Optical part coating method

Abstract

The invention relates to the technical field of optical part processing, and provides an optical part coating method which comprises the following steps: coating a first coating film on a second surface of an optical part; shielding a second area of the first surface of the optical part, and plating a second coating film on the first area of the first surface of the optical part; plating a third coating film covering the second area and the second coating film on the first surface of the optical part; wherein the parts, corresponding to the second area, of the first coating film and the third coating film form antireflection films, and the parts, corresponding to the first area, of the second coating film and the third coating film form a light splitting film together. According to the film coating method disclosed by the invention, the film coating operation is simple, regional film coating of the optical part can be conveniently realized, the film coating efficiency is high, transition regions existing among different film coating regions are eliminated, and the film coating precision of the optical part is ensured.

Description

Technical Field

[0001] The invention relates to the technical field of optical component processing, and in particular to a coating method for optical components. Background Art

[0002] Optical parts are elements or components used to control, guide and process light. Optical parts usually include prisms, lenses, optical windows, etc. These optical parts are widely used in various optical instruments and equipment, such as telescopes, microscopes, lasers, photoelectron microscopes, infrared optical equipment, etc., and play a key role in optical systems. For example, optical windows are a basic optical part. The basic function of optical windows is to separate the internal and external environments of the instrument, and to protect the optical system and electronic sensors from the influence of the external environment. In addition, optical windows are also part of the optical system to ensure that the imaging quality and light intensity of the optical system are not affected by external factors. Optical windows are designed to provide high transmittance for light in a specified wavelength band, while minimizing light reflection and absorption losses, ensuring that light can pass through the window efficiently without affecting the performance of the optical system. This places high demands on the film system coated on the surface of the optical window.

[0003] In order to meet the transmission, reflection and spectroscopic requirements of optical parts for light, regional coating is used for some surfaces of optical parts. The entire coating surface is no longer a simple and unified film system requirement, but a complex regional film system requirement, which is mainly a mixture of spectroscopic and anti-reflection, so as to play the role of transmission, reflection and spectroscopic for the incident light. In the prior art, there are usually two technical means for regional coating: one is to use a coating fixture to block the optical parts so that other surfaces or non-coated surfaces are not affected when coating one surface, and the other is to use a coating glue-like substance (such as photoresist or ink) to block the non-coated area of ​​the optical parts to achieve coating treatment of the coated area. However, in actual applications, it is found that these two coating methods are affected by the accuracy of the blocking method to a certain extent. When the regional film system requirements are inconsistent, there is an obvious transition zone between different coating areas, so that the coating accuracy is difficult to guarantee, especially the coating method using a coating fixture has high requirements on the accuracy of the coating fixture, and it is not easy for operators to operate. Summary of the invention

[0004] The present invention provides a coating method for optical parts, which is used to at least solve or improve the problem in the prior art that regional coating of optical parts is complicated in operation and difficult to ensure coating accuracy.

[0005] The present invention provides a coating method for an optical component, comprising: Plating a first coating on the second surface of the optical component; The second area of ​​the first surface of the optical component is shielded, and a second coating is applied to the first area of ​​the first surface of the optical component; Forming a third coating on the first surface of the optical component to cover the second area and the second coating; Parts of the first coating and the third coating corresponding to the second area are both formed as anti-reflection films, and parts of the second coating and the third coating corresponding to the first area are jointly formed as a beam splitting film.

[0006] According to a coating method for an optical component provided by the present invention, the step of coating a first coating on the second surface of the optical component comprises: Using a first fixture to support the periphery of the second surface of the optical component to expose the area to be plated on the second surface of the optical component; The first coating film is formed on the to-be-coated area of ​​the second surface by using an evaporation process.

[0007] According to a coating method for an optical component provided by the present invention, the first fixture comprises a first body and a support edge; The first body is annular, the support edge is arranged on the inner side of the first body and extends along the circumference of the first body; the inner wall of the first body is configured to fit with the peripheral wall of the optical component, and the support edge is configured to support the periphery of the second surface of the optical component.

