Optical waveguide structure, preparation method thereof and head-mounted display device

Abstract

The invention discloses an optical waveguide structure and a preparation method thereof, and a head-mounted display device, and relates to the technical field of optical waveguides, and the optical waveguide structure comprises an optical waveguide substrate; the optical waveguide substrate comprises a grating area, and a grating structure in the grating area is formed by cured imprinting glue; a non-grating area, except the grating area, on the optical waveguide substrate is a glare suppression area, and the optical waveguide substrate in the glare suppression area is set as follows: a, the surface of the optical waveguide substrate is not provided with impressing glue, or b, the surface of the optical waveguide substrate is provided with impressing glue, and at least partial area of the impressing glue is also provided with a first glare suppression layer; the first glare suppression layer is used for reducing the reflectivity of a non-grating area of the optical waveguide structure. Therefore, the glare effect of the existing optical waveguide structure is suppressed.

Description

Technical Field

[0001] The present application relates to the field of optical waveguide technology, and in particular to an optical waveguide structure and a preparation method thereof, and a head-mounted display device. Background Art

[0002] With the rapid development of augmented reality (AR) technology, diffractive waveguides, as core optical display devices in the AR field, play a vital role. Diffractive waveguides precisely control the propagation path of light to achieve aerial projection of image information and superposition of virtual images, providing users with an immersive visual experience.

[0003] In the manufacturing process of diffraction optical waveguides, nanoimprint technology is widely used due to its high precision and high efficiency. In the nanoimprint process, in order to enhance the diffraction effect of the grating and improve the overall efficiency of the waveguide, an imprint glue with a refractive index higher than that of the substrate material is usually selected as the material for the grating, which also leads to a significant increase in the surface reflectivity of the non-grating area. However, during the use of AR devices, when external light shines on the non-grating area, a strong reflection will occur, forming a glare effect. That is, the existing optical waveguide structure leads to a glare effect during use.

[0004] The above contents are only used to assist in understanding the technical solution of the present application and do not constitute an admission that the above contents are prior art. Summary of the invention

[0005] The main purpose of the present application is to provide an optical waveguide structure and a preparation method thereof and a head-mounted display device, aiming to solve the technical problem of glare effect caused by the existing optical waveguide structure during use.

[0006] To achieve the above-mentioned purpose, the present application proposes an optical waveguide structure, which includes: an optical waveguide substrate; The optical waveguide substrate includes a grating region, and the grating structure in the grating region is formed by a cured embossed adhesive; The non-grating area on the optical waveguide substrate except the grating area is a glare suppression area, and the optical waveguide substrate in the glare suppression area is configured as follows: a. No embossed adhesive on the surface, or b. There is embossed glue on the surface, and a first glare suppression layer is also arranged on at least a part of the embossed glue, and the first glare suppression layer is used to reduce the reflectivity of the non-grating area of ​​the optical waveguide structure.

[0007] In one embodiment, when there is no embossing glue on the surface of the optical waveguide substrate, the glare suppression region further includes a second glare suppression layer disposed on at least a portion of the optical waveguide substrate.

[0008] In one embodiment, the second glare suppression layer comprises a second anti-reflection film layer on the light waveguide substrate, and the refractive index of the second anti-reflection film layer is smaller than the refractive index of the light waveguide substrate; or, The second glare suppression layer includes at least two second anti-reflection film layers on the optical waveguide substrate, and the refractive index of the second anti-reflection film layer farthest from the optical waveguide substrate is less than or equal to the refractive index of the optical waveguide substrate.

[0009] In one embodiment, the thickness of the second anti-reflection film layer is determined according to the geometric shape and refractive index of the optical waveguide substrate and the refractive index of the second anti-reflection film layer.

[0010] In one embodiment, when there is a printed glue on the surface of the optical waveguide substrate in the glare suppression area, the first glare suppression layer includes a first anti-reflection film layer on the optical waveguide substrate, and the refractive index of the first anti-reflection film layer is less than the refractive index of the printed glue; or The first glare suppression layer includes at least two first anti-reflection film layers on the embossed adhesive, and the refractive index of the first anti-reflection film layer farthest from the embossed adhesive is less than or equal to the refractive index of the embossed adhesive.

[0011] In one embodiment, the thickness of the first anti-reflection film layer is determined according to the geometric shape and refractive index of the optical waveguide substrate, the thickness and refractive index of the embossed glue in the glare suppression area, and the refractive index of the first anti-reflection film layer.

[0012] In addition, to achieve the above-mentioned purpose, the present application also proposes a method for preparing an optical waveguide structure, the method for preparing the optical waveguide structure comprising: Performing zone-by-zone coating of the embossing glue on the grating area of ​​the optical waveguide substrate; Providing a master template for grating structure imprinting, and imprinting the imprinting glue on the optical waveguide substrate by using the master template for grating structure imprinting to form a grating structure in the grating area of ​​the optical waveguide substrate; The imprinted adhesive is cured, and the master template imprinted with the grating structure is demoulded from the imprinted adhesive to obtain an optical waveguide structure.

[0013] In one embodiment, after the step of curing the embossed embossing adhesive and demolding the master template embossed with the grating structure from the embossing adhesive, the method includes: A second glare suppression layer is plated on the non-grating area of ​​the optical waveguide substrate except the grating area, wherein the second glare suppression layer is used to reduce the reflectivity of the non-grating area of ​​the optical waveguide structure.

[0014] In one embodiment, the second glare suppression layer comprises a second anti-reflection film layer on the light waveguide substrate, and the refractive index of the second anti-reflection film layer is less than the refractive index of the light waveguide substrate; Alternatively, the second glare suppression layer comprises at least two second anti-reflection film layers on the optical waveguide substrate, and the refractive index of the second anti-reflection film layer farthest from the optical waveguide substrate is less than or equal to the refractive index of the optical waveguide substrate.

[0015] In one embodiment, before the step of coating the non-grating area on the optical waveguide substrate except the grating area with a second glare suppression layer, the method includes: Obtaining the geometric shape and refractive index of the optical waveguide substrate; Constructing an optical waveguide structure simulation model according to the geometric shape and refractive index of the optical waveguide substrate and the refractive index of the second anti-reflection film layer; Simulating a first optional thickness of the second anti-reflection film layer based on the optical waveguide structure simulation model to obtain a theoretical reflectivity of the optical waveguide structure corresponding to the first optional thickness; According to the theoretical reflectivity, the film thickness of the second anti-reflection film layer is selected from the first optional thicknesses.

[0016] In addition, to achieve the above-mentioned purpose, the present application also proposes a method for preparing an optical waveguide structure, the method for preparing the optical waveguide structure comprising: Spin coating the imprint glue on the optical waveguide substrate; Providing a master template for grating structure imprinting, and imprinting the imprinting glue on the optical waveguide substrate by using the master template for grating structure imprinting to form a grating structure in the grating area of ​​the optical waveguide substrate; The embossed embossing adhesive is cured, and the master template embossed with the grating structure is demoulded from the embossing adhesive; A first glare suppression layer is plated on the non-grating area of ​​the optical waveguide substrate except the grating area to obtain an optical waveguide structure, wherein the first glare suppression layer is used to reduce the reflectivity of the non-grating area of ​​the optical waveguide structure.

[0017] In one embodiment, the first glare suppression layer comprises a first anti-reflection film layer on the optical waveguide substrate, and the refractive index of the first anti-reflection film layer is less than the refractive index of the embossed glue; Alternatively, the first glare suppression layer includes at least two first anti-reflection film layers on the embossed adhesive, and the refractive index of the first anti-reflection film layer farthest from the embossed adhesive is less than or equal to the refractive index of the embossed adhesive.

