Design method and preparation method of chalcogenide glass substrate infrared short-medium wave 1.5-5 [mu] m durable antireflection film

Abstract

The invention provides a design method and a preparation method of a chalcogenide glass substrate infrared short-medium wave 1.5-5 [mu] m durable antireflection film. The design method of the chalcogenide glass substrate infrared short medium wave 1.5-5 [mu] m durable antireflection film comprises the following steps: Sa, selecting a 3 [mu] m as a reference wavelength for designing a 1 / 4 wavelength thickness of an optical film, using a film stack expression: Sub / 0.1 W / 0.1 L / 0.5 H / 0.3 L / 0.5 M / 1L / 0.2 W / AIR, plating the same film systems on two sides of Sub, where Sub is a chalcogenide glass substrate, AIR represents air, H represents Si, L represents YbF3, M represents ZnS, and W represents Al2O3; and generating a Sub / Al2O3 / YbF3 / Si / YbF3 / ZnS / YbF3 / Al2O3 / Air film layer structure according to a film stack expression formula, namely Sb / Al2O3 / YbF3 / Si / YbF3 / ZnS / YbF3 / Al2O3 / Air. Sc, calculating and optimizing the film thickness of the film layer through design software to obtain the optimal film thickness of the film layer, and enabling the transmittance of the optimized chalcogenide glass substrate at the infrared short and medium wave band of 1.5-5 microns to meet the requirement; and Sd, the optimized film thickness of the film layer is input into a film coating machine.

Description

Technical Field

[0001] The present disclosure relates to the field of infrared coating technology, and more specifically to a design method and a preparation method of a chalcogenide glass substrate infrared short- and medium-wave 1.5-5 μm durable anti-reflection film. Background Art

[0002] Infrared optical systems usually use crystal materials, such as ZnS, Si, GaAs, Ge, ZnSe, etc. Infrared lenses made of crystal materials are usually expensive. Chalcogenide glass, as a new type of infrared lens material, is an amorphous material based on sulfur, selenium, tellurium and other chalcogenide elements, and other elements (such as arsenic, antimony or germanium) are added. At present, chalcogenide glass can be used to batch produce complex surface optical components with consistent performance in a short time by precision molding method. Due to its high processing efficiency, the manufacturing cost and processing cycle of infrared optical systems are greatly reduced. These materials have unique optical properties in the infrared, and have high transmittance in infrared short-wave, medium-wave and long-wave. Its transmission band can cover three atmospheric windows of 1-3μm, 3-5μm and 8-12μm. The application background of chalcogenide glass in the 1.5-5μm band is mainly closely related to the development and demand of infrared technology. With the widespread application of infrared technology in military, security, environmental monitoring, medical imaging and scientific research, the demand for high-performance materials is growing. Chalcogenide glass has become one of the indispensable materials in these application fields due to its excellent performance in the above bands. In order to improve the transmittance of chalcogenide glass lenses, an anti-reflection film needs to be coated on its surface. Since the 1.5-5μm band covers a variety of atmospheric windows, it is crucial for applications such as thermal imaging and spectral analysis. However, most coating materials have varying degrees of light absorption in the 1.5-5μm range, resulting in low film transmittance. In addition, the amorphous material properties of chalcogenide glass lead to complex surface stress and poor film firmness, which has become a technical problem that needs to be urgently solved in the field of optical films. Summary of the invention

[0003] In view of the problems existing in the background technology, an object of the present disclosure is to provide a design method and a preparation method for a chalcogenide glass substrate infrared short- and medium-wave 1.5-5μm durable anti-reflection film, which can make the designed and prepared chalcogenide glass substrate infrared short- and medium-wave 1.5-5μm transmittance meet the requirements.

[0004] Another object of the present disclosure is to provide a design method and a preparation method for a chalcogenide glass substrate infrared short- and medium-wave 1.5-5 μm durable antireflection film, which can make the film layer structure on each surface of the chalcogenide glass substrate have good durability.

[0005] Thus, a design method for a chalcogenide glass substrate infrared short-medium wave 1.5-5 μm durable antireflection film comprises the following steps: Sa, selecting 3 μm as a reference wavelength for designing an optical film with a thickness of 1 / 4 wavelength, using a film stack expression: Sub / 0.1W / 0.1L / 0.5H / 0.3L / 0.5M / 1L / 0.2W / AIR, coating the same film system on both sides of Sub, wherein Sub is a chalcogenide glass substrate, AIR represents air, H represents a high refractive index material Si (silicon) with a thickness of 1 / 4 wavelength, L represents a low refractive index material YbF3 (ytterbium fluoride) with a thickness of 1 / 4 wavelength, and M represents a low refractive index material YbF3 (ytterbium fluoride) with a thickness of 1 / 4 wavelength. The long thickness intermediate refractive index material ZnS (zinc sulfide), W represents the 1 / 4 wavelength thickness of the base material and the outermost protective material Al2O3 (aluminum oxide); Sb, through the input film stack expression, generates the film structure of Sub / Al2O3 / YbF3 / Si / YbF3 / ZnS / YbF3 / Al2O3 / Air; Sc, the film thickness is calculated and optimized by the design software to obtain the best film thickness. The transmittance of the optimized chalcogenide glass substrate in the infrared short-medium wave 1.5-5μm band meets the requirements; Sd, the optimized film thickness is input into the control computer of the coating machine.

