Coated optical element, method for coating substrate with reflective film, equivalent negative-refraction flat lens, and electronic device

Abstract

A coated optical element (100), a method for coating a substrate (1) with a reflective film, an equivalent negative-refraction flat lens (200), and an electronic device (300). The coated optical element (100) comprises a substrate (1), a first light-reflecting film (3), a first protective film (5), a second light-reflecting film (7) and a second protective film (9), wherein the substrate (1) comprises a light-transmitting substrate material (11) and a special-shaped material layer (13); the first light-reflecting film (3) is disposed on the special-shaped material layer (13) and has a first thickness (H1); the first protective film (5) is disposed on the side of the first light-reflecting film (3) away from the special-shaped material layer (13); the second light-reflecting film (7) is disposed on the light-transmitting substrate material (11) and has a third thickness (H3), which is less than the first thickness (H1); and the second protective film (9) is disposed on the side of the second light-reflecting film (7) away from the light-transmitting substrate material (11).

Description

Coated optical element, method for coating a substrate with a reflective film, equivalent negative-refraction flat lens, and electronic device

[0001] Cross-reference to Related Applications

[0002] The present application is based on and claims priority to Chinese Patent Application No. 202410850610.4, filed on June 27, 2024, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0003] The present application relates to the field of optical element processing, and in particular to a coated optical element, a method for coating a substrate of the coated optical element with a reflective film, an equivalent negative-refraction flat lens comprising the coated optical element, and an electronic device comprising the equivalent negative-refraction flat lens. BACKGROUND

[0004] With the development of science and technology, more and more optical elements need to be coated with a film layer having a reflective function on the first surface and the second surface opposite to each other of the light-transmitting substrate. However, due to the processing technology of the light-transmitting substrate, the surface of the light-transmitting substrate often has a profiled material layer with a refractive index greater than that of the light-transmitting substrate. At present, when coating a reflective film on a substrate comprising a light-transmitting substrate and a profiled material layer, the same parameters are selected for magnetron sputtering coating on the first surface of the light-transmitting substrate with the profiled material layer and the second surface of the light-transmitting substrate without the profiled material layer.

[0005] However, since the refractive index of the profiled material layer is greater than that of the light-transmitting substrate, when the same parameters are selected for magnetron sputtering coating, the profiled material layer will reduce the reflectivity of the first surface coated with the reflective film layer because the refractive index of the profiled material layer is different from that of the reflective film layer. However, the second surface of the light-transmitting substrate without the profiled material layer will not reduce the reflectivity of the reflective film layer, resulting in a difference in reflectivity between the second surface of the light-transmitting substrate coated with the reflective film and the first surface of the light-transmitting substrate coated with the reflective film, and further resulting in poor uniformity of the reflective surfaces opposite to each other of the light-transmitting substrate.

[0006] For example, when the light-transmitting substrate is selected as float glass, since the float glass needs to be formed in a tin bath, the substrate of the float glass includes a light-transmitting substrate having opposite first and air surfaces and a profiled material layer (tin layer) formed on the first surface of the light-transmitting substrate, and the profiled material layer has a refractive index greater than that of the light-transmitting substrate. Since the refractive index of the tin layer is different from that of the reflective film layer, the tin layer will reduce the reflectivity of the first surface after the reflective film layer is plated, but the air surface of the light-transmitting substrate without the tin layer will not reduce the reflectivity of the reflective film layer, thereby causing a difference in reflectivity between the air surface of the light-transmitting substrate after the reflective film is plated and the first surface of the light-transmitting substrate after the reflective film is plated, and further causing a difference of about 5% between the reflectivity of the profiled material layer after the film is plated and the reflectivity of the air surface after the film is plated, thereby affecting the light-emitting performance of the optical element, and further affecting the use effect of the electronic device using the optical element. SUMMARY

[0007] The first aspect of the present application provides a coated optical element, comprising:

[0008] a substrate including a light-transmitting substrate having opposite first and second surfaces and a profiled material layer formed on the first surface of the light-transmitting substrate, the profiled material layer having a refractive index greater than that of the light-transmitting substrate;

[0009] a first light-reflecting film disposed on a side surface of the profiled material layer away from the light-transmitting substrate, the first light-reflecting film having a first thickness;

[0010] a first protective film disposed on a side surface of the first light-reflecting film away from the profiled material layer, the first protective film having a second thickness;

[0011] a second light-reflecting film disposed on the second surface of the light-transmitting substrate, the second light-reflecting film having a third thickness, the third thickness being less than the first thickness; and

[0012] a second protective film disposed on a side surface of the second light-reflecting film away from the light-transmitting substrate, the second protective film having a fourth thickness.

[0013] The film-coated optical element provided by the embodiments of the present application can effectively improve the difference in reflectivity between the first surface after film coating and the second surface after film coating caused by the fact that the refractive index of the profiled material layer is greater than the refractive index of the light-transmitting substrate, can make the reflectivity of the first surface after coating the reflective film consistent with the reflectivity of the second surface after coating the reflective film, thereby improving the uniformity of the reflectivity of the first surface and the second surface of the light-transmitting substrate after coating the reflective film, and is conducive to improving the light-emitting performance of the film-coated optical element, thereby being conducive to improving the use effect of the electronic device using the film-coated optical element. For example, when the film-coated optical element is applied to an equivalent negative refraction flat lens, the film-coated optical element is cut to form a reflective unit, and a plurality of reflective units are closely attached and orthogonally arranged to form a first optical waveguide array and a second optical waveguide array, so that the first optical waveguide array and the second optical waveguide array are closely attached and orthogonally arranged in the same plane. The film-coated optical element is conducive to improving the uniformity of the light waveguide reflective surface of the equivalent negative refraction flat lens, thereby being conducive to improving the use effect of the electronic device using the equivalent negative refraction flat lens.

[0014] The second aspect of the present application provides a method for coating a reflective film on a substrate for manufacturing the film-coated optical element as described in any of the above embodiments, comprising:

[0015] providing a substrate to be coated with a reflective film, the substrate comprising a light-transmitting substrate having opposite first and second surfaces and a profiled material layer formed on the first surface of the light-transmitting substrate, the refractive index of the profiled material layer being greater than the refractive index of the light-transmitting substrate;

[0016] forming a first light reflective film having a first thickness on the side surface of the profiled material layer away from the light-transmitting substrate;

[0017] forming a first protective film having a second thickness on the side surface of the first light reflective film away from the profiled material layer;

[0018] forming a second light reflective film having a third thickness on the second surface of the light-transmitting substrate, the third thickness being less than the first thickness;

[0019] forming a second protective film having a fourth thickness on the side surface of the second light reflective film away from the light-transmitting substrate.

