Optical phase delay reflecting film and its plating method, jig

Abstract

The application provides an optical phase delay reflection film, a plating method and a fixture, the optical phase delay reflection film is composed of a metal Ag film layer, a SiO2 film layer, a Ti3O5 film layer and an Al2O3 film layer plated on a reflection phase delay mirror, by using the medium refractive index characteristics of Al2O3, the reflection characteristics of Ag, the high refractive index characteristics of Ti3O5 and the low refractive index characteristics of SiO2, the reflectivity of the optical phase delay reflection film is high, when linearly polarized light is incident on the surface of the reflection phase delay mirror plated with the optical phase delay reflection film at an angle of 45 degrees, the light wave after superposition of the linearly polarized light can have expected polarization characteristics, so that the measurement precision and the stability of the system are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of optical technology, and particularly to an optical phase delay reflection film, a plating method thereof and a fixture. BACKGROUND

[0002] In the field of plating film in optical technology, the reflection phase difference of a mirror is required to be less than a certain value at a 45° incidence angle, mainly to control the polarization state and interference effect of light waves, and to ensure the stability and accuracy of an optical system.

[0003] Currently, for high reflection films, dielectric films and metal films are usually used for plating, but the dielectric films have a great impact on the surface shape of a substrate due to the limitation of the plating process, and are weak in controlling the phase difference due to the large number of layers. Therefore, an effective solution is urgently needed to solve the above problems. SUMMARY

[0004] To solve the above problems, the present application provides an optical phase delay reflection film, a plating method thereof and a fixture.

[0005] The present application provides an optical phase delay reflection film, which is composed of a metal silver film layer, a silicon dioxide film layer, a trititanium pentoxide film layer and an aluminum trioxide film layer plated on a reflection phase delay mirror.

[0006] According to the present application, the optical phase delay reflection film comprises, in order from near to far from the reflection phase delay mirror, a first aluminum trioxide film layer, the metal silver film layer, a second aluminum trioxide film layer, a first silicon dioxide film layer, a first trititanium pentoxide film layer, a second silicon dioxide film layer, a second trititanium pentoxide film layer and a third silicon dioxide film layer.

[0007] The present application also provides a plating method for the above-mentioned optical phase delay reflection film, comprising:

[0008] The substrate of the reflection phase delay mirror is etched and cleaned for 10-15 minutes using a Hall ion source, and the background vacuum degree is kept below 2*10 -3 Pascal, and the deposition temperature is 70-100 degrees Celsius, and the constant temperature is kept for 10-20 minutes;

[0009] The optical phase delay reflection film is plated on the surface of the reflection phase delay mirror.

[0010] According to the present application, the plating method for the optical phase delay reflection film comprises:

[0011] The first aluminum oxide film layer is deposited on the surface of the reflective phase retardation mirror by ion source assisted evaporation at a deposition rate of 2-3 angstroms per second, an oxygen flow of 10-20 standard cubic centimeters per minute, and a target thickness of the first aluminum oxide film layer;

[0012] The ion source is turned off and the deposition is paused for 4-6 minutes;

[0013] The metal silver film layer is deposited on the first aluminum oxide film layer by resistance evaporation at a deposition rate of 15 angstroms per second and a target thickness of the metal silver film layer;

[0014] The second aluminum oxide film layer is deposited on the metal silver film layer by electron beam evaporation at a deposition rate of 2-3 angstroms per second, an oxygen flow of 10-20 standard cubic centimeters per minute, and a target thickness of the second aluminum oxide film layer;

[0015] The first silicon dioxide film layer is deposited on the second aluminum oxide film layer by the electron beam evaporation at a deposition rate of 5-6 angstroms per second and a target thickness of the first silicon dioxide film layer;

[0016] The base of the first silicon dioxide film layer is cleaned using the Hall ion source for 10-15 minutes at a temperature of 100-120 degrees Celsius;

[0017] The first titanium pentoxide film layer is deposited on the first silicon dioxide film layer by ion source assisted evaporation at a deposition rate of 2-3 angstroms per second, an oxygen flow of 10-20 standard cubic centimeters per minute, and a target thickness of the first titanium pentoxide film layer;

[0018] The second silicon dioxide film layer is deposited on the first titanium pentoxide film layer by ion source assisted evaporation at a deposition rate of 5-6 angstroms per second and a target thickness of the second silicon dioxide film layer;

[0019] The second titanium pentoxide film layer is deposited on the second silicon dioxide film layer by ion source assisted evaporation at a deposition rate of 2-3 angstroms per second, an oxygen flow of 10-20 standard cubic centimeters per minute, and a target thickness of the second titanium pentoxide film layer;

[0020] The third silicon dioxide film layer is deposited on the second titanium pentoxide film layer by ion source assisted evaporation at a deposition rate of 5-6 angstroms per second and a target thickness of the third silicon dioxide film layer.

[0021] According to the application, a method for coating an optical phase delay reflection film is provided, and before coating the optical phase delay reflection film on the surface of the reflection phase delay mirror, the method further comprises:

[0022] obtaining the coating proportion parameters of each film layer in the optical phase delay reflection film and the coating target of the reflection phase delay mirror;

[0023] According to the coating target and the coating proportion parameters of each film layer in the optical phase delay reflection film, the target coating thickness of each aluminum trioxide film layer, the target coating thickness of the silver metal film layer, the target coating thickness of each silicon dioxide film layer and the target coating thickness of each titanium trioxide film layer in the optical phase delay reflection film are determined respectively.

[0024] According to the application, a method for coating an optical phase delay reflection film is provided, and the method for obtaining the coating proportion parameters of each film layer in the optical phase delay reflection film comprises:

[0025] obtaining a first test mirror, a second test mirror, a third test mirror, a fourth test mirror, a fifth test mirror and a sixth test mirror of the same base material as the reflection phase delay mirror;

[0026] coating a silver metal film layer with a first set thickness on the surface of the first test mirror; coating a titanium trioxide film layer with a second set thickness on the surface of the second test mirror; using an ion source assisted evaporation film forming method to coat an aluminum trioxide film layer with a third set thickness on the surface of the third test mirror; without using an ion source assisted evaporation film forming method to coat an aluminum trioxide film layer with a fourth set thickness on the surface of the fourth test mirror; using an ion source assisted evaporation film forming method to coat a silicon dioxide film layer with a fifth set thickness on the surface of the fifth test mirror; without using an ion source assisted evaporation film forming method to coat a silicon dioxide film layer with a sixth set thickness on the surface of the sixth test mirror;

[0027] performing simulation analysis on the first test mirror, the second test mirror, the third test mirror, the fourth test mirror, the fifth test mirror and the sixth test mirror after coating, to determine the simulation coating thickness of the silver metal film layer on the first test mirror, the simulation coating thickness of the titanium trioxide film layer on the second test mirror, the simulation coating thickness of the aluminum trioxide film layer on the third test mirror, the simulation coating thickness of the aluminum trioxide film layer on the fourth test mirror, the simulation coating thickness of the silicon dioxide film layer on the fifth test mirror and the simulation coating thickness of the silicon dioxide film layer on the sixth test mirror;

[0028] The ratio of the first set thickness to the simulated plating thickness of the metal silver film layer on the first test mirror is determined as the plating proportion parameter corresponding to the metal silver film layer; the ratio of the second set thickness to the simulated plating thickness of the titanium pentoxide film layer on the second test mirror is determined as the plating proportion parameter corresponding to the titanium pentoxide film layer; the ratio of the third set thickness to the simulated plating thickness of the aluminum trioxide film layer on the third test mirror is determined as the plating proportion parameter corresponding to the aluminum trioxide film layer under the film forming mode of ion source assisted evaporation; the ratio of the fourth set thickness to the simulated plating thickness of the aluminum trioxide film layer on the fourth test mirror is determined as the plating proportion parameter corresponding to the aluminum trioxide film layer under the film forming mode without ion source assisted evaporation; the ratio of the fifth set thickness to the simulated plating thickness of the silicon dioxide film layer on the fifth test mirror is determined as the plating proportion parameter corresponding to the silicon dioxide film layer under the film forming mode of ion source assisted evaporation; and the ratio of the sixth set thickness to the simulated plating thickness of the silicon dioxide film layer on the sixth test mirror is determined as the plating proportion parameter corresponding to the silicon dioxide film layer under the film forming mode without ion source assisted evaporation.

