Grating assembly and manufacturing method of grating assembly

Abstract

The invention provides a grating assembly and a manufacturing method of the grating assembly. The grating assembly comprises a substrate; the number of the optical cement auxiliary structures is multiple, and the multiple optical cement auxiliary structures are formed on the surface of one side of the substrate at intervals through nanoimprint; the functional layer covers the sides, away from the substrate, of the optical cement auxiliary structures in a shape follow-up mode so that the side faces and the top faces of the optical cement auxiliary structures can be wrapped by the functional layer, and gaps are reserved in the sides, away from the substrate, of the functional layer; the optical adhesive layer is arranged on the side, away from the substrate, of the optical adhesive auxiliary structure, and the projection of the optical adhesive layer on the substrate completely covers the optical adhesive auxiliary structure and the functional layer; the functional layer is a deposition layer, the grating assembly further comprises a plurality of diffraction gratings, and the diffraction gratings are filled in the gaps. The problem that the diffraction efficiency of a grating assembly in the prior art is difficult to improve is solved.

Description

[0001] This application is a divisional application of the patent application with application number 202310725904.X, application date June 16, 2023, and invention name “Grating assembly and manufacturing method of grating assembly”. Technical Field

[0002] The present invention relates to the technical field of diffraction optical equipment, and in particular to a grating component and a method for manufacturing the grating component. Background Art

[0003] With the rapid development of diffractive optical devices, various types of diffractive optical devices are undergoing upgrades to meet increasing market demand. These devices come in a variety of types. For example, near-eye displays (NEDs) typically utilize a diffraction grating within a grating assembly to transmit image light. Therefore, the material, shape, and properties of the diffraction grating all affect the quality of the resulting output image.

[0004] The diffraction gratings in existing grating assemblies are typically manufactured using nanoimprint technology. As a result, the diffraction grating material is typically optical adhesive. This limits the manufacturing process, making it difficult for the diffraction grating to meet design requirements for high diffraction efficiency and overcome material limitations. Furthermore, the width, tilt angle, or height of the diffraction grating are also limited by the manufacturing process. While wider, smaller, and shorter diffraction gratings are often easier to manufacture, narrower and taller ones are more likely to improve diffraction efficiency. This is difficult to achieve with existing diffraction gratings using traditional nanoimprint technology.

[0005] In other words, the grating assembly in the prior art has the problem of difficulty in improving the diffraction efficiency. Summary of the Invention

[0006] The main purpose of the present invention is to provide a grating assembly and a method for manufacturing the grating assembly, so as to solve the problem of difficulty in improving the diffraction efficiency of the grating assembly in the prior art.

[0007] In order to achieve the above-mentioned purpose, according to one aspect of the present invention, a grating assembly is provided, comprising: a substrate; a plurality of optical adhesive auxiliary structures, wherein the plurality of optical adhesive auxiliary structures are spaced apart and formed on a surface of one side of the substrate by nanoimprinting; a functional layer, which is a deposition layer and conformally covers the side of the plurality of optical adhesive auxiliary structures away from the substrate, so that the side and top surfaces of the optical adhesive auxiliary structures are both covered by the functional layer, and a gap is left on the side of the functional layer away from the substrate; an optical adhesive layer, which is arranged on the side of the optical adhesive auxiliary structure away from the substrate, and the projection of the optical adhesive layer on the substrate completely covers the optical adhesive auxiliary structure and the functional layer. The grating assembly also comprises a diffraction grating, wherein the plurality of diffraction gratings are filled in the gap, so that the diffraction grating and the optical adhesive auxiliary structure are separated by the deposition layer.

[0008] Furthermore, the refractive index of the diffraction grating is greater than the refractive index of the optical adhesive auxiliary structure.

[0009] Furthermore, the refractive index of the diffraction grating at a wavelength of 589 nm is not less than 1.8.

[0010] Furthermore, the surface of the diffraction grating away from the substrate is flush with the surface of the deposition layer on the top surface of the optical adhesive auxiliary structure away from the substrate, and the optical adhesive layer is in contact with the diffraction grating and part of the deposition layer at the same time.

[0011] Furthermore, the material of the diffraction grating is TiO2, Nb2O5 or HfO2.

[0012] Furthermore, the optical adhesive auxiliary structure is tiltedly arranged on one side surface of the substrate. In this case, the diffraction grating is a tilted grating.

[0013] Furthermore, the optical adhesive auxiliary structure is vertically arranged on one side surface of the substrate. In this case, the diffraction grating is a straight tooth grating.

[0014] Furthermore, the refractive index of the diffraction grating is greater than the refractive index of the substrate; the refractive index of the diffraction grating is greater than the refractive index of the deposition layer; and the refractive index of the diffraction grating is greater than the refractive index of the optical adhesive layer.

[0015] Furthermore, a ratio between the height of the diffraction grating and the thickness of the diffraction grating is greater than or equal to 0.1 and less than or equal to 50.

[0016] Furthermore, the material of the deposition layer is one of Al2O3, SiO2, HfO2, ZrO2, Ta2O5, and CeO2.