[0020] The method for coating a reflective film on a substrate provided by the embodiments of the present application can effectively improve the difference in reflectivity between the first surface after coating and the second surface after coating caused by the fact that the refractive index of the profiled material layer is greater than the refractive index of the light-transmitting substrate, can make the reflectivity of the first surface after coating a reflective film consistent with the reflectivity of the second surface after coating a reflective film, thereby improving the uniformity of the reflectivity of the first surface and the second surface of the light-transmitting substrate after coating a reflective film, and is conducive to improving the light-emitting performance of the coated optical element obtained by applying the method for coating a reflective film on the above substrate, thereby being conducive to improving the use effect of the electronic device applying the above coated optical element.

[0021] For example, when the method for coating a reflective film on a substrate is applied to coating a reflective film on a float glass, since the float glass has a tin surface and an air surface, the tin surface has a profiled material layer (tin layer) with a refractive index greater than the refractive index of the light-transmitting substrate (glass); the method for coating a reflective film on a substrate increases the first thickness of the first light-reflecting film on the side surface of the profiled material layer away from the light-transmitting substrate, so that the first thickness is greater than the third thickness of the second light-reflecting film formed by the air surface of the light-transmitting substrate, which is conducive to improving the difference in reflectivity between the tin surface and the air surface after coating a reflective film, thereby improving the uniformity of the reflectivity of the tin surface and the air surface of the light-transmitting substrate after coating a reflective film, thereby being conducive to improving the light-emitting performance of the equivalent negative refractive flat lens obtained by applying the method for coating a reflective film on the substrate, and further being conducive to improving the performance of the electronic device applying the equivalent negative refractive flat lens.

[0022] The third aspect of the present application provides an equivalent negative refractive flat lens, comprising:

[0023] two transparent substrates; and

[0024] a first light waveguide array and a second light waveguide array arranged between the two transparent substrates, the first light waveguide array and the second light waveguide array being closely adhered and orthogonally arranged in the same plane, the thickness of the first light waveguide array and the thickness of the second light waveguide array being the same, and the first light waveguide array and the second light waveguide array each being composed of a plurality of reflective elements with a rectangular cross section;

[0025] Each of the reflection units comprises a sub-base, a first sub-light reflection film, a first sub-protection film, a second sub-light reflection film, and a second sub-protection film; the sub-base comprises a sub-light-transmissive base material having opposite first and second sub-surfaces, and a sub- profiled material layer formed on the first sub-surface of the sub-light-transmissive base material, the sub-profiled material layer has a refractive index greater than that of the sub-light-transmissive base material, the first sub-light reflection film is arranged on a side surface of the sub-profiled material layer away from the sub-light-transmissive base material, the first sub-protection film is arranged on a side surface of the first sub-light reflection film away from the sub-profiled material layer, the second sub-light reflection film is arranged on the second sub-surface of the sub-light-transmissive base material, and the second sub-protection film is arranged on a side surface of the second sub-light reflection film away from the sub-light-transmissive base material.

[0026] The equivalent negative refraction flat lens provided by the embodiments of the present application is advantageous in improving the uniformity of the reflectivity of the first surface and the second surface of the reflection unit, improving the light output performance of the first light waveguide array and the second light waveguide array, and improving the use effect of the equivalent negative refraction flat lens, thereby improving the performance of the electronic device using the equivalent negative refraction flat lens.

[0027] The fourth aspect of the present application provides an electronic device, comprising:

[0028] a body; and

[0029] The equivalent negative refraction flat lens provided by any one of the embodiments described above.

[0030] The electronic device provided by the embodiments of the present application has the equivalent negative refraction flat lens described in the third aspect, and therefore has the same beneficial effects, which will not be described here.

[0031] Additional aspects and advantages of the present application will be in part apparent and in part pointed out hereinafter. BRIEF DESCRIPTION OF DRAWINGS

[0032] FIG. 1 is a structural schematic diagram of an equivalent negative refraction flat lens in the related art.

[0033] FIG. 2 is a disassembled structural schematic diagram of the equivalent negative refraction flat lens shown in FIG. 1.

[0034] FIG. 3 is a structural schematic diagram of a base according to an embodiment of the present application.

[0035] FIG. 4 is a structural schematic diagram of a coated optical element according to an embodiment of the present application.

[0036] Fig. 5 is a cross-sectional view of Fig. 4 along line V-V.

[0037] Fig. 6 is a schematic view of a chamfered structure according to an embodiment of the present application.

[0038] Fig. 7 is a flow chart of a method of coating a reflective film on a substrate according to an embodiment of the present application.

[0039] Fig. 8 is a flow chart of a method of coating a reflective film on a substrate according to another embodiment of the present application.

[0040] Fig. 9 is a comparison chart of reflectivity of a first surface and a second surface of a light-transmitting substrate according to Comparative Example 1.

[0041] Fig. 10 is a comparison chart of reflectivity of a first surface and a second surface of a light-transmitting substrate according to an embodiment of the present application.

[0042] Fig. 11 is a schematic view of a structure of an equivalent negative-refraction flat lens according to an embodiment of the present application.

[0043] Fig. 12 is a schematic view of a disassembled structure of the equivalent negative-refraction flat lens shown in Fig. 11.

[0044] Fig. 13 is a schematic view of a structure of a reflecting unit according to an embodiment of the present application.

[0045] Fig. 14 is a schematic view of an electronic device according to an embodiment of the present application.

[0046] BRIEF DESCRIPTION OF REFERENCE NUMERALS: Step S100, S101, S200, S300, S400, S500 Coated optical element 100 Substrate 1 Light-transmitting substrate 11 First surface 111 Second surface 112 Profiled material layer 13 Bevel 15 First light-reflecting film 3 First protective film 5 Second light-reflecting film 7 Second protective film 9 Equivalent negative-refraction flat plate lens 200, 200' Transparent substrate 21, 21' First light-waveguide array 23, 23' Second light-waveguide array 25, 25' Reflecting unit 230, 230' Adhesive 27 Substrate 10 Sub light-transmitting substrate 110 First sub surface 1110 Second sub surface 1120 Sub profiled material layer 130 First sub light-reflecting film 30 First sub protective film 50 Second sub light-reflecting film 70 Second sub protective film 90 First thickness H1 Second thicknessH2 third thickness H3 fourth thickness H4 electronic device 300 body 301 DETAILED DESCRIPTION

[0047] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application.

[0048] Unless otherwise defined, all technical and scientific terms used in the present application have the same meanings as commonly understood by one of ordinary skill in the art to which the present application belongs. The terms used in the specification of the present application are only for the purpose of describing the specific embodiments of the present application, and are not intended to limit the present application.

[0049] In order to further clarify the technical means and effects taken by the present application to achieve the predetermined purpose, the present application is described in detail as follows in combination with the drawings and preferred embodiments.