[0006] A method for preparing a chalcogenide glass substrate infrared short-medium wave 1.5-5μm durable anti-reflection film comprises the following steps: S1, cleaning the accompanying plated sheet and the product of the chalcogenide glass substrate as a lens before plating, and preparing four kinds of film materials, namely Si, YbF3, ZnS and Al2O3; S2, configuring the film system process parameters, wherein the film system process parameter configuration includes the background vacuum degree and temperature before plating, the optimal film thickness, the evaporation mode of the film material, the deposition rate of the film material, and the use of ion source assisted deposition, wherein the film thickness in the film system process parameters is based on the aforementioned chalcogenide glass substrate infrared short-medium wave 1.5-5μm m, the optimal film thickness of the film layer stored in the control computer of the coating machine as described in the design method of the durable anti-reflection film; S3, the cleaned lens is placed in the fixture, the fixture with the lens is hung in the cavity of the coating machine, vacuum baking and all film materials are pre-melted, degassed, impurities removed and kept at a constant temperature; S4, the lens is cleaned with an ion source; S5, film coating and monitoring, the film layer is coated on the first side of the lens according to the film system parameter process configuration of step S2; S6, constant temperature is maintained after coating; S7, cooling and taking out the piece; S8, repeating steps S1 to S7, and coating the second side of the lens.

[0007] The beneficial effects of the present disclosure are as follows.

[0008] In the design method of the chalcogenide glass substrate infrared short and medium wave 1.5-5μm durable anti-reflection film according to the present disclosure, by using four film materials of Si, YbF3, ZnS, and Al2O3, Si is used as a high refractive index material, YbF3 is used as a low refractive index material, ZnS is used as an intermediate refractive index material, Al2O3 is used as a base material of the film structure and the outermost protective material of the film structure, which plays a major moisture-proof protection role, and the second layer of YbF3, the fourth layer of YbF3, and the sixth layer of YbF3 are alternately formed with the third layer of Si and the fifth layer of ZnS, so that the designed chalcogenide glass substrate infrared short and medium wave 1.5-5μm transmittance meets the requirements.

[0009] In the design method of the chalcogenide glass substrate infrared short- and medium-wave 1.5-5μm durable anti-reflection film according to the present disclosure, a film layer structure of Sub / Al2O3 / YbF3 / Si / YbF3 / ZnS / YbF3 / Al2O3 / Air is adopted. As verified by the test in the preparation method, it can pass eight tests, including friction resistance test, blister test, adhesion test, hot and cold shock test, constant temperature and humidity test, salt spray test, low temperature test, and high temperature test. That is, the film layer structure (i.e., anti-reflection film) on each surface of the chalcogenide glass substrate obtained based on the design method and further based on the preparation method described later has good durability.

[0010] In the design method of the chalcogenide glass substrate infrared short- and medium-wave 1.5-5 μm durable anti-reflection film according to the present disclosure, a seven-layer structure of Sub / Al2O3 / YbF3 / Si / YbF3 / ZnS / YbF3 / Al2O3 / Air is adopted, and the film layer structure is simple.

[0011] In the method for preparing a chalcogenide glass substrate infrared short-medium wave 1.5-5μm durable anti-reflection film according to the present invention, steps S1 to S8 are performed and the thickness of the film layer in the film system process parameters of step S2 is based on the optimal film layer thickness stored in the control computer of the coating machine as described in the design method of the chalcogenide glass substrate infrared short-medium wave 1.5-5μm durable anti-reflection film, so that the transmittance of the prepared chalcogenide glass substrate infrared short-medium wave 1.5-5μm meets the requirements.

[0012] Similarly, by adopting the film layer structure of Sub / Al2O3 / YbF3 / Si / YbF3 / ZnS / YbF3 / Al2O3 / Air, as verified by the test, it can pass eight tests including friction resistance test, blister test, adhesion test, hot and cold shock test, constant temperature and humidity test, salt spray test, low temperature test and high temperature test. That is, the film layer structure (i.e., anti-reflection film) on each surface of the chalcogenide glass substrate obtained based on the preparation method has good durability. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic structural diagram of the film layer structure according to the design method of the chalcogenide glass substrate infrared short-medium wave 1.5-5μm durable anti-reflection film disclosed in the present invention.

[0014] Figure 2 It is a transmittance curve diagram of the chalcogenide glass substrate and the film structure on both sides after the film thickness is optimized in the design method of the chalcogenide glass substrate infrared short-medium wave 1.5-5μm durable anti-reflection film of Example 1.

[0015] Figure 3 It is a transmittance curve diagram of the accompanying coating sheet of Example 1 together with the film layer structure coated on both sides in the infrared short- and medium-wave 1.5-5 μm band. DETAILED DESCRIPTION

[0016] It will be understood that the disclosed embodiments are merely examples of the present disclosure, which may be implemented in various forms, and therefore, the specific details disclosed herein should not be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one of ordinary skill in the art to implement the present disclosure in various ways.