[0008] According to a coating method for an optical component provided by the present invention, the steps of shielding a second area of ​​a first surface of the optical component and coating a second coating on the first area of ​​the first surface of the optical component include: A second fixture is used to support the first surface of the optical component, ensuring that the shielding portion of the second fixture shields the second area of ​​the first surface, and the first area of ​​the first surface is exposed; The second coating film is formed on the first area of ​​the first surface by using an evaporation process.

[0009] According to a coating method for an optical component provided by the present invention, the second fixture includes a second body and a shielding portion; The second body is annular, the shielding portion is arranged on the inner side of the second body and connected to the inner wall of the second body; the inner wall of the second body is configured to fit with the peripheral wall of the optical component, the shielding portion is configured to be supported on the first surface of the optical component, and a groove is provided on a side of the shielding portion facing the optical component; Wherein, along the axial direction of the second body, the projection of the second area of ​​the optical component overlaps with the projection of the shielding portion, and the projection of the first area of ​​the optical component overlaps with the projection of the hollow area in the second body without the shielding portion.

[0010] According to a coating method for an optical component provided by the present invention, the step of coating a third coating covering the second region and the second coating on the first surface of the optical component comprises: Using a first fixture to support the periphery of the first surface of the optical component to expose the area to be plated on the first surface of the optical component; The third coating film is formed on the to-be-coated area of ​​the first surface by using an evaporation process.

[0011] According to a coating method for an optical component provided by the present invention, the first coating, the second coating and the third coating are all formed by stacking alternately coated high refractive index film layers and low refractive index film layers in sequence.

[0012] According to the present invention, a coating method for an optical component includes: before coating the next film layer, performing the following steps by using an evaporation process: Use ion source to etch the previous film layer for 10 to 15 minutes, and control the vacuum degree of the coating environment to be no higher than 2*10 -3 Pa, the deposition temperature is 150-200°C, and the constant temperature is maintained for 10-20 minutes; The upper film layer includes one of the high refractive index film layer and the low refractive index film layer, and the lower film layer includes the other of the high refractive index film layer and the low refractive index film layer.

[0013] A coating method for an optical component provided by the present invention comprises the steps of coating the high refractive index film layer by using an evaporation process according to the following operations: Ion source assisted evaporation is adopted to control the deposition rate of the film material corresponding to the high refractive index film layer to be 2-3 nm / s, and the oxygen filling amount to be 10-20 sccm.

[0014] A coating method for an optical component provided by the present invention comprises the steps of coating the low refractive index film layer by using an evaporation process according to the following operations: Ion source assisted evaporation is adopted to control the deposition rate of the film material corresponding to the low refractive index film material layer to be 5-6 nm / s.

[0015] The coating method for optical parts provided by the present invention first coats a first coating on the second surface of the optical part, and then sequentially coats a second coating and a third coating covering the second coating on the first surface of the optical part, so as to conveniently complete the coating processing of the optical part. The regional coating of the first surface of the optical part can be completed in a "repeated coating" manner during the coating process, and the transition area between the first area and the second area of ​​the first surface is eliminated, so that the regional coating problem no longer relies on the processing and positioning accuracy of the coating fixture to ensure the film system requirements in the area. This coating method is not only simple in coating operation, but can also conveniently realize regional coating of optical parts, and has high coating efficiency, and eliminates the transition area between different coating areas, thereby ensuring the coating accuracy of the optical parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 It is a schematic flow chart of the coating method for optical parts provided by the present invention.

[0018] Figure 2 It is a schematic diagram of the process of coating a first coating on the second surface of an optical component provided by the present invention.

[0019] Figure 3 It is a schematic cross-sectional structure diagram of the periphery of the second surface of the optical component supported by the first fixture provided by the present invention.

[0020] Figure 4 It is a schematic diagram of the three-dimensional structure of the first clamp provided by the present invention.

[0021] Figure 5 It is a schematic diagram of a process of shielding the second area of ​​the first surface of an optical component and coating the second coating on the first area of ​​the first surface of the optical component provided by the present invention.

[0022] Figure 6 It is a structural schematic diagram of the first surface of the optical component based on the second fixture supporting the optical component provided by the present invention.

[0023] Figure 7 It is a schematic diagram of the three-dimensional structure of the second fixture provided by the present invention.

[0024] Figure 8 It is a schematic diagram of a process of coating a third coating covering a second area and a second coating on a first surface of an optical component provided by the present invention.