[0050] Please refer to FIG. 1 and FIG. 2, an equivalent negative refraction flat lens 200’ is proposed in the applicant’s other invention application, which includes two transparent substrates 21’ and a first light waveguide array 23’ and a second light waveguide array 25’ arranged between the two transparent substrates 21’. The first light waveguide array 23’ and the second light waveguide array 25’ are closely adhered and orthogonally arranged in the same plane. The thicknesses of the first light waveguide array 23’ and the second light waveguide array 25’ are the same. The first light waveguide array 23’ and the second light waveguide array 25’ are respectively composed of a plurality of reflection units 230’ with rectangular cross sections, and the lengths of the reflection units 230’ are limited by the peripheral dimensions of the light waveguide arrays and thus vary in length. The extension directions (light waveguide array directions) of the reflection units 230’ in the first light waveguide array 23’ and the second light waveguide array 25’ are perpendicular to each other. From the thickness directions of the first light waveguide array 23’ and the second light waveguide array 25’, the first light waveguide array 23’ and the second light waveguide array 25’ are orthogonally arranged, so that two light beams in the orthogonal directions converge at a point, and the object image plane (the light source side and the imaging side) is symmetrical relative to the flat lens, generating an equivalent negative refraction phenomenon and realizing aerial imaging.

[0051] In actual processing, the opposite front surface and back surface of the light-transmitting substrate are first coated with a reflective film, and then the light-transmitting substrate is cut into the above-mentioned reflective units 230', which are bonded into the first light waveguide array 23' or the second light waveguide array 25' according to the peripheral size of the required light waveguide array, and the first light waveguide array 23' and the second light waveguide array 25' are stacked between the two transparent substrates 21' in a manner of closely adhering and orthogonally arranging in the same plane.

[0052] However, in the related art, when the light-transmitting substrate (master of the reflective unit 230') is coated with a reflective film, the same parameters are generally selected for magnetron sputtering coating of the front surface and back surface of the light-transmitting substrate to be coated with a reflective film. However, due to the processing technology of the light-transmitting substrate, the front surface or back surface (such as the front surface) of the light-transmitting substrate often has a profiled material layer different from the material of the light-transmitting substrate. When the refractive index of the profiled material layer is greater than the refractive index of the light-transmitting substrate, if the same parameters are selected for magnetron sputtering coating of the front surface of the light-transmitting substrate to be coated with a reflective film and the back surface of the light-transmitting substrate without a profiled material layer, the profiled material layer will reduce the reflectivity of the front surface after the reflective film layer is coated, but the back surface of the light-transmitting substrate without a profiled material layer will not reduce the reflectivity of the reflective film layer, thereby causing a difference in reflectivity between the back surface of the light-transmitting substrate after the reflective film is coated and the front surface of the light-transmitting substrate after the reflective film is coated, and further causing poor uniformity of the opposite reflective surfaces of the light-transmitting substrate.

[0053] For example, when the light-transmitting substrate selects float glass, since the float glass needs to be formed in a tin bath, the substrate of the float glass includes a light-transmitting substrate having an opposite first surface and air surface and a profiled material layer (tin layer) formed on the first surface of the light-transmitting substrate. The refractive index of the profiled material layer is greater than the refractive index of the light-transmitting substrate. Since the refractive index of the tin layer is different from the refractive index of the reflective film layer, the tin layer will reduce the reflectivity of the first surface after the reflective film layer is coated, but the air surface of the light-transmitting substrate without a tin layer will not reduce the reflectivity of the reflective film layer, thereby causing a difference in reflectivity between the air surface of the light-transmitting substrate after the reflective film is coated and the first surface of the light-transmitting substrate after the reflective film is coated, and further causing a difference of about 5% between the reflectivity of the profiled material layer after the film is coated and the reflectivity of the air surface after the film is coated, thereby affecting the light output performance of the reflective unit obtained by using the reflective film coating method of the substrate, and further affecting the imaging effect of the equivalent negative refraction flat lens.

[0054] Therefore, based on this, the present application provides a film-coated optical element.

[0055] Please refer to FIG. 3, FIG. 4 and FIG. 5, the coated optical element 100 of the embodiment of the application includes a substrate 1, a first light reflection film 3, a first protective film 5, a second light reflection film 7 and a second protective film 9. The substrate 1 includes a light-transmitting base material 11 having opposite first and second surfaces 111 and 112, and a profiled material layer 13 formed on the first surface 111 of the light-transmitting base material 11, the profiled material layer 13 having a refractive index greater than that of the light-transmitting base material 11. The first light reflection film 3 is disposed on the side surface of the profiled material layer 13 away from the light-transmitting base material 11, and has a first thickness H1. The first protective film 5 is disposed on the side surface of the first light reflection film 3 away from the profiled material layer 13, and has a second thickness H2. The second light reflection film 7 is disposed on the second surface 112 of the light-transmitting base material 11, and has a third thickness H3 less than the first thickness H1. The second protective film 9 is disposed on the side surface of the second light reflection film 7 away from the light-transmitting base material 11, and has a fourth thickness H4.

[0056] The coated optical element 100 provided by the embodiment of the application can effectively improve the difference in reflectivity between the first surface 111 after coating and the second surface 112 after coating caused by the fact that the profiled material layer 13 has a refractive index greater than that of the light-transmitting base material 11, and can make the reflectivity of the first surface 111 after coating a reflection film consistent with that of the second surface 112 after coating a reflection film, thereby improving the uniformity of the reflectivity of the first and second surfaces 111 and 112 of the light-transmitting base material 11 after coating a reflection film, and facilitating the improvement of the light-emitting performance of the coated optical element 100, thereby facilitating the improvement of the use effect of an electronic device using the coated optical element 100. For example, when the coated optical element 100 is applied to an equivalent negative refraction flat lens, the coated optical element 100 is cut to form reflection units, and a plurality of reflection units are closely attached and orthogonally arranged to form a first light waveguide array and a second light waveguide array, so that the first and second light waveguide arrays are closely attached and orthogonally arranged in the same plane. The use of the coated optical element 100 facilitates the improvement of the uniformity of the light waveguide reflection surface of the equivalent negative refraction flat lens, thereby facilitating the improvement of the use effect of an electronic device using the equivalent negative refraction flat lens.

[0057] In the embodiment, the substrate 1 is float glass, the light-transmitting base material 11 is glass, the light-transmitting base material 11 has opposite first surface 111 and second surface 112, and the profiled material layer 13 formed on the first surface 111 of the glass, the profiled material layer 13 is tin layer, and the second surface 112 is the air side of the float glass. It should be noted that "light-transmitting" means that the light-transmitting rate of the light of a specific wave band (especially the visible light, infrared light wave band and ultraviolet wave band) is high. In other embodiments, the substrate 1 can also be photovoltaic glass or other materials having a profiled material layer and the refractive index of the profiled material layer is greater than the refractive index of the base material, which is not limited in the present application.

