Design method and preparation method of long-wave infrared dual-band durable anti-reflection film in chalcogenide glass substrate

Abstract

The invention provides a design method and a preparation method of a medium-long wave infrared dual-band durable anti-reflection film on a chalcogenide glass substrate. The design method comprises the following steps: selecting 6.5 [mu] m as a reference wavelength for designing 1 / 4 wavelength thickness of an optical thin film, using a film stack expression: Sub / 0.3 H / 0.2 M / 0.6 H / 0.2 M / 0.7 H / 0.2 M / 0.4 H / W / 0.75 L / 0.03 Q / AIR, plating the same film system on two sides of Sub, the Sub being a chalcogenide glass substrate, AIR representing air, H representing Ge, L representing YbF3, M representing ZnSe, W representing ZnS, and Q representing Al2O3; a ten-layer film layer structure of Sub / Ge / ZnSe / Ge / ZnSe / Ge / ZnSe / Ge / ZnS / YbF3 / Al2O3 / AIR generated by an input film stack formula is subjected to film layer thickness optimization through design software, the optimal film layer thickness is obtained, and the transmittance of the optimized chalcogenide glass substrate in double wavebands of 3.7-4.8 microns of medium waves and 7.7-10.5 microns of long waves meets the requirement; and inputting the optimal film thickness of the film layer into a control computer of the film plating 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 mid- and long-wave infrared dual-band durable anti-reflection film. Background Art

[0002] With the progress of dual-band material preparation and device manufacturing technology, dual-band infrared imaging systems have been developed based on single detectors, especially 3.7-4.8μm (medium wave, MWIR) and 7.7-10.5μm (long wave, LWIR) infrared dual-band imaging technology, which has a wide range of applications. This kind of medium- and long-wave dual-band infrared imaging technology can obtain characteristic information such as temperature and spectral characteristics of the target through complementary advantages, which can be used for anti-interference and anti-camouflage, and improve the adaptability of equipment to various complex environments. In the selection of substrate materials for medium- and long-wave dual-band optical elements, chalcogenide glass is the most cost-effective, with excellent optical performance and a transmission band that can cover three atmospheric windows of 1-3μm, 3-5μm, and 8-12μm. With the development of infrared technology, the demand for high-performance and low-cost materials continues to grow, and chalcogenide glass has become one of the indispensable materials in the field of infrared technology. In order to improve the optical performance of chalcogenide glass medium- and long-wave dual-band infrared lenses, it is necessary not only to complete complex optical design, but more importantly, to coat a thin film on the surface of the lens to improve the transmittance. Since chalcogenide glass is a glass substance formed by chemical combination and an amorphous semiconductor material, its surface chemical properties are complex and its bonding with coating materials is weak. In addition, its thermal expansion coefficient is quite different from that of common coating materials. As a result, the coating process of chalcogenide glass substrate is complex and difficult. How to design and prepare medium- and long-wave dual-band antireflection films on chalcogenide glass substrates has become an urgent problem to be 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 mid- and long-wave infrared dual-band durable anti-reflection film, which can ensure that the transmittance of the designed and prepared chalcogenide glass substrate together with the film layer structure on both sides meets the requirements in the dual bands of 3.7-4.8μm mid-wave and 7.7-10.5μm long-wave.

[0004] Another object of the present disclosure is to provide a design method and a preparation method for a mid-wave and long-wave infrared dual-band durable anti-reflection film on a chalcogenide glass substrate, which can meet the requirements of strength and environmental adaptability.

[0005] Therefore, a design method for a mid- and long-wave infrared dual-band durable antireflection film on a chalcogenide glass substrate comprises the following steps: Sa, selecting 6.5 μm as a reference wavelength for designing an optical film with a thickness of 1 / 4 wavelength, using a film stack expression: Sub / 0.3H / 0.2M / 0.6H / 0.2M / 0.7H / 0.2M / 0.4H / W / 0.75L / 0.03Q / AI R, 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 Ge (germanium) with a thickness of 1 / 4 wavelength, and L represents a low refractive index material YbF with a thickness of 1 / 4 wavelength. 3 (Ytterbium fluoride), M represents the intermediate refractive index material ZnSe (zinc selenide) with a thickness of 1 / 4 wavelength, W represents the intermediate refractive index material ZnS (zinc sulfide) with a thickness of 1 / 4 wavelength, and Q represents the low refractive index material Al with a thickness of 1 / 4 wavelength. 2 O 3 (aluminum oxide); Sb, Sub / Ge / ZnSe / Ge / ZnSe / Ge / ZnSe / Ge / ZnS / YbF generated by the input film stack formula through the design software 3 / Al 2 O 3 / AIR's ten-layer film structure is optimized for film thickness to obtain the best film thickness. The transmittance of the optimized chalcogenide glass substrate in the dual bands of 3.7-4.8μm medium wave and 7.7-10.5μm long wave meets the requirements; Sc, the best film thickness is input into the control computer of the coating machine.

[0006] A method for preparing a mid-wave and long-wave infrared dual-band durable antireflection film on a chalcogenide glass substrate comprises the following steps: S1, configuring the film system process parameters of a coating machine and the 3 and Al 2 O 3Five kinds of film materials are prepared, and the film system process parameter configuration includes background vacuum degree, temperature, optimal film thickness of the film layer, film material evaporation mode, film material deposition rate, and use of ion source assisted deposition, wherein the film layer thickness in the film system process parameters is based on the optimal film thickness stored in the control computer of the coating machine in the design method of the long-wave infrared dual-band durable anti-reflection film on the chalcogenide glass substrate mentioned above, and the first Ge film is divided into a first Ge film base layer and a first Ge film connecting layer, and the first Ge film base layer uses ion source assistance, while the first Ge film connecting layer does not use ion source assistance. Assist; S2, before plating, clean the accompanying plating sheets and products of the chalcogenide glass substrate of the lens; S3, put the cleaned lens into the fixture, hang the fixture with the lens in place into the cavity of the coating machine, evacuate and slowly heat up and bake; S4, pre-melt all the film materials, release air, remove impurities and maintain a constant temperature; S5, clean the lens with an ion source; S6, film coating and monitoring, according to the film system parameter process configuration of step S1, coat the first side of the lens with a film layer; S7, maintain a constant temperature after plating; S8, cool down and take out the parts; S9, repeat steps S1 to S8, and coat the second side of the lens with a film layer.

