Preparation method of zinc selenide 900-1700nm reflecting film system
By depositing YbF3, ZnSe, ZnS and Y2O3 films on zinc selenide lenses, the problem of high reflectivity of zinc selenide lenses was solved, and the reflectivity was significantly reduced, thereby improving laser energy utilization and ranging accuracy.
Patent Information
- Application Number
- CN202511768664.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-28
- Publication Date
- 2026-02-24
AI Technical Summary
In existing technologies, zinc selenide lenses have high reflectivity in the 900-1700nm wavelength range, which affects laser energy utilization and ranging accuracy, and further reduction of reflectivity is needed.
An eleven-layer film system consisting of four materials—YbF3, ZnSe, ZnS, and Y2O3—was deposited on a zinc selenide substrate using vacuum deposition technology. By employing resistance heating and electron beam heating evaporation methods, combined with Hall ion source cleaning and temperature control, a double-sided antireflection film system was prepared to reduce reflectivity.
Within the test angle range of 0°-45°, the reflectivity is reduced to 1.2%-2.6%, improving laser energy utilization and ranging accuracy.
Smart Images
Figure CN121555952A_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to the field of optical coating, and more specifically to a method for preparing a zinc selenide 900-1700nm reflective film system. Background Technology
[0002] Zinc selenide (ZnSe), an important infrared optical material, falls within the short-wave infrared (SWIR) band (900-1700nm). Light in this band can penetrate smoke and haze, and can identify camouflage and distinguish different materials (such as vegetation, metals, and liquids), making it widely used in security monitoring, border patrol, and aerial remote sensing. ZnSe can also be used as an optical lens in laser transmitters / receivers (such as beam expanders and receiving lenses). Its low reflectivity reduces laser reflection loss on the lens surface, improving laser energy utilization (transmitter) and echo signal reception efficiency (receiver), thereby enhancing ranging accuracy and detection range. Therefore, further development of its reflectivity is needed. Summary of the Invention
[0003] In view of the problems existing in the background art, one object of this disclosure is to provide a method for preparing a zinc selenide 900-1700nm reflective film system, wherein the prepared zinc selenide substrate together with the film system on both sides can reduce the reflectivity in the 900-1700nm band at a test angle of 0°-45°.
[0004] Therefore, a method for preparing a zinc selenide 900-1700nm reflective film system includes the following steps: S0, cleaning the surfaces of the substrate and the product, wherein the substrate and the product serve as lenses and are both zinc selenide substrates, the substrate being a circular sheet of equal thickness and a wedge-shaped sheet with a polished surface on the first side and a rough surface on the second side; S1, placing the cleaned lenses into an oven, setting the oven temperature to 150℃, and baking for 2 hours; S2, loading the baked lenses into a fixture, and hanging the fixture with the lenses into the cavity of a vacuum coating machine, setting the cavity temperature to 150℃; S3, starting the vacuum coating machine and drawing a vacuum, achieving a vacuum degree of 1.5×10⁻⁶. -3Pa, turn on the Hall ion source of the vacuum coating machine for cleaning. The cleaning time is 6 minutes. The parameters of the Hall ion source are: anode voltage of 220V, anode current of 1.2A, neutralization current of 1.5A, neutralization gas flow rate of 10sccm, and argon flow rate of 100%. S4, on the first surface of the lens, apply an eleven-layer film system consisting of four materials: YbF3, ZnSe, ZnS, and Y2O3. Sub / 75nmYbF3 / The following film layers were sequentially deposited: 43.6nm ZnSe / 212.29nm YbF3 / 35.23nm ZnSe / 92.65nm YbF3 / 305.33nm ZnSe / 33.23nm YbF3 / 335.35nm ZnS / 136.98nm YbF3 / 10nm ZnS / 20nm Y2O3 / Air. Substrate was zinc selenide, Air was air, and YbF3 and ZnSe were also deposited. The numbers preceding ZnS and Y2O3 in nm indicate the film thickness of the corresponding layer. The YbF3, ZnSe, and ZnS layers are deposited using resistance heating evaporation, while the Y2O3 layer is deposited using electron beam heating evaporation. The deposition rate of the YbF3 layer is 0.5 nm / s, the ZnSe layer is 0.6 nm / s, the ZnS layer is 0.4 nm / s, and the Y2O3 layer is 0.3 nm / s. All layers are deposited using ion source-assisted deposition, and deposition is completed at a chamber temperature of 150°C. S5: After the film system is deposited on the first surface of the lens, the chamber is naturally cooled to below 85°C, and the fixture and lens are removed. S6: Repeat steps S0 to S5 to deposit the same film system on the second surface of the lens. The wedge is not cleaned when repeating step S0, not baked when repeating step S1, and not placed in the fixture when repeating step S2.