[0017] According to another aspect of the present invention, a method for manufacturing a grating assembly is provided. The method is used to manufacture the above-mentioned grating assembly, and the method comprises: step S1: obtaining a substrate, coating a first optical adhesive material on one surface of the substrate, and sequentially imprinting and demolding the first optical adhesive material using a master plate or a daughter plate having a surface structure to form a plurality of optical adhesive auxiliary structures of the grating assembly; step S2: growing a functional layer of the grating assembly on a side of the plurality of optical adhesive auxiliary structures away from the substrate using one of chemical vapor deposition, physical vapor deposition, and atomic layer deposition, and pre-forming a plurality of optical adhesive auxiliary structures between adjacent functional layers. leaving a gap; step S3: growing at least one of high refractive index materials of TiO2, HfO2 or Nb2O5 in the gap so that the gap is filled with the high refractive index material, thereby forming a high refractive index material layer; step S4: removing the high refractive index material layer above the top surface of the functional layer by etching or chemical mechanical polishing to form a diffraction grating of the grating assembly; step S5: spin-coating a second optical adhesive material on the surface of the side of the diffraction grating, the functional layer and the optical adhesive auxiliary structure away from the substrate, and then using a blank master to emboss the second optical adhesive material to form an optical adhesive layer of the grating assembly.

[0018] According to another aspect of the present invention, a grating assembly is provided, comprising: a substrate; a plurality of optical adhesive auxiliary structures, wherein the plurality of optical adhesive auxiliary structures are spaced apart and formed on one side surface of the substrate by nanoimprinting; a functional layer, wherein the side walls of at least part of the optical adhesive auxiliary structure are provided with a functional layer, and the two functional layers on the side facing each other of two adjacent optical adhesive auxiliary structures in at least part of the optical adhesive auxiliary structure are spaced apart to form a gap; an optical adhesive layer, wherein the optical adhesive layer is provided on the side of the optical adhesive auxiliary structure away from the substrate, and the projection of the optical adhesive layer on the substrate completely covers the optical adhesive auxiliary structure and the functional layer; wherein the optical adhesive layer covers the optical adhesive auxiliary structure and the functional layer, and the gap is filled by the optical adhesive layer, and the distance from the surface of the side of the optical adhesive layer away from the substrate to the substrate is greater than the distance from the surface of the side of the functional layer away from the substrate to the substrate.

[0019] Furthermore, the distance between the surface of the optical adhesive layer on one side away from the substrate and the substrate is greater than the distance between the surface of the optical adhesive auxiliary structure on one side away from the substrate and the substrate.

[0020] Furthermore, the functional layer is a diffraction grating, the refractive index of the diffraction grating is greater than the refractive index of the optical adhesive auxiliary structure, the refractive index of the diffraction grating is greater than the refractive index of the substrate, and the refractive index of the diffraction grating is greater than the refractive index of the optical adhesive layer.

[0021] Furthermore, the diffraction grating is one of a TiO2 grating, a Nb2O5 grating and a HfO2 grating, and the refractive index of the diffraction grating at a wavelength of 589 nm is not less than 1.8.

[0022] Furthermore, a ratio between the height of the diffraction grating and the thickness of the diffraction grating is greater than or equal to 0.1 and less than or equal to 50.

[0023] Furthermore, the diffraction grating is provided only on the sidewall of the optical adhesive auxiliary structure, and the height of the diffraction grating is the same as the height of the optical adhesive auxiliary structure.

[0024] Furthermore, the diffraction grating and the optical adhesive auxiliary structure are both arranged perpendicular to the substrate.

[0025] Furthermore, the diffraction grating and the optical adhesive auxiliary structure are both arranged obliquely to the substrate.

[0026] Furthermore, the refractive index of the optical adhesive auxiliary structure is the same as the refractive index of the optical adhesive layer.

[0027] According to another aspect of the present invention, a method for manufacturing a grating assembly is provided, and the manufacturing method is used to manufacture the above-mentioned grating assembly, and the manufacturing method includes: step S1: obtaining a substrate, coating an optical adhesive material on the surface of one side of the substrate, and using a master plate or a daughter plate with a surface structure to sequentially emboss and demold the optical adhesive material to form multiple optical adhesive auxiliary structures of the grating assembly; step S2: using one of chemical vapor deposition, physical vapor deposition and atomic layer deposition methods to grow a material layer on the side of the multiple optical adhesive auxiliary structures away from the substrate, leaving gaps between adjacent material layers; step S3: using a reactive ion beam etching method to etch away the material layer on the top surface of each optical adhesive auxiliary structure and the material layer on the substrate between adjacent optical adhesive auxiliary structures to form a functional layer of the grating assembly, so that only the side walls on both sides of the optical adhesive auxiliary structure have the functional layer; step S4: spin-coating optical adhesive on the side of the functional layer and the optical adhesive auxiliary structure away from the substrate, and then forming the optical adhesive layer of the grating assembly by embossing a blank master plate, so that the optical adhesive layer fills the gap.

[0028] According to the technical solution of the present invention, the grating assembly includes a substrate, an optical adhesive auxiliary structure, a functional layer and an optical adhesive layer. There are multiple optical adhesive auxiliary structures, and the multiple optical adhesive auxiliary structures are spaced apart and formed on the surface of one side of the substrate by nanoimprinting; the functional layer is conformally covered on the side of the multiple optical adhesive auxiliary structures away from the substrate, so that the side and top surfaces of the optical adhesive auxiliary structures are covered by the functional layer, and a gap is left on the side of the functional layer away from the substrate; the optical adhesive layer is arranged on the side of the optical adhesive auxiliary structure away from the substrate, and the projection of the optical adhesive layer on the substrate completely covers the optical adhesive auxiliary structure and the functional layer; wherein the functional layer is a deposition layer, and the grating assembly also includes a diffraction grating, there are multiple diffraction gratings, and the diffraction gratings are filled in the gap, so that the diffraction grating and the optical adhesive auxiliary structure are separated by the deposition layer.