[0017] [Design method for durable antireflection film on chalcogenide glass substrate for short- and medium-wave infrared 1.5-5μm]

[0018] The design method of the chalcogenide glass substrate infrared short- and medium-wave 1.5-5 μm durable antireflection film according to the present disclosure comprises the following steps:

[0019] Sa, 3μm is selected as the reference wavelength for the design of 1 / 4 wavelength thickness of optical thin film, and the film stack expression is used: Sub / 0.1W / 0.1L / 0.5H / 0.3L / 0.5M / 1L / 0.2W / AIR. The same film system is plated on both sides of Sub.

[0020] Wherein, Sub is the chalcogenide glass substrate, AIR represents air, H represents the high refractive index material Si (silicon) with a thickness of 1 / 4 wavelength, L represents the low refractive index material YbF3 (ytterbium fluoride) with a thickness of 1 / 4 wavelength, M represents the intermediate refractive index material ZnS (zinc sulfide) with a thickness of 1 / 4 wavelength, and W represents the base material and the outermost protective material Al2O3 (aluminum oxide) with a thickness of 1 / 4 wavelength;

[0021] Sb, through the input film stack expression, generate the film structure of Sub / Al2O3 / YbF3 / Si / YbF3 / ZnS / YbF3 / Al2O3 / Air (combined with reference Figure 1 );

[0022] Sc, the film thickness is calculated and optimized by design software to obtain the best film thickness. The transmittance of the optimized chalcogenide glass substrate in the infrared short- and medium-wave 1.5-5μm band meets the requirements;

[0023] Sd, inputs the optimized film thickness into the control computer of the coating machine.

[0024] In the design method of the chalcogenide glass substrate infrared short and medium wave 1.5-5μm durable anti-reflection film according to the present disclosure, by using four film materials of Si, YbF3, ZnS, and Al2O3, Si is used as a high refractive index material, YbF3 is used as a low refractive index material, ZnS is used as an intermediate refractive index material, Al2O3 is used as a base material of the film structure and the outermost protective material of the film structure, which plays a major moisture-proof protection role, and the second layer of YbF3, the fourth layer of YbF3, and the sixth layer of YbF3 are alternately formed with the third layer of Si and the fifth layer of ZnS, so that the designed chalcogenide glass substrate infrared short and medium wave 1.5-5μm transmittance meets the requirements.

[0025] In the design method of the chalcogenide glass substrate infrared short- and medium-wave 1.5-5μm durable anti-reflection film according to the present disclosure, a film layer structure of Sub / Al2O3 / YbF3 / Si / YbF3 / ZnS / YbF3 / Al2O3 / Air is adopted. As verified by the test in the preparation method, it can pass eight tests, including friction resistance test, blister test, adhesion test, hot and cold shock test, constant temperature and humidity test, salt spray test, low temperature test, and high temperature test. That is, the film layer structure (i.e., anti-reflection film) on each surface of the chalcogenide glass substrate obtained based on the design method and further based on the preparation method described later has good durability.

[0026] In the design method of the chalcogenide glass substrate infrared short- and medium-wave 1.5-5 μm durable anti-reflection film according to the present disclosure, a seven-layer structure of Sub / Al2O3 / YbF3 / Si / YbF3 / ZnS / YbF3 / Al2O3 / Air is adopted, and the film layer structure is simple.

[0027] For example, in step Sa, the chalcogenide glass substrate is but not limited to VIG04 or VIG06.

[0028] In one example, in step Sc, for each of the two sides of the chalcogenide glass substrate, the optimal film thickness is: the first Al2O3 film thickness is 20nm±3nm, the second YbF3 film thickness is 35.81±3nm, the third Si film thickness is 96.70±3nm, the fourth YbF3 film thickness is 116.78±3nm, the fifth ZnS film thickness is 103.45±3nm, the sixth YbF3 film thickness is 357.25±3nm, and the seventh Al2O3 film thickness is 40±3nm. In this way, for each of the two sides of the chalcogenide glass substrate, the overall thickness of the film structure is small, less than 800nm, which can effectively reduce costs and improve the coating efficiency of the preparation method described later.

[0029] Accordingly, in one example, in step Sc, the transmittance of the chalcogenide glass substrate in the infrared short- and medium-wave 1.5-5 μm band is greater than 95% on average.

[0030] In step Sa to step Sd, the design software may be, but is not limited to, TFCalc or Essential Macleod.

[0031] [Preparation method of chalcogenide glass substrate infrared short-medium wave 1.5-5μm durable antireflection film]

[0032] The method for preparing a chalcogenide glass substrate infrared short- and medium-wave 1.5-5 μm durable antireflection film according to the present disclosure comprises the following steps:

[0033] S1, before plating, the accompanying plating sheet and products of the chalcogenide glass substrate used as the lens are cleaned, and four kinds of film materials, Si, YbF3, ZnS, and Al2O3, are prepared;

[0034] S2, film system process parameter configuration, the film system process parameter configuration includes the background vacuum degree before plating, temperature, optimal film thickness, film material evaporation mode, film material deposition rate, and use of ion source assisted deposition. The film thickness in the film system process parameters is based on the optimal film thickness stored in the control computer of the coating machine as described in the design method of the chalcogenide glass substrate infrared short-medium wave 1.5-5μm durable anti-reflection film;

[0035] S3, put the cleaned lens into the fixture, hang the fixture with the lens into the cavity of the coating machine, vacuum bake, and pre-melt all the film materials, release air, remove impurities and keep the temperature constant;

[0036] S4, ion source cleaning lens;

[0037] S5, coating and monitoring the film layer, coating the film layer on the first surface of the lens according to the film system parameter process configuration of step S2;

[0038] S6, constant temperature maintenance after plating;

[0039] S7, cooling and picking up;

[0040] S8, repeating steps S1 to S7 to perform film coating on the second surface of the lens.