[0025] Fig. 9 It is a schematic cross-sectional structure diagram of the periphery of the first surface of the optical component supported by the first fixture provided by the present invention.

[0026] Fig.10 It is a schematic diagram of the cross-sectional structure of the optical component after coating provided by the present invention.

[0027] Fig.11 It is a curve diagram of the reflectivity of the first coating and the third coating provided by the present invention corresponding to the film system in the second area to light relative to the wavelength.

[0028] Fig.12 It is a curve diagram of the reflectivity of the second coating film system provided by the present invention to light relative to the wavelength.

[0029] Fig.13 It is a curve diagram of the reflectivity of the spectral film system provided by the present invention to light relative to the wavelength.

[0030] Fig.14 It is a curve diagram of the transmittance of the film system in the first area of ​​the optical component provided by the present invention to light relative to the wavelength.

[0031] Fig.15 It is a curve diagram of the reflectivity of light relative to the wavelength after the optical component provided by the present invention is coated with a first coating on the second surface and a third coating on the second area of ​​the first surface.

[0032] Reference numerals: 10. Optical parts; 100. Main parts; 101. First coating; 102. Second coating; 103. Third coating; 20. first fixture; 201. first body; 202. supporting edge; 30. Second fixture; 301. Second body; 302. Shielding portion; 3021. Groove; 300. Hollow area. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] Combine the following Figure 1-Figure 15 , the coating method of optical parts provided by the embodiment of the invention is described in detail through specific embodiments and their application scenarios.

[0035] In some embodiments, Figure 1 and Fig.10 As shown, an embodiment of the present invention provides a coating method for an optical component, comprising the following steps: Step 110 , coating a first coating 101 on the second surface of the optical component 10 ; Step 120, shielding the second area of ​​the first surface of the optical component 10, and coating the first area of ​​the first surface of the optical component 10 with a second coating 102; Step 130, coating the third coating 103 covering the second area and the second coating 102 on the first surface of the optical component 10; wherein the first coating 101 and the third coating 103 corresponding to the second area are both formed as anti-reflection films, and the second coating 102 and the third coating 103 corresponding to the first area are jointly formed as a spectroscopic film.

[0036] It can be understood that the optical component 10 shown in the embodiment of the present invention can be a prism, a lens or an optical window; the first surface and the second surface of the optical component 10 can be arranged in parallel or at an angle.

[0037] In practical applications, the first coating 101, the second coating 102 and the third coating 103 can be respectively coated by evaporation, magnetron sputtering or ion beam assisted deposition methods known in the art to form an anti-reflection film and a spectroscopic film on the surface of the optical component 10. The main function of the anti-reflection film is to reduce the reflection loss of light when passing through the optical surface, thereby increasing the intensity of the transmitted light; the spectroscopic film is mainly used to divide the light beam into two parts in a predetermined ratio, one part of the light is transmitted, and the other part of the light is reflected.

[0038] When the first coating 101 is applied, a coating fixture can be used to fix the optical component 10 to ensure that the second surface of the optical component 10 is not blocked, so that the coating area of ​​the first coating 101 covers the second surface of the optical component 10; when the second coating 102 is applied, a coating fixture or ink blocking method can be used to block the second area of ​​the first surface of the optical component 10 to ensure that the film material during coating only adheres to the first area of ​​the first surface of the optical component 10 to form the second coating 102 in the first area of ​​the first surface; when the third coating 103 is applied, a coating fixture can be used to fix the optical component 10 to ensure that the first surface of the optical component 10 is not blocked, so that the coating area of ​​the third coating 103 covers the second area of ​​the first surface and the surface of the second coating 102. This coating method can avoid the appearance of an obvious coating transition zone between the first area and the second area of ​​the first surface.

[0039] The first coating 101, the second coating 102 and the third coating 103 each include at least two deposition layers. The film material of each deposition layer can be a high refractive index material or a low refractive index material. The film materials corresponding to two adjacent deposition layers can be the same or different, and there is no specific limitation on this.

[0040] The high refractive index material includes tantalum pentoxide, titanium dioxide, niobium pentoxide and other suitable materials, and the low refractive index material may be silicon dioxide, magnesium difluoride and other suitable materials.