[0029] By conformally overlaying multiple optical adhesive auxiliary structures on the side facing away from the substrate, with the side and top surfaces of the optical adhesive auxiliary structures covered by the functional layer, a gap is left on the side of the functional layer facing away from the substrate to facilitate subsequent filling with grating material. The thickness of the deposited layer can be adjusted to adjust the aspect ratio of the diffraction grating. The combination of the functional layer and the optical adhesive auxiliary structures facilitates the formation of a diffraction grating with a larger aspect ratio, thereby improving the diffraction efficiency of the grating assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0031] Figure 1 A schematic diagram showing step S1 of the manufacturing process of the grating assembly in the first embodiment of the present invention is shown;

[0032] Figure 2 Shown Figure 1 Schematic diagram of the grating assembly in the manufacturing process through step S2;

[0033] Figure 3 Shown Figure 1 Schematic diagram of the grating assembly in the manufacturing process through step S3;

[0034] Figure 4 Shown Figure 1 Schematic diagram of the grating assembly in the manufacturing process through step S4;

[0035] Figure 5 Shown Figure 1 Schematic diagram of the structure of the grating component;

[0036] Figure 6 A schematic diagram showing step S1 of the manufacturing process of the grating assembly in the second embodiment of the present invention is shown;

[0037] Figure 7 Shown Figure 6 Schematic diagram of the grating assembly in the manufacturing process through step S2;

[0038] Figure 8 Shown Figure 6 Schematic diagram of the grating assembly in the manufacturing process through step S3;

[0039] Figure 9 Shown Figure 6 Schematic diagram of the grating assembly in the manufacturing process through step S4.

[0040] The above drawings include the following reference numerals:

[0041] 10. Substrate; 20. Optical adhesive auxiliary structure; 30. Deposition layer; 40. High refractive index material layer; 41. Diffraction grating; 50. Optical adhesive layer; 60. Material layer. DETAILED DESCRIPTION

[0042] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0043] It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meaning as commonly understood by ordinary technicians in the technical field to which this application belongs.

[0044] In the present invention, unless otherwise specified, the directional words used, such as "up, down, top, bottom", usually refer to the directions shown in the drawings, or to the components themselves in the vertical, perpendicular or gravity direction; similarly, for ease of understanding and description, "inside and outside" refer to the inside and outside relative to the outline of each component itself, but the above directional words are not used to limit the present invention.

[0045] In order to solve the problem in the prior art that it is difficult to improve the diffraction efficiency of a grating assembly, the present invention provides a grating assembly and a method for manufacturing the grating assembly.

[0046] Example 1

[0047] like Figures 1 to 5 As shown, the grating assembly includes a substrate 10, an optical adhesive auxiliary structure 20, a functional layer and an optical adhesive layer 50. There are multiple optical adhesive auxiliary structures 20, and multiple optical adhesive auxiliary structures 20 are spaced apart on the surface of one side of the substrate 10 through a nanoimprint structure; the functional layer is conformally covered on the side of the multiple optical adhesive auxiliary structures 20 away from the substrate 10, so that the side and top surfaces of the optical adhesive auxiliary structures 20 are covered by the functional layer, and a gap is left on the side of the functional layer away from the substrate; the optical adhesive layer 50 is arranged on the side of the optical adhesive auxiliary structure 20 away from the substrate 10, and the projection of the optical adhesive layer 50 on the substrate 10 completely covers the optical adhesive auxiliary structure 20 and the functional layer.

[0048] Specifically, there are multiple gaps, the functional layer serves as the deposition layer 30, and the grating assembly also includes a diffraction grating 41. There are multiple diffraction gratings 41, and the multiple diffraction gratings 41 are filled in the multiple gaps one by one, so that the diffraction grating 41 and the optical adhesive auxiliary structure 20 are separated by the deposition layer 30, thereby adjusting the thickness of the deposition layer 30 to achieve the purpose of adjusting the aspect ratio of the diffraction grating. The refractive index of the diffraction grating 41 is greater than the refractive index of the optical adhesive auxiliary structure 20.

[0049] A functional layer is formed to conformally cover the side of the multiple optical adhesive auxiliary structures 20 facing away from the substrate 10. The side and top surfaces of the optical adhesive auxiliary structures 20 are covered by the functional layer, leaving a gap on the side of the functional layer facing away from the substrate to facilitate subsequent filling with grating material. The purpose of the functional layer is to adjust the aspect ratio of the diffraction grating by setting different thicknesses. In other words, the aspect ratio of the diffraction grating can be adjusted by adjusting the thickness of the deposited layer. The combination of the functional layer and the optical adhesive auxiliary structures 20 facilitates the formation of a diffraction grating with a larger aspect ratio, thereby improving the diffraction efficiency of the grating assembly.

