Grating assembly and manufacturing method thereof

Abstract

The present invention provides a grating component and a manufacturing method thereof. The grating component includes: a substrate; a plurality of optical glue auxiliary structures which are formed on one side surface of the substrate at intervals through nanoimprinting; a functional layer which conformally covers the side away from the substrate of the plurality of optical glue auxiliary structures, so that the side surfaces and the top surfaces of the optical glue auxiliary structures are all covered by the functional layer, and a gap is left on the side away from the substrate of the functional layer; an optical glue layer which is arranged on the side away from the substrate of the optical glue auxiliary structures, and the projection of the optical glue layer on the substrate completely covers the optical glue auxiliary structures and the functional layer; the functional layer is a deposition layer, and the grating component further includes a plurality of diffraction gratings which are filled in the gaps. The present invention solves the problem that it is difficult to improve the diffraction efficiency of the grating component in the prior art.

Description

Technical Field

[0001] The present invention relates to the technical field of diffractive optical devices, and in particular, to a grating assembly and a manufacturing method of the grating assembly. Background Art

[0002] With the rapid development of the field of diffractive optical devices, various types of diffractive optical devices are updated with the continuous increase of market demand. There are various types of diffractive optical devices. Taking a near-eye display as an example, the near-eye display usually uses a diffraction grating in a grating assembly to realize the transmission of image light. Therefore, the material, morphology, and characteristics of the diffraction grating will all affect the quality of the final output image of the grating assembly.

[0003] The diffraction grating of the grating assembly in the prior art usually adopts the processing technology of nanoimprinting technology. Therefore, the diffraction grating material is usually an optical glue material, resulting in that the diffraction grating is limited by the processing technology, making it difficult for the diffraction grating to meet the design requirements of high diffraction efficiency and difficult to overcome the limitations of the material itself on the diffraction grating. At the same time, the width, tilt angle, or height of the diffraction grating is limited by the manufacturing process. Usually, a diffraction grating with a wider width, a smaller tilt angle, and a shorter height is easier to manufacture, but a diffraction grating with a narrower width and a higher height can better improve the diffraction efficiency of the diffraction grating. However, it is difficult to achieve with the existing diffraction grating using traditional nanoimprinting technology.

[0004] That is to say, the grating assembly in the prior art has the problem of difficult improvement of diffraction efficiency. Summary of the Invention

[0005] The main object of the present invention is to provide a grating assembly and a manufacturing method of the grating assembly to solve the problem that the grating assembly in the prior art has difficulty in improving diffraction efficiency.

[0006] To achieve the above object, according to one aspect of the present invention, there is provided a grating assembly, including: a substrate; an optical glue auxiliary structure, there are multiple optical glue auxiliary structures, and multiple optical glue auxiliary structures are formed on one side surface of the substrate at intervals by nanoimprinting; a functional layer, the functional layer is a deposited layer, conformally covering the side away from the substrate of multiple optical glue auxiliary structures, so that the side surface and the top surface of the optical glue auxiliary structure are both covered by the functional layer, and there is a gap on the side away from the substrate of the functional layer; an optical glue layer, the optical glue layer is arranged on the side away from the substrate of the optical glue auxiliary structure, and the projection of the optical glue layer on the substrate completely covers the optical glue auxiliary structure and the functional layer. The grating assembly further includes a diffraction grating, there are multiple diffraction gratings, and the diffraction gratings are filled in the gaps so that the diffraction gratings and the optical glue auxiliary structures are separated by the deposited layer.

[0007] Furthermore, the refractive index of the diffraction grating is greater than the refractive index of the optical glue auxiliary structure.

[0008] Furthermore, the refractive index of the diffraction grating at a wavelength of 589 nm is not less than 1.8.

[0009] Furthermore, the surface of the side of the diffraction grating away from the substrate is flush with the surface of the side of the deposition layer on the top surface of the optical glue auxiliary structure away from the substrate, and the optical glue layer is in contact with both the diffraction grating and a part of the deposition layer at the same time.

[0010] Furthermore, the material of the diffraction grating is TiO2, Nb2O5 or HfO2.

[0011] Furthermore, the optical glue auxiliary structure is inclined and arranged on one side surface of the substrate. At this time, the diffraction grating is an inclined grating.

[0012] Furthermore, the optical glue auxiliary structure is vertically arranged on one side surface of the substrate. At this time, the diffraction grating is a straight-tooth grating.

[0013] Furthermore, the refractive index of the diffraction grating is greater than that of the substrate; the refractive index of the diffraction grating is greater than that of the deposition layer, and the refractive index of the diffraction grating is greater than that of the optical glue layer.

[0014] Furthermore, the ratio between the height and the thickness of the diffraction grating is greater than or equal to 0.1 and less than or equal to 50.

[0015] Furthermore, the material of the deposition layer is one of Al2O3, SiO2, HfO2, ZrO2, Ta2O5, CeO2.