[0029] According to the present application, a plating method of an optical phase delay reflection film is provided, in which the target plating thickness of each aluminum trioxide film layer, the target plating thickness of the metal silver film layer, the target plating thickness of each silicon dioxide film layer and the target plating thickness of each titanium pentoxide film layer in the optical phase delay reflection film are determined according to the plating target and the plating proportion parameter of each film layer in the optical phase delay reflection film, comprising:

[0030] Based on the plating target, simulation analysis is performed to determine the design plating thickness of each film layer in the optical phase delay reflection film;

[0031] The design plating thickness of the first aluminum trioxide film layer is multiplied by the plating proportion parameter corresponding to the aluminum trioxide film layer under the film forming mode of ion source assisted evaporation to obtain the target plating thickness of the first aluminum trioxide film layer;

[0032] The design plating thickness of the metal silver film layer is multiplied by the plating proportion parameter corresponding to the metal silver film layer to obtain the target plating thickness of the metal silver film layer;

[0033] The design plating thickness of the second aluminum trioxide film layer is multiplied by the plating proportion parameter corresponding to the aluminum trioxide film layer under the film forming mode without ion source assisted evaporation to obtain the target plating thickness of the second aluminum trioxide film layer;

[0034] The designed plating thickness of the first silicon dioxide film layer is multiplied by the plating proportion parameter corresponding to the silicon dioxide film layer in the film forming mode without ion source assisted evaporation to obtain the target plating thickness of the first silicon dioxide film layer;

[0035] The designed plating thickness of the first titanium trioxide film layer is multiplied by the plating proportion parameter corresponding to the titanium trioxide film layer to obtain the target plating thickness of the first titanium trioxide film layer;

[0036] The designed plating thickness of the second silicon dioxide film layer is multiplied by the plating proportion parameter corresponding to the silicon dioxide film layer in the film forming mode with ion source assisted evaporation to obtain the target plating thickness of the second silicon dioxide film layer;

[0037] The designed plating thickness of the second titanium trioxide film layer is multiplied by the plating proportion parameter corresponding to the titanium trioxide film layer to obtain the target plating thickness of the second titanium trioxide film layer;

[0038] The designed plating thickness of the third silicon dioxide film layer is multiplied by the plating proportion parameter corresponding to the silicon dioxide film layer in the film forming mode with ion source assisted evaporation to obtain the target plating thickness of the third silicon dioxide film layer.

[0039] According to the present application, a plating method of an optical phase delay reflection film is provided, and the reflection phase delay mirror comprises adjacent first plating surface and second plating surface;

[0040] The plating of the optical phase delay reflection film on the surface of the reflection phase delay mirror comprises:

[0041] The edge of the reflection phase delay mirror is clamped by a set fixture, so that the first plating surface and the second plating surface are simultaneously and completely exposed to the plating area;

[0042] The optical phase delay reflection film is plated on the first plating surface and the second plating surface respectively.

[0043] According to the present application, a plating method of an optical phase delay reflection film is provided, and the edge of the reflection phase delay mirror is clamped by a set fixture, so that the first plating surface and the second plating surface are simultaneously and completely exposed to the plating area, comprising:

[0044] The included angle of the first plating surface and the second plating surface is obtained;

[0045] The supplementary angle of the included angle is calculated;

[0046] The edge of the reflection phase delay mirror is clamped by a fixture, so that the first coating surface and the second coating surface are respectively half of the supplementary angle with the tilt angle of the horizontal plane, and the first coating surface and the second coating surface are simultaneously fully exposed in the coating area.

[0047] The application further provides a fixture applied to fixing a reflection phase delay mirror to be coated with an optical phase delay reflection film, the reflection phase delay mirror comprising a first coating surface and a second coating surface, comprising:

[0048] a base, at least two test pieces arranged in a line on the base, and a pair of clamping parts arranged on the base;

[0049] The pair of clamping parts are used for clamping the reflection phase delay mirror, so that the first coating surface and the second coating surface are respectively half of the supplementary angle with the tilt angle of the horizontal plane, and the first coating surface and the second coating surface are simultaneously fully exposed in the coating area, and the supplementary angle is the included angle of the first coating surface and the second coating surface;

[0050] The at least two test pieces are used for coating test;

[0051] The test pieces are connected to the base through a reversible device, and the reversible device is used for adjusting the tilt angle of the test pieces with the horizontal plane.

[0052] The optical phase delay reflection film and the coating method and the fixture provided by the application make the reflectivity of the optical phase delay reflection film high by using the medium refractive index characteristics of Al2O3, the reflection characteristics of Ag, the high refractive index characteristics of Ti3O5 and the low refractive index characteristics of SiO2, so that when linearly polarized light is incident on the surface of the reflection phase delay mirror coated with the optical phase delay reflection film at an angle of 45°, the light wave after superposition of the linearly polarized light has the expected polarization characteristics, thereby improving the measurement accuracy and the stability of the system. In addition, the fixture provided by the application can form a film layer that should be coated multiple times at one time, thereby reducing the coating times as much as possible and improving the coating efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0053] In order to more clearly illustrate the technical solutions in the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are some embodiments of the application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0054] Figure 1 is one of the structural schematic diagrams of the fixture provided by the application.

[0055] Figure 2is a structural schematic view of a base provided by the present application.

[0056] Figure 3 is a second structural schematic view of a fixture provided by the present application.

[0057] Figure 4 is a flowchart of a plating method of an optical phase delay reflection film provided by the present application.

[0058] Figure 5 is a structural schematic view of a reflection phase delay mirror provided by the present application.

[0059] Figure 6 is a side sectional view of a fixture clamping a reflection phase delay mirror provided by the present application.

[0060] Figure 7 is a design curve schematic view of an optical phase delay reflection film provided by the present application.

[0061] Figure 8 is a measured curve schematic view of an optical phase delay reflection film provided by the present application.

[0062] Figure 9 is a reflection phase shift measured curve schematic view of an optical phase delay reflection film provided by the present application. DETAILED DESCRIPTION

[0063] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be described clearly and completely below with reference to the drawings in the present application. Obviously, the described embodiments are some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0064] The optical phase delay reflection film and the plating method and fixture thereof of the present application will be described below with reference to the drawings. Figures 1-9 The optical phase delay reflection film and the plating method and fixture thereof of the present application will be described below with reference to the drawings.

[0065] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be described clearly and completely below with reference to the drawings in the present application. Obviously, the described embodiments are some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0066] Silver (Argentum) is a kind of transition metal, and the element symbol is Ag.

[0067] Silicon dioxide is an inorganic compound, and the chemical formula is SiO2. Silicon dioxide has a very small absorption coefficient at the working wavelength, presents uniform microparticle growth, the film layer structure is amorphous, has a high laser damage threshold, and is an ideal low refractive index material.

[0068] Titanium pentoxide is a chemical substance, blue-black powder with metallic luster, molecular formula is Ti3O5.

[0069] Aluminum oxide, also known as alumina, is an inorganic substance with the chemical formula Al2O3. It is a high-hardness compound with a melting point of 2054°C and a boiling point of 2980°C. It is an ion crystal that can be ionized at high temperatures.

[0070] Vacuum evaporation: also known as evaporation, is a process method that evaporates and vaporizes the plating film material (or film material) by using a certain heating evaporation method under vacuum conditions, and the particles fly to the substrate surface to condense into a film. Evaporation is an early and widely used gas deposition technology, with the advantages of simple film forming method, high film purity and density, unique film structure and performance, etc.

[0071] Coating fixture: plays the role of carrying optical elements during vacuum evaporation of optical elements, such as planetary clamps. Unlike optical elements, coating fixtures are usually made of metal materials such as aluminum alloy, stainless steel, etc.

[0072] Angstrom, abbreviated as A, is a very small length unit or thickness unit.

[0073] Maintaining the polarization state of light mainly includes two schemes: the stability of polarized light and the superposition effect of polarized light.

[0074] Stability of polarized light: When light waves are incident on a mirror at a certain angle, their polarization components will be reflected, such as S light (Senkrecht, vertical polarization light) components and P light (Parallel, parallel polarization light) components. If the reflection phase difference is too large, it will change the phase relationship of these polarization components, affecting the polarization state of the light wave. For example, in some optical systems, it is necessary to maintain the linear polarization state of the light wave. If the reflection phase difference is too large, it may convert linearly polarized light into elliptically or circularly polarized light, affecting the performance of the system.