[0050] refer to Figure 2 , the deposition layer 30 is a whole layer. When a whole layer of deposition layer 30 is conformally covered on the surface of multiple spaced optical adhesive auxiliary structures 20, there is a gap between any two adjacent deposition layers 30, that is, there is a gap between the two adjacent optical adhesive auxiliary structures 20 covered by the deposition layer 30, so as to leave space for the diffraction grating 41. By setting the deposition layer 30, the deposition layer 30 can separate the diffraction grating 41 from the optical adhesive auxiliary structure 20, so that the aspect ratio of the diffraction grating can be adjusted by setting different thicknesses; setting the deposition layer 30 compresses the width of the gap between the two adjacent optical adhesive auxiliary structures 20, so that a diffraction grating 41 with a larger aspect ratio can be manufactured, which is beneficial to improving the diffraction efficiency. By setting the optical adhesive layer 50, the optical adhesive layer 50 can protect the diffraction grating 41 to prevent external dirt from adhering to the surface of the diffraction grating 41 and affecting the transmission of light by the diffraction grating 41. Since the diffraction grating 41 of the present application is a diffraction grating 41 with a high refractive index, a deposition layer 30 is provided to cover the bottom and side surfaces of the diffraction grating 41, and an optical adhesive layer 50 is provided to cover the top surface of the diffraction grating 41. The optical adhesive auxiliary structure 20 and the optical adhesive layer 50 are arranged so that the diffraction grating 41 has diffraction conditions. Since the diffraction grating 41 with a high refractive index is difficult to be directly realized by nanoimprinting processing, the diffraction grating 41 with a high refractive index is manufactured by using an optical adhesive auxiliary structure 20 and an optical adhesive layer 50 to cover the diffraction grating 41.

[0051] It should be noted here that the shape of the diffraction grating 41 of the present application depends on the shape of the gap. Optical adhesive auxiliary structures 20 of different shapes can be selected to achieve different gaps, thereby manufacturing a variety of diffraction gratings 41 with high aspect ratios and improving diffraction efficiency.

[0052] It should also be noted that since the deposition layer 30 has a certain thickness and is conformally covered on the side of the optical adhesive auxiliary structure 20 away from the substrate 10, in addition to the side and top surfaces of the optical adhesive auxiliary structure 20 being covered, the surface of the substrate 10 between any two adjacent optical adhesive auxiliary structures 20 among the multiple optical adhesive auxiliary structures 20 is also covered by the deposition layer 30, so that the deposition layer 30 can compress the width of the gap between the two adjacent optical adhesive auxiliary structures 20, thereby making the gap narrower, so that the width of the diffraction grating 41 subsequently filled in the gap is compressed, so as to facilitate the manufacture of a narrower diffraction grating 41 with a larger aspect ratio, so as to improve the diffraction efficiency of the diffraction grating 41.

[0053] Specifically, the refractive index of the diffraction grating 41 at a wavelength of 589 nm is not less than 1.8, and the refractive index of the diffraction grating 41 is greater than that of the substrate 10; the refractive index of the diffraction grating 41 is greater than that of the deposition layer 30, and the refractive index of the diffraction grating 41 is greater than that of the optical adhesive layer 50. This configuration ensures the high refractive index of the diffraction grating 41, thereby improving the diffraction efficiency of the diffraction grating 41 and further enhancing the final image display efficiency and display uniformity of the grating assembly. At the same time, the substrate 10, deposition layer 30, and optical adhesive layer 50 provide diffraction conditions for the diffraction grating 41, ensuring the reliability of the diffraction grating 41.

[0054] Specifically, the diffraction grating 41 is made of TiO2, Nb2O5, or HfO2. Using TiO2, Nb2O5, or HfO2 as the material for the diffraction grating 41 ensures a high refractive index and high diffraction efficiency. Using TiO2, Nb2O5, or HfO2 as the material for the diffraction grating 41 is difficult to achieve through direct embossing. Therefore, an optical adhesive auxiliary structure 20, a deposition layer 30, and an optical adhesive layer 50 are used to encapsulate the diffraction grating 41 to produce a high refractive index diffraction grating 41.

[0055] like Figure 5 As shown, the thickness of the deposited layer 30 is uniform at various locations.

[0056] In an optional embodiment, the surface of the diffraction grating 41 facing away from the substrate 10 is flush with the surface of the deposition layer 30 on the top surface of the optical adhesive auxiliary structure 20 facing away from the substrate 10. Alternatively, the surface of the diffraction grating 41 facing away from the substrate 10 can be lower than the surface of the deposition layer 30 on the top surface of the optical adhesive auxiliary structure 20. This configuration can be tailored to actual needs. The optical adhesive layer 50 is a single, integral layer. The optical adhesive layer 50 contacts both the diffraction grating 41 and a portion of the deposition layer 30. This configuration helps ensure that the optical adhesive layer 50 protects the diffraction grating 41, ensuring the structural stability and operational reliability of the diffraction grating 41.

[0057] Since the size or shape of the optical adhesive auxiliary structure 20 changes, the size or shape of the gap between two adjacent optical adhesive auxiliary structures 20 will change, further changing the size and shape of the gap. Figure 5 As shown, when the optical adhesive auxiliary structure 20 is tilted on one side of the substrate 10, the diffraction grating 41 is a tilted grating, and the tilt angle of the tilted grating is the same as the tilt angle of the optical adhesive auxiliary structure 20. When the optical adhesive auxiliary structure 20 is vertically disposed on one side of the substrate 10, the diffraction grating 41 is a straight tooth grating, and the straight tooth grating is disposed perpendicular to the substrate 10. This configuration allows the tilt angle of the optical adhesive auxiliary structure 20 to be adjusted, thereby forming a diffraction grating 41 with a larger tilt angle and higher diffraction efficiency.