[0016] According to another aspect of the present invention, a manufacturing method of a grating assembly is provided. The manufacturing method is used to manufacture the above-mentioned grating assembly, and the manufacturing method includes: Step S1: Obtain a substrate, coat a first optical glue material on one side surface of the substrate, and use a master plate or a sub-plate with a surface structure to imprint and demold the first optical glue material in sequence to form a plurality of optical glue auxiliary structures of the grating assembly; Step S2: Grow a functional layer of the grating assembly on the side of the plurality of optical glue auxiliary structures away from the substrate by using one of chemical vapor deposition method, physical vapor deposition method and atomic layer deposition method, and leave a gap between adjacent functional layers; Step S3: Grow at least one of high refractive index materials such as 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: Remove the high refractive index material layer higher than the top surface of the functional layer by means of etching or chemical mechanical polishing to form a diffraction grating of the grating assembly; Step S5: Rotate and coat a second optical glue material on the surfaces of the diffraction grating, the functional layer and the optical glue auxiliary structure away from the substrate side, and then use a blank master plate to imprint the second optical glue material, thereby forming an optical glue layer of the grating assembly.

[0017] According to another aspect of the present invention, there is provided a grating assembly, comprising: a substrate; an optical glue auxiliary structure, there are a plurality of optical glue auxiliary structures, and a plurality of optical glue auxiliary structures are formed on one side surface of the substrate at intervals by nanoimprinting; a functional layer, a functional layer is provided on the side walls of at least some of the optical glue auxiliary structures, and two functional layers on the sides facing each other of at least some adjacent two optical glue auxiliary structures in the optical glue auxiliary structures are arranged at intervals to form a gap; an optical glue layer, the optical glue layer is provided on the side of the optical glue auxiliary structure away from the substrate, and the projection of the optical glue layer on the substrate completely covers the optical glue auxiliary structure and the functional layer; wherein, the optical glue layer covers the optical glue auxiliary structure and the functional layer, and the gap is filled with the optical glue layer, and the distance from the surface of the optical glue layer away from the substrate to the substrate is greater than the distance from the surface of the functional layer away from the substrate to the substrate.

[0018] Further, the distance from the surface of the optical glue layer away from the substrate to the substrate is greater than the distance from the surface of the optical glue auxiliary structure away from the substrate to the substrate.

[0019] Further, the functional layer is a diffraction grating, the refractive index of the diffraction grating is greater than the refractive index of the optical glue auxiliary structure, and 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 glue layer.

[0020] Further, 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.

[0021] Further, the ratio between the height and the thickness of the diffraction grating is greater than or equal to 0.1 and less than or equal to 50.

[0022] Further, the diffraction grating is provided only on the side walls of the optical glue auxiliary structure, and the height of the diffraction grating is the same as the height of the optical glue auxiliary structure.

[0023] Further, both the diffraction grating and the optical glue auxiliary structure are perpendicular to the substrate.

[0024] Further, both the diffraction grating and the optical glue auxiliary structure are inclined to the substrate.

[0025] Further, the refractive index of the optical glue auxiliary structure is the same as the refractive index of the optical glue layer.

[0026] According to another aspect of the present invention, a manufacturing method of a grating assembly is provided. The manufacturing method is used to manufacture the above-mentioned grating assembly, and the manufacturing method includes: Step S1: Obtain a substrate, coat an optical glue material on one side surface of the substrate, and use a master plate or a daughter plate with a surface structure to imprint and demold the optical glue material in sequence to form a plurality of optical glue auxiliary structures of the grating assembly; Step S2: Grow a material layer on one side of the plurality of optical glue auxiliary structures away from the substrate by one of chemical vapor deposition, physical vapor deposition, and atomic layer deposition, and leave a gap between adjacent material layers; Step S3: Use the method of reactive ion beam etching to etch away the material layer on the top surface of each optical glue auxiliary structure and the material layer on the substrate between adjacent optical glue auxiliary structures to form a functional layer of the grating assembly, so that only the side walls on both sides of the optical glue auxiliary structure have the functional layer; Step S4: Spin-coat an optical glue on one side of the functional layer and the optical glue auxiliary structure away from the substrate, and then form an optical glue layer of the grating assembly by imprinting with a blank master plate, so that the optical glue layer fills the gap.

[0027] Applying the technical solution of the present invention, the grating assembly includes a substrate, optical glue auxiliary structures, a functional layer, and an optical glue layer. There are a plurality of optical glue auxiliary structures, and the plurality of optical glue auxiliary structures are formed at intervals on one side surface of the substrate by nanoimprinting; the functional layer conformally covers one side of the plurality of optical glue auxiliary structures away from the substrate, so that the side surface and the top surface of the optical glue auxiliary structure are both covered by the functional layer, and a gap is left on one side of the functional layer away from the substrate; the optical glue layer is arranged on one side of the optical glue auxiliary structure away from the substrate, and the projection of the optical glue layer on the substrate completely covers the optical glue auxiliary structure and the functional layer; wherein, the functional layer is a deposition layer, the grating assembly further includes diffraction gratings, there are a plurality of diffraction gratings, and the diffraction gratings are filled in the gap so that the diffraction gratings and the optical glue auxiliary structures are separated by the deposition layer.

