CN116360035A - Film preparation method, film grating optical waveguide and augmented reality device - Google Patents

Abstract

The application relates to a film preparation method, a film grating optical waveguide and an augmented reality device, wherein the film preparation method comprises the following steps: providing a substrate, wherein the substrate is provided with an incident grating area, an emergent grating area and a folding grating area; coating an incident grating area, an emergent grating area and a folding grating area by adopting conductive particles, and controlling the line width distribution of a coating position by an electric field so as to generate different refractive indexes at the coating position by the line width distribution to form a thin film grating; and (5) overall exposure to obtain the thin film optical waveguide. According to the film preparation method, the optical efficiency can be separately confirmed in each independent area by confirming the coated gratings in each independent area, and the conductive particles are distributed and stacked to form the gratings by utilizing charged coating, so that the problem of loss of a large amount of materials caused by the traditional rotary coating mode is avoided, the position of a specific area is accurately controlled, and the exposure effect is ensured.

Description

Film preparation method, film grating optical waveguide and augmented reality device

Technical Field

The application relates to the field of augmented reality, in particular to a film preparation method, a film grating optical waveguide and an augmented reality device.

Background

Against the technical development of augmented reality (Augmented Reality, AR) products, the current main technical trend is to adopt an optical waveguide (optical waveguide) technology, wherein the optical waveguide technology can be divided into two main application technologies, namely a geometric optical waveguide (Geometric Waveguide) and a diffraction optical waveguide (Diffractive Waveguide, also called a diffraction optical waveguide), and the volume holographic thin film optical waveguide using the diffraction optical waveguide is most developed rapidly, and the volume holographic thin film optical waveguide is realized by a volume holographic grating (Volumetric Holographic Gratings), namely, the volume holographic grating is composed of periodic microstructures with alternating high and low refractive indexes. Assuming that the incident light is a single wavelength of red light, it is divided into a plurality of diffraction orders (diffraction order) by the diffraction grating, each diffraction order is transmitted in a different direction, and light rays including reflection diffraction (R0, r±1, r±2, … …) and transmission diffraction (T0, t±1, t±2, … …) are diffracted, and the diffraction angle (θm, m= ±1, ±2, … …) corresponding to each diffraction order is determined by the incident angle (θ) of the light ray and the period (Λ) of the grating, and by designing other parameters of the grating, such as the refractive index n of the material, the thickness, etc., the diffraction efficiency of a certain diffraction order, i.e., a certain direction, can be optimized to be the highest, so that most of light propagates in this direction after diffraction. However, volume holographic gratings have a problem of chromatic dispersion.

The volume holographic film optical waveguide technology of the diffraction optical waveguide is mainly to expose the volume holographic film by using laser light to generate gratings with different refractive indexes so as to manufacture the diffraction optical waveguide, thus being very important for the development of the volume holographic film optical waveguide.

The preparation of the traditional volume holographic film adopts spin coating whole-surface coating firstly and then alignment exposure is carried out, thus the following two defects are inevitably caused: on one hand, spin coating causes a great deal of material loss, i.e., waste of coating material; on the other hand, the exposure position of the specific area is controlled by means of exposure, so that the exposure position of the specific area of the whole surface is not easy to control, for example, the exposure of the specific area such as an incident light area, a turning area and an emergent light area is poor.

Disclosure of Invention

Based on this, it is necessary to provide a thin film manufacturing method, a thin film grating optical waveguide, and an augmented reality device.

In one embodiment, a method of preparing a film includes the steps of:

s100, providing a substrate, wherein the substrate is provided with an incident grating area, an emergent grating area and a folding grating area;

s200, coating the incident grating area, the emergent grating area and the folding grating area by adopting conductive particles, and controlling the line width distribution of the coating position by an electric field so as to generate different refractive indexes at the coating position by the line width distribution to form a thin film grating;

s300, overall exposure is carried out, and the thin film optical waveguide is obtained.

According to the film preparation method, the optical efficiency can be separately confirmed in each independent area by confirming the coated gratings in each independent area, and the gratings are formed after the conductive particles are distributed and stacked by utilizing charged coating, so that the problem of loss of a large amount of materials caused by the traditional rotary coating mode is avoided, the position of a specific area is accurately controlled, the exposure effect is ensured, and the film optical waveguide prepared on the other hand can be used as a volume holographic film optical waveguide.