[0041] By coating the optical component 10 based on the coating method shown in this embodiment, it can be ensured that the relevant optical parameters of the optical component 10 after coating meet the following indicators: For the second area of ​​the first surface and the film system indicators of the second surface of the optical component 10, the reflectivity R is less than 0.5%@643nm, 0deg, which means that when the incident angle of the light is 0° and the wavelength is 643nm, the reflectivity of the film system in this area is less than 0.5%.

[0042] For the first area of ​​the first surface of the optical component 10, the ratio of transmittance T to reflectivity R is equal to 50%±3%: 50%±3%@643nm, 0deg. When the incident angle of the light is 0° and the wavelength is 643nm, the reflectivity of the film system in this area is less than 0.5%, and the width of the film layer transition zone between the first area and the second area is less than 1mm.

[0043] The optical component 10 may be an optical window plate, and the first surface and the second surface are two surfaces on the optical window plate that are parallel to each other and arranged opposite to each other.

[0044] As can be seen from the above, the coating method shown in the present invention first coats the first coating 101 on the second surface of the optical component 10, and then coats the second coating 102 and the third coating 103 covering the second coating 102 on the first surface of the optical component 10 in sequence, so as to conveniently complete the coating processing of the optical component 10. During the coating process, the regional coating of the first surface of the optical component 10 can be completed in a "repeated coating" manner, eliminating the transition area between the first area and the second area of ​​the first surface, so that the regional coating problem no longer relies on the processing and positioning accuracy of the coating fixture to ensure the film system requirements in the area. This coating method is not only simple in coating operation, but can also conveniently realize regional coating of the optical component 10 with high coating efficiency, and eliminates the transition area between different coating areas, thereby ensuring the coating accuracy of the optical component 10.

[0045] In some embodiments, Figure 2 , Figure 3 and Fig.10As shown, the first coating 101 is plated on the second surface of the optical component 10 shown in the present invention, comprising the following steps: Step 210, using the first fixture 20 to support the periphery of the second surface of the optical component 10, exposing the area to be plated on the second surface of the optical component 10; Step 220 , using an evaporation process to form a first coating 101 on the area to be coated on the second surface.

[0046] Specifically, Figure 3 and Figure 4 As shown, the first fixture 20 includes a first body 201 and a support edge 202 ; the first body 201 is annular, and the support edge 202 is disposed on the inner side of the first body 201 and extends along the circumference of the first body 201 .

[0047] Before the first coating 101 is applied, the optical component 10 is placed on the inner side of the first body 201, with the second surface of the optical component 10 placed horizontally downward. The inner wall of the first body 201 is configured to fit the peripheral wall of the optical component 10, and the support edge 202 is configured to support the periphery of the second surface of the optical component 10, that is, the inner area of ​​the support edge 202 corresponds to the area to be plated on the second surface of the optical component 10.

[0048] When the first coating 101 is being plated, since the first body 201 blocks the side wall of the optical component 10, and the support edge 202 blocks the periphery of the second surface of the optical component 10, when the second surface of the optical component 10 is plated using a vapor deposition process, it can be ensured that the film material can only adhere to the area to be plated on the second surface, thereby plating the first coating 101 on the area to be plated on the second surface.

[0049] The optical component 10 is configured as a circle, and its diameter may be 25.4 mm. The inner area of ​​the support edge 202 corresponds to a diameter of 23 mm, and the width of the support edge 202 may be 0.3-1 mm.

[0050] In some embodiments, Figure 5 , Figure 6 and Fig.10 As shown, the present invention shows that the second area of ​​the first surface of the optical component 10 is shielded, and the second coating 102 is plated on the first area of ​​the first surface of the optical component 10, including the following steps: Step 510, using the second fixture 30 to support the first surface of the optical component 10, ensuring that the shielding portion 302 of the second fixture 30 shields the second area of ​​the first surface, and the first area of ​​the first surface is exposed; Step 520 , using an evaporation process to form a second coating 102 on the first region of the first surface.