[0028] By setting the functional layer to conformally cover one side of the plurality of optical glue auxiliary structures away from the substrate, and the side surface and the top surface of the optical glue auxiliary structure are both covered by the functional layer, a gap is left on one side of the functional layer away from the substrate. The gap is convenient for filling the subsequent grating material, and the aspect ratio of the diffraction grating can be adjusted by adjusting the thickness of the deposition layer. Through the cooperation of the functional layer and the optical glue auxiliary structure, it is beneficial to form a diffraction grating with a larger aspect ratio and improve the diffraction efficiency of the grating assembly. Description of the Drawings

[0029] The specification drawings forming a part of this application are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0030] Figure 1 Shows a schematic diagram of the grating assembly in the first embodiment of the present invention after passing through Step S1 during the manufacturing process;

[0031] Figure 2 shows Figure 1 a schematic diagram of the grating component in during the manufacturing process passing through step S2;

[0032] Figure 3 shows Figure 1 a schematic diagram of the grating component in during the manufacturing process passing through step S3;

[0033] Figure 4 shows Figure 1 a schematic diagram of the grating component in during the manufacturing process passing through step S4;

[0034] Figure 5 shows Figure 1 a schematic structural diagram of the grating component in ;

[0035] Figure 6 shows a schematic diagram of the grating component of Embodiment 2 of the present invention passing through step S1 during the manufacturing process;

[0036] Figure 7 shows Figure 6 a schematic diagram of the grating component in during the manufacturing process passing through step S2;

[0037] Figure 8 shows Figure 6 a schematic diagram of the grating component in during the manufacturing process passing through step S3;

[0038] Figure 9 shows Figure 6 a schematic diagram of the grating component in during the manufacturing process passing through step S4.

[0039] Among them, the above-mentioned drawings include the following reference numerals:

[0040] 10, substrate; 20, optical glue auxiliary structure; 30, deposition layer; 40, high refractive index material layer; 41, diffraction grating; 50, optical glue layer; 60, material layer. Detailed implementation manners

[0041] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the drawings and in combination with the embodiments.

[0042] It should be pointed out that unless otherwise specified, all technical and scientific terms used in the present application have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present application belongs.

[0043] In the present invention, unless otherwise specified, the orientation terms such as "upper", "lower", "top", and "bottom" generally refer to the directions shown in the drawings or to the vertical, perpendicular, or gravitational directions of the components themselves; similarly, for the convenience of understanding and description, "inner" and "outer" refer to the inner and outer of the contours of the respective components themselves, but the above orientation terms are not used to limit the present invention.

[0044] In order to solve the problem that it is difficult to improve the diffraction efficiency of the grating component in the prior art, the present invention provides a grating component and a manufacturing method thereof.

[0045] Embodiment 1

[0046] As Figures 1 to 5 shown, the grating component includes a substrate 10, an optical glue auxiliary structure 20, a functional layer, and an optical glue layer 50. There are multiple optical glue auxiliary structures 20, and the multiple optical glue auxiliary structures 20 are spaced apart on one side surface of the substrate 10 by a nanoimprint structure; the functional layer conformally covers the side of the multiple optical glue auxiliary structures 20 away from the substrate 10, so that the side surfaces and top surfaces of the optical glue auxiliary structures 20 are all covered by the functional layer, and a gap is left on the side of the functional layer away from the substrate; the optical glue layer 50 is arranged on the side of the optical glue auxiliary structures 20 away from the substrate 10, and the projection of the optical glue layer 50 on the substrate 10 completely covers the optical glue auxiliary structures 20 and the functional layer.

[0047] Specifically, there are multiple gaps, the functional layer serves as a deposition layer 30, the grating component further includes multiple diffraction gratings 41, and the multiple diffraction gratings 41 are respectively filled in the multiple gaps one by one, so that the diffraction gratings 41 and the optical glue auxiliary structures 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 gratings. The refractive index of the diffraction gratings 41 is greater than that of the optical glue auxiliary structures 20.

[0048] By setting the functional layer to conformally cover the side of the multiple optical glue auxiliary structures 20 away from the substrate 10, and the side surfaces and top surfaces of the optical glue auxiliary structures 20 are all covered by the functional layer, a gap is left on the side of the functional layer away from the substrate. The gap facilitates the subsequent filling of the grating material. The purpose of the functional layer is to adjust the aspect ratio of the diffraction gratings by setting different thicknesses, that is, the thickness of the deposition layer can be adjusted to adjust the aspect ratio of the diffraction gratings. Through the cooperation of the functional layer and the optical glue auxiliary structures 20, it is beneficial to form diffraction gratings with a larger aspect ratio, which is beneficial to improving the diffraction efficiency of the grating component.