In one embodiment, step S100 includes: s110, grooves which are spaced from each other are formed on the same surface or different surfaces of the substrate and serve as the incident grating area, the emergent grating area and the folding grating area.

In one embodiment, the groove depth is 15 μm to 500 μm; and/or sputtering a reflecting layer on the side surface of the groove, wherein the thickness of the reflecting layer is 10nm to 300nm.

In one embodiment, after step S110, step S100 further includes: and S120, arranging a transparent conductive layer in the groove.

In one embodiment, after step S120, step S100 further includes: and S130, forming patterned transparent conductive lines on the transparent conductive layer in an etching mode.

In one embodiment, in step S200, the incident grating region, the exit grating region and the folded grating region are spot-glued or slit-coated.

In one embodiment, the thin film grating has a grating width ranging from 0.2 μm to 3 μm and a period ranging from 0.3 μm to 5 μm; and/or, the grating light-dark refractive index difference range of the thin film grating is 0.05-0.08.

In one embodiment, in step S200, the substrate is brought to an opposite charge to the conductive particles in the coating material, and then charged coating is performed.

In one embodiment, a thin film grating optical waveguide is produced using the thin film fabrication method of any of the embodiments.

In one embodiment, an augmented reality device includes a curved optical structure having the thin film grating optical waveguide of any of the embodiments.

Drawings

In order to more clearly illustrate the technical solutions of embodiments or conventional techniques of the present application, the drawings that are required to be used in the description of the embodiments or conventional techniques will be briefly described below, and it is apparent that the drawings in the following description are only some embodiments of the present application, and other drawings may be obtained according to these drawings without inventive effort for a person of ordinary skill in the art.

FIG. 1 is a schematic flow chart of an embodiment of a method for preparing a thin film according to the present application.

FIG. 2 is a schematic flow chart of another embodiment of the film forming method described in the present application.

Fig. 3 is a schematic diagram of a layout of the substrate of the embodiment shown in fig. 1.

Fig. 4 is a schematic cross-sectional view of an aspect of the embodiment shown in fig. 3.

Fig. 5 is a schematic cross-sectional view of another aspect of the embodiment shown in fig. 3.

FIG. 6 is a schematic illustration of an electric field controlled coating process according to another embodiment of the film forming method described herein.

FIG. 7 is a schematic diagram of a photo-marking of an embodiment of a thin film grating optical waveguide as described herein.

Fig. 8 is a schematic diagram of a photographic mark of another embodiment of a thin film grating optical waveguide as described herein.

Reference numerals: a substrate 100, a top surface 110, the entrance grating region 111, the exit grating region 112, the folded grating region 113, a conductive particle carrier 200, conductive particles 210, an electric field 300.

Detailed Description

In order to make the above objects, features and advantages of the present application more comprehensible, embodiments accompanied with figures are described in detail below. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. This application is, however, susceptible of embodiment in many other forms than those described herein and similar modifications can be made by those skilled in the art without departing from the spirit of the application, and therefore the application is not to be limited to the specific embodiments disclosed below.

It will be understood that when an element is referred to as being "mounted" or "disposed" on another element, it can be directly on the other element or intervening elements may also be present. When a component is considered to be "connected" to another component, it can be directly connected to the other component or intervening components may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like are used in the description of the present application for purposes of illustration only and do not represent the only embodiment.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present application, the meaning of "plurality" is at least two, such as two, three, etc., unless explicitly defined otherwise.

In this application, unless expressly stated or limited otherwise, a first feature "up" or "down" a second feature may be a direct contact of the first feature with the second feature, or an indirect contact of the first feature with the second feature via an intervening medium. Moreover, a first feature "above," "over" and "on" a second feature may be a first feature directly above or obliquely above the second feature, or simply indicate that the first feature is higher in level than the second feature. The first feature being "under", "below" and "beneath" the second feature may be the first feature being directly under or obliquely under the second feature, or simply indicating that the first feature is less level than the second feature.

Unless defined otherwise, all technical and scientific terms used in the specification of this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application. The term "and/or" as used in the specification of this application includes any and all combinations of one or more of the associated listed items.