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

[0008] In the design method of the medium- and long-wave infrared dual-band durable antireflection film on a chalcogenide glass substrate according to the present disclosure, the coating materials are selected based on the fact that chalcogenide glass is an amorphous semiconductor material, which leads to its complex surface chemical properties and weak bonding with the coating material, as well as its sensitivity to temperature. The thermal expansion coefficient is greatly different from that of the commonly used infrared coating materials, which leads to stress in the film layer, resulting in the film layer being unstable and falling off. It is found that the more suitable coating temperature range for the chalcogenide glass substrate is between 90°C and 130°C. Within this temperature range, the coating material with the smallest difference in thermal expansion coefficient between the film material and the thermal expansion coefficient of the chalcogenide glass substrate is germanium, followed by zinc selenide, zinc sulfide, ytterbium fluoride, and yttrium fluoride. However, the materials with relatively good bonding effect with the chalcogenide glass substrate include germanium and oxide materials suitable for infrared coating according to the light transmission range, such as yttrium oxide and aluminum oxide. Sub / Ge / ZnSe / Ge / ZnSe / Ge / ZnSe / Ge / ZnS / YbF are designed according to the expansion coefficient between the materials and the bonding effect between the materials. 3 / Al 2 O 3 / AIR has a ten-layer film structure, and the outermost layer of the film structure adopts a combination of ytterbium fluoride and aluminum oxide to increase the moisture resistance and durability of the film structure. Therefore, the chalcogenide glass substrate and the film system on both sides designed according to the design method of the chalcogenide glass substrate mid- and long-wave infrared dual-band durable anti-reflection film disclosed in the present invention combine and expand, moisture resistance and durability between the chalcogenide glass substrate and the film structure (i.e., strength and environmental adaptability), and the chalcogenide glass substrate and the film system on both sides are designed to meet the requirements for the dual-band transmittance of 3.7-4.8μm mid-wave and 7.7-10.5μm long-wave.

[0009] In the design method of the mid- and long-wave infrared dual-band durable antireflection film on the chalcogenide glass substrate disclosed in the present invention, the film system on each surface is Sub / Ge / ZnSe / Ge / ZnSe / Ge / ZnSe / Ge / ZnS / YbF 3 / Al 2 O 3 / AIR, on the basis of the design method, the preparation method of the mid- and long-wave infrared dual-band durable anti-reflection film on the chalcogenide glass substrate disclosed in the present invention is further implemented, and the transmittance of the dual-bands of 3.7-4.8μm mid-wave and 7.7-10.5μm long-wave of the accompanying coating film in the prepared lens together with the coated film structure on both sides meets the requirements, and can pass a total of six tests including blister test, adhesion test, hot and cold shock test, salt spray test, wet heat test, and moderate friction test, that is, it meets the strength and environmental adaptability requirements and meets the acceptance of GJB2485A-2019.

[0010] In the method for preparing a medium- and long-wave infrared dual-band durable anti-reflection film on a chalcogenide glass substrate according to the present disclosure, through steps S1 to S9, the transmittance of the accompanying coating film (i.e., the chalcogenide glass substrate) in the prepared lens together with the coated film structure on both sides in the dual-bands of 3.7-4.8μm medium wave and 7.7-10.5μm long wave meets the requirements.

[0011] Similarly, the accompanying coating sheet in the prepared lens together with the coated film structure on both sides can pass a total of six tests including blister test, adhesion test, hot and cold shock test, salt spray test, wet heat test, and moderate friction test, that is, it meets the strength and environmental adaptability requirements and complies with the acceptance of GJB2485A-2019.

[0012] In the method for preparing a mid- and long-wave infrared dual-band durable anti-reflection film on a chalcogenide glass substrate according to the present disclosure, in step S1, the first Ge film is layered into a first Ge film primer layer and a first Ge film connecting layer. The first Ge film primer layer assisted by an ion source is densely, uniformly and firmly bonded to the chalcogenide glass substrate. Combined with the first Ge film connecting layer not assisted by an ion source, the strength of the film layer structure on each side of the chalcogenide glass substrate is enhanced and the transmittance of the dual bands of 3.7-4.8μm mid-wave and 7.7-10.5μm long-wave is maintained. 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 mid-wave and long-wave infrared dual-band durable anti-reflection film on a chalcogenide glass substrate disclosed in the present invention.

[0014] Figure 2 It is a schematic structural diagram of the film layer structure according to the method for preparing the mid-wave and long-wave infrared dual-band durable anti-reflection film on a chalcogenide glass substrate disclosed in the present invention.

[0015] Figure 3 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 mid-wave and long-wave infrared dual-band durable anti-reflection film in Example 1.

[0016] Figure 4 It is a curve diagram of the transmittance of the accompanying coating sheet of Example 1 together with the film layer structure coated on both sides in the 3.7-4.8μm and 7.7-10.5μm mid-wave and long-wave infrared dual bands. DETAILED DESCRIPTION

[0017] 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.

[0018] [Design method for mid- and long-wave infrared dual-band durable antireflection film on chalcogenide glass substrate]

[0019] The design method of the mid- and long-wave infrared dual-band durable antireflection film on a chalcogenide glass substrate disclosed in the present invention comprises the following steps:

[0020] Sa, 6.5μm is selected as the reference wavelength for the design of 1 / 4 wavelength thickness of the optical film, and the film stack expression is used: Sub / 0.3H / 0.2M / 0.6H / 0.2M / 0.7H / 0.2M / 0.4H / W / 0.75L / 0.03Q / AIR. The same film system is plated on both sides of Sub.