[0049] Refer to Figure 2, the deposition layer 30 is a continuous layer. After a continuous deposition layer 30 conformally covers the surfaces of multiple spaced-apart optical adhesive auxiliary structures 20, there is a gap between any two adjacent deposition layers 30. That is to say, there is a gap between two adjacent optical adhesive auxiliary structures 20 covered by the deposition layer 30, so as to leave a setting 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 as to adjust the aspect ratio of the diffraction grating by setting different thicknesses; setting the deposition layer 30 compresses the width of the gap between 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 contaminants from adhering to the surface of the diffraction grating 41 and thus affecting the light transmission of the diffraction grating 41. Since the diffraction grating 41 of the present application is a diffraction grating 41 with a high refractive index, by setting the deposition layer 30 to cover the bottom and side surfaces of the diffraction grating 41, and setting the optical adhesive layer 50 to cover the top surface of the diffraction grating 41, combined with the arrangement positions of the optical adhesive auxiliary structure 20 and the optical adhesive layer 50, the diffraction grating 41 meets the diffraction conditions. Since it is difficult to directly implement the diffraction grating 41 with a high refractive index by means of nanoimprinting, the diffraction grating 41 with a high refractive index is manufactured by the method of covering the diffraction grating 41 with the optical adhesive auxiliary structure 20 and the optical adhesive layer 50.

[0050] It should be noted here that the shape of the diffraction grating 41 of the present application depends on the shape of the gap. Different shapes of optical adhesive auxiliary structures 20 can be selectively set to achieve different gaps, manufacture a variety of diffraction gratings 41 with high aspect ratios, and improve the diffraction efficiency.

[0051] It also should be noted that since the deposition layer 30 has a certain thickness and conformally covers 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 two adjacent optical adhesive auxiliary structures 20, making the gap narrower, and thus 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 to improve the diffraction efficiency of the diffraction grating 41.

[0052] 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. Such a setting ensures the high refractive index characteristic of the diffraction grating 41, thereby improving the diffraction efficiency of the diffraction grating 41 and further improving the final image display efficiency and display uniformity of the grating assembly; at the same time, the substrate 10, the deposition layer 30, and the optical adhesive layer 50 provide diffraction conditions for the diffraction grating 41, ensuring the reliability of the use of the diffraction grating 41.

[0053] Specifically, the material of the diffraction grating 41 is TiO2, Nb2O5, or HfO2. Using TiO2, Nb2O5, or HfO2 as the material of the diffraction grating 41 can ensure the high refractive index and high diffraction efficiency of the diffraction grating 41. It is difficult to realize TiO2, Nb2O5, or HfO2 as the material of the diffraction grating 41 by direct imprinting. Therefore, the optical adhesive auxiliary structure 20, the deposition layer 30, and the optical adhesive layer 50 are used to coat the diffraction grating 41 to fabricate the diffraction grating 41 with a high refractive index.

[0054] As Figure 5 shown, the thickness at each position of the deposition layer 30 is uniform.

[0055] In an alternative embodiment, the surface of the side of the diffraction grating 41 away from the substrate 10 is flush with the surface of the side of the deposition layer 30 on the top surface of the optical adhesive auxiliary structure 20 away from the substrate 10. Of course, it can also be set that the surface of the side of the diffraction grating 41 away from the substrate 10 is lower than the surface of the deposition layer 30 on the top surface of the optical adhesive auxiliary structure 20, which can be set according to actual needs. The optical adhesive layer 50 is a single layer. The optical adhesive layer 50 is in contact with both the diffraction grating 41 and a part of the deposition layer 30 at the same time. Such a setting is beneficial to ensuring the protection of the diffraction grating 41 by the optical adhesive layer 50 and ensuring the structural stability and reliability of the use of the diffraction grating 41.

[0056] Since the change in the size or shape of the optical adhesive auxiliary structure 20 will cause the change in the gap size or shape between two adjacent optical adhesive auxiliary structures 20, and further cause the change in the size and shape of the gap. Therefore, as Figure 5 shown, when the optical adhesive auxiliary structure 20 is inclined and arranged on one side surface of the substrate 10, at this time, the diffraction grating 41 is an inclined grating, and the inclination angle of the inclined grating is the same as the inclination angle of the optical adhesive auxiliary structure 20. When the optical adhesive auxiliary structure 20 is vertically arranged on one side surface of the substrate 10, at this time, the diffraction grating 41 is a straight-tooth grating, and the straight-tooth grating is perpendicular to the substrate 10. Such a setting can adjust the inclination angle of the optical adhesive auxiliary structure 20, so as to form a diffraction grating 41 with a larger inclination angle and higher diffraction efficiency.