On one hand, in order to overcome the problem of waste of coating materials caused by coating conductive particles on the whole surface of a volumetric holographic film in a traditional rotation mode, and on the other hand, in order to overcome the problem of inaccurate exposure positions caused by a traditional alignment exposure mode, the application discloses a film preparation method, which comprises part of steps or all steps in the following embodiments; that is, the thin film production method includes some or all of the following technical features. In one embodiment of the present application, a method for preparing a thin film is shown in fig. 1, which includes the steps of: s100, providing a substrate, wherein the substrate is provided with an incident grating area, an emergent grating area and a folding grating area; s200, coating the incident grating area, the emergent grating area and the folding grating area by adopting conductive particles, and controlling the line width distribution of the coating position by an electric field so as to generate different refractive indexes at the coating position by the line width distribution to form a thin film grating; s300, overall exposure is carried out, and the thin film optical waveguide is obtained. According to the film preparation method, the optical efficiency can be separately confirmed in each independent area by confirming the coated gratings in each independent area, and the gratings are formed after the conductive particles are distributed and stacked by utilizing charged coating, so that the problem of loss of a large amount of materials caused by the traditional rotary coating mode is avoided, the position of a specific area is accurately controlled, the exposure effect is ensured, and the film optical waveguide prepared on the other hand can be used as a volume holographic film optical waveguide.

In step S100, a substrate is provided, where the substrate is provided with the incident grating area, the exit grating area and the folded grating area; in one embodiment, the material of the substrate includes optical glass and optical plastic. In one embodiment, the optical plastic includes, but is not limited to, polymethyl methacrylate (polymethyl methacrylate, PMMA), polystyrene (PS), polycarbonate (PC), cyclic olefin copolymer (copolymers of cycloolefin, COC), cyclic olefin polymer (Cyclo Olefin Polymer, COP), and the like. It is understood that the materials of the substrate are not particularly limited in the embodiments of the present application. Further, in one embodiment, the substrate is provided with the incident grating region, the emergent grating region and the folded grating region which are spaced from each other; further, in one embodiment, the intervals of the incident grating region, the exit grating region and the folded grating region meet the technical requirement that the width of the coating position is controlled by an external electric field, so that when the incident grating region, the exit grating region and the folded grating region are coated by conductive particles in a subsequent step, the line width distribution of the coating position is controlled by the electric field. By means of the design, the thin film gratings are arranged in the partition mode, and the light efficiency can be confirmed in each independent area, so that the yield and accuracy of the whole manufacturing process are improved.

In one embodiment, step S100 includes: s110, grooves which are spaced from each other are formed on the same surface or different surfaces of the substrate and serve as the incident grating area, the emergent grating area and the folding grating area. In one embodiment, the substrate has a flat shape, for example, a rectangular or other flat shape, which has two opposite surfaces and a plurality of sides between the two surfaces, for example, a rectangular flat plate has two surfaces and four sides, and the surfaces can be divided into a bottom surface and a top surface according to the relative relationship of the positions, that is, in step S110, grooves with mutual spacing are formed on the top surface and/or the bottom surface of the substrate as the incident grating region, the exit grating region and the folded grating region; namely, grooves which are mutually spaced are formed on the top surface of the substrate and serve as the incident grating area, the emergent grating area and the folding grating area; or grooves which are mutually spaced are formed on the bottom surface of the substrate and serve as the incident grating area, the emergent grating area and the folding grating area; or one or two of the incident grating area, the emergent grating area and the folded grating area are arranged on the top surface of the substrate, and the other two or one are arranged on the bottom surface of the substrate. Generally, the surface of the substrate and the distribution of the grooves thereof are designed according to the design requirements of the thin film grating optical waveguide or the volumetric holographic film thereof.

In one embodiment, the groove depth is 15 μm to 500 μm; in one embodiment, the side of the groove is sputtered with a reflective layer, and the thickness of the reflective layer is 10nm to 300nm. Further, in one embodiment, the reflective layer has a resistivity of 1×10 ⁵ Omega/cm to 5X 10 ⁵ Omega/cm. In one of the embodiments of the present invention,the groove depth is 15 μm to 500 μm; and the side surface of the groove is sputtered with a reflecting layer, and the thickness of the reflecting layer is 10nm to 300nm. The rest of the embodiments are analogized and will not be described in detail. In one embodiment, after step S110, step S100 further includes: and S120, arranging a transparent conductive layer in the groove. The transparent conductive layer is made of indium tin oxide, zinc oxide, cadmium tin oxide, indium oxide, nano silver wires and the like. In one embodiment, after step S120, step S100 further includes: and S130, forming patterned transparent conductive lines on the transparent conductive layer in an etching mode. By the design, the incident grating area, the emergent grating area, the folded grating area and the corresponding grating distribution positions can be obtained after coating in the subsequent steps, and the grating distribution positions can be also called target positions because the grating distribution positions are targets for coating.

