Diffractive optical structure, manufacturing method thereof, light guide device and near-eye optical system
By forming a multi-layer diffraction pattern layer on the substrate, the existing grating has low efficiency and limited regulatory freedom in diffraction optical waveguides, and more efficient optical performance and better diffraction efficiency regulation are achieved.
Patent Information
- Application Number
- CN202311331584.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-10-13
- Publication Date
- 2025-04-15
AI Technical Summary
The existing gratings have problems in diffraction optical waveguides with low efficiency, high efficiency and limited regulatory freedom in specific diffraction orders, which affects the application effect of augmented reality technology.
Using the method of making a multi-layer diffraction optical structure, by forming a multi-layer diffraction pattern layer on the substrate, the materials and structures of different levels are used to improve optical performance and regulate diffraction efficiency.
The optical performance of the diffraction optical structure is improved, the efficiency control ability of diffraction of different orders is enhanced, and the performance of coupling in, turning and coupling out elements is improved.
Smart Images
Figure CN119828273A_ABST
Abstract
Description
Technical Field
[0001] The embodiments of the present application relate to the technical field of diffractive optical components, and more specifically, relate to a diffractive optical structure and a manufacturing method thereof, a light guiding device and a near-eye optical system. Background Art
[0002] Augmented Reality (AR) technology is an optical display composed of a micro display and optical elements. Without affecting the user's observation of the external environment, the image generated by the micro display is projected into the user's eyes, realizing the superposition and fusion of the real world and virtual images. It has great application prospects in education, entertainment, industry and other fields.
[0003] Diffraction optical waveguide is one of the mainstream technical solutions for realizing augmented reality. It uses the diffraction effect of micro-nano structures to couple in and out light, and combines the total reflection effect of transparent substrates to conduct light. In some existing solutions, one-dimensional or two-dimensional gratings are used as coupling, turning and outcoupling elements in optical waveguide elements. However, the existing gratings themselves as coupling, turning and outcoupling elements have a series of problems such as the efficiency of certain diffraction orders is lower than expected, the efficiency of certain diffraction orders is higher than expected, and the freedom of regulating and allocating diffraction efficiencies between different orders is limited. Summary of the invention
[0004] The purpose of this application is to provide a new technical solution for a diffractive optical structure and a manufacturing method thereof, a light-guiding device and a near-eye optical system.
[0005] In a first aspect, an embodiment of the present application provides a method for manufacturing a diffractive optical structure, and the method for manufacturing a diffractive optical structure includes:
[0006] Step S1, providing a substrate;
[0007] Step S2, forming a single-layer diffraction pattern layer on the substrate;
[0008] Step S3, making the side of the formed diffraction pattern layer away from the substrate obtain a flat surface;
[0009] Step S4, forming a next diffraction pattern layer on the diffraction pattern layer;
[0010] Repeat step S3 and step S4 to form N diffraction pattern layers on the substrate, where N≥2.
[0011] Optionally, step S2 includes:
[0012] forming an isolation layer on the substrate, wherein the isolation layer is a transparent insulating material; and
[0013] The single-layer diffraction pattern layer is formed on the isolation layer.
[0014] Optionally, the step S2 further includes:
[0015] A protective layer covering the surface of the diffraction pattern layer is formed on the substrate.
[0016] Optionally, step S3 includes:
[0017] forming a filling layer on the diffraction pattern layer, wherein the filling layer is used to fill the gaps in the diffraction pattern layer and / or to form a supporting surface with a set thickness on a side of the diffraction pattern layer away from the substrate; and
[0018] A portion of the filling layer is removed so that the filling layer has a flat surface.
[0019] Optionally, the step S4 includes: forming a next diffraction pattern layer on the filling layer.
[0020] Optionally, the manufacturing method further comprises: forming an isolation layer between two adjacent diffraction pattern layers.
[0021] Optionally, the filling layer is organic glue or a transparent dielectric material.
[0022] Optionally, the method for forming the diffraction pattern layer includes at least one of electron beam lithography, interference lithography, multiphoton lithography, scanning probe lithography, nanoimprinting, diffusion doping, ion implantation, reactive ion etching, inductively coupled plasma etching, ion beam etching, reactive ion beam etching and wet etching.