[0005] The beneficial effects of this disclosure are as follows: In the method for preparing a zinc selenide 900-1700nm reflective film system according to this disclosure, through step S4 (which is repeated in steps S4 and S6), an eleven-layer film system composed of four types of film materials—YbF3, ZnSe, ZnS, and Y2O3—is deposited on both sides of the lens (the two-sided film system constitutes an antireflective film system). This is combined with the surface cleaning of step S0 (which is repeated in steps S0 and S6), the baking of step S1 (which is repeated in steps S1 and S6), the cavity temperature of step S2 (which is repeated in steps S2 and S6), and the pressing of step S3 and S6. The repeated ion source cleaning in step S3 and the cooling in step S5 and step S6, as verified by the test process described later, show that the average reflectance of the wedge-shaped sheet in the substrate, together with the film system on the corresponding first side, is less than 1.2% (specifically 1.19%) at an 8° test angle in the 900-1700nm wavelength band, and less than 2.6% (specifically 2.59%) at a 45° test angle in the 900-1700nm wavelength band. That is, the prepared zinc selenide substrate, together with the film system on both sides, can reduce the reflectance in the 0°-45° test angle in the 900-1700nm wavelength band. Attached Figure Description
[0006] Figure 1 This is a schematic structural diagram of a zinc selenide substrate and the film system on both sides prepared according to the zinc selenide 900-1700nm reflective film system preparation method disclosed herein.
[0007] Figure 2 It is a photograph of the wedge-shaped piece in the plating sheet.
[0008] Figure 3 It is a graph showing the reflectance of the wedge-shaped sheet and the corresponding film system on the first surface in the substrate of Example 1 at an 8° test angle in the 900-1700nm wavelength band.
[0009] Figure 4 It is a graph showing the reflectance of the wedge-shaped sheet and the corresponding film system on the first surface in the substrate of Example 1 at a test angle of 45° in the 900-1700nm wavelength band. Detailed Implementation
[0010] It will be understood that the disclosed embodiments are merely examples of this disclosure, which can be implemented in various forms. Therefore, the specific details disclosed herein should not be construed as limiting, but are intended only as the basis for the claims and as an illustrative basis to teach those skilled in the art how to implement this disclosure in various ways.
[0011] [Preparation method of zinc selenide 900-1700nm reflective film system]
[0012] Reference Figure 1 and Figure 2The method for preparing the zinc selenide 900-1700nm reflective film system according to this disclosure includes the following steps:
[0013] S0, the surfaces of the coating sheet and the product are cleaned. The coating sheet and the product are lenses and both are zinc selenide substrates. The coating sheet is a round sheet of equal thickness and a wedge-shaped sheet with a polished flat surface on the first side and a rough surface on the second side.
[0014] S1. Place the cleaned lenses into the oven, set the oven temperature to 150℃, and bake for 2 hours.
[0015] S2, load the baked lens into the tooling fixture, hang the tooling fixture with the lens loaded into the vacuum coating machine cavity, and set the temperature of the cavity to 150℃.
[0016] S3, the vacuum coating machine starts vacuuming, and the vacuum level reaches 1.5×10⁻⁶. -3 Pa, turn on the Hall ion source of the vacuum coating machine for cleaning. The cleaning time is 6 minutes. The parameters of the Hall ion source are: anode voltage of 220V, anode current of 1.2A, neutralization current of 1.5A, neutralization gas flow rate of 10sccm, and argon flow rate of 100%.