In one embodiment, the film preparation method is shown in fig. 2, and includes the steps of: s110, providing a substrate, and arranging grooves which are mutually spaced on the same surface or different surfaces of the substrate as an incident grating area, an emergent grating area and a folding grating area; s120, arranging a transparent conductive layer in the groove; s130, forming a patterned transparent conductive circuit on the transparent conductive layer in an etching mode; s200, coating the incident grating area, the emergent grating area and the folding grating area by adopting conductive particles, and controlling the line width distribution of a coating position by an electric field so as to generate differential refractive indexes at the coating position by the line width distribution to form a thin film grating; s300, overall exposure is carried out, and the thin film optical waveguide is obtained. Further, in each embodiment, the incident grating region, the exit grating region, and the folded grating region are coated with a coating material with conductive particles.

As shown in fig. 3, the top surface 110 of the substrate 100 is provided with grooves spaced apart from each other, and the grooves include the incident grating region 111, the exit grating region 112 and the folded grating region 113, and the incident grating region 111, the exit grating region 112 and the folded grating region 113 are spaced apart from each other in combination with fig. 4 and 5. Example(s)For example, the substrate groove can be etched on the same side or different sides according to the design scheme, then the transparent conductive material is sputtered to form the transparent conductive layer, patterning is performed, and then the transparent conductive circuit is etched. Thus, the optical waveguide substrate structure with the groove design is completed, the grooves can be arranged on the same side or on opposite sides, the depth of the grooves is 15-500 μm, the side surfaces of the grooves can be sputtered with a reflecting layer, and the thickness is about 100-300 nm. The groove substrate has a patterned transparent conductive layer, which may be ITO or nano silver wire, with a thickness of about 100nm to 300nm, and a resistivity of 1×105Ω/cm to 5×10 ⁵ Omega/cm. The grating width is 0.2-3 μm, the period is 0.3-5 μm, and the light-dark refractive index difference is 0.05-0.08.

In step S200, conductive particles are used to coat the incident grating region, the exit grating region and the folded grating region, and the line width distribution of the coating position is controlled by an electric field, so as to generate a differential refractive index at the coating position through the line width distribution, thereby forming a thin film grating; that is, the different refractive indexes are generated by the different widths, so that each region, including the incident grating region, the emergent grating region and the folded grating region, has different refractive indexes at the coating positions of the regions to form the thin film grating. Further, in one embodiment, the incident grating region, the exit grating region, and the folded grating region are coated with a coating material with conductive particles; the coating comprises a microcapsule material and liquid optical cement, wherein the weight percentage of the microcapsule material relative to the liquid optical cement is 10-40%. The microcapsule material comprises iron-manganese black, carbon black and the like, the shell material of the microcapsule is an ultraviolet light degradable material, and the particle size of the microcapsule is 0.2-3 mu m. Further, in one of the embodiments, the driving voltage of the electric field is 10V to 100V.

In one embodiment, in step S200, the incident grating area, the exit grating area and the folded grating area are subjected to dispensing or slit coating, that is, the conductive particles are accurately guided and positioned by an electric field control by a dispensing method or a slit coating method, and are accurately disposed in the target positions of the incident grating area, the exit grating area and the folded grating area. That is, the present application proposes a substrate structure design, which is coated with conductive particles, for example, by dispensing or slit coating (Slot Die), and by controlling the electric field of the substrate during the coating, so that the substrate can achieve the desired line width distribution and simultaneously cause the difference of refractive indexes, thereby forming a thin film type grating, and finally performing integral exposure, thereby completing the thin film optical waveguide.

In one embodiment, the thin film grating has a grating width ranging from 0.2 μm to 3 μm and a period ranging from 0.3 μm to 5 μm; in one embodiment, the thin film grating has a grating width in the range of 0.5 μm to 1.5 μm and a period in the range of 1 μm to 3 μm. In one embodiment, the thin film grating has a grating light-dark refractive index difference in the range of 0.05 to 0.08; in one embodiment, the thin film grating has a grating light-dark refractive index difference in the range of 0.06 to 0.07; the range of the grating light-dark refractive index difference, namely the range of the difference of the refractive index of the grating, the height difference and the refractive index difference can influence the phase difference of light in different areas, and the embodiment of the application adopts conductive particle coating, so that the influence of the height difference is not great, and the focus can be placed on the aspect of the grating light-dark refractive index difference. In one embodiment, the grating width of the thin film grating is 1 μm, the period is 1 μm, and the grating light-dark refractive index difference of the thin film grating is 0.06. It will be appreciated that the above range values are merely examples, and that the requirements may be flexibly set in practical applications.