[0041] In the method for preparing a chalcogenide glass substrate infrared short-medium wave 1.5-5μm durable anti-reflection film according to the present invention, steps S1 to S8 are performed and the thickness of the film layer in the film system process parameters of step S2 is based on the optimal film layer thickness stored in the control computer of the coating machine as described in the design method of the chalcogenide glass substrate infrared short-medium wave 1.5-5μm durable anti-reflection film, so that the transmittance of the prepared chalcogenide glass substrate infrared short-medium wave 1.5-5μm meets the requirements.

[0042] Similarly, by adopting the film layer structure of Sub / Al2O3 / YbF3 / Si / YbF3 / ZnS / YbF3 / Al2O3 / Air, as verified by the test, it can pass eight tests including friction resistance test, blister test, adhesion test, hot and cold shock test, constant temperature and humidity test, salt spray test, low temperature test and high temperature test. That is, the film layer structure (i.e., anti-reflection film) on each surface of the chalcogenide glass substrate obtained based on the preparation method has good durability.

[0043] The cleaning in step S1 is beneficial to improving the surface state of the first surface and the second surface of the lens, and is helpful to improve the bonding performance of the film structure on each surface and the corresponding surface of the lens. For example, in step S1, the cleaning is carried out by ultrasonic cleaning and manual wiping. For example, ultrasonic cleaning is carried out by ultrasonic alcohol or isopropyl alcohol cleaning. The chalcogenide glass substrate is but not limited to VIG04 or VIG06. In one example, the thickness of the accompanying plating sheet is 1.0 mm.

[0044] In one example, in step S2, the background vacuum degree before plating is 8.0×10 -4Pa; the temperature is set to heat from 25°C to 120°C, and the temperature gradient time is controlled to be 40-45min; after the temperature reaches 120°C, the temperature is kept constant for 20min; the thickness of the film layer in the film system process parameters is based on the optimal film layer thickness stored in the control computer of the coating machine described in the design method of the chalcogenide glass substrate infrared short-medium wave 1.5-5μm durable anti-reflection film. Specifically, for each of the two sides of the chalcogenide glass substrate, the optimal film layer thickness is: the first layer of Al2O3 film thickness is 20±3nm, the second layer of YbF3 film thickness is 20±3nm. The thickness of the Si film layer is 35.81±3nm, the thickness of the third Si film layer is 96.70±3nm, the thickness of the fourth YbF3 film layer is 116.78±3nm, the thickness of the fifth ZnS film layer is 103.45±3nm, the thickness of the sixth YbF3 film layer is 357.25±3nm, and the thickness of the seventh Al2O3 film layer is 40±3nm; the evaporation mode of the film material is: Si and Al2O3 are evaporated by electron beam heating, and YbF3 and ZnS are evaporated by resistance heating; the deposition rate of the film material is: the deposition rate of the Si film layer is The deposition rate of Al2O3 film is The deposition rate of the YbF3 film was set to Deposition rate of ZnS film The use of ion source assisted deposition is as follows: except for the plating of the third Si film layer and the fifth ZnS film layer, ion source assisted deposition is not used, and the remaining film layers are all deposited using ion source assisted deposition.

[0045] Further, in one example, the ion source parameters when coating the first layer of Al2O3 film are: neutralization current 0.5A, neutralization gas flow rate 8sccm, anode voltage 180V, anode current 2A, argon gas flow rate 100%; the ion source parameters when coating the second layer of YbF3 film are: neutralization current 0.5A, neutralization gas flow rate 8sccm, anode voltage 120V, anode current 1A, argon gas flow rate 100%; the ion source parameters when coating the fourth layer of YbF3 film are: neutralization current 0.5A, The neutralization gas flow rate is 8sccm, the anode voltage is 120V, the anode current is 1A, and the argon flow rate accounts for 100%; the ion source parameters when coating the sixth layer of YbF3 film are: neutralization current 0.5A, neutralization gas flow rate 8sccm, anode voltage 120V, anode current 1A, and argon flow rate accounts for 100%; the ion source parameters when coating the seventh layer of Al2O3 film are: neutralization current 0.5A, neutralization gas flow rate 8sccm, anode voltage 150V, anode current 1.5A, and argon flow rate accounts for 100%. When coating the first layer of Al2O3 film, the energy parameter setting of ion source assisted deposition should be slightly larger, which is conducive to enhancing the adhesion of the base film layer. When coating the last layer (i.e., the seventh layer) of Al2O3 film, as the outermost protective layer, the film thickness is thicker than the thickness of the base layer. When using ion source assisted evaporation, the energy parameter setting should be slightly smaller to avoid the risk of increased film stress and film cracking caused by excessive evaporation energy.

[0046] For example, in step S2, the coating machine is Cathay Pacific GTV-1350.