[0017] S4, on the first surface of the lens, consists of an eleven-layer film system composed of four types of film materials: YbF3, ZnSe, ZnS, and Y2O3.
[0018] Sub / 75nm YbF3 / 43.6nm ZnSe / 212.29nm YbF3 / 35.23nm ZnSe / 92.65nm YbF3 / 305.33nm ZnSe / 33.23nm YbF3 / 335.35nm ZnS / 136.98nm YbF3 / 10nm ZnS / 20nm Y2O3 / Air, each film layer was deposited sequentially.
[0019] Wherein, Sub represents the zinc selenide substrate, Air represents air, and the nm numbers preceding YbF3, ZnSe, ZnS, and Y2O3 indicate the film thickness of the corresponding layer. The YbF3, ZnSe, and ZnS layers were deposited using resistance heating evaporation, while the Y2O3 layer was deposited using electron beam heating evaporation. The deposition rate of the YbF3 layer was 0.5 nm / s, the ZnSe layer was 0.6 nm / s, the ZnS layer was 0.4 nm / s, and the Y2O3 layer was 0.3 nm / s. All layers were deposited using ion source-assisted deposition, and the deposition of each layer was completed at a chamber temperature of 150°C.
[0020] S5. After the coating system is applied to the first surface of the lens, the cavity is naturally cooled to below 85°C, and the tooling fixture is removed along with the lens.
[0021] S6, repeat steps S0 to S5 to deposit the same film system on the second side of the lens, wherein the wedge is not cleaned when repeating step S0, not baked when repeating step S1, and not placed in the tooling fixture when repeating step S2.
[0022] In the method for preparing a zinc selenide 900-1700nm reflective film system according to this disclosure, step S4, which is repeated in steps S4 and S6, involves depositing an eleven-layer film system (comprising four films of YbF3, ZnSe, ZnS, and Y2O3 on both sides of the lens) using the same materials on both sides. This is combined with the surface cleaning in step S0, which is repeated in steps S1 and S6; the baking in step S1, which is repeated in steps S1 and S6; the cavity temperature in step S2, which is repeated in steps S2 and S6; and the separation in step S3, which is repeated in steps S3 and S6. As verified in Example 1 of the test process described later, the cooling of step S5, which involves cleaning the source and repeating steps S5 and S6, resulted in an average reflectance of less than 1.2% (specifically 1.19%) for the wedge-shaped sheet in the substrate along with the corresponding film system on the first side at an 8° test angle in the 900-1700nm wavelength range, and an average reflectance of less than 2.6% (specifically 2.59%) at a 45° test angle in the 900-1700nm wavelength range. That is, the prepared zinc selenide substrate along with the film system on both sides can reduce the reflectance in the 900-1700nm wavelength range at a 0°-45° test angle.
[0023] Repeating steps S0 and S6, the surface cleaning in step S0 helps improve the surface condition of each surface of the lens and improves the adhesion between the coating system on each surface and the corresponding surface of the lens. For example, in step S0, the surface of the lens is cleaned using ultrasound or by hand. Further, for example, in step S0, the surface cleaning of the lens using ultrasound involves polishing with an alumina polishing slurry followed by ultrasonic rinsing with pure water. For example, the alumina polishing slurry used is a 0.1μm polycrystalline diamond slurry from Nanjing Hengrui Precision Optics Co., Ltd.
[0024] In step S0, for example, the product is a lens or a flat sheet.
[0025] In step S0, for example, the thickness of the disc in the plating sheet is 2 mm.
[0026] The baking process in step S1 helps to remove stress from the lens.
[0027] The temperature setting of the vacuum coating machine in step S2 heats the lens through the cavity of the coating machine, which helps the film to grow from the lens and reduces the stress of film growth.