[0051] Specifically, Figure 6and Figure 7 As shown, the second fixture 30 includes a second body 301 and a shielding portion 302; the second body 301 is annular, and the shielding portion 302 is disposed inside the second body 301 and connected to the inner wall of the second body 301. Along the axial direction of the second body 301, the projection of the second area of ​​the optical component 10 overlaps with the projection of the shielding portion 302, and the projection of the first area of ​​the optical component 10 overlaps with the projection of the hollow area 300 in the second body 301 without the shielding portion 302.

[0052] Among them, an annular ring can be set on the inner side of the second body 301, the shielding part 302 is set on the inner side of the annular ring and connected to the inner wall of the annular ring, the annular ring is used to support the periphery of the first surface of the optical part 10, and the shielding part 302 is used to shield the second area of ​​the first surface.

[0053] Before the second coating 102 is applied, the optical component 10 is placed on the inner side of the second body 301, with the first surface of the optical component 10 placed horizontally downward. The inner wall of the second body 301 is configured to fit the peripheral wall of the optical component 10, and the shielding portion 302 is configured to support the second area corresponding to the first surface of the optical component 10. A groove 3021 is provided on the side of the shielding portion 302 facing the optical component 10. Based on the design of the groove 3021, the contact area between the shielding portion 302 and the second area corresponding to the first surface of the optical component 10 can be reduced, thereby preventing the shielding portion 302 from scratching the second area of ​​the optical component 10.

[0054] The groove 3021 may have a depth of 0.2-0.3 mm.

[0055] When the second coating 102 is being plated, since the second body 301 blocks the side wall of the optical component 10, and the blocking portion 302 of the second fixture 30 blocks the second area of ​​the first surface, when the first surface of the optical component 10 is plated using a vapor deposition process, it can be ensured that the film material can only adhere to the first area of ​​the first surface, thereby plating the second coating 102 in the first area of ​​the first surface.

[0056] In practical applications, the shape of the shielding portion 302 is determined according to the shape of the second area of ​​the first surface. For example, when the shape of the second area is a sector, the shielding portion 302 is a sector-shaped structure that matches the shape of the second area.

[0057] In some embodiments, Figure 8 , Fig. 9 and Fig.10 As shown, the third coating 103 covering the second area and the second coating 102 is coated on the first surface of the optical component 10 of the present invention, comprising the following steps: Step 810, using the first fixture 20 to support the periphery of the first surface of the optical component 10 to expose the area to be plated on the first surface of the optical component 10; Step 820 , using an evaporation process to form a third coating 103 on the to-be-coated area of ​​the first surface.

[0058] Specifically, Fig. 9 and Fig.10 As shown, the first fixture 20 shown in this embodiment can be used Figure 4 The structure shown, that is, the first fixture 20 shown in this embodiment, also includes a first body 201 and a support edge 202 ; the first body 201 is annular, and the support edge 202 is arranged on the inner side of the first body 201 and extends along the circumference of the first body 201 .

[0059] Before the third coating 103 is applied, the optical component 10 is placed on the inner side of the first body 201 , with the first surface of the optical component 10 placed horizontally downward, the inner wall of the first body 201 is in contact with the peripheral wall of the optical component 10 , and the support edge 202 is configured to support the periphery of the first surface of the optical component 10 .

[0060] When the third coating 103 is being plated, since the first body 201 blocks the side wall of the optical component 10 and the support edge 202 blocks the periphery of the first surface of the optical component 10, the area to be plated on the first surface of the optical component 10 is the second area of ​​the first surface and the surface area of ​​the second coating 102. When the area to be plated on the first surface is plated using a vapor deposition process, it can be ensured that the film material can only adhere to the area to be plated on the first surface, so that the third coating 103 is plated on the area to be plated on the first surface, ensuring that the third coating 103 covers the second area of ​​the first surface and the surface area of ​​the second coating 102.

[0061] In some embodiments, in order to ensure the quality of coating formation, the first coating, the second coating and the third coating are all formed by stacking alternately coated high refractive index film layers and low refractive index film layers in sequence.

[0062] The coating processes of the first coating, the second coating and the third coating are not limited to evaporation processes, and may also be coating methods such as magnetron sputtering or ion beam assisted deposition.

[0063] Meanwhile, the film material of the high refractive index film layer includes any one of tantalum pentoxide, titanium dioxide, and niobium pentoxide; and the film material of the low refractive index film layer includes silicon dioxide or magnesium difluoride.