[0021] Among them, Sub is the chalcogenide glass substrate, AIR represents air, H represents the high refractive index material Ge (germanium) with a thickness of 1 / 4 wavelength, and L represents the low refractive index material YbF with a thickness of 1 / 4 wavelength. 3 (Ytterbium fluoride), M represents the intermediate refractive index material ZnSe (zinc selenide) with a thickness of 1 / 4 wavelength, W represents the intermediate refractive index material ZnS (zinc sulfide) with a thickness of 1 / 4 wavelength, and Q represents the low refractive index material Al with a thickness of 1 / 4 wavelength. 2 O 3 (aluminium oxide);

[0022] Sb, Sub / Ge / ZnSe / Ge / ZnSe / Ge / ZnSe / Ge / ZnS / YbF generated by the input film stack formula through the design software 3 / Al 2 O 3 / AIR's ten-layer membrane structure (refer to Figure 1 ) to optimize the film thickness of the film layer to obtain the best film thickness of the film layer, and the transmittance of the optimized chalcogenide glass substrate in the dual bands of 3.7-4.8μm medium wave and 7.7-10.5μm long wave meets the requirements;

[0023] Sc, input the optimal film thickness into the control computer of the coating machine.

[0024] In the design method of the medium- and long-wave infrared dual-band durable antireflection film on a chalcogenide glass substrate according to the present disclosure, the coating materials are selected based on the fact that chalcogenide glass is an amorphous semiconductor material, which leads to its complex surface chemical properties and weak bonding with the coating material, as well as its sensitivity to temperature. The thermal expansion coefficient is greatly different from that of the commonly used infrared coating materials, which leads to stress in the film layer, resulting in the film layer being unstable and falling off. It is found that the more suitable coating temperature range for the chalcogenide glass substrate is between 90°C and 130°C. Within this temperature range, the coating material with the smallest difference in thermal expansion coefficient between the film material and the thermal expansion coefficient of the chalcogenide glass substrate is germanium, followed by zinc selenide, zinc sulfide, ytterbium fluoride, and yttrium fluoride. However, the materials with relatively good bonding effect with the chalcogenide glass substrate include germanium and oxide materials suitable for infrared coating according to the light transmission range, such as yttrium oxide and aluminum oxide. Sub / Ge / ZnSe / Ge / ZnSe / Ge / ZnSe / Ge / ZnS / YbF are designed according to the expansion coefficient between the materials and the bonding effect between the materials. 3 / Al 2 O 3 / AIR has a ten-layer film structure, and the outermost layer of the film structure adopts a combination of ytterbium fluoride and aluminum oxide to increase the moisture resistance and durability of the film structure. Therefore, the chalcogenide glass substrate and the film system on both sides designed according to the design method of the chalcogenide glass substrate mid- and long-wave infrared dual-band durable anti-reflection film disclosed in the present invention combine and expand, moisture resistance and durability between the chalcogenide glass substrate and the film structure (i.e., strength and environmental adaptability), and the chalcogenide glass substrate and the film system on both sides are designed to meet the requirements for the dual-band transmittance of 3.7-4.8μm mid-wave and 7.7-10.5μm long-wave.

[0025] In the design method of the mid- and long-wave infrared dual-band durable antireflection film on the chalcogenide glass substrate disclosed in the present invention, the film system on each surface is Sub / Ge / ZnSe / Ge / ZnSe / Ge / ZnSe / Ge / ZnS / YbF 3 / Al 2 O 3 / AIR, on the basis of this design method, the method for preparing a medium- and long-wave infrared dual-band durable anti-reflection film on a chalcogenide glass substrate according to the present disclosure as described later is further implemented, and the transmittance of the dual-bands of 3.7-4.8μm medium wave and 7.7-10.5μm long wave of the accompanying coating film in the prepared lens together with the coated film structure on both sides meets the requirements, and can pass a total of six tests including blister test, adhesion test, hot and cold shock test, salt spray test, wet heat test, and moderate friction test, that is, it meets the strength and environmental adaptability requirements and meets the acceptance of GJB2485A-2019.

[0026] For example, in step Sa, the chalcogenide glass substrate is VIG06.

[0027] In one example, in step Sb, for each of the two sides of the chalcogenide glass substrate, the optimal film thickness of the film layer is:

[0028] The thickness of the first Ge film is 118.35±3nm.

[0029] The thickness of the second ZnSe film is 145.89±3nm.

[0030] The thickness of the third Ge film is 240.08±3nm.

[0031] The thickness of the fourth ZnSe film is 138.21±3nm.

[0032] The thickness of the fifth Ge film is 303.46±3nm.

[0033] The thickness of the sixth ZnSe film is 122.29±3nm.

[0034] The thickness of the seventh Ge film is 163.05±3nm.

[0035] The thickness of the eighth ZnS film is 749.75±3nm.

[0036] Ninth floor YbF 3 The film thickness is 826.96±3nm,

[0037] Tenth layer Al 2 O 3 The film thickness is 35±3nm.

[0038] In step Sb, the average transmittance of the chalcogenide glass substrate at 3.7-4.8 μm medium wave reaches 99.7%, and the average transmittance at 7.7-10.5 μm long wave reaches 98.6%.

[0039] For example, in step Sa to step Sc, the design software is TFCalc or Essential Macleod.

[0040] [Preparation method of mid- and long-wave infrared dual-band durable antireflection film on chalcogenide glass substrate]

[0041] The method for preparing a mid- and long-wave infrared dual-band durable antireflection film on a chalcogenide glass substrate disclosed herein comprises the following steps:

[0042] S1, coating machine film system process parameter configuration and Ge, ZnSe, ZnS, YbF 3 and Al 2 O 3 Five kinds of film materials are prepared, and the film system process parameter configuration includes background vacuum degree, temperature, optimal film thickness, film material evaporation mode, film material deposition rate, and use of ion source assisted deposition. Among them, 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 in the design method of the long-wave infrared dual-band durable anti-reflection film on the chalcogenide glass substrate mentioned above, and the first Ge film is divided into the first Ge film base layer and the first Ge film connection layer (refer to Figure 2 ) and the first Ge film bottom layer is assisted by an ion source, while the first Ge film connecting layer is not assisted by an ion source;

[0043] S2, before plating, the accompanying plating sheet and products of the chalcogenide glass substrate used as the lens are cleaned;

[0044] S3, the cleaned lens is placed in a fixture, the fixture with the lens is hung in the cavity of the coating machine, vacuumed and slowly heated to bake;

[0045] S4, pre-melting of all film materials, degassing, impurity removal and constant temperature;

[0046] S5, ion source cleaning lens;

[0047] S6, 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 S1;

[0048] S7, constant temperature maintenance after plating;

[0049] S8, cooling and picking up;

[0050] S9, repeating steps S1 to S8 to perform film coating on the second surface of the lens.