[0075] Superposition effect of polarized light: In some applications such as polarized light interferometers, it is necessary to superimpose reflected light and incident light. If the reflection phase difference is controlled within a certain range, it can ensure that the superimposed light wave has the expected polarization characteristics, thereby improving the measurement accuracy and stability of the system.

[0076] Control of interference effect of light mainly includes the stability of interference fringes and the precise control of optical path difference.

[0077] Stability of interference fringes: In optical systems such as interferometers, the interference effect of light waves is the key to achieving accurate measurement. The size of the reflection phase difference will affect the distribution and stability of the interference fringes. If the phase difference is too large, it will cause the interference fringes to drift or deform, affecting the accuracy of the measurement results.

[0078] Precise control of optical path difference: In a multi-beam interference system, the control of reflection phase difference can precisely adjust the optical path difference to achieve a specific interference effect. For example, in the design of optical filters, by precisely controlling the reflection phase difference, the enhancement or suppression of specific wavelengths of light can be achieved, thereby achieving the purpose of filtering.

[0079] Improving the performance of optical systems mainly includes optimizing the beam quality and enhancing the stability of the system.

[0080] Optimization of beam quality: In lasers, optical imaging systems, etc., the reflection phase difference of the mirror will affect the quality and propagation characteristics of the light beam. Controlling the phase difference can reduce the scattering and distortion of the light beam, and improve the stability and consistency of the light beam.

[0081] Enhancement of system stability: In complex optical systems, the cumulative reflection phase difference of multiple mirrors may cause the performance of the system to decline. By precisely controlling the reflection phase difference of each mirror, the cumulative error can be effectively reduced, and the overall stability and reliability of the system can be improved.

[0082] As can be seen, controlling the reflection phase difference is of great significance for maintaining the polarization state of light waves, controlling interference effects, and improving the performance of optical systems, and is one of the key factors for achieving high-precision optical measurement and high-quality light beam output.

[0083] Currently, for high-reflective films, dielectric films and metal films are usually used for plating. However, due to the limitations of the plating process, dielectric films have a greater impact on the surface shape of the substrate. In addition, due to the large number of layers, they are at a disadvantage in controlling phase difference. The second is to use metal films for plating, but the reflectivity of pure metal films is limited and cannot reach a certain height.

[0084] Embodiments of the present application provide an optical phase delay reflective film, which is composed of a metal Ag film layer, a SiO2 film layer, a Ti3O5 film layer and an Al2O3 film layer plated on a reflective phase delay mirror.

[0085] The optical phase delay reflective film is mainly a high-reflective film. The optical phase delay reflective film adopts a G|M Ag M L H L H L|A multi-material film system structure, wherein G is a substrate, M is a medium refractive index material Al2O3, Ag is a plated Ag layer, L is a low refractive index layer SiO2, H is a high refractive index layer Ti3O5, and A is air.

[0086] Specifically, the optical phase delay reflective film contains at least one metal Ag film layer, at least one SiO2 film layer, at least one Ti3O5 film layer and at least one Al2O3 film layer.

[0087] The embodiment of the present application makes use of the medium refractive index characteristics of Al2O3, the reflection characteristics of Ag, the high refractive index characteristics of Ti3O5 and the low refractive index characteristics of SiO2 to make the reflectivity of the optical phase delay reflection film high, so that when linearly polarized light is incident on the surface of the reflection phase delay mirror (such as a long mirror) coated with the optical phase delay reflection film at an angle of 45°, the superimposed light wave of the linearly polarized light has the expected polarization characteristics, thereby improving the measurement accuracy and the stability of the system.

[0088] In one or more optional embodiments of the present application, the optical phase delay reflection film comprises two Al2O3 film layers (a first Al2O3 film layer and a second Al2O3 film layer), one metal Ag film layer, three SiO2 film layers (a first SiO2 film layer, a second SiO2 film layer and a third SiO2 film layer) and two Ti3O5 film layers (a first Ti3O5 film layer and a second Ti3O5 film layer). Correspondingly, the optical phase delay reflection film is sequentially the first Al2O3 film layer, the metal Ag film layer, the second Al2O3 film layer, the first SiO2 film layer, the first Ti3O5 film layer, the second SiO2 film layer, the second Ti3O5 film layer and the third SiO2 film layer in the order from near to far with respect to the reflection phase delay mirror.

[0089] The embodiment of the present application first coats Al2O3 on the reflection phase delay mirror to strengthen the bonding force of Ag and the substrate, then coats Ag, and finally coats Al2O3 and SiO2, while using Ti3O5 and SiO2 to strengthen the reflection force, making use of the high refractive index characteristics of Ti3O5 and the low refractive index characteristics of SiO2 to make the reflectivity high, so that when linearly polarized light is incident on the surface of the reflection phase delay mirror at an angle of 45°, the superimposed light wave of the linearly polarized light has the expected polarization characteristics, thereby improving the measurement accuracy and the stability of the system.

[0090] Figure 1 is one of the structural schematic diagrams of the fixture provided by the present application, as Figure 1 shown, the fixture is applied to fix the reflection phase delay mirror to be coated with the optical phase delay reflection film, the reflection phase delay mirror comprises a first coating surface and a second coating surface, and the fixture comprises:

[0091] a base 1, at least two test pieces 2 arranged in a line on the base 1 and a pair of clamping parts 3 arranged on the base 1;

[0092] The pair of clamping parts 3 are used to clamp the reflection phase delay mirror, so that the inclination angles between the first coating surface and the second coating surface and the horizontal plane are each half of a set angle, and the first coating surface and the second coating surface are simultaneously completely exposed in the coating area, and the set angle is the supplementary angle of the included angle of the first coating surface and the second coating surface.

[0093] The at least two test pieces 2 are used for plating test;

[0094] The test pieces 2 are connected to the base 1 through reversible devices, which are used for adjusting the inclination angle between the test pieces 2 and the horizontal plane.

[0095] It should be noted that the arrangement direction of the at least two test pieces 2 is parallel to the length direction of the reflective phase delay mirror, that is, the arrangement direction of the at least two test pieces 2 is parallel to the length of the rectangle surrounded by the pair of clamping parts 3 and the base. Figure 1 The outer shape of the middle base is disc-shaped, which is only illustrative, and the outer shape of the base can be any applicable shape, such as rectangular, triangular, etc.

[0096] Preferably, in order to clamp reflective phase delay mirrors of different sizes, at least one movable clamping part 3 is included in the pair of clamping parts 3, which can clamp the reflective phase delay mirror by moving.

[0097] In addition, referring to Figure 2 , Figure 2 is a structural schematic view of the base provided by the present application: the inside of the base 1 is provided with a rectangular through opening 1-1. The through opening 1-1 and the rectangle surrounded by the pair of clamping parts 3 are used for placing the reflective phase delay mirror. The pair of clamping parts 3 can be arranged on both sides of the length of the rectangular inside of the base, as Figure 1 shown; on the basis of Figure 1 , referring to Figure 3 , Figure 3 is a second structural schematic view of the fixture provided by the present application. The pair of clamping parts 3 can also be arranged on both sides of the width of the rectangular inside of the base 1.

[0098] The test pieces on the fixture are used for testing to ensure that the test pieces have the same optical performance as the product. At the same time, in terms of structure, the fixture is correspondingly chamfered for the film plating part of the product and the test piece.

[0099] The fixture provided by the present application can make the film layer that should be plated multiple times be plated once, thereby reducing the plating times as much as possible and improving the plating efficiency.

[0100] Figure 4 is a flowchart of the plating method of the optical phase delay reflective film provided by the present application, as Figure 4 shown, which comprises steps 401 and 402.

[0101] Step 401: etching and cleaning the substrate of the reflective phase delay mirror using a Hall ion source for 10-15 minutes (min), and keeping the background vacuum degree below 2*10 -3Pascal (Pa), deposition temperature is 70-100 degrees Celsius (℃), constant temperature 10-20 min.

[0102] In practical applications, in order to ensure the success rate of the optical phase delay reflection film, the reflection phase delay mirror to be plated needs to be pretreated before plating. That is, before plating each film layer of the reflection phase delay mirror, the substrate needs to be etched and cleaned by a Hall ion source for 10-15 min, and the background vacuum degree needs to be kept below 2*10 -3 Pa, deposition temperature is 70-100 degrees Celsius (℃), constant temperature 10-20 min.

[0103] Step 402: plating the optical phase delay reflection film on the surface of the reflection phase delay mirror.