[0064] In some embodiments, in order to ensure the bonding effect between the high refractive index film layer and the low refractive index film layer, the coating method shown in the present invention includes: before coating the next film layer, using an evaporation process to perform the following steps: Use ion source to etch the previous film layer for 10 to 15 minutes, and control the vacuum degree of the coating environment to be no higher than 2*10 -3 Pa, the deposition temperature is 150-200°C, and the constant temperature is maintained for 10-20 minutes; The upper film layer shown in this embodiment includes one of a high refractive index film layer and a low refractive index film layer, and the lower film layer includes the other of the high refractive index film layer and the low refractive index film layer.

[0065] Among them, before plating the next film layer, the etching time of the previous film layer using an ion source can be 10min, 12min, 13min, 15min and other suitable time lengths, the deposition temperature can be controlled at 150℃, 170℃, 180℃, 200℃ and other suitable temperatures, and the constant temperature maintenance time can be controlled at 10min, 12min, 15min, 18min, 20min and other suitable time lengths.

[0066] In some embodiments, the coating method of the present invention includes the following steps: using an evaporation process to coat a high refractive index film layer: By adopting ion source assisted evaporation, the deposition rate of the film material corresponding to the high refractive index film layer is controlled to be 2-3 nm / s, and the oxygen filling amount is controlled to be 10-20 sccm.

[0067] It is understandable that when the high refractive index film layer is deposited by evaporation process, a Hall ion source can be used to drive the evaporated high refractive index film material to move toward the coating surface, so as to ensure the firmness of the high refractive index film layer deposition based on auxiliary evaporation.

[0068] At the same time, by controlling the amount of oxygen during the deposition of high-refractive index film materials by ion source assisted evaporation, oxygen loss during the vapor deposition process can be prevented.

[0069] Among them, during the deposition process of the high refractive index film layer, the deposition rate of the corresponding film material of the high refractive index film layer can be controlled to 2nm / s, 2.3nm / s, 2.5nm / s, 2.8nm / s, 3nm / s and other suitable rates, and the oxygen filling amount can be controlled to 10sccm, 12sccm, 15sccm, 18sccm, 20sccm and other suitable oxygen filling rates.

[0070] In some embodiments, the coating method of the present invention includes the following steps: using an evaporation process to coat a low refractive index film layer: Ion source assisted evaporation was adopted to control the deposition rate of the corresponding film material of the low refractive index film layer to be 5-6 nm / s.

[0071] It is understandable that when the low refractive index film layer is deposited by evaporation process, a Hall ion source can be used to drive the evaporated low refractive index film material to move toward the coating surface, so as to ensure the firmness of the low refractive index film layer deposition based on auxiliary evaporation.

[0072] In the process of depositing the low refractive index film layer, the deposition rate of the film material corresponding to the low refractive index film layer can be controlled to be 5nm / s, 5.3nm / s, 5.5nm / s, 5.8nm / s, 6nm / s and other suitable rates.

[0073] The coating operation of an optical window is taken as an example to specifically describe the coating method shown in the present invention. The overall film system design adopts a high refractive index film material (Ta2O5) and a low refractive index film material (SiO2) to be cross-plated into a film. The film system structure is represented by G|αH βL|A, wherein H represents a high refractive index film material, L represents a low refractive index film material, A represents air, the coefficient α is a multiple of λ / 4, the coefficient β is a multiple of λ / 4, and λ is the wavelength of the incident light.

[0074] The first step is to coat the second side of the optical window with an anti-reflection film, as shown below: like Figure 3 As shown, the optical window is installed using a first fixture, the second surface of the optical window is placed horizontally downward, and the inner supporting edge of the first fixture is supported on the periphery of the second surface of the optical window.

[0075] A Ta2O5 layer and a SiO2 layer are sequentially deposited on the to-be-plated area of ​​the second surface by using an evaporation process, so as to form a first coating film based on the stacked Ta2O5 layer and the SiO2 layer, and the first coating film is formed as an anti-reflection film.

[0076] In a specific plating operation, before plating the first coating, the TOOLING parameters of the film material shown in Table 1 are obtained in advance based on the designed thickness of each film material deposition layer and the actual thickness obtained by measurement. The TOOLING parameters of the film material are the ratio of the actual thickness to the designed thickness.