[0018] In one embodiment, before the step of coating the non-grating area on the optical waveguide substrate except the grating area with the first glare suppression layer, the method comprises: Acquire the geometric shape and refractive index of the optical waveguide substrate, and the thickness and refractive index of the glue layer of the embossed glue in the non-grating area; Constructing an optical waveguide structure simulation model according to the geometric shape and refractive index of the optical waveguide substrate, the thickness and refractive index of the embossed adhesive layer, and the refractive index of the first anti-reflection film layer; Simulating a second optional thickness of the first anti-reflection film layer based on the optical waveguide structure simulation model to obtain a theoretical reflectivity of the optical waveguide structure corresponding to the second optional thickness; According to the theoretical reflectivity, the film thickness of the first anti-reflection film layer is selected from the second optional thicknesses.

[0019] In addition, to achieve the above objectives, the present application also proposes a head-mounted display device, which includes the optical waveguide structure as described above.

[0020] One or more technical solutions proposed in this application have at least the following technical effects: In the present application, the optical waveguide structure includes: an optical waveguide substrate; the optical waveguide substrate includes a grating area, and the grating structure in the grating area is composed of a cured imprinted adhesive; the non-grating area on the optical waveguide substrate other than the grating area is a glare suppression area, and the optical waveguide substrate in the glare suppression area is set to: a. no imprinted adhesive on the surface, or b. imprinted adhesive on the surface, and a first glare suppression layer is also provided on at least part of the imprinted adhesive, and the first glare suppression layer is used to reduce the reflectivity of the non-grating area of ​​the optical waveguide structure. Therefore, the present application performs a glare suppression treatment method on the non-grating area on the optical waveguide substrate other than the grating area, in which the imprinted adhesive is not present on the surface or the first glare suppression layer is added, so that during the use of the AR device, the glare effect when the external light is irradiated to the non-grating area is reduced, and the glare effect of the existing optical waveguide structure is suppressed. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0022] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 is a schematic diagram of the structure of an optical waveguide; Figure 2is a schematic structural diagram of an existing optical waveguide structure; Figure 3 A schematic diagram of a scene of glare effect of an existing optical waveguide structure; Figure 4 A schematic diagram of the structure of an optical waveguide structure provided in an embodiment of the present application; Figure 5 It is a structural schematic diagram of the common original optical waveguide structure; Figure 6 Schematic diagram of the reflectivity results of the original optical waveguide structure; Figure 7 A schematic diagram of reflectivity results of an optical waveguide structure provided in an embodiment of the present application; Figure 8 A schematic structural diagram of another optical waveguide structure provided in an embodiment of the present application; Fig. 9 A schematic structural diagram of another optical waveguide structure provided in an embodiment of the present application; Fig.10 A schematic diagram of the corresponding relationship between the optional thickness of the single-layer second anti-reflection film layer and the theoretical reflectivity involved in the embodiment of the present application; Fig.11 A schematic diagram of the corresponding relationship between the optional thickness of the double-layer second anti-reflection film layer and the theoretical reflectivity involved in the embodiment of the present application; Fig.12 A schematic structural diagram of another optical waveguide structure provided in an embodiment of the present application; Fig.13 A schematic structural diagram of another optical waveguide structure provided in an embodiment of the present application; Fig.14 A schematic diagram of reflectivity results of another optical waveguide structure provided in an embodiment of the present application; Fig.15 A schematic diagram of reflectivity results of another optical waveguide structure provided in an embodiment of the present application; Fig.16 A schematic structural diagram of another optical waveguide structure provided in an embodiment of the present application; Fig.17 A schematic diagram of reflectivity results of another optical waveguide structure provided in an embodiment of the present application; Fig.18 A schematic diagram of the process of the first embodiment of the method for preparing an optical waveguide structure of the present application; Fig.19 A diagram of a preparation scene involved in an embodiment of a method for preparing an optical waveguide structure of the present application; Fig. 20 A diagram of a preparation scene involved in another embodiment of the method for preparing an optical waveguide structure of the present application; Fig.21A diagram of a preparation scene involved in yet another embodiment of the method for preparing an optical waveguide structure of the present application; Fig. 22 A schematic diagram of the process of the second embodiment of the method for preparing an optical waveguide structure of the present application; Fig.23 A diagram of a preparation scene involved in another embodiment of the method for preparing an optical waveguide structure of the present application; Fig.24 A diagram of a preparation scene involved in another embodiment of the method for preparing an optical waveguide structure of the present application; Fig.25 A diagram of a preparation scene involved in yet another embodiment of the method for preparing an optical waveguide structure of the present application; Fig.26 A schematic diagram of a scenario for determining process parameters of the preparation method involved in an embodiment of the present application.

[0024] The purpose, features and advantages of this application will be further described in conjunction with the embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0025] Embodiments of the present disclosure will be described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present disclosure, and are not to be construed as limitations on the present disclosure. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present disclosure.

[0026] The features of the terms "first" and "second" in the specification and claims of the present disclosure may explicitly or implicitly include one or more of the features. In the description of the present disclosure, unless otherwise specified, "plurality" means two or more.

[0027] In the description of the present disclosure, it should be understood that the terms "center", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present disclosure and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present disclosure.

[0028] In the description of the present disclosure, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present disclosure can be understood according to specific circumstances.

[0029] In order to better understand the technical solution of the present application, a detailed description will be given below in conjunction with the accompanying drawings and specific implementation methods.

[0030] The main solution of the embodiment of the present application is: the optical waveguide substrate includes a grating area, and the grating structure in the grating area is composed of a cured imprinted glue; the non-grating area on the optical waveguide substrate except the grating area is a glare suppression area, and the glare suppression area includes an optical waveguide substrate with no imprinted glue on the surface, or the optical waveguide substrate in the glare suppression area is configured as: a. no imprinted glue on the surface, or b. imprinted glue on the surface, and a first glare suppression layer is also provided on at least part of the area of ​​the imprinted glue, and the first glare suppression layer is used to reduce the reflectivity of the non-grating area of ​​the optical waveguide structure.

[0031] In the manufacturing process of diffraction optical waveguides, nanoimprinting technology is widely used due to its high precision and high efficiency. Figure 1 As shown, Figure 1 This is a schematic diagram of the structure of the optical waveguide structure involved in this application. According to different design architectures, diffraction optical waveguides are mainly divided into two categories: one-dimensional (1D) architecture and two-dimensional (2D) structure. Although the two differ in structure and application scenarios, their common feature is that the surface contains grating areas and non-grating areas. The grating area is the key part of the diffraction optical waveguide to achieve light diffraction and guidance. Through the specific micro-nano structure design, the light is diffracted at a specific angle inside the waveguide and then guided to the user's eyes. In contrast, the non-grating area mainly plays the role of supporting and protecting the grating structure and maintaining the overall structural integrity of the waveguide.

[0032] like Figure 2 As shown in Figure 1, in order to enhance the diffraction effect of the grating and improve the overall efficiency of the waveguide, an imprinting glue with a higher refractive index than the substrate material is usually selected as the material constituting the grating, which also leads to a significant increase in the surface reflectivity of the non-grating area. Figure 3 As shown in FIG. 1 , when the AR device is used, when the external light is irradiated to the non-grating area, a strong reflection will occur, forming a glare effect. That is, the existing optical waveguide structure causes the glare effect during use.

[0033] The present application provides a solution, by performing a glare suppression treatment method in which the non-grating area other than the grating area on the optical waveguide substrate does not have a surface embossed glue or adds a first glare suppression layer, so that during the use of the AR device, the glare effect when the external light irradiates the non-grating area is reduced, and the glare effect of the existing optical waveguide structure is suppressed. .

[0034] Based on this, Figure 4 As shown, an embodiment of the present application provides an optical waveguide structure, the optical waveguide structure comprising: an optical waveguide substrate; The optical waveguide substrate includes a grating region, and the grating structure in the grating region is formed by a cured embossed adhesive; The non-grating area on the optical waveguide substrate except the grating area is a glare suppression area, and the optical waveguide substrate in the glare suppression area is configured as follows: a. there is no embossed glue on the surface, or b. there is embossed glue on the surface, and a first glare suppression layer is also arranged on at least part of the area of ​​the embossed glue, and the first glare suppression layer is used to reduce the reflectivity of the non-grating area of ​​the optical waveguide structure.