[0051] In the method for preparing a medium- and long-wave infrared dual-band durable anti-reflection film on a chalcogenide glass substrate according to the present disclosure, through steps S1 to S9, the transmittance of the accompanying coating film (i.e., the chalcogenide glass substrate) in the prepared lens together with the coated film structure on both sides in the dual-bands of 3.7-4.8μm medium wave and 7.7-10.5μm long wave meets the requirements.

[0052] Similarly, the accompanying coating sheet in the prepared lens together with the coated film structure on both sides can pass a total of six tests including blister test, adhesion test, hot and cold shock test, salt spray test, wet heat test, and moderate friction test, that is, it meets the strength and environmental adaptability requirements and complies with the acceptance of GJB2485A-2019.

[0053] In the method for preparing a mid- and long-wave infrared dual-band durable anti-reflection film on a chalcogenide glass substrate according to the present disclosure, in step S1, the first Ge film is layered into a first Ge film primer layer and a first Ge film connecting layer. The first Ge film primer layer assisted by an ion source is densely, uniformly and firmly bonded to the chalcogenide glass substrate. Combined with the first Ge film connecting layer not assisted by an ion source, the strength of the film layer structure on each side of the chalcogenide glass substrate is enhanced and the transmittance of the dual bands of 3.7-4.8μm mid-wave and 7.7-10.5μm long-wave is maintained.

[0054] In one example, in step S1, the background vacuum degree is (6.0-8.0)×10 -4Pa; the temperature is set to heat from 25°C to 120°C, the temperature gradient time is controlled to be 35-40min, and the temperature is kept constant for 30min after reaching 120°C; the thickness of the film layer in the film system process parameters is based on the aforementioned optimal film layer thickness stored in the control computer of the coating machine and the aforementioned first Ge film thickness is modified to the first Ge film base layer thickness of 30±3nm and the first Ge film connecting layer thickness of 88.35±3nm, that is, for each of the two sides of the chalcogenide glass substrate, the optimal film layer thickness is: the first Ge film base layer The thickness of the first Ge film connecting layer is 30±3nm, the thickness of the second ZnSe film is 145.89±3nm, the thickness of the third Ge film is 240.08±3nm, the thickness of the fourth ZnSe film is 138.21±3nm, the thickness of the fifth Ge film is 303.46±3nm, the thickness of the sixth ZnSe film is 122.29±3nm, the thickness of the seventh Ge film is 163.05±3nm, the thickness of the eighth ZnS film is 749.75±3nm, the thickness of the ninth YbF film is 145.89±3nm, the thickness of the third ZnSe film is 145.89 ... third ZnSe film is 145.89±3nm, the thickness of the third ZnSe film is 145.89±3nm, the thickness of the third ZnSe film is 145.89±3nm, the thickness of the third ZnSe film is 145.89±3nm, the thickness of the third ZnSe film is 145.89±3nm, the thickness of the third ZnSe film is 145.89±3nm, the thickness of the third ZnSe film is 145.89±3nm, the thickness of the third ZnSe film is 145.89±3nm, 3 The thickness of the film is 826.96±3nm, and the tenth layer of Al 2 O 3 The film thickness is 35±3nm; the evaporation mode of the film material is: Ge film material and Al 2 O 3 The film materials were placed in crucibles and evaporated by electron beam heating. ZnSe film materials, ZnS film materials and YbF 3 The film materials were placed in molybdenum boats and evaporated using resistance heating; the deposition rate of the film materials was: the deposition rate of the Ge film was Al 2 O 3 The film deposition rate is The deposition rate of ZnSe film is Deposition rate of ZnS film Yb 3 The deposition rate of the film layer is set to The use of ion source assisted deposition is: the first layer of Ge film is the base layer, the ninth layer of YbF 3 Film and the tenth layer of Al 2 O 3 The film was deposited with ion source assistance, and the remaining layers were not deposited with ion source assistance. Using ion source assisted deposition can make the film more dense, so that the first layer of Ge film is firmly bonded to the chalcogenide glass substrate, and the ninth layer of YbF 3 Film and the tenth layer of Al 2 O 3The film improves moisture resistance and durability, and the remaining layers of the film are not deposited using ion source assisted deposition to ensure the quality and uniformity of the film structure. The above temperature setting (corresponding to the baking in step S3) can reduce the stress of the film structure and improve the adhesion of the film structure on the chalcogenide glass substrate.

[0055] Furthermore, in one example, the ion source is a Hall ion source, and the ion source parameters when coating the first layer of Ge film are: neutralization current 0.5A, neutralization gas flow rate 8sccm, anode voltage 150V, anode current 1.5A, and argon gas flow rate 100%; when coating the ninth layer of YbF 3 The ion source parameters during the film deposition were: neutralization current 0.5A, neutralization gas flow 8sccm, anode voltage 100V, anode current 1A, and argon gas flow 100%; the tenth layer of Al 2 O 3 The ion source parameters during membrane deposition were: neutralization current 0.5 A, neutralization gas flow rate 8 sccm, anode voltage 180 V, anode current 2 A, argon gas flow rate 20%, and oxygen flow rate 80%.

[0056] In step S1, for example, the coating machine is Cathay Pacific GTV-1350.

[0057] In step S2, for example, the cleaning is carried out by ultrasonic isopropyl alcohol cleaning or manual wiping, and the cleaned lens is placed in a fixture and the fixture with the lens placed is hung in the cavity of the coating machine within 30 minutes. If the time exceeds 30 minutes, it needs to be cleaned again. If it takes a long time to wait for coating, the lens is stored in a nitrogen cabinet or a vacuum chamber. For example, the thickness of the accompanying coating sheet is 1.0 mm.