[0058] like Figure 5 As shown, both sides of the optical adhesive layer 50 are planar, so that the optical adhesive layer 50 and the substrate 10 sandwich the optical adhesive auxiliary structure 20, the deposition layer 30, and the diffraction grating 41 therebetween. This arrangement allows the optical adhesive auxiliary structure 20, the deposition layer 30, the diffraction grating 41, and the optical adhesive layer 50 to form a single unit, increasing the overall structural compactness and performance stability.

[0059] It should be noted that the materials of the optical adhesive auxiliary structure 20 and the optical adhesive layer 50 are both nanoimprint photoresist. By using nanoimprint photoresist, the specific shape of the optical adhesive auxiliary structure 20 can be imprinted to facilitate the high-refractive-index diffraction grating 41 to fill the gap, forming a high-refractive-index tilted grating or straight tooth grating.

[0060] Specifically, the ratio of the height of the diffraction grating 41 to the thickness of the diffraction grating 41 is greater than or equal to 0.1 and less than or equal to 50. By reasonably restricting the range of the ratio between the height and thickness of the diffraction grating 41, it is helpful to ensure that the diffraction grating 41 has a large aspect ratio, which helps to ensure the high refractive index and high diffraction efficiency characteristics of the diffraction grating 41.

[0061] Specifically, the width of the gap can be adjusted by adjusting the thickness of the deposition layer 30; the greater the thickness of the deposition layer 30, the smaller the width of the gap, thereby forming a diffraction grating 41 with a larger aspect ratio, breaking through the limitations of traditional processes. This method can ensure that the diffraction efficiency of the diffraction light dispersion is improved while not increasing the processing difficulty.

[0062] Specifically, the material of the deposition layer 30 is one of Al2O3, SiO2, HfO2, ZrO2, Ta2O5, and CeO2.

[0063] like Figures 1 to 5 As shown, the present invention also provides a method for manufacturing a grating component, the manufacturing method is used to manufacture the above-mentioned grating component, Figures 1 to 5The diagram shows the different manufacturing steps when the optical adhesive auxiliary structure 20 is tilted on one side of the substrate 10 and the diffraction grating 41 is a tilted grating. Of course, the method is also applicable when the optical adhesive auxiliary structure 20 is vertically arranged on one side of the substrate 10 and the diffraction grating 41 is a straight tooth grating. The manufacturing method includes:

[0064] like Figure 1 As shown, step S1: obtain a substrate 10, apply a first optical adhesive material on one side surface of the substrate 10, and use a master plate or a daughter plate with a specific surface structure to emboss and demold the first optical adhesive material in sequence to form a plurality of spaced optical adhesive auxiliary structures 20 of the grating assembly; a accommodating space for the diffraction grating 41 and the deposition layer 30 is formed between any two adjacent optical adhesive auxiliary structures 20 among the plurality of optical adhesive auxiliary structures 20; it should be noted here that when the optical adhesive auxiliary structure 20 is embossed, some residual adhesive will exist, which is not shown in the figure, but can be understood by those skilled in the art.

[0065] like Figure 2 As shown, step S2: on the side of the multiple optical adhesive auxiliary structures 20 away from the substrate 10, one of the chemical vapor deposition method, physical vapor deposition method and atomic layer deposition method is used to grow the deposition layer 30 of the grating component, and the deposition layer 30 is a whole layer, so that the deposition layer 30 is conformally covered on the side of the multiple optical adhesive auxiliary structures 20 away from the substrate 10, so that the top surface, side surface of the optical adhesive auxiliary structure 20 and the surface of the substrate 10 exposed between any two adjacent optical adhesive auxiliary structures 20 are covered by the deposition layer 30, and gaps are reserved between adjacent deposition layers 30; the optical adhesive auxiliary structure 20 and the deposition layer 30 covering it form a whole, and the adjacent deposition layers 30 here refer to the two adjacent wholes, and the gap is located on the side of the deposition layer 30 away from the substrate 10.

[0066] like Figure 3 As shown, step S3: growing one of high-refractive-index materials such as TiO2, HfO2, and Nb2O5 in the gap between two adjacent optical adhesive auxiliary structures 20 among the multiple optical adhesive auxiliary structures 20 on the side of the deposition layer 30 away from the substrate 10, so that the gap is filled with the high-refractive-index material, thereby forming a high-refractive-index material layer 40; as can be seen from the figure, at this time, the high-refractive-index material layer 40 is higher than the optical adhesive auxiliary structure 20 and the deposition layer 30 on the top surface thereof;

[0067] like Figure 4As shown, step S4: removing the high refractive index material layer 40 above the top surface of the deposition layer 30 by etching or chemical mechanical polishing, that is, removing the high refractive index material layer 40 above the deposition layer 30 on the optical adhesive auxiliary structure 20, to form a diffraction grating 41 of the grating assembly; at this time, the surface of the formed diffraction grating 41 on the side away from the substrate 10 is flush with the surface of the deposition layer 30 on the top surface of the optical adhesive auxiliary structure 20 away from the substrate 10;

[0068] Step S5: Spin-coat a second optical adhesive material on the surface of the diffraction grating 41, the deposition layer 30 and the optical adhesive auxiliary structure 20 away from the substrate 10, and then use a blank master to emboss the second optical adhesive material to form an optical adhesive layer 50 of the grating assembly.