[0035] In this embodiment, the optical waveguide substrate is a substrate of an optical waveguide structure made of an inorganic or polymeric light-transmitting material, such as silicon dioxide, fused quartz, borosilicate glass, polymethyl methacrylate, polystyrene, polycarbonate, poly-4-methylpentene-1, styrene-acrylonitrile copolymer, allyl diglycol dicarbonate, etc. The grating structure in the grating region is composed of a cured embossed adhesive with a specific structure, which is used to achieve light diffraction and guidance, and the non-grating region is the region on the optical waveguide substrate other than the grating region. The embossed adhesive is a heat-sensitive or photosensitive curing adhesive with good light-transmitting properties used in the nanoimprint process.

[0036] In the nanoimprint process, in order to enhance the diffraction effect of the grating structure and improve the overall efficiency of the optical waveguide, an imprint glue with a higher refractive index than the base material is usually selected as the material constituting the grating. Therefore, under this design, when there is an imprint glue layer with a higher refractive index on the surface of the optical waveguide substrate with a lower refractive index, according to the Fresnel equation, it can be seen that when the low refractive index medium is incident on the high refractive index medium, more light energy is reflected back to the original medium, which also leads to a significant increase in the surface reflectivity of the non-grating area. Therefore, in this embodiment, the non-grating area other than the grating area on the optical waveguide substrate is processed as a glare suppression area, which is used to reduce the reflectivity of the non-grating area of ​​the optical waveguide structure, so as to reduce the glare effect when external light is irradiated to the non-grating area, thereby suppressing the glare effect of the optical waveguide structure. Figure 4As shown, as an example, since the significant increase in the surface reflectivity of the non-grating area is caused by the imprinted adhesive layer with a higher refractive index, the present embodiment can perform zoned smearing of the imprinted adhesive on the grating area of ​​the optical waveguide substrate, that is, only the grating area of ​​the optical waveguide substrate is smeared, thereby the grating area of ​​the optical waveguide substrate is embossed and cured, and the optical waveguide structure obtained does not have the imprinted adhesive in the non-grating area, so the glare effect caused by the high refractive index of the imprinted adhesive layer can be avoided. As another example, the present embodiment can also perform spin coating of the imprinted adhesive on the optical waveguide substrate, that is, the imprinted adhesive is evenly applied to the entire optical waveguide substrate. Then, the grating area of ​​the optical waveguide substrate is embossed and cured, and at this time, the non-grating area of ​​the optical waveguide substrate except the grating area will also have an imprinted adhesive layer. The non-grating area of ​​the optical waveguide substrate except the grating area is plated with a first glare suppression layer to obtain an optical waveguide structure, wherein the first glare suppression layer is used to reduce the reflectivity of the non-grating area of ​​the optical waveguide structure. It is understandable that, due to the different structures of devices using the optical waveguide structure, ambient light may not be incident on the entire non-grating area, so the first glare suppression layer plated on the embossed adhesive in the non-grating area may only cover a portion of the non-grating area, or may cover the entire non-grating area. The portion of the area covered by the first glare suppression layer is the area on the embossed adhesive in the non-grating area where ambient light is incident.

[0037] Therefore, this embodiment changes the refractive index of the surface of the optical waveguide substrate by adding a coating layer, thereby achieving the purpose of reducing the glare effect.

[0038] This embodiment also provides another optical waveguide structure, which can also achieve the purpose of suppressing the glare effect on the basis of the existing optical waveguide structure. The optical waveguide substrate in the glare suppression area is configured to have a printed adhesive on the surface, and a first glare suppression layer is also provided on at least part of the printed adhesive, and the first glare suppression layer is used to reduce the reflectivity of the non-grating area of ​​the optical waveguide structure.

[0039] In this embodiment, a second glare suppression layer may be plated on the embossed adhesive in the non-grating area of ​​the optical waveguide substrate to reduce the reflectivity of the non-grating area. In this embodiment, a first glare suppression layer may be plated on the embossed adhesive in the non-grating area of ​​the optical waveguide substrate by physical vapor deposition, inkjet printing, etc. The first glare suppression layer may be composed of one or more first anti-reflection film layers. Exemplarily, the first glare suppression layer includes a first anti-reflection film layer on the optical waveguide substrate, and the refractive index of the first anti-reflection film layer is less than the refractive index of the embossed adhesive. It can be understood that the refractive index of the first anti-reflection film layer needs to be greater than the refractive index of air; or, the first glare suppression layer may also include at least two first anti-reflection film layers on the embossed adhesive, and the refractive index of the second anti-reflection film layer farthest from the embossed adhesive is less than or equal to the refractive index of the optical waveguide substrate.

[0040] In addition, this embodiment provides a specific example for illustration: Figure 5 As shown, this example provides a conventional original optical waveguide structure, which includes an optical waveguide substrate with a refractive index of 1.58, and an embossed adhesive with a refractive index of 1.7 and a thickness of 0.35 microns on the optical waveguide substrate. Figure 6 , Figure 6 The horizontal axis of the left graph is the incident angle, the vertical axis is the wavelength, and the color depth is the reflectivity. Figure 6 The right graph in the figure describes the average reflectivity of the solid surface at a vertical incident angle. The horizontal axis of the graph on the right is wavelength and the vertical axis is reflectivity. Figure 6 As shown in FIG. 1 , the reflectivity of the original waveguide structure is within the wavelength range of 400nm-800nm, and the reflectivity of ambient light with an incident angle of 0-60° can reach a maximum of about 10%, which will produce a relatively strong glare effect. Figure 7 , Figure 7 This embodiment relates to a test result diagram of an optical waveguide structure in which the glare suppression area includes an optical waveguide substrate with no embossed glue on the surface. Figure 7 The horizontal axis of the left graph is the incident angle, the vertical axis is the wavelength, and the color depth is the reflectivity. Figure 7 The right graph in the figure describes the average reflectivity of the solid surface at a vertical incident angle. The horizontal axis of the graph on the right is wavelength and the vertical axis is reflectivity. Figure 7 As shown, in this embodiment, the glare suppression area includes an optical waveguide substrate with no embossed glue on the surface, which reduces the overall reflectivity to about 5%. Compared with the original optical waveguide structure with a maximum reflectivity of about 10% for ambient light, this embodiment has certain improvements.

[0041] In some embodiments, when there is no embossing glue on the surface of the optical waveguide substrate in the glare suppression region, the glare suppression region further includes a second glare suppression layer disposed on at least a portion of the optical waveguide substrate.

[0042] It is understandable that, due to the different structures of devices using the optical waveguide structure, ambient light may not be incident on the entire non-grating area, so the second glare suppression layer plated on the optical waveguide substrate in the non-grating area may only cover a portion of the non-grating area, or may cover the entire non-grating area. The portion of the area covered by the second glare suppression layer is the area of ​​the non-grating area where ambient light is incident.

[0043] For the optical waveguide substrate whose glare suppression area includes a surface without embossing glue, in order to further improve the glare effect of the non-grating area, the present embodiment can also plate a second glare suppression layer on the non-grating area of ​​the optical waveguide substrate to further reduce the reflectivity of the non-grating area. In the present embodiment, the second glare suppression layer can be plated on the non-grating area of ​​the optical waveguide substrate by physical vapor deposition, inkjet printing, etc., and the second glare suppression layer can be composed of one or more second anti-reflection film layers. Exemplarily, the second glare suppression layer includes a second anti-reflection film layer on the optical waveguide substrate, and the refractive index of the second anti-reflection film layer is less than the refractive index of the optical waveguide substrate. It can be understood that the refractive index of the second anti-reflection film layer needs to be greater than the refractive index of air; or, the second glare suppression layer can also include at least two second anti-reflection film layers on the optical waveguide substrate, and the refractive index of the second anti-reflection film layer farthest from the optical waveguide substrate is less than or equal to the refractive index of the optical waveguide substrate.

[0044] In some embodiments, the second glare suppression layer includes a second anti-reflection film layer on the light waveguide substrate, and the refractive index of the second anti-reflection film layer is less than the refractive index of the light waveguide substrate; or The second glare suppression layer includes at least two second anti-reflection film layers on the optical waveguide substrate, and the refractive index of the second anti-reflection film layer farthest from the optical waveguide substrate is less than or equal to the refractive index of the optical waveguide substrate.