[0058] The baking in step S3 heats the lens, fully eliminates the water vapor on the surface of the chalcogenide glass substrate, reduces the stress of the film structure, and improves the adhesion of the film structure on the chalcogenide glass substrate. In one example, in step S3, 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 S1.

[0059] The pre-melting of the film material in step S4 can release the gas in the film material and remove the impurities in the film material, ensuring 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 S6 described later. In one example, in step S4, when the vacuum reaches (4.0-8.0)×10 -3 Pa, the film material is pre-melted. After the film material is pre-melted, the temperature of the chamber of the coating machine reaches 120℃ and is kept constant for 30 minutes. The pre-melting treatment uses electron beam heating and resistance heating. The Ge film material and Al 2 O 3The film material is pre-melted by electron beam heating, ZnSe film material, ZnS film material and YbF 3 The film material is pre-melted using resistance heating.

[0060] The ion source cleaning in step S5 uses source ions to bombard and clean the microstructure of the lens surface, which can eliminate the surface oxide layer, make the surface cleaner, and facilitate the firm adhesion and growth of the film layer. Specifically, in one example, in step S5, when the vacuum degree of the coating machine reaches the background vacuum degree, the ion source of the vacuum coating machine is started. The ion source is a Hall ion source, and the parameters of the ion source are: neutralization current is 0.5A, neutralization gas flow rate is 8sccm, anode voltage is 150V, anode current is 1.5A, argon gas flow ratio is 100%, and cleaning time is 10min.

[0061] In step S6, for example, 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 new crystal oscillator of the multiple crystal oscillators to work accordingly, and the crystal oscillator frequency is not less than 5.7 MHz.

[0062] The post-plating constant temperature maintenance in step S7 is used to improve the quality, performance and stability of the film structure. In one example, in step S7, the chamber is kept at a constant temperature of 120° C. for 15 minutes after the plating is completed.

[0063] The cooling and taking out of the lens in step S8 prevents the lens taking out from being too high in temperature, which affects the quality and stability of the film layer. In one example, in step S8, after the constant temperature in step S7 is completed, the coating machine is closed for baking in a vacuum state, and the temperature of the cavity of the coating machine is naturally cooled to below 50°C or room temperature, and the door is opened for taking out the lens.

[0064] [test]

[0065] Example 1

[0066] Part I: Design method of durable antireflection film for mid- and long-wave infrared dual-band on chalcogenide glass substrate

[0067] The design method of the mid- and long-wave infrared dual-band durable antireflection film on a chalcogenide glass substrate of Example 1 adopts the following steps:

[0068] Sa, 6.5μm is selected as the reference wavelength for the design of 1 / 4 wavelength thickness of the optical film, and the film stack expression is used: Sub / 0.3H / 0.2M / 0.6H / 0.2M / 0.7H / 0.2M / 0.4H / W / 0.75L / 0.03Q / AIR. The same film system is plated on both sides of Sub.

[0069] Sub is the chalcogenide glass substrate VIG06, AIR represents air, H represents the high refractive index material Ge (germanium) with a thickness of 1 / 4 wavelength, and L represents the low refractive index material YbF with a thickness of 1 / 4 wavelength. 3 (Ytterbium fluoride), M represents the intermediate refractive index material ZnSe (zinc selenide) with a thickness of 1 / 4 wavelength, W represents the intermediate refractive index material ZnS (zinc sulfide) with a thickness of 1 / 4 wavelength, and Q represents the low refractive index material Al with a thickness of 1 / 4 wavelength. 2 O 3 (aluminium oxide);

[0070] Sb, Sub / Ge / ZnSe / Ge / ZnSe / Ge / ZnSe / Ge / ZnS / YbF generated by the input film stack formula through the design software 3 / Al 2 O 3 / AIR's ten-layer film structure is used to optimize the film thickness and obtain the best film thickness. The transmittance of the optimized chalcogenide glass substrate in the dual bands of 3.7-4.8μm medium wave and 7.7-10.5μm long wave meets the requirements.

[0071] In step Sb, for each of the two sides of the chalcogenide glass substrate, the optimal film thickness of the film layer is:

[0072] The thickness of the first Ge film is 118.35nm.

[0073] The thickness of the second ZnSe film is 145.89nm.

[0074] The thickness of the third Ge film is 240.08nm.

[0075] The thickness of the fourth ZnSe film is 138.21 nm.

[0076] The thickness of the fifth Ge film is 303.46nm.

[0077] The thickness of the sixth ZnSe film is 122.29 nm.

[0078] The thickness of the seventh Ge film is 163.05nm.

[0079] The thickness of the eighth ZnS film is 749.75nm.

[0080] Ninth floor YbF 3 The film thickness is 826.96nm.

[0081] Tenth layer Al 2 O 3 The film thickness of the membrane is 35 nm;

[0082] Sc, input the optimal film thickness into the control computer of the coating machine, the coating machine is Cathay Pacific GTV-1350;

[0083] In step Sa to step Sc, the design software is TFCalc.

[0084] Figure 3 The 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 mid- and long-wave infrared dual-band durable antireflection film of Example 1. Figure 3 The average transmittance of the chalcogenide glass substrate at 3.7-4.8μm medium waves reaches 99.7%, and the average transmittance at 7.7-10.5μm long waves reaches 98.6%.