[0023] Optionally, the method for forming the isolation layer includes at least one of spin coating, inkjet printing, screen printing, sol-gel method, thermal evaporation deposition, electron beam evaporation deposition, magnetron sputtering, chemical vapor deposition and atomic layer deposition.
[0024] Optionally, the method for forming the filling layer includes at least one of spin coating, inkjet printing, screen printing, sol-gel method, thermal evaporation deposition, electron beam evaporation deposition, magnetron sputtering, chemical vapor deposition and atomic layer deposition.
[0025] Optionally, the N diffraction pattern layers include a one-dimensional periodic structure, a two-dimensional periodic structure, a superlens or a supersurface.
[0026] In a second aspect, an embodiment of the present application provides a diffractive optical structure, which is prepared by the manufacturing method described in the first aspect.
[0027] In a third aspect, an embodiment of the present application provides a diffractive optical structure, which includes a substrate and N diffraction pattern layers arranged on the substrate, wherein N≥2.
[0028] In a fourth aspect, an embodiment of the present application provides a light guide device. The light guide device includes:
[0029] A substrate, and an in-coupling element and an out-coupling element disposed on the substrate;
[0030] The coupling-in element and / or the coupling-out element adopts the diffractive optical structure as described in the second aspect or the third aspect.
[0031] In a fifth aspect, an embodiment of the present application provides a near-eye optical system. The near-eye optical system comprises: the light guide device as described in the fourth aspect.
[0032] The beneficial effects of this application are:
[0033] According to an embodiment of the present application, a new manufacturing method for obtaining a multi-layer diffraction optical structure is provided, which can form two, three or more stacked diffraction pattern layers, and each diffraction pattern layer can be a one-dimensional periodic structure, a two-dimensional periodic structure or a non-periodic structure, and the materials, structures, periods, etc. between each diffraction pattern layer can be the same or different, which is beneficial to improving the optical performance of the formed diffraction optical structure and can realize the free control of the diffraction optical structure.
[0034] Other features and advantages of the present specification will become apparent from the following detailed description of exemplary embodiments of the present specification with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS
[0035] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the specification and, together with the description, serve to explain the principles of the specification.
[0036] Figure 1 A flow chart of a method for manufacturing a diffractive optical structure provided in an embodiment of the present application;
[0037] Figure 2 A schematic diagram of a partial structure of a diffractive optical structure provided in an embodiment of the present application (single-layer diffraction pattern layer);
[0038] Figure 3 One of the schematic diagrams of forming a filling layer on the diffraction pattern layer provided in an embodiment of the present application;
[0039] Figure 4 The second schematic diagram of forming a filling layer on the diffraction pattern layer provided in an embodiment of the present application;
[0040] Figure 5a , Figure 5band Figure 5c They are schematic diagrams of removing part of the filling layer in the embodiments of the present application;
[0041] Figure 6 A method flow for manufacturing a diffractive optical structure provided for a specific example of the present application (single-layer diffraction pattern layer);
[0042] Figure 7 A schematic diagram of a diffractive optical structure provided for a specific example of the present application;
[0043] Figure 8 A schematic structural diagram of a light guide device provided in an embodiment of the present application. DETAILED DESCRIPTION
[0044] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that unless otherwise specifically stated, the relative arrangement of components and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present application.
[0045] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the present application, its application, or uses.
[0046] Techniques and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the techniques and equipment should be considered part of the specification.
[0047] In all examples shown and discussed herein, any specific values should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.
[0048] It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.
[0049] The following is a detailed description of the diffractive optical structure and its manufacturing method, the light guide device and the near-eye optical system provided in the embodiments of the present application in conjunction with the accompanying drawings.
[0050] According to one aspect of an embodiment of the present application, a method for manufacturing a diffractive optical structure is provided, which can be used to obtain a multi-layer diffractive optical structure, which is different from a conventional single-layer diffractive optical structure.
[0051] The diffraction optical structure provided in the embodiment of the present application is a multi-layer diffraction structure, which can be applied to the light-guiding device in the AR optical system.
[0052] The method for manufacturing the diffractive optical structure provided in the embodiment of the present application is shown in Figure 1, the production method comprises the following steps:
[0053] Step S1, providing a substrate 100;
[0054] Step S2, forming a single-layer diffraction pattern layer 200 on the substrate 100;
[0055] Step S3, making the side of the formed diffraction pattern layer 200 away from the substrate obtain a flat surface;
[0056] Step S4, forming a next diffraction pattern layer 200 on the diffraction pattern layer 200;
[0057] Repeat step S3 and step S4 to form N diffraction pattern layers 200 on the substrate 100, where N≥2. Figure 7 .