[0045] like Figure 8 As shown, in this embodiment, the second glare suppression layer includes a second anti-reflection film layer on the optical waveguide substrate, and the refractive index of the second anti-reflection film layer is less than the refractive index of the optical waveguide substrate. It can be understood that the refractive index of the second anti-reflection film layer needs to be greater than the refractive index of air. Thus, the second anti-reflection film layer is used as a refractive index transition between the optical waveguide substrate and the air to reduce the reflection caused by the sudden change of the refractive index.

[0046] like Fig. 9As shown, in this embodiment, the second glare suppression layer may also include at least two second anti-reflection film layers on the optical waveguide substrate, and the refractive index of the second anti-reflection film layer farthest from the optical waveguide substrate is less than or equal to the refractive index of the optical waveguide substrate. It can be understood that Fig. 9 Only two layers of the second anti-reflection film layers are shown in FIG. 1 . In fact, the second glare suppression layer may include more first reflective film layers. As an example, at least two layers of the second anti-reflection film layers may be multiple coatings with a first refractive index and a second refractive index interlaced, wherein the first refractive index is greater than the second refractive index, and the second refractive index is less than or equal to the refractive index of the optical waveguide substrate. The multiple coatings with a first refractive index and a second refractive index interlaced utilize the interference effect. Through the alternating arrangement of coatings with different refractive indices, some reflected light waves cancel each other out, so as to achieve the effect of reducing the reflectivity. As another example, at least two layers of the second anti-reflection film layers may be multiple coatings with continuously reduced refractive indices, wherein the refractive index of the second anti-reflection film layer gradually decreases from the second anti-reflection film layer closest to the optical waveguide substrate to the second anti-reflection film layer farthest from the optical waveguide substrate (i.e., in the direction from the optical waveguide substrate to the air). Multiple coatings with continuously reduced refractive indices can smoothly transition the refractive index difference between the optical waveguide substrate and the air, reduce reflection at the interface, and also achieve the effect of reducing the reflectivity. It can be understood that the thickness of each second anti-reflection film layer in this embodiment can be obtained by simulating the refractive index of the film material selected for the second anti-reflection film layer, the refractive index and thickness of the optical waveguide substrate and the refractive index of the second anti-reflection film layer, and then the target thickness can be selected from the optional thicknesses according to the theoretical reflectivity. Fig.10 and Fig.11 , Fig.10 Described is the corresponding relationship between the optional thickness of the second anti-reflection film layer and the theoretical reflectivity in a scenario where the second glare suppression layer includes a second anti-reflection film layer on the optical waveguide substrate. Fig.11 Described is the corresponding relationship between the optional thickness of the second anti-reflection film layer and the theoretical reflectivity in a scenario where the second glare suppression layer includes at least two second anti-reflection film layers on the optical waveguide substrate. Fig.10 The horizontal axis is the optional thickness, and the vertical axis is the theoretical reflectivity. Fig.11 The horizontal axis and the vertical axis represent the optional thicknesses of the two second anti-reflection film layers, respectively, and the vertical axis represents the theoretical reflectivity. Therefore, in this embodiment, the optional thickness with the lowest theoretical reflectivity can be selected as the target thickness.

[0047] In one embodiment, the thickness of the second anti-reflection film layer is determined according to the geometric shape and refractive index of the optical waveguide substrate and the refractive index of the second anti-reflection film layer.

[0048] Since the geometric shape and refractive index of the optical waveguide substrate, the film thickness and refractive index of the second anti-reflection film layer will affect the reflectivity. The geometric shape and refractive index of the optical waveguide substrate and the refractive index of the second anti-reflection film layer are relatively fixed parameters, so this embodiment can determine the film thickness of the second anti-reflection film layer according to the geometric shape and refractive index of the optical waveguide substrate and the refractive index of the second anti-reflection film layer. Exemplarily, this embodiment can obtain the geometric shape and refractive index of the optical waveguide substrate; construct an optical waveguide structure simulation model according to the geometric shape and refractive index of the optical waveguide substrate and the refractive index of the second anti-reflection film layer; simulate the first optional thickness of the second anti-reflection film layer based on the optical waveguide structure simulation model to obtain the theoretical reflectivity of the optical waveguide structure corresponding to the first optional thickness; select the film thickness of the second anti-reflection film layer from the first optional thickness according to the theoretical reflectivity. In this way, the film thickness of the second anti-reflection film layer when the theoretical reflectivity is the lowest can be obtained, and then the second glare suppression layer is plated according to the film thickness of the second anti-reflection film layer, which helps to further reduce the reflectivity of the optical waveguide structure.

[0049] In one embodiment of the present application, the optical waveguide structure includes: an optical waveguide substrate; the optical waveguide substrate includes a grating area, and the grating structure in the grating area is composed of a cured imprinted adhesive; the non-grating area on the optical waveguide substrate other than the grating area is a glare suppression area, and the optical waveguide substrate in the glare suppression area is set to: a. no imprinted adhesive on the surface, or b. imprinted adhesive on the surface, and a first glare suppression layer is also provided on at least part of the imprinted adhesive, and the first glare suppression layer is used to reduce the reflectivity of the non-grating area of ​​the optical waveguide structure. Therefore, this embodiment performs a glare suppression treatment method of not having imprinted adhesive on the surface of the non-grating area on the optical waveguide substrate other than the grating area, or adding a first glare suppression layer, so that during the use of the AR device, the glare effect when the external light irradiates the non-grating area is reduced, and the glare effect of the existing optical waveguide structure is suppressed.

[0050] like Fig.12 As shown, the embodiment of the present application further provides an optical waveguide structure, when there is a printed glue on the surface of the optical waveguide substrate in the glare suppression area, the first glare suppression layer includes a first anti-reflection film layer on the optical waveguide substrate, and the refractive index of the first anti-reflection film layer is less than the refractive index of the printed glue; or, The first glare suppression layer includes at least two first anti-reflection film layers on the embossed adhesive, and the refractive index of the first anti-reflection film layer farthest from the embossed adhesive is less than or equal to the refractive index of the embossed adhesive.

[0051] like Fig.13As shown, in this embodiment, the first glare suppression layer includes a first anti-reflection film layer on the optical waveguide substrate, and the refractive index of the first anti-reflection film layer is less than the refractive index of the embossed adhesive. It can be understood that the refractive index of the first anti-reflection film layer needs to be greater than the refractive index of air. Thus, this first anti-reflection film layer is used as a refractive index transition between the embossed adhesive and the air to reduce the reflection caused by the sudden change in refractive index. As a specific example, this example still uses the existing common original optical waveguide structure, which includes an optical waveguide substrate with a refractive index of 1.58, and there is an embossed adhesive with a refractive index of 1.7 and a thickness of 0.35 microns on the optical waveguide substrate. See Fig.14 , Fig.14 The horizontal axis of the left graph is the incident angle, the vertical axis is the wavelength, and the color depth is the reflectivity. Fig.14 The right graph in the figure describes the average reflectivity of the solid surface at a vertical incident angle. The horizontal axis of the graph on the right is wavelength and the vertical axis is reflectivity. This embodiment uses a material with a lower refractive index than the embossed adhesive as the first anti-reflection film layer. For example, SiO2 can be used. After simulation, when the target thickness of SiO2 is selected as 0.095um, the reflectivity can be reduced to 2.5%. Of course, in order to further improve the glare effect, a material with a lower refractive index can be selected as the first anti-reflection film layer. See Fig.15 , Fig.15 The horizontal axis of the left graph is the incident angle, the vertical axis is the wavelength, and the color depth is the reflectivity. Fig.15 The right graph in the middle describes the average reflectivity of the solid surface at a vertical incident angle, and the horizontal axis of the right graph is the wavelength and the vertical axis is the reflectivity. In this embodiment, a material with a refractive index of 1.4 is selected as the first anti-reflection film layer. Similarly, after simulation, a material with a refractive index of 1.4 and a target thickness of 0.1um is selected, and a reflectivity of 1%-2% can be obtained. In this embodiment, when the first glare suppression layer includes a first anti-reflection film layer on the optical waveguide substrate, when the refractive index of this first anti-reflection film layer is lower than the refractive index of the embossed glue, the reflectivity will be reduced more significantly, that is, the glare effect will be better suppressed.