[0028] Step S3 uses a Hall ion source for cleaning, which removes impurities and oil molecules adsorbed on the surface of each surface of the lens, significantly improving the interface state and enhancing the adhesion between the film and the corresponding surfaces of the lens. Simultaneously, cleaning with a Hall ion source heats the corresponding surfaces of the lens, aiding in film growth and reducing growth stress. For example, the vacuum coating machine is a Hall ion source with a neutralizer manufactured and sold by Chengdu Xiwoke Vacuum Technology Co., Ltd., and the Hall ion source with the neutralizer was purchased from Boton Optoelectronics Technology Co., Ltd.
[0029] In step S4, in one example, a Hall ion source is used. When depositing the YbF3 film, the ion source parameters are: neutralization current of 0.6A, neutralization gas flow rate of 8sccm, anode voltage of 130V, anode current of 1.3A, argon flow rate ratio of 30%, and oxygen flow rate ratio of 70%. When depositing the ZnSe and ZnS films, the ion source parameters are: neutralization current of 0.5A, neutralization gas flow rate of 8sccm, anode voltage of 90V, anode current of 1.0A, and argon flow rate ratio of 100%. When depositing the Y2O3 film, the ion source parameters are: neutralization current of 0.5A, neutralization gas flow rate of 8sccm, anode voltage of 100V, anode current of 1.2A, and argon flow rate ratio of 100%.
[0030] In step S4, in one example, argon gas is introduced and a vacuum is drawn during the deposition of each film layer to maintain a flow-through constant vacuum. The flow-through constant vacuum setting is not lower than 5.0 × 10⁻⁶. -3 Pa; The crystal oscillator method is used to monitor the film thickness by using the corresponding crystal oscillators of multiple crystal oscillators in the crystal controller. After cleaning with the ion source, the crystal controller controls the new crystal oscillator in the multiple crystal oscillators to work accordingly. The crystal oscillator frequency is not less than 5.99MHz.
[0031] In one example, after step S6, the wedge-shaped sheet in the substrate, together with the film system on the corresponding first side, has an average reflectance of less than 1.2% in the 900-1700nm band at an 8° test angle and an average reflectance of less than 2.6% in the 900-1700nm band at a 45° test angle. After step S6, the circular sheet in the substrate, together with the film systems on both sides, passes the water immersion test, salt spray test, adhesion test, thermal shock test, constant temperature and humidity test, abrasion resistance test, low temperature test, and high temperature test.
[0032] [test]
[0033] Example 1
[0034] Example 1 uses the following steps:
[0035] S0, the surfaces of the substrate and the product are cleaned. The substrate and the product are lenses and both are zinc selenide substrates. The substrate is a circular piece of equal thickness and a wedge-shaped piece with a polished surface on the first side and a rough surface on the second side. The thickness of the circular piece in the substrate is 2mm. The product is a lens. The surface of the lens is cleaned by ultrasonic cleaning. The ultrasonic cleaning of the lens surface is performed by polishing with alumina polishing fluid and then ultrasonic cleaning with pure water. The alumina polishing fluid is 0.1μm polycrystalline diamond fluid from Nanjing Hengrui Precision Optics Co., Ltd.
[0036] S1. Place the cleaned lenses into the oven, set the oven temperature to 150℃, and bake for 2 hours.
[0037] S2, load the baked lens into the tooling fixture, hang the tooling fixture with the lens loaded into the vacuum coating machine cavity, and set the temperature of the cavity to 150℃. The vacuum coating machine is a vacuum coating machine with a Hall ion source equipped with a neutralizer manufactured and sold by Chengdu Xiwoke Vacuum Technology Co., Ltd. The Hall ion source equipped with a neutralizer was purchased from Boton Optoelectronics Technology Co., Ltd.
[0038] S3, the vacuum coating machine starts vacuuming, and the vacuum level reaches 1.5×10⁻⁶. -3 Pa, turn on the Hall ion source of the vacuum coating machine for cleaning. The cleaning time is 6 minutes. The parameters of the Hall ion source are: anode voltage of 220V, anode current of 1.2A, neutralization current of 1.5A, neutralization gas flow rate of 10sccm, and argon flow rate of 100%.