[0058] Please refer to FIG. 3 and FIG. 6, in the embodiment, the light-transmitting base material 11 is provided with a chamfer 15 on one side edge perpendicular to the first surface 111. The chamfer 15 is used to distinguish the first surface 111 and the second surface 112 of the light-transmitting base material 11. The chamfer 15 can be processed on both the first surface 111 and the first surface 111, or only on the first surface 111. For example, during the production of float glass, when it is transferred from the tin bath to the cutting machine, the cutting machine processes the chamfer 15 on the side edge perpendicular to the first surface 111 of the light-transmitting base material 11. Assuming that the tin side is upward, if the cutting machine processes the chamfer 15 on the side edge perpendicular to the first surface 111 of the light-transmitting base material 11 on the upper right side of the light-transmitting base material 11, when the cutting and chamfering of the light-transmitting base material 11 are completed, the producer can determine the position of the profiled material layer 13 by the position of the chamfer 15 on the upper right side of the light-transmitting base material 11 or the lower left side of the light-transmitting base material 11. By processing the chamfer 15 on the light-transmitting base material 11, when the light-transmitting base material 11 to be plated with a reflective film is fed into the magnetron sputtering coating machine, the position of the chamfer 15 can be used to distinguish the position of the first surface 111 with the profiled material layer 13 and the position of the second surface 112 without the profiled material layer 13, thereby facilitating the setting of the parameters of the magnetron sputtering coating machine according to the positions of the first surface 111 and the second surface 112. It should be noted that the size of the chamfer 15 should not be too large or too small. For example, when the size of the light-transmitting base material 11 is 400mm×300mm×0.7mm, the size of the chamfer 15 can be 2mm×2mm.

[0059] In other embodiments, a marking part can also be formed on the light-transmitting base material 11 to distinguish the first surface 111 and the second surface 112, such as punching or setting a marker at any position of the light-transmitting base material 11, which is not limited in the present application.

[0060] Please refer to FIG. 4 and FIG. 5 again, the material of the first light reflection film 3 and the second light reflection film 7 is one of aluminum and silver respectively. In the embodiment, the material of the first light reflection film 3 and the second light reflection film 7 is aluminum. In other embodiments, the material of the first light reflection film 3 and the second light reflection film 7 can also be different, for example, the material of the first light reflection film 3 is silver, and the material of the second light reflection film 7 is aluminum; or, the material of the first light reflection film 3 is aluminum, and the material of the second light reflection film 7 is silver, which is not limited in the present application. The thickness difference between the third thickness H3 of the second light reflection film 7 and the first thickness H1 of the first light reflection film 3 is in the range of 10nm-15nm (for example, 10nm-12nm, 12nm-13nm or 13nm-15nm), and the third thickness H3 is less than the first thickness H1. By setting the first thickness H1 of the first light reflection film 3 to be greater than the third thickness H3 of the second light reflection film 7, the difference in reflectivity of the first surface 111 after coating and the second surface 112 after coating caused by the refractive index of the shaped material layer 13 being greater than the refractive index of the light-transmitting substrate 11 can be effectively improved, the reflectivity of the first surface 111 after coating the reflection film can be consistent with the reflectivity of the second surface 112 after coating the reflection film, thereby improving the uniformity of the reflectivity of the first surface 111 and the second surface 112 of the light-transmitting substrate 11 after coating the reflection film, and being beneficial to improving the light-emitting performance of the coated optical element 100.

[0061] The first thickness H1 is in a range of 80-85 nm (for example, 80-82 nm, 82-83 nm, or 83-85 nm). If the first thickness H1 is less than 80 nm, the first light reflection film 3 has a small thickness, which can cause part of the visible light refracted by the first light reflection film 3 to pass through the first light reflection film 3 or even the light-transmitting base material 11, and is not conducive to improving the reflectivity of the coated base 1 as a whole. If the first thickness H1 is greater than 85 nm, the first thickness H1 has a large thickness, which can cause the coated base 1 as a whole to have a large thickness, is not conducive to popularization and application, and has a high cost. By setting the first thickness H1 in the range of 80-85 nm, the first thickness H1 of the first light reflection film 3 is moderate, which is conducive to reducing the thickness of the coated base 1 as a whole and making the structure light and thin. In other embodiments, the material of the first light reflection film 3 can also be silver, which is not limited in the present application. The third thickness H3 is in a range of 70-75 nm (for example, 70-72 nm, 72-73 nm, or 73-75 nm). If the third thickness H3 is less than 70 nm, the second light reflection film 7 has a small thickness, which can cause part of the visible light refracted by the second light reflection film 7 to pass through the second light reflection film 7 or even the light-transmitting base material 11, and is not conducive to improving the reflectivity of the coated base 1 as a whole. If the third thickness H3 is greater than 75 nm, the third thickness H3 has a large thickness, which can cause the coated base 1 as a whole to have a large thickness, is not conducive to popularization and application, and has a high cost. By setting the third thickness H3 in the range of 80-85 nm, the third thickness H3 of the second light reflection film 7 is moderate, which is conducive to reducing the thickness of the coated base 1 as a whole and making the structure light and thin. In other embodiments, the material of the second light reflection film 7 can also be silver, which is not limited in the present application.

[0062] In the present embodiment, the materials of the first protective film 5 and the second protective film 9 are the same. The materials of the first protective film 5 and the second protective film 9 are both silicon dioxide. In other embodiments, the materials of the first protective film 5 and the second protective film 9 can also be different, for example, the material of the first protective film 5 is silicon dioxide, and the material of the second protective film 9 is niobium oxide; or the material of the first protective film 5 is niobium oxide, and the material of the second protective film 9 is silicon dioxide, which is not limited in the present application.

[0063] The second thickness H2 of the first protective film 5 ranges from 20nm to 25nm (for example, from 20nm to 22nm, from 22nm to 23nm, or from 23nm to 25nm). The fourth thickness H4 of the second protective film 9 ranges from 20nm to 25nm (for example, from 20nm to 22nm, from 22nm to 23nm, or from 23nm to 25nm). When the thickness of the silicon dioxide film layer is small (less than 20nm), the refractive path of light in the silicon dioxide film layer is too short, which is not conducive to improving the reflectivity of the coated substrate 1. When the thickness of the silicon dioxide film layer is large (greater than 25nm), the refractive path of light in the silicon dioxide film layer is too long, which is not conducive to improving the reflectivity of the coated substrate 1. By setting the second thickness H2 and the fourth thickness H4 to range from 20nm to 25nm, it is conducive to coating a silicon dioxide film layer with a suitable thickness on the light-transmitting substrate 11, thereby improving the reflectivity of the coated substrate 1 to light.

[0064] The coated optical element 100 provided by the embodiments of the present application can effectively improve the difference in reflectivity between the first surface 111 and the second surface 112 after coating caused by the fact that the refractive index of the profiled material layer 13 is greater than the refractive index of the light-transmitting substrate 11, can make the reflectivity of the first surface 111 after coating a reflective film consistent with the reflectivity of the second surface 112 after coating a reflective film, thereby improving the uniformity of the reflectivity of the first surface 111 and the second surface 112 of the light-transmitting substrate 11 after coating a reflective film, and is conducive to improving the light-emitting performance of the coated optical element 100, thereby being conducive to improving the use effect of the electronic device using the above-mentioned coated optical element 100.