[0104] After the reflection phase delay mirror to be plated is pretreated, the reflection phase delay mirror to be plated can be fixed by using a plating fixture, and then a metal Ag film layer, a SiO2 film layer, a Ti3O5 film layer and an Al2O3 film layer, i.e. the optical phase delay reflection film, can be plated on the surface (convex surface and concave surface) of the reflection phase delay mirror.

[0105] Among them, at least one of ion source assisted evaporation, electron beam evaporation and vacuum evaporation can be used to plate the optical phase delay reflection film.

[0106] The plating method of the optical phase delay reflection film provided by the application can make the reflectivity of the reflection phase delay mirror plated with the optical phase delay reflection film higher, and can ensure that the superimposed light wave of the linearly polarized light has the expected polarization characteristics when the linearly polarized light is incident on the surface of the reflection phase delay mirror plated with the optical phase delay reflection film at an angle of 45°, thereby improving the measurement accuracy and the stability of the system.

[0107] Preferably, the first Al2O3 film layer, the metal Ag film layer, the second Al2O3 film layer, the first SiO2 film layer, the first Ti3O5 film layer, the second SiO2 film layer, the second Ti3O5 film layer and the third SiO2 film layer can be plated on the surface of the reflection phase delay mirror in sequence.

[0108] In one or more optional embodiments of the application, the plating of the optical phase delay reflection film on the surface of the reflection phase delay mirror comprises:

[0109] The deposition rate is controlled to be 2-3 angstroms per second (A / s), the oxygen filling amount is 10-20 standard cubic centimeters per minute (SCCM), and the first Al2O3 film layer is plated on the surface of the reflection phase delay mirror by ion source assisted evaporation according to the target plating thickness of the first Al2O3 film layer.

[0110] Turning off the ion source, pausing the plating for 4-6 minutes;

[0111] Controlling the deposition rate to be 15 A / s, and according to the target plating thickness of the metal Ag film layer, plating the metal Ag film layer on the first Al2O3 film layer by the film forming method of resistance evaporation;

[0112] Controlling the deposition rate to be 2-3 A / s, the oxygen supply to be 10-20 SCCM, and according to the target plating thickness of the second Al2O3 film layer, plating the second Al2O3 film layer on the metal Ag film layer by the film forming method of electron beam evaporation;

[0113] Controlling the deposition rate to be 5-6 A / s, and according to the target plating thickness of the first SiO2 film layer, plating the first SiO2 film layer on the second Al2O3 film layer by the film forming method of electron beam evaporation;

[0114] Cleaning the substrate of the first SiO2 film layer for 10-15 minutes using the Hall ion source, and setting the temperature to be 100-120 degrees Celsius;

[0115] Controlling the deposition rate to be 2-3 A / s, the oxygen supply to be 10-20 SCCM, and according to the target plating thickness of the first Ti3O5 film layer, plating the first Ti3O5 film layer on the first SiO2 film layer by the film forming method of ion source assisted evaporation;

[0116] Controlling the deposition rate to be 5-6 A / s, and according to the target plating thickness of the second SiO2 film layer, plating the second SiO2 film layer on the first Ti3O5 film layer by the film forming method of ion source assisted evaporation;

[0117] Controlling the deposition rate to be 2-3 A / s, the oxygen supply to be 10-20 SCCM, and according to the target plating thickness of the second Ti3O5 film layer, plating the second Ti3O5 film layer on the second SiO2 film layer by the film forming method of ion source assisted evaporation;

[0118] Controlling the deposition rate to be 5-6 A / s, and according to the target plating thickness of the third SiO2 film layer, plating the third SiO2 film layer on the second Ti3O5 film layer by the film forming method of ion source assisted evaporation.

[0119] In practical applications, the optical phase delay reflection film includes a first Al2O3 film layer, a metal Ag film layer, a second Al2O3 film layer, a first SiO2 film layer, a first Ti3O5 film layer, a second SiO2 film layer, a second Ti3O5 film layer, and a third SiO2 film layer, which need to be plated in sequence.

[0120] In the first 4 layers combination (the first Al2O3 film layer, the metal Ag film layer, the second Al2O3 film layer and the first SiO2 film layer), when plating the first layer, when plating the first Al2O3 film layer, the first Al2O3 film layer is a bonding layer for bonding the substrate and the metal Ag film layer, and the deposition rate needs to be controlled to be 2-3 A / s, the oxygen supply amount is 10-20 SCCM, and the film is formed by the ion source assisted evaporation. After plating the first Al2O3 film layer, the ion source is turned off, and the ion source is stopped for about 5 minutes (4-6 minutes) to prevent the ion source radiation from causing oxidation of the metal Ag and causing absorption. When plating the metal Ag film layer, the deposition rate is controlled to be 15 A / s, and the film is formed by resistance evaporation. Then, when plating the second Al2O3 film layer and the first SiO2 film layer, in order to prevent the ion source from affecting the metal Ag film layer, the ion source is not used for auxiliary plating when plating the second Al2O3 film layer and the first SiO2 film layer, and ordinary electron beam evaporation is used to form the film. Among them, when plating the second Al2O3 film layer, the second Al2O3 film layer is a bonding layer for bonding the metal Ag film layer and the first SiO2 film layer, and the deposition rate needs to be controlled to be 2-3 A / s, and the oxygen supply amount is 10-20 SCCM. When plating the first SiO2 film layer, the deposition rate is controlled to be 5-6 A / s, and both layers are electron beam evaporation processes.

[0121] When titanium-silicon (Ti-Si) four-layer film layers (the first Ti3O5 film layer, the second SiO2 film layer, the second Ti3O5 film layer and the third SiO2 film layer) are carried out, they mainly serve as a reinforcing function, and the first SiO2 film layer needs to be cleaned for 10-15 minutes by using a Hall ion source to strengthen the firmness of the previous 4 layers. At the same time, the temperature is set to 100-120°C, and the following four layers are all assisted by ion beam (ion source) evaporation. Among them, when plating the Ti3O5 film layer (the first Ti3O5 film layer and the second Ti3O5 film layer), the deposition rate is controlled to be 2-3 A / s, and the oxygen supply amount is 10-20 SCCM. When plating the second SiO2 film layer and the third SiO2 film layer, the deposition rate is controlled to be 5-6 A / s.

[0122] In one or more optional embodiments of the application, before the optical phase delay reflective film is plated on the surface of the reflective phase delay mirror, it further comprises:

[0123] Obtaining the plating proportion parameters of each film layer in the optical phase delay reflective film and the plating target corresponding to the reflective phase delay mirror;

[0124] According to the tooling target and the plating proportion parameter of each film layer in the optical phase delay reflection film, target plating thicknesses of each Al2O3 film layer, target plating thickness of the metal Ag film layer, target plating thicknesses of each SiO2 film layer and target plating thicknesses of each Ti3O5 film layer in the optical phase delay reflection film are determined respectively.

[0125] Specifically, the plating proportion parameter (Tooling) refers to a ratio of an actual plating thickness (actual thickness) to a design plating thickness, wherein the design plating thickness refers to a film layer thickness designed in software for the reflection phase delay mirror in software simulation. The tooling target refers to optical parameters and surface shape parameters of the optical phase delay reflection film for forming an optical element for the reflection phase delay mirror. The target plating thickness refers to a thickness of a film layer actually to be plated for the optical phase delay reflection film, i.e., the actual plating thickness.

[0126] In actual application, the plating proportion parameter and the tooling target corresponding to the reflection phase delay mirror can be acquired first, wherein Al2O3, metal Ag, SiO2 and Ti3O5 can share one plating proportion parameter or can correspond to respective plating proportion parameters. The plating proportion parameter can be preset or can be calculated according to actual conditions. The present application does not limit this.

[0127] Then, simulation, analysis and calculation are performed based on the tooling target and the plating proportion parameter, so as to obtain the target plating thicknesses of each film layer in the optical phase delay reflection film, i.e., target plating thicknesses of each Al2O3 film layer, target plating thickness of the metal Ag film layer, target plating thicknesses of each SiO2 film layer and target plating thicknesses of each Ti3O5 film layer in the optical phase delay reflection film.

[0128] The present embodiment determines the target plating thicknesses through the plating proportion parameter and the tooling target, and then performs plating of the optical phase delay reflection film, so as to not only ensure accuracy of the optical phase delay reflection film, but also improve optical accuracy of an optical element based on the optical phase delay reflection film.