[0039] S4, on the first surface of the lens, consists of an eleven-layer film system composed of four types of film materials: YbF3, ZnSe, ZnS, and Y2O3.
[0040] Sub / 75nm YbF3 / 43.6nm ZnSe / 212.29nm YbF3 / 35.23nm ZnSe / 92.65nm YbF3 / 305.33nm ZnSe / 33.23nm YbF3 / 335.35nm ZnS / 136.98nm YbF3 / 10nm ZnS / 20nm Y2O3 / Air, each film layer was deposited sequentially.
[0041] Wherein, Sub represents the zinc selenide substrate, Air represents air, and the nm numbers preceding YbF3, ZnSe, ZnS, and Y2O3 indicate the film thickness of the corresponding layer. The YbF3, ZnSe, and ZnS layers were deposited using resistance heating evaporation, while the Y2O3 layer was deposited using electron beam heating evaporation. The deposition rate of the YbF3 layer was 0.5 nm / s, the ZnSe layer was 0.6 nm / s, the ZnS layer was 0.4 nm / s, and the Y2O3 layer was 0.3 nm / s. All layers were deposited using ion source-assisted deposition, and the deposition of each layer was completed at a chamber temperature of 150°C.
[0042] S5. After the coating system is applied to the first surface of the lens, the cavity is naturally cooled to 85°C, and the tooling fixture is taken out along with the lens.
[0043] S6. Repeat steps S0 to S5 to deposit the same film system on the second side of the lens. The wedge is not cleaned when repeating step S0, not baked when repeating step S1, and not placed in the tooling fixture when repeating step S2.
[0044] In step S4,
[0045] The ion source used is a Hall ion source.
[0046] When depositing the YbF3 film, the ion source parameters are as follows: neutralization current is 0.6A, neutralization gas flow rate is 8sccm, anode voltage is 130V, anode current is 1.3A, argon flow rate accounts for 30%, and oxygen flow rate accounts for 70%.
[0047] When depositing ZnSe and ZnS films, the ion source parameters are as follows: neutralization current is 0.5A, neutralization gas flow rate is 8sccm, anode voltage is 90V, anode current is 1.0A, and argon flow rate is 100%.
[0048] When depositing the Y2O3 film, the ion source parameters are: neutralization current of 0.5A, neutralization gas flow rate of 8sccm, anode voltage of 100V, anode current of 1.2A, and argon flow rate of 100%.
[0049] Argon gas is introduced and a vacuum is drawn during the deposition of each film layer to maintain a constant vacuum in the flow path. The constant vacuum in the flow path is set to be no less than 5.0 × 10⁻⁶. -3 Pa;
[0050] The crystal oscillator method is used to monitor the film thickness by using the corresponding crystal oscillators of multiple crystal oscillators in the crystal controller. After cleaning with the ion source, the crystal controller controls the new crystal oscillator in the multiple crystal oscillators to work accordingly, and the crystal oscillator frequency is not less than 5.99MHz.
[0051] Figure 3It is a graph showing the reflectance of the wedge-shaped sheet and the corresponding film system on the first surface in the substrate of Example 1 at an 8° test angle in the 900-1700nm wavelength band. Figure 4 This is a graph showing the reflectance of the wedge-shaped sheet and the corresponding film system on the first surface in the substrate of Example 1 at a 45° test angle in the 900-1700nm wavelength range. Figure 3 and Figure 4 As shown, the wedge-shaped sheet in the substrate, together with the corresponding film system on the first surface, has an average reflectance of 1.19% (less than 1.2%) at an 8° test angle in the 900-1700nm wavelength band, and an average reflectance of 2.59% (less than 2.6%) at a 45° test angle in the 900-1700nm wavelength band.
[0052] The following tests were performed on the discs in Example 1 after coating both sides.
[0053] Water immersion test: Take tap water and conduct a water immersion test for 2 hours. Observe whether the film layer on each surface of the disc in the immersion sheet falls off from the disc in the immersion sheet, and observe whether the film layer on each surface of the disc in the immersion sheet cracks.