[0058] According to the above embodiment, the thickness of the substrate 100 can be reasonably selected as needed, and multiple diffraction pattern layers 200 can be stacked on the substrate 100 .
[0059] The substrate 100 may be a dielectric layer or a polymer layer.
[0060] Specifically, the material of the substrate 100 can be silicon oxide, silicon nitride, silicon carbide, titanium oxide, aluminum oxide, lithium niobate, photoresist, electron beam resist or other materials.
[0061] For the above step S2, for example, a part of the material on the substrate 100 may be removed and a part of the material may be retained to form a one-dimensional periodic, two-dimensional periodic or non-periodic diffraction pattern layer 200 on one surface thereof. The diffraction pattern layer 200 may also be a superlens or a supersurface.
[0062] It should be noted that, in any diffraction pattern layer 200 , a patterned refractive index distribution layer is formed by changing the material composition at some positions or the refractive index at some positions.
[0063] The embodiment of the present application provides a multi-layer diffraction optical structure, which is mainly composed of a plurality of diffraction pattern layers 200 stacked together. In order to enable each of the diffraction pattern layers 200 to be better stacked, it is necessary to form a flat surface on the top surface of each diffraction pattern layer 200 (i.e., the surface away from the substrate 100).
[0064] According to an embodiment of the present application, a new manufacturing method for obtaining a multi-layer diffraction optical structure is provided, which can form two, three or more stacked diffraction pattern layers 200, and each diffraction pattern layer 200 can be a one-dimensional periodic structure, a two-dimensional periodic structure or a non-periodic structure, and the materials, structures, periods, etc. between each diffraction pattern layer can be the same or different, which is beneficial to improving the optical performance of the formed diffraction optical structure and can realize the free regulation of the diffraction optical structure.
[0065] According to the manufacturing method provided in the embodiment of the present application, a multi-layer diffractive optical structure can be obtained, which can be used, for example, as a coupling element, a coupling element or a turning element on an optical waveguide element. The multi-layer diffractive optical structure can improve the efficiency of the optical waveguide element, improve the color uniformity of the imaging, and at the same time improve the light leakage phenomenon and rainbow pattern phenomenon in the coupling area.
[0066] For some examples based on this application, please see Figure 1 , step S2 in the production method comprises the following steps:
[0067] Step S201: forming an isolation layer 300 on the substrate 100, wherein the isolation layer 300 is a transparent insulating material; and
[0068] Step S202 , forming the single-layer diffraction pattern layer 200 on the isolation layer 300 .
[0069] According to the above example, before forming a layer of the diffraction pattern layer 200 on the substrate 100, an isolation layer 300 can be formed on the substrate 100 in advance. The isolation layer 300 is attached to the surface of the substrate 100, and can play a certain protective role on the substrate 100, and can separate the subsequently formed diffraction pattern layer 200 from the substrate 100.
[0070] In the manufacturing method provided in the embodiment of the present application, an isolation layer 300 may be pre-formed on the substrate 100 , and the isolation layer 300 may only be used under special conditions.
[0071] For example, when the substrate 100 contains an imprinted glue or other organic materials, and the diffraction pattern layer 200 needs to be formed by wet etching or the formed diffraction pattern layer 200 needs to be chemically mechanically polished, in order to protect the materials in the substrate 100 from the influence of chemical reagents / acids / alkalis, the isolation layer 300 can be added to play a blocking role to protect the substrate 100 below.
[0072] For the isolation layer 300 mentioned in the above example, see Figure 7, a layer of isolation layer 300 separated from the diffraction pattern layer 200 may be formed on the substrate 100. An isolation layer 300 may also be introduced between two adjacent diffraction pattern layers 200.
[0073] The material of the isolation layer 300 may be a transparent insulating material, a dielectric material, etc.
[0074] It should be noted that the isolation layer 300 on the substrate 100 may be omitted in some examples.
[0075] According to some examples of this application, see Figure 2 The step S2 further includes: forming a protective layer 400 on the substrate 100 to cover the surface of the diffraction pattern layer 200 .
[0076] The protective layer 400 and the isolation layer 300 may be made of the same material.