[0052] like Fig.16 As shown, in this embodiment, the first glare suppression layer may also include at least two first anti-reflection film layers on the embossed adhesive, and the refractive index of the second anti-reflection film layer farthest from the embossed adhesive is less than or equal to the refractive index of the optical waveguide substrate. It can be understood that Fig.16Only two layers of the second anti-reflection film layers are shown in the figure. In fact, the second glare suppression layer may include more first reflective film layers. As an example, at least two layers of the second anti-reflection film layers may be multiple coatings with a second refractive index and a fourth refractive index interlaced, wherein the second refractive index is greater than the fourth refractive index, and the fourth refractive index is less than or equal to the refractive index of the embossed adhesive. The multiple coatings with a second refractive index and a fourth refractive index interlaced utilize the interference effect. By alternating the coatings with different refractive indices, some reflected light waves cancel each other out, thereby achieving the effect of reducing the reflectivity. As another example, at least two layers of the first anti-reflection film layers may be multiple coatings with continuously reduced refractive indices. The multiple coatings with continuously reduced refractive indices may smoothly transition the refractive index difference between the embossed adhesive and the air, reduce reflection at the interface, and also achieve the effect of reducing the reflectivity. As a specific example, this example still uses the existing common original optical waveguide structure, which includes an optical waveguide substrate with a refractive index of 1.58, and an embossed adhesive with a refractive index of 1.7 and a thickness of 0.35 microns exists on the optical waveguide substrate. See. Fig.17 , Fig.17 The horizontal axis of the left graph is the incident angle, the vertical axis is the wavelength, and the color depth is the reflectivity. Fig.17 The right graph in the middle describes the average reflectivity of the solid surface at a vertical incident angle. The horizontal axis of the right graph is wavelength and the vertical axis is reflectivity. This embodiment uses SiO2 and a material with a refractive index of 1.3 as the first anti-reflection film layer. Similarly, after simulation, a material with a refractive index of 1.3 with a target thickness of 0.09um and a target thickness of SiO2 of 0.04um are selected. This embodiment can suppress the reflectivity of the main band of visible wavelengths to less than 0.5%. Compared with the structure of a single-layer film, the structure of a multi-layer film has a better glare suppression effect.

[0053] In one embodiment, the thickness of the first anti-reflection film layer is determined according to the geometric shape and refractive index of the optical waveguide substrate, the thickness and refractive index of the embossed glue in the glare suppression area, and the refractive index of the first anti-reflection film layer.

[0054] Similarly, there is also a printed glue in the glare suppression area of ​​the optical waveguide structure. Due to the different geometric shapes and refractive indexes of the optical waveguide substrate, the glue layer thickness and refractive index of the printed glue in the glare suppression area, the glue layer thickness and refractive index of the printed glue in the glare suppression area, and the film layer thickness and refractive index of the first anti-reflection film layer, the reflectivity will be affected. The geometric shape and refractive index of the optical waveguide substrate, the glue layer thickness and refractive index of the printed glue in the glare suppression area, and the refractive index of the first anti-reflection film layer are relatively fixed parameters. Therefore, this embodiment can determine the film layer thickness of the first anti-reflection film layer according to the geometric shape and refractive index of the optical waveguide substrate, the glue layer thickness and refractive index of the printed glue in the glare suppression area, and the refractive index of the first anti-reflection film layer. Exemplarily, in this embodiment, the geometric shape and refractive index of the optical waveguide substrate, and the thickness and refractive index of the adhesive layer of the embossed adhesive in the glare suppression area can be obtained; according to the geometric shape and refractive index of the optical waveguide substrate, the thickness and refractive index of the adhesive layer of the embossed adhesive in the glare suppression area, and the refractive index of the first anti-reflection film layer, an optical waveguide structure simulation model can be constructed; based on the optical waveguide structure simulation model, the second optional thickness of the first anti-reflection film layer is simulated to obtain the theoretical reflectivity of the optical waveguide structure corresponding to the second optional thickness; according to the theoretical reflectivity, the film thickness of the first anti-reflection film layer is selected from the second optional thickness. In this way, the film thickness of the first anti-reflection film layer when the theoretical reflectivity is the lowest can be obtained, and then the first glare suppression layer is plated according to the film thickness of the first anti-reflection film layer, which helps to further reduce the reflectivity of the optical waveguide structure.

[0055] It can be understood that, in the present embodiment, the thickness of each first anti-reflection film layer can be obtained by simulating the refractive index of the film material selected for the first anti-reflection film layer, the refractive index and thickness of the optical waveguide substrate and the imprinted glue, and the refractive index of the first anti-reflection film layer, and then the target thickness of the first anti-reflection film layer can be selected from the optional thicknesses according to the theoretical reflectivity.

[0056] In another embodiment of the present application, the glare suppression area includes an optical waveguide substrate with an imprinted adhesive on the surface, and a first glare suppression layer on the imprinted adhesive. Therefore, this embodiment does not need to change the existing process step of spin coating and coating, and only needs to plate the first glare suppression layer on the imprinted adhesive in the non-grating area after completing the imprinting and curing, which can also effectively suppress the glare effect. This embodiment can effectively suppress the glare effect of the optical waveguide structure while reducing the cost of process modification.

[0057] Reference Fig.18 , Fig.18 FIG. 1 is a schematic flow chart of a first embodiment of a method for preparing an optical waveguide structure of the present application.

[0058] In this embodiment, the method for preparing the optical waveguide structure includes steps S10 to S30: Step S10, performing zone-by-zone coating of the embossing glue on the grating area of ​​the optical waveguide substrate; Step S20, providing a master template for grating structure imprinting, and imprinting the imprinting glue on the optical waveguide substrate by using the master template for grating structure imprinting to form a grating structure in the grating region of the optical waveguide substrate; Step S30 , curing the imprinted adhesive, and demoulding the master template imprinted with the grating structure from the imprinted adhesive to obtain an optical waveguide structure.

[0059] It should be noted that the optical waveguide substrate is a matrix of an optical waveguide structure made of an inorganic or polymer light-transmitting material, and the imprinting glue is a heat-sensitive or photosensitive curing glue with good light-transmitting properties used in the nanoimprinting process.

[0060] In addition, it should be noted that the preparation method of this embodiment is applicable to an optical waveguide structure in which the non-grating region is an optical waveguide substrate with no embossing glue on the surface.

[0061] like Fig.19 As shown, in this embodiment, the embossing glue is evenly sprayed on the grating area of ​​the optical waveguide substrate by a print nozzle to achieve the zoned leveling of the embossing glue on the grating area of ​​the optical waveguide substrate. Furthermore, in this embodiment, the grating structure in the grating area of ​​the optical waveguide substrate is embossed on the embossing glue in the grating area of ​​the optical waveguide substrate by the master template corresponding to the grating structure in the grating area of ​​the optical waveguide substrate, so that the grating in the grating area is formed, and then the embossed embossing glue is cured, and the master template embossed with the grating structure is demoulded from the embossing glue to obtain the optical waveguide structure. Therefore, since the significant increase in the surface reflectivity of the non-grating area is caused by the embossing glue layer with a higher refractive index, the present embodiment can perform zoned leveling of the embossing glue on the grating area of ​​the optical waveguide substrate, that is, only the grating area of ​​the optical waveguide substrate is leveled, thereby the grating area of ​​the optical waveguide substrate is embossed and cured, and the optical waveguide structure obtained has no embossing glue in the non-grating area, and the glare suppression area includes the optical waveguide substrate without embossing glue on the surface, so that the glare effect caused by the high refractive index of the embossing glue layer can be avoided.