[0069] It should be noted that the above-mentioned first optical adhesive material is an optical adhesive with a refractive index of 1.46 at a wavelength of 589nm; in step S2, it is preferred to use atomic layer deposition to grow a deposition layer 30 of SiO2 with a refractive index of 1.46 at a wavelength of 589nm; in step S3, it is preferred to use atomic layer deposition to grow high-refractive index materials such as TiO2 and Nb2O5; in step S4, it is preferred to use a corrosion process to remove part of the high-refractive index material layer 40 that is higher than the deposition layer 30 on the top surface of the optical adhesive auxiliary structure 20.

[0070] Since it is difficult to form a diffraction grating 41 of high refractive index materials such as TiO2, HfO2, and Nb2O5 using the traditional nanoimprinting method, and it is difficult to process a diffraction grating 41 with a large inclination angle, a small width, and a large aspect ratio due to the limitations of traditional processes, this manufacturing method is used to produce the above-mentioned grating assembly.

[0071] The grating assembly manufactured using the method of the present invention can not only break through process limitations and use TiO2 and Nb2O5 materials with higher refractive index as the material of the diffraction grating 41, but also adjust the inclination angle and shape of the diffraction grating 41 by providing an optical adhesive auxiliary structure 20, so that a diffraction grating 41 with a larger inclination angle and a shape that is more conducive to increasing the refractive index can be formed without increasing the difficulty of processing; by providing a deposition layer 30 of a reasonable thickness, the width of the gap between any two adjacent deposition layers 30 can be adjusted, thereby forming a diffraction grating 41 with a narrower width and a larger aspect ratio. A diffraction grating 41 with a narrower width and a higher height can better improve the diffraction efficiency of the diffraction grating 41, further improving the diffraction efficiency of the diffraction grating 41 and ensuring the high imaging quality of the image finally output by the grating assembly.

[0072] Example 2

[0073] like Figures 6 to 9As shown, a grating component is provided, which includes a substrate 10, an optical adhesive auxiliary structure 20, a functional layer and an optical adhesive layer 50. There are multiple optical adhesive auxiliary structures 20, and the multiple optical adhesive auxiliary structures 20 are formed on the surface of one side of the substrate 10 by nanoimprinting; a functional layer is arranged on the side wall of the optical adhesive auxiliary structure 20, and the two functional layers on the side where two adjacent optical adhesive auxiliary structures 20 in the optical adhesive auxiliary structure 20 face each other are spaced to form a gap; the optical adhesive layer 50 is arranged on the side of the optical adhesive auxiliary structure 20 away from the substrate 10, and the projection of the optical adhesive layer 50 on the substrate 10 completely covers the optical adhesive auxiliary structure 20 and the functional layer.

[0074] A plurality of spaced optical adhesive auxiliary structures 20 are provided on one side surface of the substrate 10 by nanoimprinting, and a functional layer is provided on the side wall of the optical adhesive auxiliary structure 20, so that the optical adhesive auxiliary structure 20 can support the functional layer on its side wall, which is beneficial to ensure the molding stability and reliability of the functional layer. Functional layers are provided on the side walls of the plurality of optical adhesive auxiliary structures 20, and any two adjacent optical adhesive auxiliary structures 20 in the plurality of optical adhesive auxiliary structures 20 are spaced apart from each other between the two functional layers on one side to leave a gap between them. This arrangement compresses the width of the functional layer, and the functional layer is a diffraction grating 41, so that a diffraction grating 41 with a larger aspect ratio can be manufactured, which is beneficial to improve the diffraction efficiency. By providing an optical adhesive layer 50, the optical adhesive layer 50 can protect the diffraction grating 41 to prevent external dirt from adhering to the surface of the diffraction grating 41 and affecting the transmission of light by the diffraction grating 41.

[0075] like Figure 9 As shown, the optical adhesive layer 50 is disposed on the side of the diffraction grating 41 and the optical adhesive auxiliary structure 20 away from the substrate 10, so that the gap is filled by the optical adhesive layer 50 and the optical adhesive auxiliary structure 20 and the diffraction grating 41 are covered by the optical adhesive layer 50. The distance from the surface of the optical adhesive layer 50 away from the substrate 10 to the substrate 10 is greater than the distance from the surface of the diffraction grating 41 away from the substrate 10 to the substrate 10, and the distance from the surface of the optical adhesive layer 50 away from the substrate 10 to the substrate 10 is greater than the distance from the surface of the optical adhesive auxiliary structure 20 away from the substrate 10 to the substrate 10. This arrangement allows the diffraction grating 41 to be covered by the substrate 10, the optical adhesive auxiliary structure 20, and the optical adhesive layer 50, thereby ensuring the structural and shape stability of the diffraction grating 41 and the high refractive index characteristics of the diffraction grating 41.

[0076] Since it is difficult to directly realize the diffraction grating 41 with a high refractive index through nanoimprinting, the diffraction grating 41 with a high refractive index is manufactured by using an optical adhesive auxiliary structure 20 and an optical adhesive layer 50 to cover the diffraction grating 41 .

[0077] It should be noted here that the shape of the diffraction grating 41 of the present application depends on the shape of the optical adhesive auxiliary structure 20 and the thickness of the diffraction grating 41. Different shapes of the optical adhesive auxiliary structure 20 or thicknesses of the diffraction grating 41 can be selected to achieve high refractive index diffraction gratings 41 of different sizes to improve the diffraction efficiency.

