;

[0046] S3, fix the substrate on the lower surface of the rotating table, and evacuate the process chamber to 5.0×10 -5 Pa;

[0047] S4, using an RF ion source to clean the surface of the substrate, wherein the process parameters of the RF ion source cleaning are: 100 sccm Ar gas is introduced into the RF ion source, the cleaning time is 3 min, the RF ion source power is set to 4 KW, the forward power is 3.994 KW, and the reverse power is 6 W;

[0048] S5, magnetron sputtering equipment captures Nb2O5 / SiO2 data, introduces Ar gas into the Nb2O5 target position equipped with medium frequency power supply, introduces oxygen into the RF ion source and maintains exhaust in the process chamber to plate Nb2O5, introduces Ar gas into the Si target position equipped with medium frequency power supply, introduces oxygen into the RF ion source and maintains exhaust in the process chamber to plate SiO2,

[0049] in,

[0050] In step S5, the process of acquiring the Nb2O5 / SiO2 data captured by the magnetron sputtering device includes the following sub-steps:

[0051] Sa, at least four single-layer films with a thickness of 1 / 4 wavelength of Nb2O5 / SiO2 are deposited on the cleaned BK7 substrate, and then the spectral data of the single-layer film material is tested by a spectrophotometer, such as Figure 3 and Figure 4 As shown;

[0052] Sb, using TFC to calculate the refractive index data of the two film layers in the required band through spectral data, where the refractive index N of Nb2O5 at a wavelength of 550nm is 2.36, and the refractive index of SiO2 is 1.455;

[0053] Sc, using TFC to simulate the average transmittance of 400-740nm wavelength range ≥95% and 900-1100nm transmittance ≤15% at an incident angle of 0° on a BK7 substrate, and obtain the Nb2O5 / SiO2 film system data. The Nb2O5 / SiO2 film system data is 12.36nmNb2O5 / 34.66nmSiO2 / 111.07nmNb2O5 / 169.23nmSiO2 / 101.66nm

[0054] Nb2O5 / 166.50nmSiO2 / 98.65nmNb2O5 / 165.25nmSiO2 / 101.67nmNb2O5 / 84.

[0055] 39nmSiO2 has ten film layers, and the numbers in nm before Nb2O5 and SiO2 are the thickness of the film layers;

[0056] Sd, import the obtained Nb2O5 / SiO2 film system data into the control system of the magnetron sputtering coating machine;

[0057] S6, the rotating table drives the substrate to rotate, and based on the Nb2O5 / SiO2 film system data, the rotation of the targets corresponding to the coated film layers among the two Nb2O5 targets and the two Si targets is started, and at the same time, the intermediate frequency power supplies and RF ion sources corresponding to the two Nb2O5 targets and the two Si targets are turned on, and the introduction of Ar gas and oxygen gas is controlled accordingly, and the process chamber is exhausted to maintain the flow pressure of the process chamber.

[0058] Among them, in step S6,

[0059] The rotation speed of the rotating table was 250 rpm;

[0060] Based on the Nb2O5 / SiO2 film system data, when coating each Nb2O5 film layer:

[0061] The power of the medium frequency power supply for the two Nb2O5 targets is 12KW;

[0062] The Ar gas flow rate at the two Nb2O5 targets is 200 sccm.

[0063] The oxygen flow rate at the RF ion source is 100 sccm.

[0064] The RF ion source was set to 4KW, with a forward power of 3.992KW and a reverse power of 8W;

[0065] The deposition rate of Nb2O5 film is

[0066] The flow pressure is 2.2×10 -1 Pa;

[0067] The number of deposition cycles of the first Nb2O5 film layer is 244;

[0068] The deposition number of the third Nb2O5 film layer is 2195;

[0069] The deposition number of the fifth Nb2O5 film layer is 2009;

[0070] The deposition number of the seventh Nb2O5 film layer is 1950;

[0071] The deposition number of the ninth Nb2O5 film layer is 2009;

[0072] Among them, in step S6,

[0073] The rotation speed of the rotating table was 250 rpm;

[0074] Based on the Nb2O5 / SiO2 film system data, when coating each SiO2 film layer:

[0075] The power of the medium frequency power supply for the two Si targets is 6KW;

[0076] The Ar gas flow rate at the two Si targets is 200 sccm.

[0077] The oxygen flow rate at the RF ion source is 100 sccm.