[0047] The baking in step S3 is to prepare the temperature for the pre-melting of the film material. The pre-melting of the film material can release the gas in the film material and remove the impurities in the film material to ensure the purity of the film material, thereby reducing the adverse factors that affect the quality of the film layer during the film coating process in step S5 described later. In addition, baking also heats the lens. Specifically, in one example, the vacuum is first evacuated to 5×10 -2 Pa, then the cavity of the coating machine starts heating to perform the baking, and the heating is performed according to the temperature of step S2; when the vacuum reaches (4.0-6.0)×10 -3 Pa, the film material is pre-melted, after the pre-melting of the film material is completed, the temperature of the cavity of the coating machine reaches 120 ° C, and the constant temperature is maintained for 10 minutes. In step S3, the pre-melting treatment adopts electron beam heating and resistance heating. Si film material and Al2O3 film material are pre-melted by electron beam heating, and ZnS film material and Al2O3 film material are pre-melted by resistance heating.

[0048] The ion source cleaning in step S4 uses ion bombardment to clean the surface microstructure of the lens, which can eliminate the oxide layer on the surface of the lens, making the surface of the lens cleaner and conducive to the firm adhesion and growth of the film layer. Specifically, in one example, in step S4, the ion source is a Hall ion source, and the parameters of the ion source are: neutralization current 0.75A, neutralization gas flow rate 10sccm, anode voltage 150V, anode current 1.5A, argon gas flow rate 100%, and the cleaning time is set to 10min.

[0049] In one example, in step S5, the crystal oscillator method is used to monitor the film thickness using the corresponding crystal oscillator of the multiple crystal oscillators of the crystal controller. After the ion source is cleaned, the crystal controller controls the corresponding operation of the new crystal oscillator among the multiple crystal oscillators, and the crystal oscillator frequency is not less than 5.99 MHz.

[0050] In one example, in step S6, after plating is completed, the chamber is kept at a constant temperature of 120° C. for 10 minutes;

[0051] In one example, in step S7, the door is opened to take out the items after the temperature drops below 60°C.

[0052] [test]

[0053] Example 1

[0054] Part 1: Design method of durable antireflection film for short and medium-wave infrared (1.5-5μm) on chalcogenide glass substrate

[0055] The design method of the chalcogenide glass substrate infrared short- and medium-wave 1.5-5 μm durable antireflection film of Example 1 adopts the following steps:

[0056] Sa, 3μm is selected as the reference wavelength for the design of 1 / 4 wavelength thickness of optical thin film, and the film stack expression is used: Sub / 0.1W / 0.1L / 0.5H / 0.3L / 0.5M / 1L / 0.2W / AIR. The same film system is plated on both sides of Sub.

[0057] Wherein, Sub is the chalcogenide glass substrate VIG06, AIR represents air, H represents the high refractive index material Si (silicon) with a thickness of 1 / 4 wavelength, L represents the low refractive index material YbF3 (ytterbium fluoride) with a thickness of 1 / 4 wavelength, M represents the intermediate refractive index material ZnS (zinc sulfide) with a thickness of 1 / 4 wavelength, and W represents the base material and the outermost protective material Al2O3 (aluminum oxide) with a thickness of 1 / 4 wavelength;

[0058] Sb, through the input film stack expression, generates the film structure of Sub / Al2O3 / YbF3 / Si / YbF3 / ZnS / YbF3 / Al2O3 / Air;

[0059] Sc, the film thickness is calculated and optimized by design software to obtain the best film thickness. The transmittance of the optimized chalcogenide glass substrate in the infrared short- and medium-wave 1.5-5μm band meets the requirements;

[0060] Sd, input the optimized film thickness into the control computer of the coating machine, the coating machine is Cathay Pacific GTV-1350;

[0061] in,

[0062] In step Sc, for each of the two sides of the chalcogenide glass substrate, the optimal film thickness of the film is:

[0063] The thickness of the first Al2O3 film is 20nm.

[0064] The thickness of the second YbF3 film is 35.81nm.

[0065] The thickness of the third Si film layer is 96.70nm.

[0066] The thickness of the fourth YbF3 film is 116.78nm.

[0067] The thickness of the fifth ZnS film is 103.45nm.

[0068] The thickness of the sixth YbF3 film is 357.25nm.

[0069] The thickness of the seventh Al2O3 film layer is 40nm;

[0070] In step Sa to step Sd, the design software is TFCalc.

[0071] Figure 2 This is a transmittance curve of the chalcogenide glass substrate and the film structure on both sides after the film thickness is optimized in the design method of the chalcogenide glass substrate infrared short-medium wave 1.5-5μm durable anti-reflection film of Example 1. Figure 2 In step Sc, the transmittance of the chalcogenide glass substrate in the infrared short- and medium-wave 1.5-5 μm band is greater than 95% on average.

[0072] Part II: Preparation method of chalcogenide glass substrate infrared short- and medium-wave 1.5-5μm durable antireflection film

[0073] The method for preparing the chalcogenide glass substrate infrared short-medium wave 1.5-5 μm durable antireflection film of Example 1 adopts the following steps:

[0074] S1, before plating, ultrasonic alcohol is used to clean the accompanying plating sheet and the product of the chalcogenide glass substrate as the lens, and four kinds of film materials, Si, YbF3, ZnS, and Al2O3, are prepared. Among them, the chalcogenide glass substrate is VIG06, and the thickness of the accompanying plating sheet is 1.0mm;

[0075] S2, film system process parameter configuration, the film system process parameter configuration includes the background vacuum degree before plating, temperature, optimal film thickness, film material evaporation mode, film material deposition rate, and use of ion source assisted deposition. The film thickness in the film system process parameters is based on the optimal film thickness stored in the control computer of the coating machine as described in the design method of the chalcogenide glass substrate infrared short-medium wave 1.5-5μm durable anti-reflection film.