[0077] Table 1: TOOLING parameters of film materials under evaporation process conditions

[0078] Next, according to the TOOLING parameters of various film materials obtained in Table 1, the first coating is completed according to the above operation steps based on the actual coating parameters of the first coating shown in Table 2. The film system structure used in the first coating is G|0.3837H 1.5374L|A.

[0079] Table 2: Actual coating parameters of the first coating (AR coating) on ​​the second surface

[0080] Fig.11 The graph of the reflectivity of the first coating system to light relative to the wavelength is shown, where: Fig.11 The ordinate is reflectivity, and the abscissa is wavelength. Fig.11 It can be seen that at a wavelength of 643nm, the reflectivity of the first coating to light is close to zero, and the reflectivity is less than 0.5%, which meets the design requirements.

[0081] The second step is to coat the beam splitter and anti-reflection films on the first side of the optical window, as shown below: like Figure 6 As shown, the optical window is installed by using a second fixture, the first surface of the optical window is placed horizontally downward, the shielding portion shields the second area corresponding to the first surface, and the first area of ​​the first surface is exposed. The Ta2O5 layer and the SiO2 layer are alternately deposited in the first area of ​​the first surface by using an evaporation process to form a second coating based on the stacked Ta2O5 layer and the SiO2 layer.

[0082] like Fig. 9 As shown, the optical window is installed by using a first fixture, the first surface of the optical window is placed horizontally downward, and the inner edge of the first fixture is supported on the periphery of the first surface of the optical window. The Ta2O5 layer and the SiO2 layer are sequentially deposited on the to-be-plated area of ​​the first surface by using an evaporation process, so as to form a third coating based on the stacked Ta2O5 layer and the SiO2 layer, and the third coating covers the second area of ​​the first surface and the surface area of ​​the second coating.

[0083] In the specific coating operation, based on the coating parameters corresponding to the beam splitting film and the anti-reflection film on the first surface of the optical window piece shown in Table 3 below, the coating of the beam splitting film and the anti-reflection film on the first surface is completed.

[0084] Table 3: Actual coating parameters corresponding to the beam splitting film and anti-reflection film on the first surface

[0085] In the above Table 3, the 1st to 5th layers form the second coating of the present embodiment, the 6th to 7th layers form the third coating of the present embodiment, the second coating and the third coating corresponding to the first area together form a dichroic film on the first surface, and the third coating corresponding to the second area forms an anti-reflection film on the first surface.

[0086] At the same time, the film structure of the spectroscopic film is G∣1.2865H 1.2683L 1.2865H 1.2801L1.2865H 1.3028L 0.2654H 0.3837H 1.5374L∣A.

[0087] Fig.12 The graph showing the reflectivity of the second coating system to light relative to wavelength. Fig.13 The graph showing the reflectivity of the beam splitter coating system to light relative to wavelength is shown in the figure. Fig.12 and Fig.13 The vertical axis is the reflectivity, and the horizontal axis is the wavelength. Fig.12 and Fig.13 It can be seen that since the second coating lacks the last two layers of film material deposition (lacking the 6th to 7th layers) compared to the spectroscopic film, the reflectivity of the second coating is slightly higher by about 2% than that of the spectroscopic film, and the spectroscopic film has a wider band corresponding to a reflectivity of around 50% than the second coating.

[0088] After completing the coating operation of the third coating, the coating operation of the optical window piece is completed. According to the film structure adopted by the spectroscopic film, the portion of the third coating corresponding to the second area is formed as an anti-reflection film. The anti-reflection film adopts the same film structure as the above-mentioned first coating, and the film structure of the anti-reflection film will not be repeated.

[0089] Fig.14 The graph of the transmittance of the film system of the first area of ​​the optical window piece to light relative to the wavelength is shown, wherein: Fig.14 The vertical axis is the transmittance, and the horizontal axis is the wavelength. Fig.14 It can be seen that at the wavelength of 643nm, the overall transmittance of the optical window is 52.214%, which meets the design requirements.