[0057] As shown Figure 5 in the figure, both side surfaces of the optical adhesive layer 50 are flat surfaces, 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. Such a setting enables the optical adhesive auxiliary structure 20, the deposition layer 30, the diffraction grating 41, and the optical adhesive layer 50 to form an integral body, increasing the overall structural compactness and performance stability.

[0058] It should be noted that the materials of the optical adhesive auxiliary structure 20 and the optical adhesive layer 50 are both nanoimprint lithography adhesives. By using nanoimprint lithography adhesives, a specific shape of the optical adhesive auxiliary structure 20 can be imprinted, so as to facilitate the filling of the gap by the diffraction grating 41 with a high refractive index, and a diffraction grating 41 with a high refractive index, such as an inclined grating or a straight-tooth grating, can be formed.

[0059] 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 ratio range between the height and the thickness of the diffraction grating 41, it is beneficial to ensure that the diffraction grating 41 has a relatively large aspect ratio, and it is beneficial to ensure the high refractive index characteristic and the high diffraction efficiency characteristic of the diffraction grating 41.

[0060] Specifically, the thickness of the deposition layer 30 can be adjusted, and then the width of the gap can be adjusted; the greater the thickness of the deposition layer 30, the smaller the width of the gap, so that a diffraction grating 41 with a larger aspect ratio can be formed, breaking through the limitations of traditional processes. By adopting this method, it is possible to improve the diffraction efficiency of diffracted light while ensuring that the processing difficulty is not increased.

[0061] Specifically, the material of the deposition layer 30 is one of Al2O3, SiO2, HfO2, ZrO2, Ta2O5, CeO2.

[0062] As Figures 1 to 5 shown in the figure, the present invention also provides a manufacturing method for a grating assembly. The manufacturing method is used to manufacture the above-mentioned grating assembly. Figures 1 to 5 The figure shows the state diagrams of different manufacturing steps when the optical adhesive auxiliary structure 20 is inclinedly arranged on one side surface of the substrate 10 and the diffraction grating 41 is an inclined grating. Of course, this method is also applicable when the optical adhesive auxiliary structure 20 is vertically arranged on one side surface of the substrate 10 and the diffraction grating 41 is a straight-tooth grating. The manufacturing method includes:

[0063] As Figure 1As shown, step S1: Obtain a substrate 10. Coat a first optical adhesive material on one side surface of the substrate 10, and use a master plate or a sub-plate with a specific surface structure to imprint 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 receiving 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 imprinting to generate the optical adhesive auxiliary structure 20, there will be some residual glue, which is not shown in the figure, but those skilled in the art can understand.

[0064] As Figure 2 shown, step S2: On the side of the plurality of optical adhesive auxiliary structures 20 away from the substrate 10, grow the deposition layer 30 of the grating assembly by one of the methods of chemical vapor deposition, physical vapor deposition, and atomic layer deposition. The deposition layer 30 is a single layer, so that the deposition layer 30 conformally covers the side of the plurality of 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 all covered by the deposition layer 30, and a gap is reserved between adjacent deposition layers 30; the optical adhesive auxiliary structure 20 and the deposition layer 30 covering it form a whole. Here, between adjacent deposition layers 30 refers to between adjacent wholes, and the gap is located on the side of the deposition layer 30 away from the substrate 10.

[0065] As Figure 3 shown, step S3: Grow one of the high refractive index materials of TiO2, HfO2, Nb2O5 in the gap between any two adjacent optical adhesive auxiliary structures 20 among the plurality of 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; it can be seen from the figure that at this time, the high refractive index material layer 40 is set higher than the optical adhesive auxiliary structure 20 and the deposition layer 30 on its top surface;

[0066] As Figure 4 shown, step S4: Remove the high refractive index material layer 40 higher than the top surface of the deposition layer 30 through a process method of etching or chemical mechanical polishing, that is, remove the high refractive index material layer 40 higher than the deposition layer 30 on the optical adhesive auxiliary structure 20, so as to form the 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 on the side away from the substrate 10;

[0067] Step S5: Spin-coat a second optical adhesive material on the side surfaces 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 plate to imprint the second optical adhesive material, thereby forming the optical adhesive layer 50 of the grating assembly.

[0068] 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 589 nm; in step S2, an atomic layer deposition method is preferably used to grow a deposition layer 30 of SiO2 with a refractive index of 1.46 at a wavelength of 589 nm; in step S3, an atomic layer deposition method is preferably used to grow high refractive index materials of TiO2 and Nb2O5; in step S4, a corrosion process method is preferably used to remove a part of the high refractive index material layer 40 of the deposition layer 30 above the top surface of the optical adhesive auxiliary structure 20.