[0076] in,

[0077] The coating machine is Cathay GTV-1350,

[0078] The background vacuum degree before plating is 8.0×10 -4 Pa;

[0079] The temperature was set to heat from 25°C to 120°C, and the temperature gradient time was controlled to 45min;

[0080] After the temperature reaches 120°C, keep the temperature constant for 20 minutes;

[0081] The thickness of the film layer in the film system process parameters is based on the optimal film layer thickness stored in the control computer of the coating machine as described in the design method of the aforementioned chalcogenide glass substrate infrared short-medium wave 1.5-5μm durable antireflection film;

[0082] The evaporation mode of the film materials is: Si and Al2O3 are evaporated by electron beam heating, and YbF3 and ZnS are evaporated by resistance heating;

[0083] The deposition rate of the film material is: The deposition rate of the Si film layer is The deposition rate of Al2O3 film is The deposition rate of the YbF3 film was set to Deposition rate of ZnS film

[0084] The use of ion source assisted deposition is as follows: except for the deposition of the third Si film layer and the fifth ZnS film layer, the ion source assisted deposition is not used, and the remaining film layers are all deposited by ion source assisted deposition;

[0085] The ion source parameters when depositing the first layer of Al2O3 film are: neutralization current 0.5A, neutralization gas flow rate 8sccm, anode voltage 180V, anode current 2A, argon gas flow rate 100%;

[0086] The ion source parameters when coating the second layer of YbF3 film are: neutralization current 0.5A, neutralization gas flow rate 8sccm, anode voltage 120V, anode current 1A, argon gas flow rate 100%;

[0087] The ion source parameters when coating the fourth layer of YbF3 film are: neutralization current 0.5A, neutralization gas flow rate 8sccm, anode voltage 120V, anode current 1A, argon gas flow rate 100%;

[0088] The ion source parameters when coating the sixth layer of YbF3 film are: neutralization current 0.5A, neutralization gas flow rate 8sccm, anode voltage 120V, anode current 1A, argon gas flow rate 100%;

[0089] The ion source parameters when depositing the seventh layer of Al2O3 film are: neutralization current 0.5A, neutralization gas flow rate 8sccm, anode voltage 150V, anode current 1.5A, argon gas flow rate 100%;

[0090] S3, put the cleaned lens into the fixture, hang the fixture with the lens into the cavity of the coating machine, vacuum bake, pre-melt all the film materials, release air, remove impurities and keep the temperature constant.

[0091] Among them, in step S3,

[0092] First vacuum to 5×10 -2 Pa, then the cavity of the coating machine starts heating to perform the baking, and the heating is performed according to the temperature of step S2;

[0093] When the vacuum reaches 5.0×10 -3 Pa, the film material is pre-melted. After the film material is pre-melted, the temperature of the cavity of the coating machine reaches 120℃ and is kept constant for 10 minutes.

[0094] The pre-melting treatment adopts two methods: electron beam heating and resistance heating. Si film and Al2O3 film are pre-melted by electron beam heating, and ZnS film and Al2O3 film are pre-melted by resistance heating.

[0095] S4, ion source cleaning lens, the ion source is Hall ion source, the ion source parameters are: neutralization current 0.75A, neutralization gas flow rate 10sccm, anode voltage 150V, anode current 1.5A, argon gas flow rate 100%, cleaning time is set to 10min;

[0096] S5, film coating and monitoring, coating the first surface of the lens with a film according to the film system parameter process configuration of step S2, using a crystal oscillator method to monitor the film thickness using a corresponding crystal oscillator of a plurality of crystal oscillators of a crystal controller, after the ion source is cleaned, the crystal controller controls a new crystal oscillator of the plurality of crystal oscillators to work correspondingly, and the crystal oscillator frequency is not less than 5.99 MHz;

[0097] S6, after plating is completed, the cavity is kept at a constant temperature of 120°C for 10 minutes;

[0098] S7, wait until the temperature drops to 60°C, open the door and take out the items;

[0099] S8, repeating steps S1 to S7 to perform film coating on the second surface of the lens.

[0100] Comparative Example 1

[0101] Except that Ge is used to replace Si as the high refractive index material in the first part and the second part (ie, only the material is replaced), the rest is the same as in Example 1.

[0102] Comparative Example 2

[0103] Except that YF3 is used instead of YbF3 as the low refractive index material in the first part and the second part (i.e., only the material is replaced), the rest is the same as Example 1.

[0104] Comparative Example 3

[0105] Except that ZnSe is used to replace ZnS as the medium refractive index material in the first part and the second part (ie, only the material is replaced), the rest is the same as in Example 1.

[0106] Comparative Example 4

[0107] Except that the ion source parameters when depositing the seventh Al2O3 film layer in step S2 in the second part are adjusted to be the same as the ion source parameters when depositing the first Al2O3 film layer (i.e., the ion source parameters when depositing the seventh Al2O3 film layer are adjusted to be the same as the ion source parameters when depositing the first Al2O3 film layer), the rest is the same as Example 1.