Based on the opposite attraction effect, in one embodiment, in step S200, the substrate is brought to an opposite charge to the conductive particles in the coating material, and then charged coating is performed. Further, in one embodiment, a target position of the substrate is brought into the electric field with positive charges, where the target position is a grating distribution position of the incident grating region, the exit grating region, and the folded grating region; and (3) carrying negative charges on conductive particles in the coating, coating the incident grating area, the emergent grating area and the folding grating area of the electric field with positive charges on the substrate by adopting the conductive particles with negative charges, and controlling the line width distribution of the coating position by the electric field with positive charges on the substrate. Further, in one embodiment, for the incident grating area, the exit grating area and the folded grating area of the substrate, an electric field with a first charge is sequentially applied to the preset coating positions according to a coating sequence, the width distribution of the first charge is controlled by the electric field, and then a second charge which is opposite to the first charge is used for coating, so that the line width distribution of the second charge on the coating positions is controlled, and the second charge is accurately distributed on the coating positions, so that the positions with different refractive indexes, namely positions with different refractive indexes, are provided through the line width distribution of the second charges of the incident grating area, the exit grating area and the folded grating area, so that the thin film grating is formed. For example, the first charge is a positive charge and the second charge is a negative charge; referring to fig. 6, the conductive particle carrier 200 precisely coats the negatively charged conductive particles 210 on the target location under the guidance of the positively charged electric field 300, and the incident grating region 111, the exit grating region 112 and the folded grating region 113 of the substrate 100 are respectively obtained through the subsequent exposure step, that is, the gratings are formed on the target location, thereby obtaining the thin film optical waveguide. By means of the design, on one hand, accurate control of partition coating is achieved by virtue of partition accurate electrified coating, so that the consumption of coating materials is saved; on the other hand, the electric field can be precisely controlled, so that the coating position of the conductive particles can be precisely controlled through the opposite-phase attractive effect, and the precision of the thin film grating is ensured.

In step S300, the entire body is exposed to light, thereby obtaining a thin film optical waveguide. Further, in one embodiment, in step S300, the entire surface is exposed to light, so as to obtain a thin film optical waveguide, that is, the entire surface of the substrate is exposed to light. Further, in one embodiment, in step S100, grooves spaced from each other are formed on the same side of the substrate as the incident grating region, the exit grating region and the folded grating region, so that in step S300, exposure can be performed on only one side of the substrate, which is beneficial to improving the processing efficiency. In other embodiments, in step S100, grooves spaced apart from each other are formed on different sides of the substrate as the incident grating region, the exit grating region and the folded grating region, so that a more significant position difference can be formed. When the incident grating area, the emergent grating area and the folded grating area are positioned on the same surface, exposure is only needed once; when the incident grating region, the emergent grating region and the folded grating region are positioned on different surfaces of the substrate, the exposure is required to be performed twice, or both surfaces of the substrate are positioned in an exposable environment. Compared with the traditional problem that the alignment exposure position of a specific area of the whole surface is not easy to control, the design ensures the exposure effect of the incident grating area, the emergent grating area and the folding grating area through the preposition process, and the whole exposure has the advantage of simple process and improves the production efficiency.

In step S300, the thin film optical waveguide obtained after the entire exposure has a volume hologram grating, and thus may be referred to as a volume hologram thin film optical waveguide. In practical use, one embodiment of the resulting thin film optical waveguide is shown in FIG. 7, wherein the length of the bright line to bright line is 5.406 μm, the length of the dark line to dark line is 5.140 μm, the bright line width is 2.715 μm, and the dark line width is 2.397 μm. Another example of the resulting thin film optical waveguide is shown in FIG. 8, in which the length of the bright line to bright line is 0.477 μm, the length of the dark line to dark line is 0.436 μm, the bright line width is 0.248 μm, and the dark line width is 0.221 μm. The obtained thin film optical waveguide can meet the requirements of grating design on one hand and has a certain width range on the other hand.