[0085] Part II: Preparation method of mid- and long-wave infrared dual-band durable antireflection film on chalcogenide glass substrate

[0086] The method for preparing the mid-wave and long-wave infrared dual-band durable antireflection film on a chalcogenide glass substrate of Example 1 comprises the following steps:

[0087] S1, coating machine film system process parameter configuration and Ge, ZnSe, ZnS, YbF 3 and Al 2 O 3 Five kinds of film materials are prepared, and the film system process parameter configuration includes background vacuum degree, temperature, optimal film thickness of the film layer, film material evaporation mode, film material deposition rate, and use of ion source assisted deposition, wherein the film layer thickness in the film system process parameters is based on the optimal film layer thickness stored in the control computer of the coating machine in the design method of the mid- and long-wave infrared dual-band durable anti-reflection film on the chalcogenide glass substrate in the first part mentioned above, and the first Ge film is divided into a first Ge film base layer and a first Ge film connecting layer, and the first Ge film base layer is assisted by an ion source, while the first Ge film connecting layer is not assisted by an ion source,

[0088] in,

[0089] The coating machine is Cathay GTV-1350;

[0090] The background vacuum degree is 8.0×10 -4 Pa;

[0091] The temperature was set to heat from 25°C to 120°C, the temperature gradient time was controlled to be 40 min, and the temperature was kept constant for 30 min after reaching 120°C;

[0092] The thickness of the film layer in the film system process parameters is based on the optimal film thickness stored in the control computer of the coating machine in the design method of the long-wave infrared dual-band durable anti-reflection film on the chalcogenide glass substrate in the first part, and the film thickness of the first Ge film in the design method of the long-wave infrared dual-band durable anti-reflection film on the chalcogenide glass substrate in the first part is modified to the film thickness of the first Ge film base layer is 30nm and the film thickness of the first Ge film connecting layer is 88.35nm;

[0093] The evaporation mode of the film material is: Ge film material and Al 2 O 3 The film materials were placed in crucibles and evaporated by electron beam heating. ZnSe film materials, ZnS film materials and YbF 3 The film materials are placed in molybdenum boats and evaporated using resistance heating;

[0094] The deposition rate of the film material is: The deposition rate of the Ge film is Al 2 O 3 The film deposition rate is The deposition rate of ZnSe film is Deposition rate of ZnS film

[0095] Yb 3 The deposition rate of the film layer is set to

[0096] The use of ion source assisted deposition is: the first layer of Ge film is the base layer, the ninth layer of YbF 3 Film and the tenth layer of Al 2 O 3 The film was deposited with ion source assistance, and the remaining layers of the film were not deposited with ion source assistance. The ion source was a Hall ion source. The ion source parameters for the first Ge film were: neutralization current 0.5A, neutralization gas flow 8sccm, anode voltage 150V, anode current 1.5A, and argon gas flow 100%; the ninth layer of YbF was deposited with ion source assisted deposition. 3 The ion source parameters during the film deposition were: neutralization current 0.5A, neutralization gas flow 8sccm, anode voltage 100V, anode current 1A, and argon gas flow 100%; the tenth layer of Al 2 O 3 The ion source parameters during membrane formation were: neutralization current 0.5 A, neutralization gas flow rate 8 sccm, anode voltage 180 V, anode current 2 A, argon gas flow rate 20%, and oxygen flow rate 80%;

[0097] S2, before plating, the accompanying plating sheet and the product of the chalcogenide glass substrate of the lens are cleaned, wherein the cleaning is carried out by ultrasonic isopropyl alcohol cleaning, the cleaned lens is placed in a fixture, and the fixture with the lens placed is hung in the cavity of the coating machine within 30 minutes, and the thickness of the accompanying plating sheet is 1.0 mm;

[0098] S3, the cleaned lens is placed in a fixture, the fixture with the lens is hung in the cavity of the coating machine, and vacuum is slowly heated and baked. The vacuum is slowly heated and baked as follows: 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 S1;

[0099] S4, when the vacuum reaches 6.0×10 -3 Pa, all the film materials are pre-melted to release gas and remove impurities. The pre-melting treatment adopts two methods: electron beam heating and resistance heating. 2 O 3 The film material is pre-melted by electron beam heating, ZnSe film material, ZnS film material and YbF 3 The film material is pre-melted by resistance heating. After the pre-melting of the film material is completed, the temperature of the cavity of the coating machine reaches 120℃ and the constant temperature is maintained for 30 minutes;

[0100] S5, when the vacuum degree of the coating machine reaches the background vacuum degree, start the ion source of the vacuum coating machine to clean the lens. The ion source is a Hall ion source. The parameters of the ion source are: neutralization current is 0.5A, neutralization gas flow rate is 8sccm, anode voltage is 150V, anode current is 1.5A, argon gas flow rate ratio is 100%, and cleaning time is 10min;

[0101] S6, film coating and monitoring, coating the first surface of the lens with a film according to the film system parameter process configuration of step S1, using the crystal oscillator method 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 of the multiple crystal oscillators, and the crystal oscillator frequency is not less than 5.7MHz;

[0102] S7, after plating is completed, the chamber is kept at a constant temperature of 120°C for 15 minutes;

[0103] S8, after the constant temperature in step S7 is completed, the coating machine is closed for baking in a vacuum state, the temperature of the cavity of the coating machine is naturally cooled to below 50° C. or to room temperature, and the door is opened to take out the parts;

[0104] S9, repeating steps S1 to S8 to perform film coating on the second surface of the lens.

[0105] Comparative Example 1

[0106] Except that in step S1 in the second part, the first Ge film is not divided into the first Ge film base layer and the first Ge film connecting layer (ie, the first Ge film is a single layer) and the entire first Ge film is not deposited using an ion source assisted deposition, the rest is the same as in Example 1.

[0107] Comparative Example 2

[0108] Except for the tenth layer Al in step S1 in the second part 2 O 3 Film omitted (i.e. the tenth layer of Al 2 O 3 Except that the film plating is not performed, the rest is the same as Example 1.

[0109] Comparative Example 3

[0110] Except for the tenth layer Al in step S1 in the second part 2 O 3 Membrane replaced by Y 2 O 3 Except for the membrane (i.e., only the material is replaced), the rest is the same as in Example 1.

[0111] Comparative Example 4

[0112] Except that the temperature in step S1 in the second part is set to be heated from 25° C. to 120° C. and the temperature ramp time is controlled to be 15 min, the rest is the same as in Example 1.

[0113] Comparative Example 5

[0114] Except for the ninth layer YbF in step S1 in the second part 3 Membrane replaced by YF 3 Except for the membrane (i.e., only the material is replaced), the rest is the same as in Example 1.