[0108] Figure 3 This is a transmittance curve of the accompanying plate of Example 1 together with the film structure plated on both sides in the infrared short- and medium-wave 1.5-5μm band. Figure 3 The transmittance of the accompanying plated sheet together with the film layer structure plated on both sides in the infrared short- and medium-wave 1.5-5μm band is greater than 95% (specifically 95.5%) on average.

[0109] According to GJB2485A-2019, the following tests were performed on Example 1 and Comparative Examples 1-4 after coating on both sides.

[0110] Friction resistance test (moderate friction test): Wrap the rubber friction head of the friction machine with degreased cloth, apply a pressure of 4.9N on the film surface of the accompanying plating sheet and rub it 50 times (25 times back and forth), and observe whether there are signs of scratches or damage on the surface of the film layer.

[0111] Water bubble test: Take tap water to conduct a water bubble test for 2 hours to observe whether the film layer on each surface falls off from the accompanying plating sheet and whether the film layer on each surface is cracked.

[0112] Adhesion test: Use hand to stick 3M tape on each side of the plating sheet and pull the tape in the direction opposite to the sticking end to observe whether the film layer is pulled up.

[0113] Thermal shock test: In a high and low temperature box, perform thermal shock test in the range of -40℃ to 85℃ for 24 hours to observe whether the film layers on each side of the accompanying plating sheet fall off or crack.

[0114] Constant temperature and humidity test: In a constant temperature and humidity chamber, at 50°C and 95% relative humidity for 48 hours, observe whether the film layers on each side of the accompanying plating sheet fall off or crack.

[0115] Salt spray test: neutral salt spray test for 48 hours, observe whether the film layer on each side of the accompanying plating sheet falls off, observe whether the film layer on each side of the accompanying plating sheet cracks.

[0116] Low temperature test: In a low temperature box, at -40℃ for 48h, observe whether the film layers on each side of the accompanying plating sheet fall off, and observe whether the film layers on each side of the accompanying plating sheet crack.

[0117] High temperature test: In a high temperature box, at 85℃ for 48h, observe whether the film layers on each side of the accompanying plating sheet fall off, and observe whether the film layers on each side of the accompanying plating sheet crack.

[0118] Table 1 shows the transmittance of Example 1 and Comparative Examples 1-4 and the results of various tests.

[0119] Table 1 Transmittance of Example 1 and Comparative Examples 1-4 and results of various tests

[0120]

[0121] 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 design method for a chalcogenide glass substrate infrared short- and medium-wave 1.5-5 μm durable antireflection film, characterized in that: Includes steps: Sa, 3μm is selected as the reference wavelength for the design of 1 / 4 wavelength thickness of optical thin film, and the film stack expression is used: Sub / 0.1W / 0.1L / 0.5H / 0.3L / 0.5M / 1L / 0.2W / AIR. The same film system is plated on both sides of Sub. Wherein, Sub is the chalcogenide glass substrate, AIR represents air, H represents the high refractive index material Si (silicon) with a thickness of 1 / 4 wavelength, L represents the low refractive index material YbF3 (ytterbium fluoride) with a thickness of 1 / 4 wavelength, M represents the intermediate refractive index material ZnS (zinc sulfide) with a thickness of 1 / 4 wavelength, and W represents the base material and the outermost protective material Al2O3 (aluminum oxide) with a thickness of 1 / 4 wavelength; Sb, through the input film stack expression, generates the film structure of Sub / Al2O3 / YbF3 / Si / YbF3 / ZnS / YbF3 / Al2O3 / Air; Sc, the film thickness is calculated and optimized by design software to obtain the best film thickness. The transmittance of the optimized chalcogenide glass substrate in the infrared short- and medium-wave 1.5-5μm band meets the requirements; Sd, inputs the optimized film thickness into the control computer of the coating machine.

2. The design method of the chalcogenide glass substrate infrared short- and medium-wave 1.5-5 μm durable antireflection film according to claim 1, characterized in that: In step Sa, the chalcogenide glass substrate is VIG04 or VIG06.

3. The design method of the chalcogenide glass substrate infrared short- and medium-wave 1.5-5 μm durable antireflection film according to claim 1, characterized in that: In step Sc, for each of the two sides of the chalcogenide glass substrate, the optimal film thickness of the film is: The thickness of the first Al2O3 film is 20±3nm. The thickness of the second YbF3 film is 35.81±3nm. The thickness of the third Si film layer is 96.70±3nm. The thickness of the fourth YbF3 film is 116.78±3nm. The thickness of the fifth ZnS film is 103.45±3nm. The thickness of the sixth YbF3 film is 357.25±3nm. The thickness of the seventh Al2O3 film is 40±3nm. In step Sc, the transmittance of the chalcogenide glass substrate in the infrared short- and medium-wave 1.5-5 μm band is greater than 95% on average.