[0129] In one or more optional embodiments of the present application, the acquisition of the plating proportion parameter of each film layer in the optical phase delay reflection film comprises:

[0130] A first test mirror, a second test mirror, a third test mirror, a fourth test mirror, a fifth test mirror and a sixth test mirror of the same substrate material as the reflection phase delay mirror are acquired.

[0131] plating a metal Ag film layer of a first set thickness on the first test mirror surface; plating a Ti3O5 film layer of a second set thickness on the second test mirror surface; plating an Al2O3 film layer of a third set thickness on the third test mirror surface using an ion source assisted evaporation film forming method; plating an Al2O3 film layer of a fourth set thickness on the fourth test mirror surface without using the ion source assisted evaporation film forming method; plating a SiO2 film layer of a fifth set thickness on the fifth test mirror surface using the ion source assisted evaporation film forming method; and plating a SiO2 film layer of a sixth set thickness on the sixth test mirror surface without using the ion source assisted evaporation film forming method;

[0132] The first test mirror, the second test mirror, the third test mirror, the fourth test mirror, the fifth test mirror and the sixth test mirror after plating are respectively subjected to simulation analysis to determine a simulated plating thickness of the metal Ag film layer on the first test mirror, a simulated plating thickness of the Ti3O5 film layer on the second test mirror, a simulated plating thickness of the Al2O3 film layer on the third test mirror, a simulated plating thickness of the Al2O3 film layer on the fourth test mirror, a simulated plating thickness of the SiO2 film layer on the fifth test mirror and a simulated plating thickness of the SiO2 film layer on the sixth test mirror.

[0133] A ratio of the first set thickness to the simulated plating thickness of the metal Ag film layer on the first test mirror is determined as a plating proportion parameter corresponding to the metal Ag film layer; a ratio of the second set thickness to the simulated plating thickness of the Ti3O5 film layer on the second test mirror is determined as a plating proportion parameter corresponding to the Ti3O5 film layer; a ratio of the third set thickness to the simulated plating thickness of the Al2O3 film layer on the third test mirror is determined as a plating proportion parameter corresponding to the Al2O3 film layer under the ion source assisted evaporation film forming method; a ratio of the fourth set thickness to the simulated plating thickness of the Al2O3 film layer on the fourth test mirror is determined as a plating proportion parameter corresponding to the Al2O3 film layer under the film forming method without using the ion source assistance evaporation; a ratio of the fifth set thickness to the simulated plating thickness of the SiO2 film layer on the fifth test mirror is determined as a plating proportion parameter corresponding to the SiO2 film layer under the ion source assisted evaporation film forming method; and a ratio of the sixth set thickness to the simulated plating thickness of the SiO2 film layer on the sixth test mirror is determined as a plating proportion parameter corresponding to the SiO2 film layer under the film forming method without using the ion source assistance evaporation.

[0134] Specifically, the first set thickness to the sixth set thickness are all 150-300 nanometers (nm). The first test mirror to the sixth test mirror can be the same six plane mirrors. The first set thickness to the sixth set thickness can be the same or different, wherein the first set thickness to the sixth set thickness are respectively the actual plating thicknesses of the film layers plated on the first test mirror to the sixth test mirror. The simulated plating thickness refers to the thickness of each film layer in the software when the software simulation is performed.

[0135] In actual application, in order to ensure the accuracy of the plating ratio parameters, the plating ratio parameters can be obtained through actual test, i.e. the plating ratio parameters are obtained by plating film layers on the test mirrors. Further, in order to ensure the reliability of the plating ratio parameters, the plating of metal Ag, the plating ratio parameters of Ti3O5, the plating ratio parameters of Al2O3 when the ion source is used for auxiliary evaporation and when the ion source is not used for auxiliary evaporation, and the plating ratio parameters of SiO2 when the ion source is used for auxiliary evaporation and when the ion source is not used for auxiliary evaporation need to be obtained on the first test mirror to the sixth test mirror which are made of the same substrate material as the reflective phase retardation mirror.

[0136] Specifically, the first set thickness to the sixth set thickness are all 150-300 nanometers (nm). The first test mirror to the sixth test mirror can be the same six plane mirrors. The first set thickness to the sixth set thickness can be the same or different, wherein the first set thickness to the sixth set thickness are respectively the actual plating thicknesses of the film layers plated on the first test mirror to the sixth test mirror. The simulated plating thickness refers to the thickness of each film layer in the software when the software simulation is performed.

[0137] Then, the first test mirror plated with the metal Ag film layer is simulated and analyzed by the film system software to determine the simulated plating thickness of the metal Ag film layer on the first test mirror; the second test mirror plated with the Ti3O5 film layer is simulated and analyzed by the film system software to determine the simulated plating thickness of the Ti3O5 film layer on the second test mirror; the third test mirror plated with the Al2O3 film layer using the ion source for auxiliary plating is simulated and analyzed by the film system software to determine the simulated plating thickness of the Al2O3 film layer on the third test mirror; the fourth test mirror plated with the Al2O3 film layer without using the ion source for auxiliary plating is simulated and analyzed by the film system software to determine the simulated plating thickness of the Al2O3 film layer on the fourth test mirror; the fifth test mirror plated with the SiO2 film layer using the ion source for auxiliary plating is simulated and analyzed by the film system software to determine the simulated plating thickness of the SiO2 film layer on the fifth test mirror; and the sixth test mirror plated with the SiO2 film layer without using the ion source for auxiliary plating is simulated and analyzed by the film system software to determine the simulated plating thickness of the SiO2 film layer on the sixth test mirror.

[0138] Further, the first set thickness is divided by the simulation plating thickness of the simulation plating thickness of the Ag film layer on the first test mirror to obtain a plating ratio parameter corresponding to the Ag film layer; the second set thickness is divided by the simulation plating thickness of the simulation plating thickness of the Ti3O5 film layer on the second test mirror to obtain a plating ratio parameter corresponding to the Ti3O5 film layer; the third set thickness is divided by the simulation plating thickness of the simulation plating thickness of the Al2O3 film layer on the third test mirror to obtain a plating ratio parameter corresponding to the Al2O3 film layer under the film forming mode of ion source assisted evaporation; the fourth set thickness is divided by the simulation plating thickness of the simulation plating thickness of the Al2O3 film layer on the fourth test mirror to obtain a plating ratio parameter corresponding to the Al2O3 film layer under the film forming mode without ion source assisted evaporation; the fifth set thickness is divided by the simulation plating thickness of the simulation plating thickness of the SiO2 film layer on the fifth test mirror to obtain a plating ratio parameter corresponding to the SiO2 film layer under the film forming mode of ion source assisted evaporation; and the sixth set thickness is divided by the simulation plating thickness of the simulation plating thickness of the SiO2 film layer on the sixth test mirror to obtain a plating ratio parameter corresponding to the SiO2 film layer under the film forming mode without ion source assisted evaporation.

[0139] In one or more optional embodiments of the present application, the target plating thickness of each Al2O3 film layer, the target plating thickness of the Ag film layer, the target plating thickness of each SiO2 film layer and the target plating thickness of each Ti3O5 film layer in the optical phase delay reflection film are determined according to the plating target and the plating ratio parameter of each film layer in the optical phase delay reflection film, comprising:

[0140] Based on the simulation analysis of the plating target, the design plating thickness of each film layer in the optical phase delay reflection film is determined;

[0141] The design plating thickness of the first Al2O3 film layer is multiplied by the plating ratio parameter corresponding to the Al2O3 film layer under the film forming mode of ion source assisted evaporation to obtain the target plating thickness of the first Al2O3 film layer;

[0142] The design plating thickness of the Ag film layer is multiplied by the plating ratio parameter corresponding to the Ag film layer to obtain the target plating thickness of the Ag film layer;

[0143] The design plating thickness of the second Al2O3 film layer is multiplied by the plating ratio parameter corresponding to the Al2O3 film layer under the film forming mode without ion source assisted evaporation to obtain the target plating thickness of the second Al2O3 film layer;

[0144] The design plating thickness of the first SiO2 film layer is multiplied by the plating ratio parameter corresponding to the SiO2 film layer in the film forming mode without ion source assisted evaporation to obtain the target plating thickness of the first SiO2 film layer;

[0145] The design plating thickness of the first Ti3O5 film layer is multiplied by the plating ratio parameter corresponding to the Ti3O5 film layer to obtain the target plating thickness of the first Ti3O5 film layer;

[0146] The design plating thickness of the second SiO2 film layer is multiplied by the plating ratio parameter corresponding to the SiO2 film layer in the film forming mode with ion source assisted evaporation to obtain the target plating thickness of the second SiO2 film layer;

[0147] The design plating thickness of the second Ti3O5 film layer is multiplied by the plating ratio parameter corresponding to the Ti3O5 film layer to obtain the target plating thickness of the second Ti3O5 film layer;

[0148] The design plating thickness of the third SiO2 film layer is multiplied by the plating ratio parameter corresponding to the SiO2 film layer in the film forming mode with ion source assisted evaporation to obtain the target plating thickness of the third SiO2 film layer.