[0069] Since it is difficult to form a diffraction grating 41 of high refractive index materials such as TiO2, HfO2, and Nb2O5 by using the traditional nanoimprint method, and at the same time, due to the limitations of the traditional process, it is difficult to process a diffraction grating 41 with a large tilt angle, a small width, and a large aspect ratio, so the above-mentioned grating assembly is produced by using this manufacturing method.

[0070] The grating assembly manufactured by using the method of the present invention can not only break through the process limitations and use higher refractive index materials such as TiO2 and Nb2O5 as the materials of the diffraction grating 41, but also can adjust the tilt angle and shape of the diffraction grating 41 by setting the optical adhesive auxiliary structure 20, and can form a diffraction grating 41 with a larger tilt angle and a shape more conducive to increasing the refractive index without increasing the processing difficulty; by setting a deposition layer 30 with a reasonable thickness, the width of the gap between any two adjacent deposition layers 30 can be adjusted, so as to form 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 improve the diffraction efficiency of the diffraction grating 41 more, 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.

[0071] Embodiment 2

[0072] As Figures 6 to 9 shown, a grating assembly is provided. 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 the multiple optical adhesive auxiliary structures 20 are formed on one side surface of the substrate 10 at intervals by nanoimprinting; a functional layer is provided on the side wall of the optical adhesive auxiliary structure 20, and two functional layers on the opposite sides of two adjacent optical adhesive auxiliary structures 20 in the optical adhesive auxiliary structure 20 are arranged at intervals to form a gap; the optical adhesive layer 50 is provided 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.

[0073] A plurality of spaced optical glue auxiliary structures 20 are arranged on one side surface of the substrate 10 through nanoimprinting, and a functional layer is arranged on the side wall of the optical glue auxiliary structure 20, so that the optical glue auxiliary structure 20 can support the functional layer on its side wall, which is beneficial to ensuring the forming stability and use reliability of the functional layer. Functional layers are arranged on the side walls of the plurality of optical glue auxiliary structures 20, and any two adjacent optical glue auxiliary structures 20 among the plurality of optical glue auxiliary structures 20 are spaced apart from each other on the side facing one side, so as to leave a gap therebetween. Such a setting compresses the width of the functional layer. 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 improving the diffraction efficiency. By arranging the optical glue layer 50, the optical glue layer 50 can protect the diffraction grating 41 to prevent external contaminants from adhering to the surface of the diffraction grating 41 and thus affecting the light transmission of the diffraction grating 41.

[0074] As Figure 9 shown, the optical glue layer 50 is filled and arranged on the side of the diffraction grating 41 and the optical glue auxiliary structure 20 away from the substrate 10, so that the gap is filled with the optical glue layer 50, and at the same time, the optical glue layer 50 covers the optical glue auxiliary structure 20 and the diffraction grating 41. The distance from the side surface of the optical glue layer 50 away from the substrate 10 to the substrate 10 is greater than the distance from the side surface of the diffraction grating 41 away from the substrate 10 to the substrate 10, and the distance from the side surface of the optical glue layer 50 away from the substrate 10 to the substrate 10 is greater than the distance from the side surface of the optical glue auxiliary structure 20 away from the substrate 10 to the substrate 10. Such a setting enables the diffraction grating 41 to be covered by the substrate 10, the optical glue auxiliary structure 20 and the optical glue layer 50, so as to ensure the structural stability and shape stability of the diffraction grating 41 and ensure the high refractive index characteristic of the diffraction grating 41.

[0075] Since it is difficult to directly realize the diffraction grating 41 with a high refractive index through the processing method of nanoimprinting, the method of covering the diffraction grating 41 with the optical glue auxiliary structure 20 and the optical glue layer 50 is adopted to manufacture the diffraction grating 41 with a high refractive index.

[0076] It should be noted here that the shape of the diffraction grating 41 of the present application depends on the shape of the optical glue auxiliary structure 20 and the thickness of the diffraction grating 41. Different shapes of the optical glue auxiliary structure 20 or the thickness of the diffraction grating 41 can be selectively set, so as to realize high refractive index diffraction gratings 41 of different sizes and improve the diffraction efficiency.

[0077] Specifically, the refractive index of the diffraction grating 41 is greater than that of the optical glue auxiliary structure 20, greater than that of the substrate 10, and greater than that of the optical glue layer 50. Such a setting not only enables the optical glue auxiliary structure 20, the substrate 10, and the optical glue layer 50 to cover the diffraction grating 41, making the diffraction grating 41 meet the diffraction conditions and ensuring the reliability of the use of the diffraction grating 41, but also can ensure the high refractive index characteristics of the diffraction grating 41.