4. A method for preparing a chalcogenide glass substrate infrared short- and medium-wave 1.5-5 μm durable antireflection film, characterized in that: Includes steps: S1, before plating, the accompanying plating sheet and products of the chalcogenide glass substrate used as the lens are cleaned, and four kinds of film materials, Si, YbF3, ZnS, and Al2O3, are prepared; S2, film system process parameter configuration, the film system process parameter configuration includes the background vacuum degree before plating, temperature, optimal film thickness of the film layer, evaporation mode of the film material, deposition rate of the film material, and use of ion source assisted deposition. The thickness of the film layer in the film system process parameters is based on the optimal film thickness of the film layer stored in the control computer of the coating machine according to any one of claims 1 to 3; S3, put the cleaned lens into the fixture, hang the fixture with the lens into the cavity of the coating machine, vacuum bake, and pre-melt all the film materials, release air, remove impurities and keep the temperature constant; S4, ion source cleaning lens; S5, coating and monitoring the film layer, coating the film layer on the first surface of the lens according to the film system parameter process configuration of step S2; S6, constant temperature maintenance after plating; S7, cooling and picking up; S8, repeating steps S1 to S7 to perform film coating on the second surface of the lens.

5. The method for preparing a chalcogenide glass substrate infrared short- and medium-wave 1.5-5 μm durable antireflection film according to claim 4, characterized in that: In step S1, The chalcogenide glass substrate is VIG04 or VIG06; Cleaning is done by ultrasonic cleaning and manual wiping; The thickness of the accompanying plating sheet is 1.0 mm.

6. The method for preparing a chalcogenide glass substrate infrared short- and medium-wave 1.5-5 μm durable antireflection film according to claim 4, characterized in that: In step S2, The background vacuum degree before plating is 8.0×10 -4 Pa; The temperature is set to heat from 25°C to 120°C, and the temperature gradient time is controlled to be 40-45min; after the temperature reaches 120°C, keep the constant temperature for 20min; The thickness of the film layer in the film system process parameters is based on the optimal film thickness of the film layer stored in the control computer of the coating machine according to claim 2; The evaporation mode of the film materials is: Si and Al2O3 are evaporated by electron beam heating, and YbF3 and ZnS are evaporated by resistance heating; The deposition rate of the film material is: The deposition rate of the Si film layer is The deposition rate of Al2O3 film is The deposition rate of the YbF3 film was set to Deposition rate of ZnS film The use of ion source assisted deposition is as follows: except for the plating of the third Si film layer and the fifth ZnS film layer, ion source assisted deposition is not used, and the remaining film layers are all deposited using ion source assisted deposition.

7. The method for preparing a chalcogenide glass substrate infrared short- and medium-wave 1.5-5 μm durable antireflection film according to claim 6, characterized in that: The ion source parameters when depositing the first layer of Al2O3 film are: neutralization current 0.5A, neutralization gas flow rate 8sccm, anode voltage 180V, anode current 2A, argon gas flow rate 100%; The ion source parameters when coating the second layer of YbF3 film are: neutralization current 0.5A, neutralization gas flow rate 8sccm, anode voltage 120V, anode current 1A, argon gas flow rate 100%; The ion source parameters when coating the fourth layer of YbF3 film are: neutralization current 0.5A, neutralization gas flow rate 8sccm, anode voltage 120V, anode current 1A, argon gas flow rate 100%; The ion source parameters when coating the sixth layer of YbF3 film are: neutralization current 0.5A, neutralization gas flow rate 8sccm, anode voltage 120V, anode current 1A, argon gas flow rate 100%; The ion source parameters when depositing the seventh layer of Al2O3 film are: neutralization current 0.5A, neutralization gas flow rate 8sccm, anode voltage 150V, anode current 1.5A, and argon gas flow rate 100%.

8. The method for preparing a chalcogenide glass substrate infrared short- and medium-wave 1.5-5 μm durable antireflection film according to claim 4, characterized in that: In step S3, First vacuum to 5×10 -2 Pa, then the cavity of the coating machine starts heating to perform the baking, and the heating is performed according to the temperature of step S2; When the vacuum reaches (4.0-6.0)×10 -3 Pa, the film material is pre-melted. After the film material is pre-melted, the temperature of the cavity of the coating machine reaches 120℃ and is kept constant for 10 minutes. In step S3, the pre-melting treatment adopts two methods: electron beam heating and resistance heating. The Si film material and the Al2O3 film material are pre-melted by electron beam heating, and the ZnS film material and the Al2O3 film material are pre-melted by resistance heating.

9. The method for preparing a chalcogenide glass substrate infrared short- and medium-wave 1.5-5 μm durable antireflection film according to claim 4, characterized in that: In step S4, The ion source is a Hall ion source. The parameters of the ion source are: neutralization current 0.75A, neutralization gas flow rate 10sccm, anode voltage 150V, anode current 1.5A, argon gas flow rate 100%, and the cleaning time is set to 10min.

10. The method for preparing a chalcogenide glass substrate infrared short- and medium-wave 1.5-5 μm durable antireflection film according to claim 4, characterized in that: In step S5, the film thickness is monitored by using a corresponding crystal oscillator of a plurality of crystal oscillators of a crystal controller using a crystal oscillator method, and after the ion source is cleaned, the crystal controller controls a new crystal oscillator of the plurality of crystal oscillators to work correspondingly, and the crystal oscillator frequency is not less than 5.99 MHz; In step S6, after the plating is completed, the cavity is kept at a constant temperature of 120°C for 10 minutes; In step S7, the door is opened to take out the items when the temperature drops below 60°C.

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