[0062] In some embodiments, after the step of curing the embossed adhesive and demolding the master template with the grating structure embossed thereon in step S30, the method further includes step 31: Step S31, coating a second glare suppression layer on the non-grating area of ​​the optical waveguide substrate except the grating area, wherein the second glare suppression layer is used to reduce the reflectivity of the non-grating area of ​​the optical waveguide structure.

[0063] In order to further improve the glare effect suppression effect, in this embodiment, after the grating area of ​​the optical waveguide substrate is embossed and cured, a second glare suppression layer is plated on the non-grating area of ​​the optical waveguide substrate except the grating area to obtain an optical waveguide structure, wherein the second glare suppression layer is used to reduce the reflectivity of the non-grating area of ​​the optical waveguide structure. In this embodiment, the second glare suppression layer can be plated on the non-grating area of ​​the optical waveguide substrate by physical vapor deposition, inkjet printing, etc., and the second glare suppression layer can be composed of one or more second anti-reflection film layers. Exemplarily, the second glare suppression layer includes a second anti-reflection film layer on the optical waveguide substrate, and the refractive index of the second anti-reflection film layer is less than the refractive index of the optical waveguide substrate. It can be understood that the refractive index of the second anti-reflection film layer needs to be greater than the refractive index of air; or, the second glare suppression layer can also include at least two second anti-reflection film layers on the optical waveguide substrate, and the refractive index of the second anti-reflection film layer farthest from the optical waveguide substrate is less than or equal to the refractive index of the optical waveguide substrate.

[0064] In some embodiments, the second glare suppression layer includes a second anti-reflection film layer on the light waveguide substrate, and the refractive index of the second anti-reflection film layer is less than the refractive index of the light waveguide substrate; Alternatively, the second glare suppression layer comprises at least two second anti-reflection film layers on the optical waveguide substrate, and the refractive index of the second anti-reflection film layer farthest from the optical waveguide substrate is less than or equal to the refractive index of the optical waveguide substrate.

[0065] In this embodiment, the second glare suppression layer can be plated on the non-grating area of ​​the optical waveguide substrate by physical vapor deposition, inkjet printing, etc. The glare suppression layer can be composed of one or more second anti-reflection film layers. Fig. 20 As shown, exemplarily, the second glare suppression layer includes a second anti-reflection film layer on the optical waveguide substrate, the refractive index of the second anti-reflection film layer is less than the refractive index of the optical waveguide substrate, and it can be understood that the refractive index of the second anti-reflection film layer needs to be greater than the refractive index of air. Thus, the second anti-reflection film layer is used as a refractive index transition between the optical waveguide substrate and the air to reduce the reflection caused by the sudden change of the refractive index.

[0066] like Fig.21As shown, the second glare suppression layer may also include at least two second anti-reflection film layers on the optical waveguide substrate, and the refractive index of the second anti-reflection film layer farthest from the optical waveguide substrate is less than or equal to the refractive index of the optical waveguide substrate. As an example, the at least two second anti-reflection film layers may be a plurality of coating layers with a first refractive index and a second refractive index interlaced, wherein the first refractive index is greater than the second refractive index, and the second refractive index is less than or equal to the refractive index of the optical waveguide substrate. The plurality of coating layers with a first refractive index and a second refractive index interlaced utilize the interference effect, and the alternating arrangement of coating layers with different refractive indices makes part of the reflected light waves cancel each other out, so as to achieve the effect of reducing the reflectivity. As another example, the at least two second anti-reflection film layers may be a plurality of coating layers with a continuously reduced refractive index, and the plurality of coating layers with a continuously reduced refractive index may smoothly transition the refractive index difference between the optical waveguide substrate and the air, reduce the reflection at the interface, and also achieve the effect of reducing the reflectivity. It can be understood that the thickness of each second anti-reflection film layer in the present embodiment can be obtained by simulating the refractive index of the film material selected for the second anti-reflection film layer, the refractive index and thickness of the optical waveguide substrate and the refractive index of the second anti-reflection film layer, and then the target thickness can be selected from the optional thicknesses according to the theoretical reflectivity.

[0067] In one embodiment, before the step of coating the non-grating area on the optical waveguide substrate except the grating area with a second glare suppression layer, the step includes: Step S21, obtaining the geometric shape and refractive index of the optical waveguide substrate; Step S22, constructing an optical waveguide structure simulation model according to the geometric shape and refractive index of the optical waveguide substrate and the refractive index of the second anti-reflection film layer; Step S23, simulating a first optional thickness of the second anti-reflection film layer based on the optical waveguide structure simulation model to obtain a theoretical reflectivity of the optical waveguide structure corresponding to the first optional thickness; Step S24: selecting a film thickness of the second anti-reflection film layer from the first optional thicknesses according to the theoretical reflectivity.

[0068] Since the geometric shape and refractive index of the optical waveguide substrate, the film thickness and refractive index of the second anti-reflection film layer will affect the reflectivity. The geometric shape and refractive index of the optical waveguide substrate and the refractive index of the second anti-reflection film layer are relatively fixed parameters, so this embodiment can determine the film thickness of the second anti-reflection film layer according to the geometric shape and refractive index of the optical waveguide substrate and the refractive index of the second anti-reflection film layer. Exemplarily, this embodiment can obtain the geometric shape and refractive index of the optical waveguide substrate; construct an optical waveguide structure simulation model according to the geometric shape and refractive index of the optical waveguide substrate and the refractive index of the second anti-reflection film layer; simulate the first optional thickness of the second anti-reflection film layer based on the optical waveguide structure simulation model to obtain the theoretical reflectivity of the optical waveguide structure corresponding to the first optional thickness; select the film thickness of the second anti-reflection film layer from the first optional thickness according to the theoretical reflectivity. In this way, the film thickness of the second anti-reflection film layer when the theoretical reflectivity is the lowest can be obtained, and then the second glare suppression layer is plated according to the film thickness of the second anti-reflection film layer. Therefore, this embodiment helps to further reduce the reflectivity of the optical waveguide structure by finely controlling the film thickness of each second anti-reflection film layer in the second glare suppression layer.

[0069] In one embodiment of the preparation method of the present application, the optical waveguide structure is obtained by performing zoned uniform coating of the embossing glue on the grating area of ​​the optical waveguide substrate, and then embossing and curing the grating area of ​​the optical waveguide substrate. The optical waveguide structure prepared by this embodiment does not have a high refractive index embossing glue in the non-grating area other than the grating area on the optical waveguide substrate, thereby reducing the reflectivity of the non-grating area, so that during the use of the AR device, the glare effect when the external light irradiates the non-grating area is reduced, and the glare effect of the optical waveguide structure is suppressed.

[0070] Reference Fig. 22 , Fig. 22 It is a schematic flow chart of the second embodiment of the method for preparing the optical waveguide structure of the present application.

[0071] In this embodiment, the method for preparing the optical waveguide structure includes steps A10 to A40: Step A10, performing spin coating of the imprinting glue on the optical waveguide substrate; Step A20, providing a master template for grating structure imprinting, and imprinting the imprinting glue on the optical waveguide substrate by using the master template for grating structure imprinting to form a grating structure in the grating region of the optical waveguide substrate; Step A30, curing the embossed adhesive and demoulding the master template embossed with the grating structure from the embossed adhesive; Step A40, coating a first glare suppression layer on the non-grating area of ​​the optical waveguide substrate except the grating area to obtain an optical waveguide structure, wherein the first glare suppression layer is used to reduce the reflectivity of the non-grating area of ​​the optical waveguide structure.

[0072] It should be noted that the preparation method of this embodiment is applicable to an optical waveguide structure in which the non-grating region is an optical waveguide substrate with an imprinted glue on the surface.

[0073] like Fig.23 As shown, in this embodiment, the optical waveguide substrate can be subjected to spin coating of the embossed adhesive by spin coating, so that a uniform embossed adhesive film is formed on the optical waveguide substrate, and then in this embodiment, the grating structure in the grating region of the optical waveguide substrate is embossed on the embossed adhesive in the grating region of the optical waveguide substrate by a master template corresponding to the grating structure in the grating region of the optical waveguide substrate, so that the grating in the grating region is formed and cured. Since the spin coating method is adopted, there is an embossed adhesive layer on the surface of the non-grating region of the optical waveguide substrate.