[0149] Specifically, the design plating thickness refers to the thickness of each film layer in the optical phase delay reflection film designed for the reflection phase delay mirror in the software during software simulation.

[0150] In actual application, after the plating target is obtained, the plating target can be simulated by film system software simulation, that is, the optical phase delay reflection film of the reflection phase delay mirror is simulated in the film system software to achieve the plating target. When the plating target is achieved, the design plating thickness of each film layer in the optical phase delay reflection film recorded in the film system software is read, that is, the design plating thickness of the first Al2O3 film layer, the design plating thickness of the metal Ag film layer, the design plating thickness of the second Al2O3 film layer, the design plating thickness of the first SiO2 film layer, the design plating thickness of the first Ti3O5 film layer, the design plating thickness of the second SiO2 film layer, the design plating thickness of the second Ti3O5 film layer and the design plating thickness of the third SiO2 film layer.

[0151] Further, the design plating thickness of the first Al2O3 film layer is multiplied by the plating ratio parameter corresponding to the Al2O3 film layer in the film forming mode using ion source assisted evaporation to obtain the target plating thickness of the first Al2O3 film layer; the design plating thickness of the metal Ag film layer is multiplied by the plating ratio parameter corresponding to the metal Ag film layer to obtain the target plating thickness of the metal Ag film layer; the design plating thickness of the second Al2O3 film layer is multiplied by the plating ratio parameter corresponding to the Al2O3 film layer in the film forming mode without using ion source assisted evaporation to obtain the target plating thickness of the second Al2O3 film layer; the design plating thickness of the first SiO2 film layer is multiplied by the plating ratio parameter corresponding to the SiO2 film layer in the film forming mode without using ion source assisted evaporation to obtain the target plating thickness of the first SiO2 film layer; the design plating thickness of the first Ti3O5 film layer is multiplied by the plating ratio parameter corresponding to the Ti3O5 film layer to obtain the target plating thickness of the first Ti3O5 film layer; the design plating thickness of the second SiO2 film layer is multiplied by the plating ratio parameter corresponding to the SiO2 film layer in the film forming mode using ion source assisted evaporation to obtain the target plating thickness of the second SiO2 film layer; the design plating thickness of the second Ti3O5 film layer is multiplied by the plating ratio parameter corresponding to the Ti3O5 film layer to obtain the target plating thickness of the second Ti3O5 film layer; and the design plating thickness of the third SiO2 film layer is multiplied by the plating ratio parameter corresponding to the SiO2 film layer in the film forming mode using ion source assisted evaporation to obtain the target plating thickness of the third SiO2 film layer.

[0152] In one or more optional embodiments of the application, the reflective phase retardation mirror comprises adjacent first and second plating surfaces; and the plating of the optical phase retardation reflective film on the surface of the reflective phase retardation mirror comprises:

[0153] The edge of the reflective phase retardation mirror is clamped by a jig, so that the first and second plating surfaces are simultaneously and completely exposed to the plating area;

[0154] The optical phase retardation reflective film is plated on the first and second plating surfaces, respectively.

[0155] Specifically, the first and second plating surfaces are adjacent, i.e., the first and second plating surfaces share the same edge of the reflective phase retardation mirror. The reflective phase retardation mirror can be a long strip mirror.

[0156] In practical applications, the reflective phase retardation mirror comprises adjacent first and second plating surfaces. When two surfaces need to be plated, one surface is usually plated first, and then the other surface is plated, which increases the plating time.

[0157] In order to improve plating efficiency and reduce plating time, the edge of the reflective phase delay mirror is fixed by using a set fixture, so that the first plating surface and the second plating surface are simultaneously and completely exposed to the plating area. Thus, when the plating film machine plating the plating surface in the plating area, the first plating surface and the second plating surface can be simultaneously and completely plated with the optical phase delay reflective film.

[0158] In one or more optional embodiments of the application, the use of a set fixture to clamp the edge of the reflective phase delay mirror allows the first plating surface and the second plating surface to be simultaneously and completely exposed to the plating area, comprising:

[0159] Obtaining the included angle of the first plating surface and the second plating surface;

[0160] Calculating the supplementary angle of the included angle;

[0161] The edge of the reflective phase delay mirror is clamped by using a set fixture, so that the inclination angle of the first plating surface and the second plating surface with the horizontal plane is half of the supplementary angle, and the first plating surface and the second plating surface are simultaneously and completely exposed to the plating area.

[0162] In practical applications, the inclination angle of the first plating surface and the second plating surface with the horizontal plane can be calculated, i.e. θ1=θ2=(180°-θ 12 ) / 2, where θ1 is the inclination angle of the first plating surface with the horizontal plane, θ2 is the inclination angle of the second plating surface with the horizontal plane, and θ 12 is the included angle of the first plating surface and the second plating surface.

[0163] Then, the edge of the reflective phase delay mirror is clamped by using a set fixture, so that the inclination angle of the first plating surface and the second plating surface with the horizontal plane is (180-θ 12 ) / 2, and the first plating surface and the second plating surface are simultaneously and completely exposed to the plating area. In this way, the precision of plating the optical phase delay reflective film on the first plating surface and the second plating surface can be ensured.

[0164] In addition, a test piece is provided on the fixture, and the inclination angle of the test piece with the horizontal plane can be adjusted. In order to ensure that the optical performance of the test piece is the same as that of the product (reflective phase delay mirror), the inclination angle of the test piece with the horizontal plane can be adjusted to be the same as the inclination angle of the first plating surface or the second plating surface with the horizontal plane. When the optical performance on the test piece meets the plating requirements, the reflective phase delay mirror is plated.

[0165] The plating method of the optical phase delay reflective film provided by the application will be further described below. Figures 5 to 9

[0166] Referring to Figure 5 ,​Figure 5 is a structural schematic diagram of a reflective phase retardation mirror provided by the present application: according to Figure 5 The two diagrams on the left side of the figure show that the reflective phase retardation mirror is a long mirror; according to Figure 5 The three diagrams in the figure show that the long mirror comprises two coating surfaces S1 and S2; according to Figure 5 The diagram on the right side of the figure shows that the included angle θ 12 = 135°.

[0167] The base material of the reflective phase retardation mirror is quartz, and the film system requirements (coating targets) are reflectivity: Rs≥98%, Rp≥98% @ 45±0.5 AOI, λ=632.8nm; reflective phase difference ≤3°, that is, when the incident angle is 45±0.5°, the S light reflectivity (Rs) at 632.8nm is greater than or equal to 98%, the P light reflectivity (Rp) at 632.8nm is greater than or equal to 98%, and the reflective phase difference at 632.8nm is less than or equal to 3°.

[0168] Since the S1 and S2 surfaces need to simultaneously meet the film system requirements, the fixture clamping reflective phase retardation mirror provided by the present application can simultaneously consider S2 when coating S1, so that the double-sided film formation and the film system indicators can simultaneously meet the requirements.

[0169] Referring to Figure 1 and Figure 6 , Figure 6 is a side sectional view of the fixture clamping reflective phase retardation mirror provided by the present application: by using the angle characteristics of the two coating surfaces of the product and the vacuum evaporation coating characteristics, the angle of the relative planes of S1 and S2 is equal, θ1=θ2=(180°-135°) / 2=22.5°. Since the inclined coating method of S1 and S2 is different from the conventional coating method, in order to ensure that the spectral curve is qualified, test pieces (front, middle, and rear) with the same angle are arranged on the fixture disc at the non-product positions to perform tests, and the inclined angle of the test pieces is equal to 22.5° to ensure that the optical performance of the test pieces is the same as that of the product. At the same time, in terms of structure, the fixture is correspondingly chamfered for the coating parts of the product and the test pieces, and the product is designed with “L” type flanges on both sides to ensure that the relative angles of the two surfaces are equal.