[0054] Salt spray test: Neutral salt spray test for 48 hours, observe whether the film layer on each surface of the disc in the surcharged sheet peels off, and observe whether the film layer on each surface of the disc in the surcharged sheet cracks.
[0055] Adhesion test: Apply 3M tape to each side of the disc in the coating sheet by hand, and pull the tape in the opposite direction to the adhesive end to observe whether the film layer is pulled up.
[0056] Thermal shock test: The film is subjected to thermal shock in the range of -40℃ to 85℃ for 24 hours in a high and low temperature chamber. Observe whether the film layer on each surface of the disc in the substrate peels off and whether the film layer on each surface of the disc in the substrate cracks.
[0057] Constant temperature and humidity test: In a constant temperature and humidity chamber, at 50℃ and 95% relative humidity for 48 hours, observe whether the film layer on each surface of the disc in the substrate peels off and whether the film layer on each surface of the disc in the substrate cracks.
[0058] Friction resistance test (medium friction test): Wrap the rubber friction head of the rubber with degreased cloth and apply a pressure of 4.9N to the film surface of the coated sheet for 50 cycles (25 back and forth). Observe whether there are scratches or signs of damage on the film surface.
[0059] Low temperature test: In a low temperature chamber, at -40℃ for 48 hours, observe whether the film layer on each surface of the disc in the substrate peels off and whether the film layer on each surface of the disc in the substrate cracks.
[0060] High temperature test: In a high temperature chamber, at 85℃ for 48 hours, observe whether the film layer on each surface of the disc in the substrate has peeled off and whether the film layer on each surface of the disc in the substrate has cracked.
[0061] In the water immersion test, salt spray test, thermal shock test, constant temperature and humidity test, low temperature test, and high temperature test, the film layer did not peel off or crack; in the adhesion test, the film layer was not pulled up; in the abrasion resistance test, there were no signs of scratch damage on the film layer surface, i.e., it can withstand moderate abrasion. In other words, the disc in the surcharge sheet of Example 1, together with the film system on both sides, passed a total of eight tests, including the water immersion test, salt spray test, adhesion test, thermal shock test, constant temperature and humidity test, abrasion resistance test, low temperature test, and high temperature test.
[0062] Several exemplary embodiments have been described in detail above, but this document is not intended to limit itself to the explicitly disclosed combinations. Therefore, unless otherwise stated, the various features disclosed herein can be combined to form several other combinations, which are not shown for simplicity.
Claims
1. A method for preparing a zinc selenide 900-1700nm reflective film system, characterized in that, Including the following steps: S0, the surfaces of the coating sheet and the product are cleaned. The coating sheet and the product are lenses and both are zinc selenide substrates. The coating sheet is a round sheet of equal thickness and a wedge-shaped sheet with a polished flat surface on the first side and a rough surface on the second side. S1. Place the cleaned lenses into the oven, set the oven temperature to 150℃, and bake for 2 hours. S2, load the baked lens into the tooling fixture, hang the tooling fixture with the lens loaded into the vacuum coating machine cavity, and set the temperature of the cavity to 150℃. S3, the vacuum coating machine starts vacuuming, and the vacuum level reaches 1.5×10⁻⁶. -3 Pa, turn on the Hall ion source of the vacuum coating machine for cleaning. The cleaning time is 6 minutes. The parameters of the Hall ion source are: anode voltage of 220V, anode current of 1.2A, neutralization current of 1.5A, neutralization gas flow rate of 10sccm, and argon flow rate of 100%. S4, on the first surface of the lens, consists of an eleven-layer film system composed of four types of film materials: YbF3, ZnSe, ZnS, and Y2O3. Sub / 75nm YbF3 / 43.6nm ZnSe / 212.29nm YbF3 / 35.23nm ZnSe / 92.65nm YbF3 / 305.33nm ZnSe / 33.23nm YbF3 / 335.35nm ZnS / 136.98nm YbF3 / 10nm ZnS / 20nm Y2O3 / Air, each film layer was deposited sequentially. Wherein, Sub represents the zinc selenide substrate, Air represents air, and the nm numbers preceding YbF3, ZnSe, ZnS, and Y2O3 indicate the film thickness of the corresponding layer. The YbF3, ZnSe, and ZnS layers were deposited using resistance heating evaporation, while the Y2O3 layer was deposited using electron beam heating evaporation. The deposition rate of the YbF3 layer was 0.5 nm / s, the ZnSe layer was 0.6 nm / s, the ZnS layer was 0.4 nm / s, and the Y2O3 layer was 0.3 nm / s. All layers were deposited using ion source-assisted deposition, and the deposition of each layer was completed at a chamber temperature of 150°C. S5. After the coating system is applied to the first surface of the lens, the cavity is naturally cooled to below 85°C, and the tooling fixture is removed along with the lens. S6, repeat steps S0 to S5 to deposit the same film system on the second side of the lens, wherein the wedge is not cleaned when repeating step S0, not baked when repeating step S1, and not placed in the tooling fixture when repeating step S2.