[0078] In this embodiment, the diffraction grating 41 is provided only on the side wall of the optical glue auxiliary structure 20, and the height of the diffraction grating 41 is the same as that of the optical glue auxiliary structure 20. That is to say, the height of the diffraction grating 41 is closely related to the height of the optical glue auxiliary structure 20, and the shape and height of the optical glue auxiliary structure 20 can be adjusted according to actual conditions to form diffraction gratings 41 with different heights and shapes.

[0079] 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 indices and high diffraction efficiencies. It is difficult to realize the TiO2 grating, the Nb2O5 grating, and the HfO2 grating by direct imprinting. Therefore, a method of covering the diffraction grating 41 with the optical glue auxiliary structure 20 and the optical glue layer 50 is adopted to fabricate the diffraction grating 41 with a high refractive index. 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 glue 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. On the one hand, the diffraction grating 41 of the grating assembly of the present application selects materials with high refractive indices, such as TiO2, Nb2O5, and HfO2, to increase the refractive index and diffraction efficiency. On the other hand, by increasing the height of the diffraction grating 41, reducing the thickness (width), and adjusting the structure of the diffraction grating 41, the diffraction efficiency of the diffraction grating 41 is further increased. In this way, the diffraction efficiency of the diffraction grating 41 of the present application is greatly improved, thereby improving the final image display efficiency and display uniformity of the grating assembly.

[0080] 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 ratio range between the height and the thickness of the diffraction grating 41, it is beneficial to ensure that the diffraction grating 41 is a diffraction grating with a large ratio of height to width, which is beneficial to ensuring the high diffraction efficiency characteristics of the diffraction grating 41.

[0081] Since the change in the size or shape of the optical glue auxiliary structure 20 will cause the size or shape of the diffraction grating 41 to change. When the optical glue auxiliary structure 20 is inclined and arranged on one side surface of the substrate 10, at this time, since the diffraction grating 41 covers the side wall of the optical glue auxiliary structure 20, the included angle between the diffraction grating 41 and the substrate 10 is the same as the included angle between the optical glue auxiliary structure 20 and the substrate 10. In this way, the inclination angle of the diffraction grating 41 can be adjusted by adjusting the inclination angle of the optical glue auxiliary structure 20, and then the diffraction efficiency can be adjusted.

[0082] Specifically, the material of the optical glue auxiliary structure 20 and the material of the optical glue layer 50 are both nanoimprint lithography glue, and the refractive index of the optical glue auxiliary structure 20 is the same as that of the optical glue layer 50. The specific shape of the optical glue auxiliary structure 20 is formed by nanoimprinting, so that the high-refractive-index diffraction grating 41 covers the side wall of the optical glue auxiliary structure 20, forming a high-refractive-index inclined or vertical diffraction grating 41. At the same time, setting the refractive index of the optical glue auxiliary structure 20 to be the same as that of the optical glue layer 50 provides diffraction conditions for the diffraction grating 41 and ensures feasibility.

[0083] This embodiment also provides a manufacturing method of a grating assembly, and this manufacturing method is used to manufacture the grating assembly of the second embodiment. The manufacturing method includes:

[0084] As Figure 6 shown, step S1: Obtain the substrate 10, coat the optical glue on the surface of the substrate 10, and perform imprinting and demolding with a master plate or a daughter plate with a surface structure to form a plurality of optical glue auxiliary structures 20; it should be noted here that when the optical glue auxiliary structure 20 is generated by imprinting, there will be some residual glue, which is not shown in the figure, but those skilled in the art can understand.

[0085] As Figure 7 shown, step S2: Use chemical vapor deposition, physical vapor deposition or atomic layer deposition to grow a whole layer of material layer 60 on the side surface of the optical glue auxiliary structure 20 away from the substrate 10, and leave a gap 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 glue auxiliary structures 20. The material of the material layer 60 is one of TiO2, Nb2O5 and HfO2. Such a setting can effectively control the aspect ratio of the subsequent diffraction grating 41 by controlling the thickness of the material layer 60, and manufacture a diffraction grating 41 with a larger aspect ratio.

[0086] As Figure 8As shown, step S3: Using the method of reactive ion beam etching, etch away the material layer 60 on the top surface of each optical glue auxiliary structure 20 and the material layer 60 on the substrate 10 between adjacent optical glue auxiliary structures 20 to form a diffraction grating 41, so that there is a diffraction grating 41 only on the side wall of the optical glue auxiliary structure 20.

[0087] As Figure 9 shown, step S4: Spin-coat optical glue on the side of the diffraction grating 41 and the optical glue auxiliary structure 20 away from the substrate 10, and then form an optical glue layer 50 by the method of imprinting with a blank master, so that the optical glue layer 50 fills the gap and at the same time coats the top surface and side surface of the diffraction grating 41.

[0088] In this embodiment, in step S1, the substrate 10 is a glass substrate, and the spin-coated optical glue is an optical glue with a wavelength of 589 nm and a refractive index of 1.46. In step S2, it is preferred to grow TiO2 with a wavelength of 589 nm and a refractive index of 2.35 by atomic layer deposition to form the material layer 60.