[0065] Referring to FIGS. 4 and 7, the present application also provides a method for coating a reflective film on a substrate 1, which is used to manufacture the coated optical element 100 as described in any of the above embodiments, and includes the following steps:

[0066] Step S100: providing a substrate to be coated with a reflective film, the substrate including a light-transmitting substrate having opposite first and second surfaces and a profiled material layer formed on the first surface of the light-transmitting substrate, the refractive index of the profiled material layer being greater than the refractive index of the light-transmitting substrate.

[0067] Step S200: forming a first light-reflecting film having a first thickness on the side surface of the profiled material layer away from the light-transmitting substrate.

[0068] Step S300: forming a first protective film having a second thickness on the side surface of the first light-reflecting film away from the profiled material layer.

[0069] Step S400: forming a second light reflection film with a third thickness on the second surface of the light transmission substrate, the third thickness being smaller than the first thickness.

[0070] Step S500: forming a second protective film with a fourth thickness on the side surface of the second light reflection film away from the light transmission substrate.

[0071] It should be noted that the method for plating the reflective film of the substrate 1 of the present application is not limited to the order of the above steps, and in other embodiments, the method for plating the reflective film of the substrate 1 of the present embodiment can only include part of the above steps, or part of the steps can be deleted.

[0072] The method for plating the reflective film of the substrate 1 provided in the present application can effectively improve the difference in reflectivity between the first surface 111 after plating and the second surface 112 after plating caused by the refractive index of the profiled material layer 13 being greater than the refractive index of the light transmission substrate 11, can make the reflectivity of the first surface 111 after plating the reflective film consistent with the reflectivity of the second surface 112 after plating the reflective film, thereby improving the uniformity of the reflectivity of the first surface 111 and the second surface 112 of the light transmission substrate 11 after plating the reflective film, and is conducive to improving the light output performance of the plated optical element 100 obtained by applying the above method for plating the reflective film of the substrate 1, thereby being conducive to improving the use effect of the electronic device using the plated optical element 100.

[0073] For example, when the method for plating the reflective film of the substrate 1 is applied to plate the reflective film of a float glass, since the float glass has a tin side and an air side, the tin side has a profiled material layer 13 (tin layer), and the refractive index of the profiled material layer 13 is greater than the refractive index of the light transmission substrate 11 (glass). The method for plating the reflective film of the substrate 1 increases the first thickness H1 of the first light reflection film 3 on the side surface of the profiled material layer 13 away from the light transmission substrate 11, so that the first thickness H1 is greater than the third thickness H3 of the second light reflection film 7 formed on the air side of the light transmission substrate 11, which is conducive to improving the difference in reflectivity between the tin side and the air side after plating the reflective film, thereby improving the uniformity of the reflectivity of the tin side and the air side of the light transmission substrate 11 after plating the reflective film, and is conducive to improving the light output performance of the equivalent negative refractive flat lens obtained by using the method for plating the reflective film of the substrate 1, and further conducive to improving the performance of the electronic device using the equivalent negative refractive flat lens.

[0074] Specifically, in step S100, a substrate 1 to be plated with a reflective film is provided, the substrate 1 is a float glass, the light-transmitting base material 11 is glass, the glass has opposite first and second surfaces 111 and 112, and a profiled material layer 13 is formed on the first surface 111 of the glass, the profiled material layer 13 is a tin layer, and the second surface 112 is the air side of the float glass. It should be noted that "light-transmitting" means that the light-transmitting rate of light of a specific wavelength band (especially, the visible light, infrared light, and ultraviolet light wavelength bands) is high.

[0075] Referring to FIG. 8, in another embodiment, before the first light-reflecting film 3 having a first thickness H1 is formed on the side surface of the profiled material layer 13 away from the light-transmitting base material 11 in step S200, the following step is further included:

[0076] Step S101: forming a marking part on the substrate, the marking part being used to distinguish the first surface and the second surface.

[0077] In the present embodiment, the step of forming the marking part on the substrate 1 in step S101 is: chamfering 15 any one side edge of the light-transmitting base material 11 perpendicular to the first surface 111. The chamfer 15 is used to distinguish the first surface 111 and the second surface 112, and the chamfer 15 can be performed on both the first surface 111 and the second surface 112, or only on the first surface 111. It should be noted that the size of the chamfer 15 should not be too large or too small, for example, when the size of the light-transmitting base material 11 is 400 mm x 300 mm x 0.7 mm, the size of the chamfer 15 can be 2 mm x 2 mm. In other embodiments, the step of forming the marking part on the substrate 1 in step S101 can also be: punching or setting a marker at any position of the light-transmitting base material 11, and the present application is not limited thereto.

[0078] Referring to FIGS. 4, 6, and 7, specifically, steps S200 to S500 are completed by using an RF-V0002405 model magnetron sputtering film plating machine, but the present application is not limited thereto.

[0079] In step S200, a direct current power source with a rated power of no more than 40 kW and a first target material are used, and argon gas with a first volume flow rate is introduced to form the first light reflection film 3 with the first thickness H1 on the side surface of the profiled material layer 13 away from the light transmission base material 11. The first target material is aluminum, and in other embodiments, the first target material can also be silver, which is determined according to the material of the reflection film layer to be plated by the user, and the present application is not limited. The direct current power source outputs the first power, and the first power ranges from 20 KW to 21 KW (for example, from 20 KW to 20.5 KW or from 20.5 KW to 21 KW). In this embodiment, the coating line speed is 1 m / min, but is not limited thereto. When the first power is less than 20 KW, the first thickness H1 can be small, which is not conducive to improving the reflectivity of the first surface 111 after coating. When the first power is greater than 21 KW, the first thickness H1 can be too large, and the refractive path of light in the first light reflection film 3 is too long, which is not conducive to improving the reflectivity of the first surface 111 after coating. The first volume flow rate ranges from 180 sccm to 220 sccm (for example, from 180 sccm to 190 sccm, from 190 sccm to 200 sccm, from 200 sccm to 210 sccm, or from 210 sccm to 220 sccm). When the first volume flow rate of argon gas is greater than 220 sccm, the first thickness H1 can be large, and vice versa. The first thickness H1 ranges from 80 nm to 85 nm (for example, from 80 nm to 82 nm, from 82 nm to 83 nm, or from 83 nm to 85 nm). If the first thickness H1 is less than 80 nm, the thickness of the first light reflection film 3 is small, which can cause part of the visible light refracted by the first light reflection film 3 to pass through the first light reflection film 3 or even the light transmission base material 11, which is not conducive to improving the reflectivity of the entire base 1 after coating. If the first thickness H1 is greater than 85 nm, the thickness of the first thickness H1 is large, which can cause the thickness of the entire base 1 after coating to be large, which is not conducive to popularization and application and has a high cost. By setting the first thickness H1 to range from 80 nm to 85 nm, the first thickness H1 of the first light reflection film 3 is moderate, which is conducive to reducing the thickness of the entire base 1 after coating and making the structure light and thin.