[0078] The RF ion source was set to 4KW, with a forward power of 3.994KW and a reverse power of 6W;

[0079] The deposition rate of SiO2 film is

[0080] The flow pressure is 2.2×10 -1 Pa;

[0081] The deposition number of the second SiO2 film layer is 411;

[0082] The number of deposition cycles of the fourth SiO2 film layer is 2006;

[0083] The deposition number of the sixth SiO2 film layer is 1973;

[0084] The deposition number of the eighth SiO2 film layer is 1958;

[0085] The number of deposition turns of the tenth SiO2 film layer is 1000 turns;

[0086] S7, after the entire film system is plated according to the film system data, the prepared sample is taken out;

[0087] After step S7 is completed, Figure 5 As shown, after the entire film system is plated, the substrate has an average transmittance of 95.15% (ie ≥95%) in the wavelength range of 400-740nm and an average transmittance of 12.7% (ie ≤15%) in the wavelength range of 900-1100nm at an incident angle of 0°.

[0088] After the entire film system was plated, the substrate was subjected to pencil hardness and Mohs hardness tests, and the film system reached a pencil hardness of 9H and a Mohs hardness of 3.5.

[0089] After the entire film system was plated, the substrate was subjected to a 48-hour salt spray test, and the film system did not fall off or crack.

[0090] After the entire film system was plated, the substrate was subjected to a 100-grid test with 3M tape after salt spray, and the film system did not fall off.

[0091] The above detailed description is used to describe multiple exemplary embodiments, but this document is not intended to be limited to the explicitly disclosed combinations. Therefore, unless otherwise stated, the various features disclosed herein can be combined together to form multiple additional combinations that are not shown for the sake of simplicity.

Claims

1. A coating process with high transmittance of 400-740nm and cut-off of 900-1100nm band, characterized in that: Includes steps: S1, cleaning the surface of the substrate; S2, two Nb2O5 targets, two Si targets, and an RF ion source are selected for the process chamber of the magnetron sputtering equipment, and all the targets and the RF ion source are lower than the rotating table at the top of the process chamber; S3, fix the substrate on the lower surface of the rotating table, and evacuate the process chamber to a vacuum of less than 9.0×10 -5 Pa; S4, cleaning the surface of the substrate using an RF ion source; S5, magnetron sputtering equipment captures Nb2O5 / SiO2 data, introduces Ar gas into the Nb2O5 target position equipped with a medium frequency power supply, introduces oxygen into the RF ion source and maintains exhaust in the process chamber to plate Nb2O5, and introduces Ar gas into the Si target position equipped with a medium frequency power supply, introduces oxygen into the RF ion source and maintains exhaust in the process chamber to plate SiO2; S6, the rotating table drives the substrate to rotate, and based on the Nb2O5 / SiO2 film system data, the rotation of the targets corresponding to the plated film layers among the two Nb2O5 targets and the two Si targets is started, and at the same time, the intermediate frequency power supplies and RF ion sources corresponding to the two Nb2O5 targets and the two Si targets are started, and the introduction of Ar gas and oxygen gas is controlled accordingly, and the process chamber is exhausted to maintain the flow pressure of the process chamber; S7, after the entire film system is plated according to the film system data, the prepared sample is taken out; After step S7 is finished, the substrate after the entire film system is plated has an average transmittance of ≥95% in the wavelength range of 400-740nm and an average transmittance of ≤15% in the wavelength range of 900-1100nm at an incident angle of 0°.

2. The coating process with high transmittance of 400-740nm and cut-off wavelength of 900-1100nm according to claim 1, characterized in that: In step S1, the sample preparation substrate is BK7 optical glass, and BK7 optical glass is also used to collect single-layer film data.

3. The coating process with high transmittance of 400-740nm and cut-off wavelength of 900-1100nm according to claim 1, characterized in that: In step S1, the substrate is cleaned using ultrasonic waves.

4. The coating process with high transmittance of 400-740nm and cut-off wavelength of 900-1100nm according to claim 3, characterized in that: In step S1, the substrate is cleaned by ultrasonic vibration in pure water, with an ultrasonic frequency of 50 KHz, a temperature of 45°C and a power of 400W.

5. The coating process with high transmittance of 400-740nm and cut-off wavelength of 900-1100nm according to claim 1, characterized in that: In step S2, the purity of the Nb2O5 target and the Si target is 5N; and / or In step S3, the process chamber is evacuated to a vacuum of 5.0×10 -5 Pa; and / or In step S4, the process parameters for RF ion source cleaning are: 100 sccm Ar gas is introduced into the RF ion source, the cleaning time is 3 min, the RF ion source power is set to 4 KW, the forward power is 3.994 KW, and the reverse power is 6W.