In one embodiment, a thin film grating optical waveguide is produced using the thin film fabrication method of any of the embodiments. In one embodiment, the thin film grating optical waveguide is manufactured by the steps of S100, providing a substrate, wherein the substrate is provided with the incident grating region, the emergent grating region and the folded grating region; s200, coating the incident grating area, the emergent grating area and the folding grating area by adopting conductive particles, and controlling the line width distribution of the coating position by an electric field so as to generate different refractive indexes at the coating position by the line width distribution to form a thin film grating; s300, performing overall exposure to obtain the thin film optical waveguide, namely the thin film grating optical waveguide, namely the volume holographic thin film optical waveguide. The rest of the embodiments are analogized and will not be described in detail. By adopting the design, the optical efficiency can be separately confirmed in each independent area by confirming the coated gratings in each independent area, and the gratings are formed after the conductive particles are distributed and stacked by utilizing charged coating, so that the problem of loss of a large amount of materials caused by the traditional rotary coating mode is avoided, the position of a specific area is accurately controlled, and the exposure effect is ensured.

In one embodiment, an augmented reality device includes a curved optical structure having the thin film grating optical waveguide of any of the embodiments. In one embodiment, the augmented reality device comprises a wearable device, such as glasses or a helmet. In one embodiment, the augmented reality device or the curved optical structure thereof is a near-eye display optical element, or the augmented reality device or the curved optical structure thereof includes a near-eye display optical element, the structure and the process of the near-eye display optical element can perform coated grating confirmation for respective regions, each region can independently and separately confirm the light efficiency, and the conductive particles are distributed and stacked to form a grating by using charged coating; by the design, the problem that the traditional rotation mode is used for coating conductive particles on the whole surface of the volume holographic film to cause waste of coating materials is solved, and the problem that the traditional alignment exposure mode is used for causing inaccurate exposure positions is solved.

It should be noted that other embodiments of the present application also include a thin film preparation method, a thin film grating optical waveguide, and an augmented reality device that can be implemented by combining the technical features of the foregoing embodiments.

The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above examples only represent a few embodiments of the present application, which are described in more detail and are not to be construed as limiting the scope of the claims. It should be noted that it would be apparent to those skilled in the art that various modifications and improvements could be made without departing from the spirit of the present application, which would be within the scope of the present application. Accordingly, the scope of the present application is to be determined by the following claims.

Claims (10)

1. A method of producing a film comprising the steps of:

s100, providing a substrate, wherein the substrate is provided with an incident grating area, an emergent grating area and a folding grating area;

s200, coating the incident grating area, the emergent grating area and the folding grating area by adopting conductive particles, and controlling the line width distribution of a coating position by an electric field so as to generate differential refractive indexes at the coating position by the line width distribution to form a thin film grating;

s300, overall exposure is carried out, and the thin film optical waveguide is obtained.

2. The method of producing a thin film according to claim 1, wherein step S100 comprises: s110, grooves which are spaced from each other are formed on the same surface or different surfaces of the substrate and serve as the incident grating area, the emergent grating area and the folding grating area.

3. The method of producing a film according to claim 2, wherein the groove depth is 15 μm to 500 μm; and/or sputtering a reflecting layer on the side surface of the groove, wherein the thickness of the reflecting layer is 10nm to 300nm.

4. The method of manufacturing a thin film according to claim 2, wherein after step S110, step S100 further comprises: and S120, arranging a transparent conductive layer in the groove.

5. The method of manufacturing a thin film according to claim 4, wherein after step S120, step S100 further comprises: and S130, forming patterned transparent conductive lines on the transparent conductive layer in an etching mode.

6. The method according to claim 1, wherein in step S200, the incident grating region, the exit grating region, and the folded grating region are spot-glued or slit-coated.

7. The method of producing a thin film according to claim 1, wherein the thin film grating has a grating width ranging from 0.2 μm to 3 μm and a period ranging from 0.3 μm to 5 μm; and/or, the grating light-dark refractive index difference range of the thin film grating is 0.05-0.08.

8. The method according to any one of claims 1 to 7, wherein in step S200, the substrate is charged to a charge opposite to that of the conductive particles in the coating material, and then charged coating is performed.

9. A thin film grating optical waveguide produced by the thin film production method according to any one of claims 1 to 8.

10. An augmented reality device comprising a curved optical structure having the thin film grating optical waveguide of claim 9.

Images