[0078] Specifically, the refractive index of the diffraction grating 41 is greater than that of the optical adhesive auxiliary structure 20, the refractive index of the diffraction grating 41 is greater than that of the substrate 10, and the refractive index of the diffraction grating 41 is greater than that of the optical adhesive layer 50. This configuration not only allows the optical adhesive auxiliary structure 20, the substrate 10, and the optical adhesive layer 50 to encapsulate the diffraction grating 41, thus ensuring diffraction conditions for the diffraction grating 41 and ensuring its reliability, but also ensures the high refractive index characteristics of the diffraction grating 41.

[0079] In this embodiment, the diffraction grating 41 is provided only on the sidewalls of the optical adhesive auxiliary structure 20, and the height of the diffraction grating 41 is the same as the height of the optical adhesive auxiliary structure 20. In other words, the height of the diffraction grating 41 is closely related to the height of the optical adhesive auxiliary structure 20. The shape and height of the optical adhesive auxiliary structure 20 can be adjusted according to actual conditions to form diffraction gratings 41 of different heights and shapes.

[0080] Specifically, the diffraction grating 41 is one of a TiO2 grating, a Nb2O5 grating and a HfO2 grating, and the refractive index of the diffraction grating 41 is not less than 1.8. The TiO2 grating, the Nb2O5 grating and the HfO2 grating all have high refractive index and high diffraction efficiency. The TiO2 grating, the Nb2O5 grating and the HfO2 grating are difficult to realize by direct imprinting, so the diffraction grating 41 with a high refractive index is manufactured by coating the diffraction grating 41 with an optical adhesive auxiliary structure 20 and an optical adhesive layer 50. The TiO2 grating, the Nb2O5 grating and the HfO2 grating can be obtained by chemical vapor deposition, physical vapor deposition or atomic layer deposition. At the same time, since the diffraction grating 41 is a layer structure attached to the optical adhesive auxiliary structure 20, the thickness of the diffraction grating 41 can be adjusted, so that a diffraction grating 41 with a larger aspect ratio can be processed. The diffraction grating 41 of the grating assembly of the present application is made of a high-refractive-index material, such as TiO2, Nb2O5, and HfO2, to increase the refractive index and diffraction efficiency. Furthermore, the diffraction efficiency of the diffraction grating 41 is further increased by increasing the height, reducing the thickness (width), and adjusting the structure of the diffraction grating 41. This greatly improves the diffraction efficiency of the diffraction grating 41 of the present application, thereby enhancing the final image display efficiency and display uniformity of the grating assembly.

[0081] Specifically, the ratio of the height of the diffraction grating 41 to the thickness of the diffraction grating 41 is greater than or equal to 0.1 and less than or equal to 50. By reasonably restricting the range of the ratio between the height and thickness of the diffraction grating 41, it is helpful to ensure that the diffraction grating 41 has a large height-to-width ratio, which helps to ensure high diffraction efficiency characteristics of the diffraction grating 41.

[0082] Changing the size or shape of the optical adhesive auxiliary structure 20 will also cause the size or shape of the diffraction grating 41 to change. When the optical adhesive auxiliary structure 20 is tilted on one side of the substrate 10, the diffraction grating 41 covers the sidewall of the optical adhesive auxiliary structure 20, so the angle between the diffraction grating 41 and the substrate 10 is the same as the angle between the optical adhesive auxiliary structure 20 and the substrate 10. This allows the diffraction efficiency to be adjusted by adjusting the tilt angle of the optical adhesive auxiliary structure 20.

[0083] Specifically, the material of the optical adhesive auxiliary structure 20 and the material of the optical adhesive layer 50 are both nanoimprint photoresist, and the refractive index of the optical adhesive auxiliary structure 20 is the same as the refractive index of the optical adhesive layer 50. The specific shape of the optical adhesive auxiliary structure 20 is formed by nanoimprinting so that the high-refractive-index diffraction grating 41 covers the sidewalls of the optical adhesive auxiliary structure 20, forming a high-refractive-index inclined or vertical diffraction grating 41. Furthermore, setting the refractive index of the optical adhesive auxiliary structure 20 to be the same as that of the optical adhesive layer 50 provides diffraction conditions for the diffraction grating 41, ensuring feasibility.

[0084] This embodiment also provides a method for manufacturing a grating assembly, which is used to manufacture the grating assembly of the second embodiment. The manufacturing method includes:

[0085] like Figure 6 As shown, step S1: obtain a substrate 10, apply optical glue on the surface of the substrate 10, and use a motherboard or a daughterboard with a surface structure to perform stamping and demolding to form a plurality of optical glue auxiliary structures 20; it should be noted here that when the optical glue auxiliary structure 20 is stamped, some residual glue will exist, which is not shown in the figure, but can be understood by those skilled in the art.

[0086] like Figure 7As shown, step S2: a whole material layer 60 is grown on the surface of the optical adhesive auxiliary structure 20 away from the substrate 10 using chemical vapor deposition, physical vapor deposition, or atomic layer deposition. A gap is left between adjacent material layers 60. The gap is located on the side of the material layer 60 away from the substrate 10 and between two adjacent optical adhesive auxiliary structures 20. The material of the material layer 60 is one of TiO2, Nb2O5, and HfO2. This arrangement can effectively control the aspect ratio of the subsequent diffraction grating 41 by controlling the thickness of the material layer 60, thereby producing a diffraction grating 41 with a larger aspect ratio.

[0087] like Figure 8 As shown, step S3: using the reactive ion beam etching method, the material layer 60 on the top surface of each optical adhesive auxiliary structure 20 and the material layer 60 on the substrate 10 between adjacent optical adhesive auxiliary structures 20 are etched away to form a diffraction grating 41, so that the diffraction grating 41 is only on the side wall of the optical adhesive auxiliary structure 20.