[0089] In addition, the grating assembly of the present application is mainly applied to AR glasses, so that the display effect of the AR glasses is better, but it is not limited to this.

[0090] Obviously, the above-described embodiments are only a part of the embodiments of the present invention, rather than all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0091] It should be noted that the terms used here are only for describing specific embodiments, rather than intending to limit the exemplary embodiments according to the present application. As used here, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should also be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0092] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above drawings are used to distinguish similar objects, and do not have to be used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present application described here can be implemented in an order other than those illustrated or described here.

[0093] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A grating component, characterized in that, Comprising: A substrate (10); An optical adhesive auxiliary structure (20), there are multiple of the optical adhesive auxiliary structures (20), and through nanoimprinting, the multiple optical adhesive auxiliary structures (20) are spaced and formed on one side surface of the substrate (10); A functional layer, the functional layer conformally covers the side of the multiple optical adhesive auxiliary structures (20) away from the substrate (10), so that the side surfaces and top surfaces of the optical adhesive auxiliary structures (20) are all covered by the functional layer, and a gap is left on the side of the functional layer away from the substrate (10); An optical adhesive layer (50), 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; Wherein, the functional layer is a deposition layer (30), the grating assembly further includes a diffraction grating (41), there are multiple diffraction gratings (41), the diffraction gratings (41) are filled in the gap, and the diffraction gratings (41) and the optical adhesive auxiliary structure (20) are separated by the deposition layer (30); The functional layer is used to adjust the aspect ratio of the diffraction grating (41) filled into the gap by adjusting the thickness.

2. The grating component according to claim 1, wherein The refractive index of the diffraction grating (41) is greater than the refractive index of the optical adhesive auxiliary structure (20).

3. The grating component according to claim 1, characterized in that, The refractive index of the diffraction grating (41) at a wavelength of 589 nm is not less than 1.

8.

4. The grating component according to claim 1, characterized in that The side surface of the diffraction grating (41) away from the substrate (10) is flush with the side surface of the deposition layer (30) on the top surface of the optical adhesive auxiliary structure (20) away from the substrate (10), and the optical adhesive layer (50) is in contact with the diffraction grating (41) and part of the deposition layer (30) at the same time.

5. The grating component according to claim 1, wherein The material of the diffraction grating (41) is TiO2, Nb2O5 or HfO2.

6. The grating component according to claim 1, characterized in that, The optical adhesive auxiliary structure (20) is inclined and arranged on one side surface of the substrate (10), and at this time, the diffraction grating (41) is an inclined grating.

7. The grating component according to claim 1, characterized in that, The optical adhesive auxiliary structure (20) is vertically arranged on one side surface of the substrate (10), and at this time, the diffraction grating (41) is a straight-tooth grating.

8. The grating assembly according to any one of claims 1 to 7, the refractive index of the diffraction grating (41) is greater than the refractive index of the substrate (10); the refractive index of the diffraction grating (41) is greater than the refractive index of the deposition layer (30), and the refractive index of the diffraction grating (41) is greater than the refractive index of the optical adhesive layer (50).

9. The grating assembly according to any one of claims 1 to 7, the ratio between the height and the thickness of the diffraction grating (41) is greater than or equal to 0.1 and less than or equal to 50.

10. The grating assembly according to any one of claims 1 to 7, the material of the deposition layer (30) is one of Al2O3, SiO2, HfO2, ZrO2, Ta2O5, CeO2.

11. A manufacturing method of a grating component, characterized in that, The manufacturing method is used to manufacture the grating assembly according to any one of claims 1 to 10, and the manufacturing method includes: Step S1: Obtain a substrate (10), coat a first optical glue material on one side surface of the substrate (10), and perform imprinting and demolding on the first optical glue material in sequence using a master plate or a daughter plate with a surface structure to form a plurality of optical glue auxiliary structures (20) of the grating assembly; Step S2: Grow a functional layer of the grating assembly on one side of the plurality of optical glue auxiliary structures (20) away from the substrate (10) by using one of chemical vapor deposition, physical vapor deposition, and atomic layer deposition, and leave a gap between adjacent functional layers; Step S3: Grow at least one of high refractive index materials such as 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 (40); Step S4: Remove the high refractive index material layer (40) higher than the top surface of the functional layer by means of etching or chemical mechanical polishing to form a diffraction grating (41) of the grating assembly; Step S5: Rotate and coat a second optical glue material on the side surface of the diffraction grating (41), the functional layer, and the optical glue auxiliary structure (20) away from the substrate (10), and then perform imprinting on the second optical glue material using a blank master plate to form an optical glue layer (50) of the grating assembly. The functional layer is used to adjust the aspect ratio of the diffraction grating (41) filled into the gap by adjusting the thickness.

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