[0080] Specifically, in step S300, a middle frequency power source with a power less than 50 kW and a second target material are adopted, and argon with a first volume flow rate and oxygen with a second volume flow rate are introduced to form the first protective film 5 with the second thickness H2 on the side surface of the first light reflection film 3 away from the profiled material layer 13. The second target material is silicon, and the middle frequency power source outputs the second power, which ranges from 20 KW to 25 KW (for example, from 20 KW to 21 KW, from 21 KW to 22 KW, from 22 KW to 23 KW, or from 23 KW to 25 KW). In this embodiment, the coating line speed is 1 m / min, but is not limited thereto. When the second power is less than 20 KW, the second thickness H2 may be small, which is not conducive to improving the reflectivity of the entire substrate 1 after coating. When the second power is greater than 25 KW, the second thickness H2 may be too large, and the refractive path of light in the first protective film 5 is too long, which is not conducive to improving the reflectivity of the entire substrate 1 after coating. The first volume flow rate ranges from 180 sccm to 220 sccm (for example, from 180 sccm to 190 sccm, from 190 sccm to 200 sccm, from 200 sccm to 210 sccm, or from 210 sccm to 220 sccm). When the first volume flow rate of argon is greater than 220 sccm, the second thickness H2 will be large, and vice versa. The second volume flow rate ranges from 45 sccm to 55 sccm (for example, from 45 sccm to 47 sccm, from 47 sccm to 49 sccm, from 49 sccm to 52 sccm, or from 53 sccm to 55 sccm). When the amount of oxygen introduced is small (less than 45 sccm), silicon may not be completely oxidized to form silicon dioxide, which is not conducive to coating the first protective film 5, thereby affecting the reflectivity of the substrate 1 to light after coating. When the amount of oxygen introduced is large (greater than 55 sccm), the amount of oxygen introduced during the coating process is large, and too much oxygen is introduced, which causes waste of oxygen and potential safety hazards. Therefore, by setting the second volume flow rate to range from 45 sccm to 55 sccm, the amount of oxygen introduced is moderate, which is conducive to coating the first protective film 5 with a suitable thickness, thereby improving the reflectivity of the substrate 1 to light after coating. The second thickness H2 ranges from 20 nm to 25 nm (for example, from 20 nm to 22 nm, from 22 nm to 23 nm, or from 23 nm to 25 nm). The fourth thickness H4 of the second protective film 9 ranges from 20 nm to 25 nm (for example, from 20 nm to 22 nm, from 22 nm to 23 nm, or from 23 nm to 25 nm).When the thickness of the silicon dioxide film layer is small (less than 20 nm), the refractive path of light in the silicon dioxide film layer is too short, which is not conducive to improving the reflectivity of the whole substrate 1 after plating. When the thickness of the silicon dioxide film layer is large (greater than 25 nm), the refractive path of light in the silicon dioxide film layer is too long, which is not conducive to improving the reflectivity of the substrate 1 after plating. By setting the second thickness H2 and the fourth thickness H4 to be in the range of 20 nm-25 nm, it is conducive to plating a silicon dioxide film layer with a suitable thickness on the light-transmitting substrate 11, thereby improving the reflectivity of the substrate 1 to light after plating.

[0081] Specifically, in step S400, a direct current power source with a rated power of not more than 40 kw and a first target material are used, and argon gas with a first volume flow rate is introduced to form the second light reflecting film 7 with the third thickness H3 on the second surface 112 of the light-transmitting substrate 11. The first target material is aluminum, and in other embodiments, the first target material can also be silver, which is determined according to the reflecting film layer material required by the user, and the present application is not limited. The direct current power source outputs the third power, and the range of the third power is 18 KW-19 KW. In this embodiment, the plating line speed is 1 m / min, but is not limited thereto. When the third power is less than 18 KW, it can result in a small third thickness H3, which is not conducive to improving the reflectivity of the second surface 112 after plating. When the third power is greater than 19 KW, it can result in a large third thickness H3, and the refractive path of light in the second light reflecting film 7 is too long, which is not conducive to improving the reflectivity of the second surface 112 after plating. The range of the first volume flow rate is 180 sccm-220 sccm (for example, 180 sccm-190 sccm, 190 sccm-200 sccm, 200 sccm-210 sccm, or 210 sccm-220 sccm). When the first volume flow rate of argon gas is greater than 220 sccm, it can affect the third thickness H3, so that the third thickness H3 becomes large, and vice versa. The range of the third thickness H3 is 70 nm-75 nm (for example, 70 nm-72 nm, 72 nm-73 nm, or 73 nm-75 nm). If the third thickness H3 is less than 70 nm, the thickness of the second light reflecting film 7 is small, which can result in that part of the visible light refracted by the second light reflecting film 7 transmits through the second light reflecting film 7 or even the light-transmitting substrate 11, which is not conducive to improving the reflectivity of the whole substrate 1 after plating. If the third thickness H3 is greater than 75 nm, the thickness of the third thickness H3 is large, which can result in that the whole thickness of the substrate 1 after plating is large, which is not conducive to popularization and application and has a high cost. By setting the third thickness H3 to be in the range of 80 nm-85 nm, the third thickness H3 of the second light reflecting film 7 is moderate, which is conducive to reducing the thickness of the whole substrate 1 after plating and making the structure light and thin.

[0082] The process condition for forming the second protective film 9 with the fourth thickness H4 in step S500 is the same as that for forming the first protective film 5 with the second thickness H2. The second protective film 9 with the fourth thickness H4 is formed on the side surface of the second light-reflecting film 7 away from the light-transmitting substrate 11 by using a medium-frequency power source with a power not more than 50 kW, a second target material, and by introducing argon gas with a first volume flow rate and oxygen gas with a second volume flow rate, wherein the second target material is silicon, and the medium-frequency power source outputs the fourth power in the range of 20-25 kW (for example, 20-21 kW, 21-22 kW, 22-23 kW, or 23-25 kW). In the present embodiment, the coating line speed is 1 m / min, but is not limited thereto. When the fourth power is less than 20 kW, the fourth thickness H4 can be small, which is not conducive to improving the reflectivity of the entire substrate 1 after coating. When the fourth power is greater than 25 kW, the fourth thickness H4 can be too large, and the light has a too long refractive path in the second protective film 9, which is not conducive to improving the reflectivity of the entire substrate 1 after coating. The first volume flow rate is in the range of 180-220 sccm (for example, 180-190 sccm, 190-200 sccm, 200-210 sccm, or 210-220 sccm). The second volume flow rate is in the range of 45-55 sccm (for example, 45-47 sccm, 47-49 sccm, 49-52 sccm, or 53-55 sccm). The fourth thickness H4 is in the range of 20-25 nm (for example, 20-22 nm, 22-23 nm, or 23-25 nm). When the thickness of the silicon dioxide film layer is small (less than 20 nm), the light has a too short refractive path in the silicon dioxide film layer, which is not conducive to improving the reflectivity of the entire substrate 1 after coating. When the thickness of the silicon dioxide film layer is large (greater than 25 nm), the light has a too long refractive path in the silicon dioxide film layer, which is not conducive to improving the reflectivity of the substrate 1 after coating. By setting the second thickness H2 and the fourth thickness H4 in the range of 20-25 nm, it is conducive to coating a silicon dioxide film layer with a suitable thickness on the light-transmitting substrate 11, thereby improving the reflectivity of the substrate 1 to light after coating.