[0090] Fig.15 Two curves of reflectivity of light relative to wavelength after the optical window is coated with a first coating on the second surface and a third coating on the second area of ​​the first surface are shown, wherein: Fig.15 The ordinate is reflectivity, and the abscissa is wavelength. Fig.15 From the two curves in the figure, we can see that at the 643nm band, the reflectivity of the optical window is 0.044% and 0.048% respectively. These two reflectivities are much less than 0.5% and can meet the design requirements.

[0091] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A coating method for optical parts, characterized in that: include: Plating a first coating on the second surface of the optical component; The second area of ​​the first surface of the optical component is shielded, and a second coating is applied to the first area of ​​the first surface of the optical component; Forming a third coating on the first surface of the optical component to cover the second area and the second coating; Parts of the first coating and the third coating corresponding to the second area are both formed as anti-reflection films, and parts of the second coating and the third coating corresponding to the first area are jointly formed as a beam splitting film.

2. The optical component coating method according to claim 1, characterized in that: The step of coating the first coating on the second surface of the optical component comprises: Using a first fixture to support the periphery of the second surface of the optical component to expose the area to be plated on the second surface of the optical component; The first coating film is formed on the to-be-coated area of ​​the second surface by using an evaporation process.

3. The coating method for optical components according to claim 2, characterized in that: The first fixture comprises a first body and a support edge; The first body is annular, the support edge is arranged on the inner side of the first body and extends along the circumference of the first body; the inner wall of the first body is configured to fit with the peripheral wall of the optical component, and the support edge is configured to support the periphery of the second surface of the optical component.

4. The optical component coating method according to claim 1, characterized in that: The step of shielding the second area of ​​the first surface of the optical component and coating the first area of ​​the first surface of the optical component with a second coating comprises: A second fixture is used to support the first surface of the optical component, ensuring that the shielding portion of the second fixture shields the second area of ​​the first surface, and the first area of ​​the first surface is exposed; The second coating film is formed on the first area of ​​the first surface by using an evaporation process.

5. The optical component coating method according to claim 4, characterized in that: The second fixture includes a second body and a shielding portion; The second body is annular, the shielding portion is arranged on the inner side of the second body and connected to the inner wall of the second body; the inner wall of the second body is configured to fit with the peripheral wall of the optical component, the shielding portion is configured to be supported on the first surface of the optical component, and a groove is provided on a side of the shielding portion facing the optical component; Wherein, along the axial direction of the second body, the projection of the second area of ​​the optical component overlaps with the projection of the shielding portion, and the projection of the first area of ​​the optical component overlaps with the projection of the hollow area in the second body without the shielding portion.

6. The optical component coating method according to claim 1, characterized in that: The step of coating the third coating covering the second area and the second coating on the first surface of the optical component comprises: Using a first fixture to support the periphery of the first surface of the optical component to expose the area to be plated on the first surface of the optical component; The third coating film is formed on the to-be-coated area of ​​the first surface by using an evaporation process.

7. The method for coating an optical component according to any one of claims 1 to 6, characterized in that: The first coating film, the second coating film and the third coating film are all formed by stacking alternately coated high refractive index film layers and low refractive index film layers in sequence.

8. The optical component coating method according to claim 7, characterized in that: include: Before depositing the next film layer, the following steps are performed using the evaporation process: Use ion source to etch the previous film layer for 10 to 15 minutes, and control the vacuum degree of the coating environment to be no higher than 2*10 -3 Pa, the deposition temperature is 150-200°C, and the constant temperature is maintained for 10-20 minutes; The upper film layer includes one of the high refractive index film layer and the low refractive index film layer, and the lower film layer includes the other of the high refractive index film layer and the low refractive index film layer.

9. The coating method for optical components according to claim 7, characterized in that: include: The steps of coating the high refractive index film layer by using the evaporation process are as follows: Ion source assisted evaporation is adopted to control the deposition rate of the film material corresponding to the high refractive index film material layer to be 2-3 nm / s, and the oxygen filling amount to be 10-20 sccm.

10. The optical component coating method according to claim 7, characterized in that: include: The steps of coating the low refractive index film layer by using the evaporation process are as follows: Ion source assisted evaporation is adopted to control the deposition rate of the film material corresponding to the low refractive index film material layer to be 5-6 nm / s.

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