[0074] like Fig.24 As shown, in this embodiment, the non-grating area on the optical waveguide substrate except the grating area can be coated with a first glare suppression layer to obtain an optical waveguide structure, wherein the first glare suppression layer is used to reduce the reflectivity of the non-grating area of ​​the optical waveguide structure. The first glare suppression layer includes a coating layer having an effect of reducing reflectivity. Exemplarily, the first glare suppression layer may include a first anti-reflection film layer on the optical waveguide substrate, and the refractive index of the first anti-reflection film layer is less than the refractive index of the embossed adhesive. The first glare suppression layer may also include at least two first anti-reflection film layers on the embossed adhesive, and the refractive index of the first anti-reflection film layer farthest from the embossed adhesive is less than or equal to the refractive index of the embossed adhesive.

[0075] In one embodiment, the first glare suppression layer comprises a first anti-reflection film layer on the optical waveguide substrate, and the refractive index of the first anti-reflection film layer is less than the refractive index of the embossed glue; Alternatively, the first glare suppression layer includes at least two first anti-reflection film layers on the embossed adhesive, and the refractive index of the first anti-reflection film layer farthest from the embossed adhesive is less than or equal to the refractive index of the embossed adhesive.

[0076] In this embodiment, the second glare suppression layer can be plated on the embossed adhesive in the non-grating area of ​​the optical waveguide substrate by physical vapor deposition, inkjet printing, etc. The first glare suppression layer can be composed of one or more first anti-reflection film layers. Fig.24As shown, exemplarily, the first glare suppression layer includes a first anti-reflection film layer on the optical waveguide substrate, the refractive index of the first anti-reflection film layer is less than the refractive index of the embossed adhesive, and it can be understood that the refractive index of the first anti-reflection film layer needs to be greater than the refractive index of air. Thus, the first anti-reflection film layer is used as a refractive index transition between the optical waveguide substrate and the air to reduce the reflection caused by the sudden change of the refractive index.

[0077] like Fig.25 As shown, the first glare suppression layer may also include at least two first anti-reflection film layers on the embossed adhesive, and the refractive index of the first anti-reflection film layer farthest from the embossed adhesive is less than or equal to the refractive index of the embossed adhesive. It can be understood that due to the different materials of the multiple first anti-reflection film layers, the coating processes that may need to be adopted may also be different, so multiple coating processes can be used alternately. As an example, at least two second anti-reflection film layers can be multiple coating layers with a second refractive index and a fourth refractive index interlaced, wherein the second refractive index is greater than the fourth refractive index, and the fourth refractive index is less than or equal to the refractive index of the embossed adhesive. The multiple coating layers with a second refractive index and a fourth refractive index interlaced utilize the interference effect, and the alternating arrangement of coating layers with different refractive indices makes part of the reflected light waves cancel each other to achieve the effect of reducing the reflectivity. As another example, at least two first anti-reflection film layers can be multiple coating layers with continuously reduced refractive indices, and the multiple coating layers with continuously reduced refractive indices can smoothly transition the refractive index difference between the embossed adhesive and the air, reduce the reflection at the interface, and also achieve the effect of reducing the reflectivity. It can be understood that, in the present embodiment, the thickness of each first anti-reflection film layer can be obtained by simulating the refractive index of the film material selected for the first anti-reflection film layer, the refractive index and thickness of the optical waveguide substrate and the imprinted glue, and the refractive index of the first anti-reflection film layer, and then the target thickness of the first anti-reflection film layer can be selected from the optional thicknesses according to the theoretical reflectivity.

[0078] In one embodiment, before the step of coating the non-grating area on the optical waveguide substrate except the grating area with the first glare suppression layer in step A40, the method includes: Step A41, obtaining the geometric shape and refractive index of the optical waveguide substrate, and the thickness and refractive index of the glue layer of the embossed glue in the non-grating area; Step A42, constructing an optical waveguide structure simulation model according to the geometric shape and refractive index of the optical waveguide substrate, the thickness and refractive index of the embossed adhesive layer, and the refractive index of the first anti-reflection film layer; Step A43, simulating a second optional thickness of the first anti-reflection film layer based on the optical waveguide structure simulation model to obtain a theoretical reflectivity of the optical waveguide structure corresponding to the second optional thickness; Step A44: selecting a film thickness of the first anti-reflection film layer from the second optional thicknesses according to the theoretical reflectivity.

[0079] Similarly, there is also a printed glue in the glare suppression area of ​​the optical waveguide structure. Due to the different geometric shapes and refractive indexes of the optical waveguide substrate, the glue layer thickness and refractive index of the printed glue in the glare suppression area, the glue layer thickness and refractive index of the printed glue in the glare suppression area, and the film layer thickness and refractive index of the first anti-reflection film layer, the reflectivity will be affected. The geometric shape and refractive index of the optical waveguide substrate, the glue layer thickness and refractive index of the printed glue in the glare suppression area, and the refractive index of the first anti-reflection film layer are relatively fixed parameters. Therefore, this embodiment can determine the film layer thickness of the first anti-reflection film layer according to the geometric shape and refractive index of the optical waveguide substrate, the glue layer thickness and refractive index of the printed glue in the glare suppression area, and the refractive index of the first anti-reflection film layer. Exemplarily, this embodiment can obtain the geometric shape and refractive index of the optical waveguide substrate, and the thickness and refractive index of the adhesive layer of the embossed adhesive in the glare suppression area; construct an optical waveguide structure simulation model according to the geometric shape and refractive index of the optical waveguide substrate, the thickness and refractive index of the adhesive layer of the embossed adhesive in the glare suppression area, and the refractive index of the first anti-reflection film layer; simulate the second optional thickness of the first anti-reflection film layer based on the optical waveguide structure simulation model to obtain the theoretical reflectivity of the optical waveguide structure corresponding to the second optional thickness; select the film thickness of the first anti-reflection film layer from the second optional thickness according to the theoretical reflectivity. In this way, the film thickness of the first anti-reflection film layer when the theoretical reflectivity is the lowest can be obtained, and then the first glare suppression layer is plated according to the film thickness of the first anti-reflection film layer. This embodiment also takes into account the influence of the embossed adhesive layer on the reflectivity layer, which is used to finely control the film thickness of each first anti-reflection film layer in the first glare suppression layer, which helps to further reduce the reflectivity of the optical waveguide structure.

[0080] In another embodiment of the preparation method of the present application, the optical waveguide substrate is subjected to spin coating of the embossed adhesive, the grating region of the optical waveguide substrate is embossed and cured, and the non-grating region of the optical waveguide substrate except the grating region is plated with a first glare suppression layer to obtain an optical waveguide structure, wherein the first glare suppression layer is used to reduce the reflectivity of the non-grating region of the optical waveguide structure. Therefore, this embodiment does not need to change the existing process step of spin coating, and only needs to plate the first glare suppression layer on the embossed adhesive in the non-grating region after the embossing and curing, which can also effectively suppress the glare effect. This embodiment can effectively suppress the glare effect of the optical waveguide structure while reducing the cost of process modification.

[0081] As an optional embodiment of the present application, see Fig.26, the selection of specific process parameters in the preparation method of the optical waveguide structure in the embodiment of the present application can be determined in the following manner. In this embodiment, the reflectivity of the non-grating area of ​​the original optical waveguide structure to be improved can be simulated to obtain the reflectivity of the non-grating area of ​​the original optical waveguide structure. It is judged whether the reflectivity is greater than a predetermined reflection threshold (such as 4%, 5%, 6%, etc.) to determine whether the original optical waveguide structure needs to suppress the glare effect, and then the corresponding main body improvement scheme is selected (i.e., the improvement direction of removing the non-grating area embossed glue, single-layer film layer, multi-layer film layer, etc.), and then the film layer material that meets the refractive index requirements for the coating layer is selected from the material library, and then the theoretical reflectivity corresponding to the optional thickness of the film layer is obtained after simulation according to the refractive index and thickness of the optical waveguide substrate and the embossed glue and the refractive index of the film layer material, and then the target thickness of the film layer is selected from the optional thickness according to the theoretical reflectivity. Then, the film layer material adopts different processes for coating, and the corresponding coating processes (such as inkjet printing and physical vapor deposition) are matched. The main body improvement scheme, the materials of each film layer and its target thickness, and the adopted coating process are used as specific process parameters in the preparation method of the optical waveguide structure.