2. The method for preparing the zinc selenide 900-1700nm reflective film system according to claim 1, characterized in that, In step S0, the surface of the lens is cleaned using ultrasound or by hand.
3. The method for preparing the zinc selenide 900-1700nm reflective film system according to claim 2, characterized in that, In step S0, the surface cleaning treatment of the lens is performed by polishing with an alumina polishing liquid followed by ultrasonic cleaning with pure water.
4. The method for preparing the zinc selenide 900-1700nm reflective film system according to claim 3, characterized in that, In step S0, the alumina polishing slurry is a 0.1μm polycrystalline diamond slurry.
5. The method for preparing the zinc selenide 900-1700nm reflective film system according to claim 1, characterized in that, In step S0, the product is a lens or a flat sheet.
6. The method for preparing the zinc selenide 900-1700nm reflective film system according to claim 1, characterized in that, In step S0, the thickness of the disc in the plating sheet is 2 mm.
7. The method for preparing the zinc selenide 900-1700nm reflective film system according to claim 1, characterized in that, In step S4, The ion source used is a Hall ion source. When depositing the YbF3 film, the ion source parameters are as follows: neutralization current is 0.6A, neutralization gas flow rate is 8sccm, anode voltage is 130V, anode current is 1.3A, argon flow rate accounts for 30%, and oxygen flow rate accounts for 70%. When depositing ZnSe and ZnS films, the ion source parameters are as follows: neutralization current is 0.5A, neutralization gas flow rate is 8sccm, anode voltage is 90V, anode current is 1.0A, and argon flow rate is 100%. When depositing the Y2O3 film, the ion source parameters are as follows: neutralization current is 0.5A, neutralization gas flow rate is 8sccm, anode voltage is 100V, anode current is 1.2A, and argon flow rate is 100%.
8. The method for preparing the zinc selenide 900-1700nm reflective film system according to claim 1, characterized in that, In step S4, Argon gas is introduced and a vacuum is drawn during the deposition of each film layer to maintain a constant flow vacuum. The constant flow vacuum setting is not lower than 5.0 × 10⁻⁶. -3 Pa; The crystal oscillator method is used to monitor the film thickness by using the corresponding crystal oscillators of multiple crystal oscillators in the crystal controller. After cleaning with the ion source, the crystal controller controls the new crystal oscillator in the multiple crystal oscillators to work accordingly, and the crystal oscillator frequency is not less than 5.99MHz.
9. The method for preparing the zinc selenide 900-1700nm reflective film system according to claim 1, characterized in that, After step S6 is completed, the wedge-shaped sheet in the substrate, together with the film system on the corresponding first surface, has an average reflectance of less than 1.2% in the 900-1700nm band at an 8° test angle and an average reflectance of less than 2.6% in the 900-1700nm band at a 45° test angle. After step S6 is completed, the disc in the substrate, together with the film system on both sides, undergoes water immersion test, salt spray test, adhesion test, thermal shock test, constant temperature and humidity test, abrasion resistance test, low temperature test, and high temperature test.