[0115] Figure 4 The transmittance curve of the accompanying plate of Example 1 and the film structure plated on both sides in the mid- and long-wave infrared dual bands of 3.7-4.8 μm and 7.7-10.5 μm is shown. Figure 4 The average transmittance of the accompanying plated sheet together with the film layer structure plated on both sides reaches 98.3% at the medium wave 3.7-4.8μm and the average transmittance at the long wave 7.7-10.5μm reaches 96.1%.

[0116] The following tests were performed on Example 1 and Comparative Examples 1-5 after coating on both sides.

[0117] Water bubble test: Take an appropriate amount of 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 cracks.

[0118] 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 (pulling frequency is not less than 10 times) to observe whether the film layer is pulled up.

[0119] Thermal shock test: In a high and low temperature box, perform thermal shock test in the range of -46℃ to 71℃ for 24 hours to observe whether the film layers on each side of the accompanying plating sheet fall off or crack.

[0120] 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.

[0121] Wet heat test: temperature 50 ℃, relative humidity 95% test for 48h, 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.

[0122] Moderate friction test: Use a friction test tool with a pressure of 4.9N and a rubber friction head wrapped with a degreased cloth to rub the film surface of the accompanying plated sheet 50 times (25 back and forth) to observe whether there are scratches and signs of damage on the film surface.

[0123] Table 1 shows the transmittance of Example 1 and Comparative Examples 1-5 and the results of various tests.

[0124] Table 1 Transmittance of Example 1 and Comparative Examples 1-5 and results of various tests

[0125]

[0126]

[0127] By comparing Example 1 and Comparative Example 1, it can be seen that Example 1 and Comparative Example 1 have the same average transmittance in the two bands. Comparative Example 1 does not perform layered ion source priming on the first layer of Ge film. During the adhesion test, the film layer on the accompanying coating sheet is pulled up, which indicates that the first layer of Ge film in Example 1 is layered so that the first layer of Ge film is primed with the bottom layer ion source, which can improve the adhesion between the film layer structure on each surface of the chalcogenide glass substrate and the chalcogenide glass substrate.

[0128] By comparing Example 1 with Comparative Example 2, it can be seen that Comparative Example 2 does not use Al 2 O 3 As plated YbF 3 The outermost moisture-proof protective layer behind the film, YbF 3 The film is directly used as the outermost layer. The average transmittance in the long-wave 7.7-10μm band is slightly improved, but the medium friction resistance test effect is poor. In the wet heat test, YbF 3 The membrane easily absorbs moisture, resulting in unstable membrane structure.

[0129] By comparing Example 1 with Comparative Example 3, it can be seen that in Comparative Example 3, the tenth layer of Al 2 O 3 Membrane replaced by Y 2 O 3 The average pass rate of the two bands is slightly improved, but from the moderate friction test, it can be seen that Al 2 O 3 Material relative Y 2 O 3 The material makes the membrane structure more durable.

[0130] By comparing Example 1 and Comparative Example 4, it can be seen that the average transmittance of Example 1 and Comparative Example 4 in the two bands is the same, and the chalcogenide glass substrate is more sensitive to temperature control, especially in the heating and baking stage. Too fast heating will cause excessive stress on the lens surface, which will directly affect the adhesion of the film structure. In the adhesion test, the film layer of Comparative Example 4 was pulled up.

[0131] By comparing Example 1 with Comparative Example 5, it can be seen that in Comparative Example 5, the ninth layer of YbF 3 Membrane replaced by YF 3 The average transmittance of the two bands of the film was slightly reduced, but the film layer of Comparative Example 5 was detached and cracked in the wet heat test.

[0132] 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 mid- and long-wave infrared dual-band durable antireflection film on a chalcogenide glass substrate, characterized in that: Includes steps: Sa, 6.5μm is selected as the reference wavelength for the design of 1 / 4 wavelength thickness of the optical film, and the film stack expression is used: Sub / 0.3H / 0.2M / 0.6H / 0.2M / 0.7H / 0.2M / 0.4H / W / 0.75L / 0.03Q / AIR. The same film system is plated on both sides of Sub. Wherein, Sub is a chalcogenide glass substrate, AIR represents air, H represents a high refractive index material Ge (germanium) with a thickness of 1 / 4 wavelength, L represents a low refractive index material YbF3 (ytterbium fluoride) with a thickness of 1 / 4 wavelength, M represents an intermediate refractive index material ZnSe (zinc selenide) with a thickness of 1 / 4 wavelength, W represents an intermediate refractive index material ZnS (zinc sulfide) with a thickness of 1 / 4 wavelength, and Q represents a low refractive index material Al2O3 (aluminum oxide) with a thickness of 1 / 4 wavelength; Sb, the film thickness of the ten-layer film structure of Sub / Ge / ZnSe / Ge / ZnSe / Ge / ZnSe / Ge / ZnS / YbF3 / Al2O3 / AIR generated by the input film stack formula was optimized by design software to obtain the optimal film thickness. The transmittance of the optimized chalcogenide glass substrate in the dual bands of 3.7-4.8μm medium wave and 7.7-10.5μm long wave met the requirements; Sc, input the optimal film thickness into the control computer of the coating machine.

2. The design method of the mid-wave and long-wave infrared dual-band durable antireflection film on a chalcogenide glass substrate according to claim 1, characterized in that: In step Sb, for each of the two sides of the chalcogenide glass substrate, the optimal film thickness of the film layer is: The thickness of the first Ge film is 118.35±3nm. The thickness of the second ZnSe film is 145.89±3nm. The thickness of the third Ge film is 240.08±3nm. The thickness of the fourth ZnSe film is 138.21±3nm. The thickness of the fifth Ge film is 303.46±3nm. The thickness of the sixth ZnSe film is 122.29±3nm. The thickness of the seventh Ge film is 163.05±3nm. The thickness of the eighth ZnS film is 749.75±3nm. The thickness of the ninth layer of YbF3 film is 826.96±3nm. The thickness of the tenth Al2O3 film is 35±3nm. In step Sb, the average transmittance of the chalcogenide glass substrate at 3.7-4.8 μm medium wave reaches 99.7%, and the average transmittance at 7.7-10.5 μm long wave reaches 98.6%.