6. The coating process with high transmittance of 400-740nm and cut-off wavelength of 900-1100nm according to claim 2, characterized in that: In step S5, the process of acquiring the Nb2O5 / SiO2 data captured by the magnetron sputtering device includes the following sub-steps: Sa, at least four single-layer films with a thickness of 1 / 4 wavelength of two Nb2O5 / SiO2 films are deposited on the cleaned BK7 substrate, and then the spectral data of the single-layer film materials are tested by a spectrophotometer; Sb, uses TFC to calculate the refractive index data of the two film layers in the required band through spectral data; Sc, using TFC to simulate the average transmittance of 400-740nm at an incident angle of 0° on a BK7 substrate, the average transmittance is ≥95% and the average transmittance of 900-1100nm is ≤15%, and the Nb2O5 / SiO2 film system data is obtained; Sd, import the obtained Nb2O5 / SiO2 film system data into the control system of the magnetron sputtering coating machine.

7. The coating process with high transmittance of 400-740nm and cut-off wavelength of 900-1100nm according to claim 6, characterized in that: In sub-step Sb, the refractive index N of Nb2O5 at a wavelength of 550 nm is 2.36, and the refractive index of SiO2 is 1.455; In sub-step Sc, the data of the Nb2O5 / SiO2 film system is that a total of ten film layers are plated on the substrate in sequence: 12.36nmNb2O5 / 34.66nmSiO2 / 111.07nmNb2O5 / 169.23nmSiO2 / 101.66nmNb2O5 / 166.50nmSiO2 / 98.65nmNb2O5 / 165.25nmSiO2 / 101.67nmNb2O5 / 84.39nmSiO2. The numbers with nm before Nb2O5 and SiO2 are the thickness of the film layers.

8. The coating process with high transmittance of 400-740nm and cut-off wavelength of 900-1100nm according to claim 7, characterized in that: In step S6, The rotation speed of the rotating table was 250 rpm; Based on the Nb2O5 / SiO2 film system data, when coating each Nb2O5 film layer: The power of the medium frequency power supply for the two Nb2O5 targets is 12KW; The Ar gas flow rate at the two Nb2O5 targets is 200 sccm. The oxygen flow rate at the RF ion source is 100 sccm. The RF ion source was set to 4KW, with a forward power of 3.992KW and a reverse power of 8W; The deposition rate of Nb2O5 film is / lock up; The flow pressure is 2.2×10 -1 Pa; The number of deposition cycles of the first Nb2O5 film layer is 244; The deposition number of the third Nb2O5 film layer is 2195; The deposition number of the fifth Nb2O5 film layer is 2009; The deposition number of the seventh Nb2O5 film layer is 1950; The deposition number of the ninth Nb2O5 film layer is 2009.

9. The coating process with high transmittance of 400-740nm and cut-off wavelength of 900-1100nm according to claim 7, characterized in that: In step S6, The rotation speed of the rotating table was 250 rpm; Based on the Nb2O5 / SiO2 film system data, when coating each SiO2 film layer: The power of the medium frequency power supply for the two Si targets is 6KW; The Ar gas flow rate at the two Si targets is 200 sccm. The oxygen flow rate at the RF ion source is 100 sccm. The RF ion source was set to 4KW, with a forward power of 3.994KW and a reverse power of 6W; The deposition rate of SiO2 film is / lock up; The flow pressure is 2.2×10 -1 Pa; The deposition number of the second SiO2 film layer is 411; The number of deposition cycles of the fourth SiO2 film layer is 2006; The deposition number of the sixth SiO2 film layer is 1973; The deposition number of the eighth SiO2 film layer is 1958; The number of deposition turns of the tenth SiO2 film layer is 1000 turns.

10. The coating process with high transmittance of 400-740nm and cut-off wavelength of 900-1100nm according to claim 1, characterized in that: After step S7 is completed, the substrate after the entire film system is plated has an average transmittance of 95.15% in the wavelength range of 400-740nm and an average transmittance of 12.7% in the wavelength range of 900-1100nm at an incident angle of 0°; After the entire film system is plated, the substrate is subjected to pencil hardness and Mohs hardness tests, and the film system reaches a pencil hardness of 9H and a Mohs hardness of 3.5; After the entire film system was plated, the substrate was subjected to a 48-hour salt spray test, and the film system did not fall off or crack; After the entire film system was plated, the substrate was subjected to a 100-grid test with 3M tape after salt spray, and the film system did not fall off.

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