[0082] In addition, an embodiment of the present application further provides a head-mounted display device, the head-mounted display device comprising the optical waveguide structure as described above. Exemplarily, the head-mounted display device is a device with optical waveguide function requirements, such as AR glasses, AR helmets, etc.

[0083] It should be noted that the above examples are only used to understand the present application and do not constitute a limitation on the optical waveguide structure and preparation method thereof of the present application. More simple transformations based on this technical concept are all within the protection scope of the present application.

[0084] The above descriptions are only some embodiments of the present application, and are not intended to limit the patent scope of the present application. All equivalent structural changes made using the contents of the present application specification and drawings under the technical concept of the present application, or direct / indirect applications in other related technical fields are included in the patent protection scope of the present application.

Claims

1. An optical waveguide structure, characterized in that: The optical waveguide structure comprises: an optical waveguide substrate; The optical waveguide substrate includes a grating region, and the grating structure in the grating region is formed by a cured embossed adhesive; The non-grating area on the optical waveguide substrate except the grating area is a glare suppression area, and the optical waveguide substrate in the glare suppression area is configured as follows: a. No embossed adhesive on the surface, or b. There is embossed glue on the surface, and a first glare suppression layer is also arranged on at least a part of the embossed glue, and the first glare suppression layer is used to reduce the reflectivity of the non-grating area of ​​the optical waveguide structure.

2. The optical waveguide structure according to claim 1, wherein: When there is no embossing glue on the surface of the optical waveguide substrate in the glare suppression region, the glare suppression region further comprises a second glare suppression layer disposed on at least a portion of the optical waveguide substrate.

3. The optical waveguide structure according to claim 2, characterized in that: The second glare suppression layer comprises a second anti-reflection film layer on the optical waveguide substrate, wherein the refractive index of the second anti-reflection film layer is smaller than the refractive index of the optical waveguide substrate; or The second glare suppression layer includes at least two second anti-reflection film layers on the optical waveguide substrate, and the refractive index of the second anti-reflection film layer farthest from the optical waveguide substrate is less than or equal to the refractive index of the optical waveguide substrate.

4. The optical waveguide structure according to claim 3, characterized in that: The thickness of the second anti-reflection film layer is determined according to the geometric shape and refractive index of the optical waveguide substrate and the refractive index of the second anti-reflection film layer.

5. The optical waveguide structure according to claim 1, wherein: When there is a printed glue on the surface of the optical waveguide substrate in the glare suppression area, the first glare suppression layer includes a first anti-reflection film layer on the optical waveguide substrate, and the refractive index of the first anti-reflection film layer is less than the refractive index of the printed glue; or The first glare suppression layer includes at least two first anti-reflection film layers on the embossed adhesive, and the refractive index of the first anti-reflection film layer farthest from the embossed adhesive is less than or equal to the refractive index of the embossed adhesive.

6. The optical waveguide structure according to claim 5, characterized in that The thickness of the first anti-reflection film layer is determined according to the geometric shape and refractive index of the optical waveguide substrate, the thickness and refractive index of the embossed glue in the glare suppression area, and the refractive index of the first anti-reflection film layer.

7. A method for preparing an optical waveguide structure, characterized in that: The method for preparing the optical waveguide structure comprises: Performing zone-by-zone coating of the embossing glue on the grating area of ​​the optical waveguide substrate; Providing a master template for grating structure imprinting, and imprinting the imprinting glue on the optical waveguide substrate by using the master template for grating structure imprinting to form a grating structure in the grating area of ​​the optical waveguide substrate; The imprinted adhesive is cured, and the master template imprinted with the grating structure is demoulded from the imprinted adhesive to obtain an optical waveguide structure.

8. The method for preparing an optical waveguide structure according to claim 7, characterized in that: After the step of curing the embossed embossing adhesive and demoulding the master template embossed with the grating structure from the embossing adhesive, the method comprises: A second glare suppression layer is plated on the non-grating area of ​​the optical waveguide substrate except the grating area, wherein the second glare suppression layer is used to reduce the reflectivity of the non-grating area of ​​the optical waveguide structure.

9. The method for preparing an optical waveguide structure according to claim 8, characterized in that: The second glare suppression layer comprises a second anti-reflection film layer on the optical waveguide substrate, wherein the refractive index of the second anti-reflection film layer is less than the refractive index of the optical waveguide substrate; Alternatively, the second glare suppression layer comprises at least two second anti-reflection film layers on the optical waveguide substrate, and the refractive index of the second anti-reflection film layer farthest from the optical waveguide substrate is less than or equal to the refractive index of the optical waveguide substrate.

10. The method for preparing an optical waveguide structure according to claim 9, characterized in that: Before the step of coating the non-grating area on the optical waveguide substrate except the grating area with a second glare suppression layer, the method comprises: Obtaining the geometric shape and refractive index of the optical waveguide substrate; Constructing an optical waveguide structure simulation model according to the geometric shape and refractive index of the optical waveguide substrate and the refractive index of the second anti-reflection film layer; Simulating a first optional thickness of the second anti-reflection film layer based on the optical waveguide structure simulation model to obtain a theoretical reflectivity of the optical waveguide structure corresponding to the first optional thickness; According to the theoretical reflectivity, the film thickness of the second anti-reflection film layer is selected from the first optional thicknesses.

11. A method for preparing an optical waveguide structure, characterized in that: The method for preparing the optical waveguide structure comprises: Spin coating the imprint glue on the optical waveguide substrate; Providing a master template for grating structure imprinting, and imprinting the imprinting glue on the optical waveguide substrate by using the master template for grating structure imprinting to form a grating structure in the grating area of ​​the optical waveguide substrate; The embossed embossing adhesive is cured, and the master template embossed with the grating structure is demoulded from the embossing adhesive; A first glare suppression layer is plated on the non-grating area of ​​the optical waveguide substrate except the grating area to obtain an optical waveguide structure, wherein the first glare suppression layer is used to reduce the reflectivity of the non-grating area of ​​the optical waveguide structure.

12. The method for preparing an optical waveguide structure according to claim 11, characterized in that: The first glare suppression layer comprises a first anti-reflection film layer on the optical waveguide substrate, wherein the refractive index of the first anti-reflection film layer is less than the refractive index of the embossed glue; Alternatively, the first glare suppression layer includes at least two first anti-reflection film layers on the embossed adhesive, and the refractive index of the first anti-reflection film layer farthest from the embossed adhesive is less than or equal to the refractive index of the embossed adhesive.

13. The method for preparing an optical waveguide structure according to claim 12, wherein: Before the step of coating the non-grating area on the optical waveguide substrate except the grating area with the first glare suppression layer, the method comprises: Acquire the geometric shape and refractive index of the optical waveguide substrate, and the thickness and refractive index of the glue layer of the embossed glue in the non-grating area; Constructing an optical waveguide structure simulation model according to the geometric shape and refractive index of the optical waveguide substrate, the thickness and refractive index of the embossed adhesive layer, and the refractive index of the first anti-reflection film layer; Simulating a second optional thickness of the first anti-reflection film layer based on the optical waveguide structure simulation model to obtain a theoretical reflectivity of the optical waveguide structure corresponding to the second optional thickness; According to the theoretical reflectivity, the film thickness of the first anti-reflection film layer is selected from the second optional thicknesses.

14. A head mounted display device, characterized in that: The head-mounted display device comprises the optical waveguide structure according to any one of claims 1 to 6.

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