[0083] Please refer to Fig. 9 and Fig. 10 together, Fig. 9 is a comparison chart of the reflectivity of the first surface 111 and the second surface 112 of the light-transmitting substrate 11 after the reflection film plating in a comparative example, the difference between the reflectivity of the first surface 111 and the reflectivity of the second surface 112 is 0.5%. Fig. 10 is a comparison chart of the reflectivity of the first surface 111 and the second surface 112 of the light-transmitting substrate 11 after the reflection film plating obtained by applying the reflection film plating method of the light-transmitting substrate 11 described above in the present application, the difference between the reflectivity of the first surface 111 and the reflectivity of the second surface 112 is less than 0.1%.

[0084] The reflection film plating method of the substrate 1 provided by the embodiments of the present application can effectively improve the difference between the reflectivity of the first surface 111 and the reflectivity of the second surface 112 caused by the refractive index of the profiled material layer 13 being greater than the refractive index of the light-transmitting substrate 11, can make the reflectivity of the first surface 111 after the reflection film plating consistent with the reflectivity of the second surface 112 after the reflection film plating, thereby improving the uniformity of the reflectivity of the first surface 111 and the second surface 112 of the light-transmitting substrate 11 after the reflection film plating, and is conducive to improving the light-emitting performance of the coated optical element 100 obtained by applying the reflection film plating method of the substrate 1 described above, thereby being conducive to improving the use effect of the electronic device applying the coated optical element 100 described above.

[0085] Please refer to Fig. 11 and Fig. 12 together, the equivalent negative refraction flat panel lens 200 of the embodiments of the present application includes two transparent substrates 21 and a first light waveguide array 23 and a second light waveguide array 25 arranged between the two transparent substrates 21. The first light waveguide array 23 and the second light waveguide array 25 are closely adhered and orthogonally arranged in the same plane, the thickness of the first light waveguide array 23 and the thickness of the second light waveguide array 25 are the same, and the first light waveguide array 23 and the second light waveguide array 25 are respectively composed of a plurality of reflection units 230 with a rectangular cross section.

[0086] Please refer to FIG. 12 and FIG. 13, the reflective unit 230 is cut by the coated optical element 100, each of the reflective unit 230 includes a sub-base 10, a first sub-light reflecting film 30, a first sub-protective film 50, a second sub-light reflecting film 70 and a second sub-protective film 90. The sub-base 10 includes a sub-transparent base material 110 with opposite first and second sub-surfaces 1110 and 1120, and a sub-profiled material layer 130 formed on the first sub-surface 1110 of the sub-transparent base material 110, the refractive index of the sub-profiled material layer 130 is greater than the refractive index of the sub-transparent base material 110. Specifically, the first sub-light reflecting film 30 is disposed on the side surface of the sub-profiled material layer 130 away from the sub-transparent base material 110, the first sub-protective film 50 is disposed on the side surface of the first sub-light reflecting film 30 away from the sub-profiled material layer 130, the second sub-light reflecting film 70 is disposed on the second sub-surface 1120 of the sub-transparent base material 110, and the second sub-protective film 90 is disposed on the side surface of the second sub-light reflecting film 70 away from the sub-transparent base material 110.

[0087] The first sub-light reflecting film 30 and the second sub-light reflecting film 70 are respectively disposed on both sides of the reflective unit 230 along the arrangement direction of the reflective unit 230. Among them, in the arrangement direction of the first light waveguide array 23 or the second light waveguide array 25, the two sides of each reflective unit 230 are coated with a reflecting film (the first sub-light reflecting film 30 or the second sub-light reflecting film 70), and the first sub-light reflecting film 30 and the second sub-light reflecting film 70 are used to prevent light from entering the adjacent light waveguide array to form stray light and affect imaging due to not being totally reflected. The first sub-protective film 50 and the second sub-protective film 90 are used to improve the light reflectivity. A plurality of the reflective unit 230 is glued and spliced by the adhesive 27 to form the first light waveguide array 23 or the second light waveguide array 25. The adhesive 27 can be a thermosetting glue, and the surfaces of the coatings (coatings with the first sub-light reflecting film 30 or the second sub-light reflecting film 70) on both sides of the strip-shaped reflective unit 230 are adhered and spliced to form a plate of the strip-shaped light waveguide array as shown in FIG. 13, and then the adhesive is cured to form a strip-shaped light waveguide array plate. Since the master of the reflective unit 230 is processed by the coating method of the base as described above, the reflectivity of the first surface 111 and the reflectivity of the second surface 112 of the reflective unit 230 have uniformity, so the application does not limit where the coatings of the two reflective units 230 with the sub-profiled material layer are bonded. For example, the two reflective units can be bonded by the adhesive 27 on one side with the first sub-light reflecting film 30, or one of the two reflective units can be bonded by the adhesive 27 on one side with the first sub-light reflecting film 30 and the other on one side with the second sub-light reflecting film 70. The specific bonding method is determined according to the user's needs, and the application does not make any limitation.

[0088] The equivalent negative refraction flat lens 200 provided by the embodiment of the present application is cut from the coating optical element 100 in any of the above embodiments to form the reflection unit 230 of the first optical waveguide array 23 and the second optical waveguide array 25, which is conducive to improving the uniformity of the reflectivity of the first sub-surface 1110 and the second sub-surface 1120 of the reflection unit 230, improving the light output performance of the first optical waveguide array 23 and the second optical waveguide array 25, and thus improving the imaging effect of the equivalent negative refraction flat lens 200, and further improving the performance of the electronic device using the equivalent negative refraction flat lens 200.

[0089] Referring to FIG. 14, the electronic device 300 provided by the embodiment of the present application includes a body 301 and an equivalent negative refraction flat lens 200. The electronic device 300 can be a household appliance (e.g., a refrigerator, a washing machine, a dishwasher, etc.), a self-service terminal (e.g., a medical self-service machine, a bank self-service machine, etc.). The electronic device 300 can further include a detection module (not shown), a control module (not shown), etc. The user can operate the floating real image (not shown) generated by the equivalent negative refraction flat lens 200. The detection module is used to detect the operation of the user on the floating real image and feed back the detected interaction signal to the control module. The control module generates a corresponding control signal to control the electronic device 300 according to the interaction signal, so as to realize touchless operation and achieve cleaner and more sanitary operation.