[0170] Al2O3 and SiO2 are both under two process conditions of using an ion source and not using an ion source. Under the same process conditions and using the same film material, the coating proportion parameters of each film layer are shown in Table 1.

[0171] Table 1

[0172]

[0173] Referring to Table 2, the table shows the plating parameters (design plating thickness, plating ratio parameters, target plating thickness, and whether to use an ion source) of each film layer in the optical phase delay reflective film provided by the application.

[0174] Table 2

[0175]

[0176] Generally, ordinary Ag can also achieve a certain level of residual reflectivity, but such a film system index of single-point > 98% requires the use of dielectric for reflectivity enhancement after the ordinary Ag film.

[0177] Process preparation: in the first 4-layer combination, the substrate needs to be etched and cleaned for 10-15 minutes using a Hall ion source, and the background vacuum degree before plating needs to be kept below 2*10 -3 Pa, and the deposition temperature is 70-100°C, and the constant temperature is maintained for 10-20 minutes. Among them, when plating the first layer, when plating the first Al2O3 film layer, the first Al2O3 film layer is a bonding layer for bonding the substrate and the metal Ag film layer, and the deposition rate needs to be controlled at 2-3 A / s, the oxygen flow is 10-20 SCCM, and the film is formed by ion source assisted evaporation. After plating the first Al2O3 film layer, the ion source is turned off, and the pause is about 5 minutes (4-6 minutes) to prevent the ion source radiation from causing oxidation of the metal Ag and causing absorption. When plating the metal Ag film layer, the deposition rate is controlled at 15 A / s, and the film is formed by resistance evaporation. Then, when plating the second Al2O3 film layer and the first SiO2 film layer, in order to prevent the ion source from affecting the metal Ag film layer, the second Al2O3 film layer and the first SiO2 film layer are not plated using an ion source for auxiliary plating, and ordinary electron beam evaporation is used to form the film. Among them, when plating the second Al2O3 film layer, the second Al2O3 film layer is a bonding layer for bonding the metal Ag film layer and the first SiO2 film layer, and the deposition rate needs to be controlled at 2-3 A / s, and the oxygen flow is 10-20 SCCM. When plating the first SiO2 film layer, the deposition rate is controlled at 5-6 A / s, and both layers are electron beam evaporation processes.

[0178] When the titanium-silicon (Ti-Si) four-layer film layer (the first Ti3O5 film layer, the second SiO2 film layer, the second Ti3O5 film layer and the third SiO2 film layer) is formed, the first SiO2 film layer is cleaned for 10-15 min by using a Hall ion source mainly as a reinforcing action, the firmness of the previous four-layer film layer is enhanced, the temperature is set to 100-120 ℃, and the ion beam (ion source) assisted evaporation is used for the following four layers, wherein the deposition rate of the Ti3O5 film layer (the first Ti3O5 film layer and the second Ti3O5 film layer) is controlled to be 2-3 A / s, the oxygen filling amount is 10-20 SCCM, and the deposition rate of the second SiO2 film layer and the third SiO2 film layer is controlled to be 5-6 A / s.

[0179] Figure 7 is a design curve schematic diagram of the optical phase delay reflection film provided by the application, referring to Figure 7 : the design curve of the optical phase delay reflection film, the incident angle is 45°, the substrate is a quartz substrate, the light source is white light, the incident medium is air, the substrate refractive index is 1.46, the exit refractive index is 1.46, the detection is ideal state, the center wavelength is 550 nm, the first surface is the front surface, the polarization state has three kinds of light, average, S and P, and the reflectivity in the 450-750 nm wave band is very high, from top to bottom, the first curve is the reflectivity curve of S light, the second curve is the average reflectivity curve of S light and P light, and the third curve is the reflectivity curve of P light, the reflectivity Rs thereof at 633 nm is 99.5%, the reflectivity Rp is 99.3%, and it can be seen that the design value can reach the index requirement of the plating target.

[0180] Figure 8 is a measured curve schematic diagram of the optical phase delay reflection film provided by the application, referring to Figure 8 : the measured curve of the optical phase delay reflection film, the incident angle is 45°, the substrate is a quartz substrate, from top to bottom, the first curve is the reflectivity curve of S light, and the second curve is the reflectivity curve of P light, the reflectivity Rs thereof at 633 nm is 99.731%, the reflectivity Rp is 98.935%, and the measured value can reach the index requirement of the plating target.

[0181] The measured value and the design value have some differences, which may be caused by the problems of too much or too little plating of some film layers in the actual plating, and belong to processing errors.

[0182] Figure 9 is a measured curve schematic diagram of the optical phase delay reflection film provided by the application, referring to Figure 9The measured curve of the reflection phase shift of the optical phase delay reflection film, the incident angle is 45°, the substrate is quartz substrate, the light source is white light, the incident medium is air, the substrate refractive index is 1.46, the exit refractive index is 1.46, the detection is ideal state, the center wavelength is 550nm, the first surface is the front surface, the polarization state has three kinds of light, average, S and P, from left to right, the first curve and the fourth curve are the reflection phase shift curves of P light, the second curve is the reflection phase shift curve of S light, and the third curve is the reflection phase shift average curve of S light and P light, the reflection phase shift thereof at 633nm is 180.765deg-180deg=0.765deg, which can meet the index requirements of the plating target.

[0183] Table 3 shows the phase delay difference detection data of the optical phase delay reflection film, as shown in the data in Table 3, the phase delay difference thereof at 632.8nm is 180.51°-180°=0.51°, the value of which is less than 3°, which can meet the index requirements of the plating target.

[0184] Table 3

[0185]

[0186] The plating method of the optical phase delay reflection film provided by the embodiment of the present application, by setting the optical phase delay reflection film, adopting the multi-material film system structure of G|M Ag M L H L H L|A, wherein G is a substrate, M is a medium refractive index material Al2O3, Ag is a plated Ag layer, L is a low refractive index layer SiO2, H is a high refractive index layer Ti3O5, and A is air. In the present application, on the reflection phase delay mirror, Al2O3 is first plated to strengthen the bonding force of Ag and the substrate, then Ag is plated, and finally Al2O3 and SiO2 are plated, and Ti3O5 and SiO2 are used for reflection strength enhancement treatment, the high refractive index characteristics of Ti3O5 and the low refractive index characteristics of SiO2 are used to make the reflectivity high, so that when linearly polarized light is incident on the surface of the reflection phase delay mirror at an angle of 45°, the superimposed light wave of the linearly polarized light has the expected polarization characteristics, thereby improving the measurement accuracy and the stability of the system. At the same time, during the plating process, a set fixture is used for plating, so that the film layers that should be plated multiple times are formed at one time, the plating times are reduced as much as possible, and the plating efficiency is improved.