3. The design method of the mid-wave and long-wave infrared dual-band durable antireflection film on a chalcogenide glass substrate according to claim 1, characterized in that: In step Sa, the chalcogenide glass substrate is VIG06; and / or In step Sa to step Sc, the design software is TFCalc or EssentialMacleod.

4. A method for preparing a mid-wave and long-wave infrared dual-band durable antireflection film on a chalcogenide glass substrate, characterized in that: Includes steps: S1, configuration of film system process parameters of the coating machine and preparation of five kinds of film materials, namely Ge, ZnSe, ZnS, YbF3 and Al2O3, wherein the configuration of film system process parameters includes background vacuum degree, 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, wherein 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 1-3, and the first Ge film layer is divided into a first Ge film base layer and a first Ge film connection layer, and the first Ge film base layer uses ion source assistance while the first Ge film connection layer does not use ion source assistance; S2, before plating, the accompanying plating sheet and products of the chalcogenide glass substrate used as the lens are cleaned; S3, the cleaned lens is placed in a fixture, the fixture with the lens is hung in the cavity of the coating machine, and the vacuum is drawn and the temperature is slowly increased for baking; S4, pre-melting of all film materials, degassing, impurity removal and constant temperature; S5, ion source cleaning lens; S6, 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 S1; S7, constant temperature maintenance after plating; S8, cooling and picking up; S9, repeating steps S1 to S8 to perform film coating on the second surface of the lens.

5. The method for preparing a mid-wave and long-wave infrared dual-band durable antireflection film on a chalcogenide glass substrate according to claim 4, characterized in that: In step S1, The background vacuum degree is (6.0-8.0)×10 -4 Pa; The temperature is set to heat from 25°C to 120°C, the temperature gradient time is controlled to be 35-40min, and the temperature is kept constant for 30min after reaching 120°C; 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, and the film thickness of the first Ge film in claim 2 is modified to the film thickness of the first Ge film base layer being 30±3nm and the film thickness of the first Ge film connection layer being 88.35±3nm; The evaporation mode of the film materials is as follows: Ge film materials and Al2O3 film materials are placed in crucibles and evaporated by electron beam heating, while ZnSe film materials, ZnS film materials and YbF3 film materials are placed in molybdenum boats and evaporated by resistance heating. The deposition rate of the film material is: The deposition rate of the Ge film is The deposition rate of Al2O3 film is The deposition rate of ZnSe film is Deposition rate of ZnS film The deposition rate of the YbF3 film was set to The use of ion source assisted deposition is as follows: the first Ge film as the base layer, the ninth YbF3 film and the tenth Al2O3 film are deposited with ion source assistance, and the remaining film layers are not deposited with ion source assistance.

6. The method for preparing a mid-wave and long-wave infrared dual-band durable antireflection film on a chalcogenide glass substrate according to claim 5, characterized in that: The ion source is a Hall ion source. The ion source parameters when depositing the first layer of Ge film as the base layer are: neutralization current 0.5A, neutralization gas flow rate 8sccm, anode voltage 150V, anode current 1.5A, and argon gas flow rate 100%; The ion source parameters when depositing the ninth layer of YbF3 film are: neutralization current 0.5A, neutralization gas flow rate 8sccm, anode voltage 100V, anode current 1A, and argon gas flow rate 100%; The ion source parameters when depositing the tenth layer of Al2O3 film are: neutralization current 0.5A, neutralization gas flow rate 8sccm, anode voltage 180V, anode current 2A, argon gas flow rate 20%, and oxygen flow rate 80%.

7. The method for preparing the mid-wave and long-wave infrared dual-band durable antireflection film on a chalcogenide glass substrate according to claim 4, In step S1, the coating machine is Cathay Pacific GTV-1350; and / or In step S2, the cleaning is carried out by ultrasonic isopropyl alcohol cleaning or manual wiping. The cleaned lens is placed in a fixture and the fixture with the lens placed is hung in the cavity of the coating machine within 30 minutes. If the time exceeds 30 minutes, it needs to be cleaned again. If it takes a long time to wait for coating, the lens is stored in a nitrogen cabinet or a vacuum chamber; and / or The thickness of the accompanying plating sheet is 1.0 mm.

8. The method for preparing a mid-wave and long-wave infrared dual-band durable antireflection film on a chalcogenide glass substrate according to claim 5, 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 S1.

9. The method for preparing a mid-wave and long-wave infrared dual-band durable antireflection film on a chalcogenide glass substrate according to claim 8, characterized in that: In step S4, When the vacuum reaches (4.0-8.0)×10 -3 The film material is pre-melted at Pa. After the pre-melting of the film material is completed, the temperature of the cavity of the coating machine reaches 120℃ and is kept constant for 30 minutes. The pre-melting treatment adopts two methods: electron beam heating and resistance heating. Ge film and Al2O3 film are pre-melted by electron beam heating, and ZnSe film, ZnS film and YbF3 film are pre-melted by resistance heating.

10. The method for preparing a mid-wave and long-wave infrared dual-band durable antireflection film on a chalcogenide glass substrate according to claim 4, characterized in that: In step S5, when the vacuum degree of the coating machine reaches the background vacuum degree, the ion source of the vacuum coating machine is started, the ion source is a Hall ion source, and the parameters of the ion source are: neutralization current is 0.5A, neutralization gas flow rate is 8sccm, anode voltage is 150V, anode current is 1.5A, argon gas flow rate ratio is 100%, and cleaning time is 10min; and / or In step S6, 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. 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 5.7 MHz; and / or In step S7, after the plating is completed, the cavity is kept at a constant temperature of 120° C. for 15 minutes; and / or In step S8, after the constant temperature in step S7 is completed, the coating machine is closed for baking in a vacuum state, the temperature of the cavity of the coating machine is naturally cooled to below 50°C or room temperature, and the door is opened to take out the parts.

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