[0090] The electronic device 300 provided by the embodiment of the present application uses the equivalent negative refraction flat lens 200, which is conducive to improving the uniformity of the light reflectivity of the electronic device 300, improving the light output performance of the electronic device 300, and thus improving the use effect of the electronic device 300, and further improving the performance of the electronic device 300.

[0091] Those skilled in the art should recognize that the above embodiments are only used to illustrate the present application, and are not used as a limitation to the present application. Any appropriate changes and modifications to the above embodiments within the spirit and principles of the present application are within the scope of the present application.

Claims

1. A coated optical element, comprising: a substrate comprising a light-transmitting base material having opposite first and second surfaces and a profiled material layer formed on the first surface of the light-transmitting base material, the profiled material layer having a refractive index greater than that of the light-transmitting base material; a first light-reflecting film disposed on a side surface of the profiled material layer away from the light-transmitting base material, the first light-reflecting film having a first thickness; a first protective film disposed on a side surface of the first light-reflecting film away from the profiled material layer, the first protective film having a second thickness; a second light-reflecting film disposed on the second surface of the light-transmitting base material, the second light-reflecting film having a third thickness, the third thickness being less than the first thickness; and a second protective film disposed on a side surface of the second light-reflecting film away from the light-transmitting base material, the second protective film having a fourth thickness. The substrate is a float glass, the profiled material layer is a tin layer, and the second surface is an air surface of the float glass.

2. The coated optical element of claim 1, wherein, The first light-reflecting film and the second light-reflecting film are made of one of aluminum and silver.

3. The coated optical element according to claim 1 or 2, wherein The thickness difference between the third thickness and the first thickness ranges from 10 nm to 15 nm.

4. The coated optical element of claim 3, wherein, The first thickness ranges from 80 nm to 85 nm, and the third thickness ranges from 70 nm to 75 nm.

5. The coated optical element of claim 4, wherein, The first protective film and the second protective film are made of the same material.

6. The coated optical element according to any one of claims 1 to 5, wherein The first protective film and the second protective film are both made of silicon dioxide.

7. The coated optical element of claim 6, wherein, The second thickness ranges from 20 nm to 25 nm, and the fourth thickness ranges from 20 nm to 25 nm.

8. The coated optical element of claim 7, wherein, A chamfer is disposed on a side edge of the light-transmitting base material perpendicular to the first surface.

9. The coated optical element according to any one of claims 1 to 8, wherein, 10.A method for coating a substrate with a reflecting film, for manufacturing the coated optical element of any one of claims 1-9, comprising: providing a substrate to be coated with a reflecting film, the substrate comprising a light-transmitting base material having opposite first and second surfaces and a profiled material layer formed on the first surface of the light-transmitting base material, the profiled material layer having a refractive index greater than that of the light-transmitting base material; forming a first light-reflecting film having a first thickness on a side surface of the profiled material layer away from the light-transmitting base material; forming a first protective film having a second thickness on a side surface of the first light-reflecting film away from the profiled material layer; forming a second light-reflecting film having a third thickness on the second surface of the light-transmitting base material, the third thickness being less than the first thickness; and forming a second protective film having a fourth thickness on a side surface of the second light-reflecting film away from the light-transmitting base material. forming the first light-reflecting film having the first thickness on the side surface of the profiled material layer away from the light-transmitting base material by using a direct current power source with a rated power not exceeding 40 kw and a first target material and introducing argon gas with a first volume flow rate; 11. The method of claim 10, wherein the method of coating a reflective film on a substrate is a method of coating a reflective film on a substrate by a vacuum deposition method. wherein the first target material is aluminum, the direct current power source outputs a first power, the first power ranges from 20 kw to 21 kw, and the first volume flow rate ranges from 180 sccm to 220 sccm. ​ 12. The method of claim 10, wherein the substrate is a glass substrate. Forming the second light reflection film with the third thickness on the second surface of the light transmission substrate by using a direct current power source with a power not more than 40kw and a first target material and inputting argon gas with a first volume flow rate; Wherein, the first target material is aluminum, the direct current power source outputs a third power, the third power ranges from 18KW to 19KW, and the first volume flow rate ranges from 180sccm to 220sccm.

13. The method of claim 10, wherein the method of coating a reflective film on a substrate is a method of coating a reflective film on a substrate by a vacuum deposition method. Forming the first protection film with the second thickness on the side surface of the first light reflection film away from the profiled material layer by using a medium frequency power source with a power not more than 50kw and a second target material and inputting argon gas with a first volume flow rate and oxygen gas with a second volume flow rate; Wherein, the second target material is silicon, the medium frequency power source outputs a second power, the second power ranges from 20KW to 25KW, the first volume flow rate ranges from 180sccm to 220sccm, the second volume flow rate ranges from 45sccm to 55sccm, and the process condition for forming the second protection film with the fourth thickness is the same as the process condition for forming the first protection film with the second thickness.

14. The method of claim 10, wherein The step before forming the first light reflection film with the first thickness on the side surface of the profiled material layer away from the light transmission substrate further comprises: forming a mark part on the substrate, the mark part being used to distinguish the first surface and the second surface.

15. An equivalent negative-index slab lens, wherein, The equivalent negative refraction flat lens comprises: two transparent substrates; and a first light waveguide array and a second light waveguide array arranged between the two transparent substrates, the first light waveguide array and the second light waveguide array being closely adhered and orthogonally arranged in the same plane, the thickness of the first light waveguide array being the same as the thickness of the second light waveguide array, and the first light waveguide array and the second light waveguide array each being composed of a plurality of reflection units with rectangular cross sections; Wherein, each reflection unit comprises a sub-substrate, a first sub-light reflection film, a first sub-protection film, a second sub-light reflection film, and a second sub-protection film; the sub-substrate comprises a sub-light transmission substrate with opposite first and second sub-surfaces and a sub-profiled material layer formed on the first sub-surface of the sub-light transmission substrate, the refractive index of the sub-profiled material layer being greater than the refractive index of the sub-light transmission substrate, the first sub-light reflection film being arranged on the side surface of the sub-profiled material layer away from the sub-light transmission substrate, the first sub-protection film being arranged on the side surface of the first sub-light reflection film away from the sub-profiled material layer, the second sub-light reflection film being arranged on the second sub-surface of the sub-light transmission substrate, and the second sub-protection film being arranged on the side surface of the second sub-light reflection film away from the sub-light transmission substrate.

16. An electronic device comprising: a body; and the equivalent negative refraction flat lens as claimed in claim 15.