[0187] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method of coating an optical phase retardation reflecting film, characterized by, The method comprises the following steps: The substrate of the reflective phase retardation mirror is etched and cleaned using a Hall ion source for 10-15 minutes, and the background vacuum is kept below 2*10 -3 Pascals, at a deposition temperature of 70-100 degrees Celsius, for 10-20 minutes. coating an optical phase delay reflection film on the surface of the reflection phase delay mirror, the optical phase delay reflection film comprises, in order from near to far with respect to the reflection phase delay mirror, a first aluminum oxide film layer, a metal silver film layer, a second aluminum oxide film layer, a first silicon dioxide film layer, a first titanium pentoxide film layer, a second silicon dioxide film layer, a second titanium pentoxide film layer, and a third silicon dioxide film layer; before the step of coating the optical phase delay reflection film on the surface of the reflection phase delay mirror, the method further comprises the following steps: obtaining a coating proportion parameter of each film layer in the optical phase delay reflection film and a coating target corresponding to the reflection phase delay mirror; determining a target coating thickness of each aluminum oxide film layer in the optical phase delay reflection film, a target coating thickness of the metal silver film layer, a target coating thickness of each silicon dioxide film layer, and a target coating thickness of each titanium pentoxide film layer according to the coating target and the coating proportion parameter of each film layer in the optical phase delay reflection film; the step of obtaining the coating proportion parameter of each film layer in the optical phase delay reflection film comprises the following steps: obtaining a first test mirror, a second test mirror, a third test mirror, a fourth test mirror, a fifth test mirror, and a sixth test mirror made of the same base material as the reflection phase delay mirror; coating a metal silver film layer with a first set thickness on the surface of the first test mirror; coating a titanium pentoxide film layer with a second set thickness on the surface of the second test mirror; coating an aluminum oxide film layer with a third set thickness on the surface of the third test mirror by using an ion source assisted evaporation film forming method; coating an aluminum oxide film layer with a fourth set thickness on the surface of the fourth test mirror without using the ion source assisted evaporation film forming method; coating a silicon dioxide film layer with a fifth set thickness on the surface of the fifth test mirror by using the ion source assisted evaporation film forming method; and coating a silicon dioxide film layer with a sixth set thickness on the surface of the sixth test mirror without using the ion source assisted evaporation film forming method; performing simulation analysis on the first test mirror, the second test mirror, the third test mirror, the fourth test mirror, the fifth test mirror, and the sixth test mirror after coating, to determine a simulated coating thickness of the metal silver film layer on the first test mirror, a simulated coating thickness of the titanium pentoxide film layer on the second test mirror, a simulated coating thickness of the aluminum oxide film layer on the third test mirror, a simulated coating thickness of the aluminum oxide film layer on the fourth test mirror, a simulated coating thickness of the silicon dioxide film layer on the fifth test mirror, and a simulated coating thickness of the silicon dioxide film layer on the sixth test mirror; and determining the coating proportion parameter of each film layer in the optical phase delay reflection film according to the simulated coating thicknesses of the first test mirror, the second test mirror, the third test mirror, the fourth test mirror, the fifth test mirror, and the sixth test mirror. The ratio of the first set thickness to the simulated plating thickness of the metal silver film layer on the first test mirror is determined as the plating proportion parameter corresponding to the metal silver film layer; the ratio of the second set thickness to the simulated plating thickness of the titanium trioxide film layer on the second test mirror is determined as the plating proportion parameter corresponding to the titanium trioxide film layer; the ratio of the third set thickness to the simulated plating thickness of the aluminum trioxide film layer on the third test mirror is determined as the plating proportion parameter corresponding to the aluminum trioxide film layer under the film forming mode of ion source assisted evaporation; the ratio of the fourth set thickness to the simulated plating thickness of the aluminum trioxide film layer on the fourth test mirror is determined as the plating proportion parameter corresponding to the aluminum trioxide film layer under the film forming mode without ion source assisted evaporation; the ratio of the fifth set thickness to the simulated plating thickness of the silicon dioxide film layer on the fifth test mirror is determined as the plating proportion parameter corresponding to the silicon dioxide film layer under the film forming mode of ion source assisted evaporation; and the ratio of the sixth set thickness to the simulated plating thickness of the silicon dioxide film layer on the sixth test mirror is determined as the plating proportion parameter corresponding to the silicon dioxide film layer under the film forming mode without ion source assisted evaporation. The determining of the target plating thickness of each aluminum trioxide film layer, the target plating thickness of the metal silver film layer, the target plating thickness of each silicon dioxide film layer and the target plating thickness of each titanium trioxide film layer in the optical phase delay reflection film according to the plating target and the plating proportion parameter of each film layer in the optical phase delay reflection film respectively comprises: performing simulation analysis based on the plating target to determine the design plating thickness of each film layer in the optical phase delay reflection film; multiplying the design plating thickness of the first aluminum trioxide film layer by the plating proportion parameter corresponding to the aluminum trioxide film layer under the film forming mode of ion source assisted evaporation to obtain the target plating thickness of the first aluminum trioxide film layer; multiplying the design plating thickness of the metal silver film layer by the plating proportion parameter corresponding to the metal silver film layer to obtain the target plating thickness of the metal silver film layer; multiplying the design plating thickness of the second aluminum trioxide film layer by the plating proportion parameter corresponding to the aluminum trioxide film layer under the film forming mode without ion source assisted evaporation to obtain the target plating thickness of the second aluminum trioxide film layer; multiplying the design plating thickness of the first silicon dioxide film layer by the plating proportion parameter corresponding to the silicon dioxide film layer under the film forming mode without ion source assisted evaporation to obtain the target plating thickness of the first silicon dioxide film layer; multiplying the design plating thickness of the first titanium trioxide film layer by the plating proportion parameter corresponding to the titanium trioxide film layer to obtain the target plating thickness of the first titanium trioxide film layer; multiplying the design plating thickness of the second silicon dioxide film layer by the plating proportion parameter corresponding to the silicon dioxide film layer under the film forming mode of ion source assisted evaporation to obtain the target plating thickness of the second silicon dioxide film layer; The designed plating thickness of the second titanium pentoxide film layer is multiplied by the plating proportion parameter corresponding to the titanium pentoxide film layer to obtain the target plating thickness of the second titanium pentoxide film layer; The designed plating thickness of the third silicon dioxide film layer is multiplied by the plating proportion parameter corresponding to the silicon dioxide film layer under the film forming mode of ion source assisted evaporation to obtain the target plating thickness of the third silicon dioxide film layer.

2. The method of coating an optical phase retardation reflecting film according to claim 1, wherein The surface of the reflective phase delay mirror is plated with an optical phase delay reflective film, including: The deposition rate is controlled to be 2-3 angstroms per second, the oxygen supply is controlled to be 10-20 standard cubic centimeters per minute, and the first aluminum trioxide film layer is plated on the surface of the reflective phase delay mirror by the film forming mode of ion source assisted evaporation according to the target plating thickness of the first aluminum trioxide film layer; The ion source is turned off, and the plating is suspended for 4-6 minutes; The deposition rate is controlled to be 15 angstroms per second, and the metal silver film layer is plated on the first aluminum trioxide film layer by the film forming mode of resistance evaporation according to the target plating thickness of the metal silver film layer; The deposition rate is controlled to be 2-3 angstroms per second, the oxygen supply is controlled to be 10-20 standard cubic centimeters per minute, and the second aluminum trioxide film layer is plated on the metal silver film layer by the film forming mode of electron beam evaporation according to the target plating thickness of the second aluminum trioxide film layer; The deposition rate is controlled to be 5-6 angstroms per second, and the first silicon dioxide film layer is plated on the second aluminum trioxide film layer by the film forming mode of electron beam evaporation according to the target plating thickness of the first silicon dioxide film layer; The substrate of the first silicon dioxide film layer is cleaned for 10-15 minutes by using the Hall ion source, and the temperature is set to 100-120 degrees Celsius; The deposition rate is controlled to be 2-3 angstroms per second, the oxygen supply is controlled to be 10-20 standard cubic centimeters per minute, and the first titanium pentoxide film layer is plated on the first silicon dioxide film layer by the film forming mode of ion source assisted evaporation according to the target plating thickness of the first titanium pentoxide film layer; The deposition rate is controlled to be 5-6 angstroms per second, and the second silicon dioxide film layer is plated on the first titanium pentoxide film layer by the film forming mode of ion source assisted evaporation according to the target plating thickness of the second silicon dioxide film layer; The deposition rate is controlled to be 2-3 angstroms per second, the oxygen supply is controlled to be 10-20 standard cubic centimeters per minute, and the second titanium pentoxide film layer is plated on the second silicon dioxide film layer by the film forming mode of ion source assisted evaporation according to the target plating thickness of the second titanium pentoxide film layer; The deposition rate is controlled to be 5-6 angstroms per second, and the third silicon dioxide film layer is plated on the second titanium pentoxide film layer by the film forming mode of ion source assisted evaporation according to the target plating thickness of the third silicon dioxide film layer.

3. The method of coating an optical phase retardation reflecting film according to claim 1 or 2, characterized in that, The reflective phase delay mirror includes adjacent first and second plating surfaces; The surface of the reflective phase delay mirror is plated with an optical phase delay reflective film, including: The edge of the reflective phase delay mirror is clamped by a fixture, so that the first coating surface and the second coating surface are simultaneously and completely exposed in a coating area; The optical phase delay reflective film is coated on the first coating surface and the second coating surface respectively.

4. The method of coating an optical phase retardation reflecting film according to claim 3, wherein The edge of the reflective phase delay mirror is clamped by a fixture, so that the first coating surface and the second coating surface are simultaneously and completely exposed in a coating area, including: An included angle between the first coating surface and the second coating surface is obtained; A supplementary angle of the included angle is calculated; The edge of the reflective phase delay mirror is clamped by a fixture, so that the first coating surface and the second coating surface respectively have a tilt angle of one half of the supplementary angle with a horizontal plane, and the first coating surface and the second coating surface are simultaneously and completely exposed in a coating area.

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