[0088] like Figure 9 As shown, step S4: optical glue is spin-coated on the side of the diffraction grating 41 and the optical glue auxiliary structure 20 away from the substrate 10, and then an optical glue layer 50 is formed by blank master stamping, so that the optical glue layer 50 fills the gap and covers the top and side surfaces of the diffraction grating 41.

[0089] In this embodiment, in step S1, the substrate 10 is a glass substrate, and the applied optical adhesive is an optical adhesive with a refractive index of 1.46 at a wavelength of 589 nm. In step S2, TiO2 with a refractive index of 2.35 at a wavelength of 589 nm is preferably grown by atomic layer deposition to form a material layer 60.

[0090] In addition, the grating component of the present application is mainly used in AR glasses, so as to make the display effect of AR glasses better, but it is not limited to this.

[0091] Obviously, the embodiments described above are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0092] It should be noted that the terms used herein are intended only to describe specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, tasks, devices, components and / or combinations thereof.

[0093] It should be noted that the terms "first," "second," and the like in the specification and claims of this application and the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein.

[0094] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A grating assembly, characterized in that: include: substrate (10); An optical adhesive auxiliary structure (20), wherein the optical adhesive auxiliary structure (20) is multiple, and the multiple optical adhesive auxiliary structures (20) are formed at intervals on one side surface of the substrate (10) by nanoimprinting; A functional layer, wherein the functional layer is provided on the sidewalls of at least a portion of the optical adhesive auxiliary structures (20), and two adjacent optical adhesive auxiliary structures (20) in at least a portion of the optical adhesive auxiliary structures (20) are spaced apart on a side facing each other to form a gap; an optical adhesive layer (50), the optical adhesive layer (50) being arranged on a side of the optical adhesive auxiliary structure (20) away from the substrate (10), the projection of the optical adhesive layer (50) on the substrate (10) completely covering the optical adhesive auxiliary structure (20) and the functional layer; The optical adhesive layer (50) covers the optical adhesive auxiliary structure (20) and the functional layer, and the gap is filled by the optical adhesive layer (50), and the distance from the side surface of the optical adhesive layer (50) away from the substrate (10) to the substrate (10) is greater than the distance from the side surface of the functional layer away from the substrate (10) to the substrate (10).

2. The grating assembly according to claim 1, wherein The distance between the side surface of the optical adhesive layer (50) away from the substrate (10) and the substrate (10) is greater than the distance between the side surface of the optical adhesive auxiliary structure (20) away from the substrate (10) and the substrate (10).

3. The grating assembly according to claim 1, wherein The functional layer is a diffraction grating (41), the refractive index of the diffraction grating (41) is greater than the refractive index of the optical adhesive auxiliary structure (20), the refractive index of the diffraction grating (41) is greater than the refractive index of the substrate (10), and the refractive index of the diffraction grating (41) is greater than the refractive index of the optical adhesive layer (50).

4. The grating assembly according to claim 3, characterized in that The diffraction grating (41) is one of a TiO2 grating, a Nb2O5 grating and a HfO2 grating, and the refractive index of the diffraction grating (41) at a wavelength of 589 nm is not less than 1.

8.

5. The grating assembly according to claim 3, characterized in that The ratio between the height of the diffraction grating (41) and the thickness of the diffraction grating (41) is greater than or equal to 0.1 and less than or equal to 50.

6. The grating assembly according to claim 3, characterized in that The diffraction grating (41) is provided only on the side wall of the optical adhesive auxiliary structure (20), and the height of the diffraction grating (41) is the same as the height of the optical adhesive auxiliary structure (20).

7. The grating assembly according to claim 3, characterized in that The diffraction grating (41) and the optical adhesive auxiliary structure (20) are both arranged perpendicular to the substrate (10).

8. The grating assembly according to claim 3, wherein: The diffraction grating (41) and the optical adhesive auxiliary structure (20) are both arranged obliquely with respect to the substrate (10).

9. The grating assembly according to claim 1, wherein: The refractive index of the optical adhesive auxiliary structure (20) is the same as the refractive index of the optical adhesive layer (50).

10. A method for manufacturing a grating assembly, characterized in that: The manufacturing method is used to manufacture the grating assembly according to any one of claims 12 to 20, and the manufacturing method comprises: Step S1: obtaining a substrate (10), coating an optical adhesive material on one side surface of the substrate (10), and sequentially embossing and demolding the optical adhesive material using a master plate or a daughter plate having a surface structure to form a plurality of optical adhesive auxiliary structures (20) of the grating assembly; Step S2: growing a material layer (60) on a side of the plurality of optical adhesive auxiliary structures (20) away from the substrate (10) by using one of chemical vapor deposition, physical vapor deposition, and atomic layer deposition, leaving gaps between adjacent material layers (60); Step S3: using a reactive ion beam etching method to etch away the material layer (60) on the top surface of each optical adhesive auxiliary structure (20) and the material layer (60) on the substrate (10) between adjacent optical adhesive auxiliary structures (20) to form a functional layer of the grating component, so that only the side walls on both sides of the optical adhesive auxiliary structure (20) have the functional layer; Step S4: Rotatingly coating optical glue on the side of the functional layer and the optical glue auxiliary structure (20) away from the substrate (10), and then forming the optical glue layer (50) of the grating assembly by blank master printing, so that the optical glue layer (50) fills the gap.

Images