[0077] The protection layer 400 can be used to protect the diffraction pattern layer 200 and can also protect the bottom substrate 100 .
[0078] The protective layer 400 on the diffraction pattern layer 200 may be omitted in some examples.
[0079] In addition, the isolation layer 300 and the protection layer 400 can be used simultaneously or one of them can be used selectively, and the selection can be made according to the specific situation, which is not limited in this application. Both of them can protect the structure below to prevent the newly formed material layer above from affecting the structure below.
[0080] According to some examples of the present application, step S3 includes the following steps:
[0081] Step S301: forming a filling layer 500 on the diffraction pattern layer 200, wherein the filling layer 500 is used to fill the gaps in the diffraction pattern layer 200 and / or to form a support surface of a set thickness on a side of the diffraction pattern layer 200 away from the substrate 100, see Figure 3 and Figure 4 ;and
[0082] Step S302: remove part of the filling layer to make the filling layer have a flat surface, see Figure 5a , Figure 5b and Figure 5c .
[0083] According to the manufacturing method of the diffractive optical structure provided in the embodiment of the present application, a filling layer 500 can be formed on the diffraction pattern layer 200, the protective layer 400 or the isolation layer 300. It should be noted that the diffraction pattern layer 200 is definitely present, and the protective layer 400 and the isolation layer 300 are provided as required.
[0084] The filling layer 500 can fill the gaps in the diffraction pattern layer 200 or form an additional layer with uniform thickness, mainly to prepare for the formation of the next diffraction pattern layer 200 .
[0085] It should be noted that the filling layer 500 may be omitted in some examples.
[0086] For example, see Figure 6 , Figure 6 The first figure in FIG. 1 shows a grating pattern 600 in an imprinted plastic obtained on a substrate 100. The advantage of this design is that there is no need to perform subsequent filling layer 500 and filling layer 500 removal steps, and a diffraction pattern layer 200 with a flat top can be directly obtained. Figure 6 The second figure in FIG. 1 shows that the diffraction pattern layer 200 can be directly introduced on the top of the substrate 100 (the top is flat), for example, the diffraction pattern layer 200 can be embedded in the substrate 100 by ion implantation or diffusion doping. Figure 6 As shown in the third figure, after forming a layer of the diffraction pattern layer 200, the grating pattern 600 in the embossed glue is removed, and the top surface of the diffraction pattern layer 200 is flat, so that when the next diffraction pattern layer is subsequently formed, there is no need to introduce a filling layer 500.
[0087] See also Figure 3 The top surface of the filling layer 500 formed on the diffraction pattern layer 200 is not flat. In this case, a portion of the filling layer 500 can be removed. Alternatively, when the filling layer 500 is formed, its top surface is controlled to be flat. Figure 4 ,exist Figure 4 In this case, it is possible to ensure that the next diffraction pattern layer 200 is formed smoothly.
[0088] Remove part of the filling layer 500 to make the top surface of the filling layer 500 flat. Figure 5a , the filling layer 500 may be higher than the diffraction pattern layer 200 .
[0089] See also Figure 5b , the filling layer 500 may also be at the same height as the diffraction pattern layer 200 .
[0090] In addition, in some examples, a portion of the filling layer 500 and the diffraction pattern layer 200 may be removed simultaneously, see Figure 5c .
[0091] In the above step S302, for example, the filling layer 500 may be partially removed by chemical mechanical polishing, ion milling, reactive ion etching, inductively coupled plasma etching, ion beam etching, reactive ion beam etching, wet etching or a combination of the above methods to make the top surface flat. Of course, this step may be omitted in some examples.
[0092] Among them, some materials can be removed by chemical mechanical polishing (CMP) to obtain an optically smooth surface (eg, roughness <1 nm).
[0093] Among them, wet etching, such as etching with acid or alkali solution, may have lower cost and faster rate, but may require more complex control to obtain a smoother surface.
[0094] Each of the ion etching methods may have less impact on the substrate 100 and other structures, and can also obtain a relatively flat surface. In addition, each of the above ion beam methods may also perform additional local trimming and removal, such as targeted removal of some uneven locations.
[0095] According to some examples of the present application, the step S4 includes: forming a next diffraction pattern layer 200 on the filling layer 500 .
[0096] According to the preparation method provided in the embodiments of the present application, the following two situations are included:
[0097] One case is to directly form the next diffraction pattern layer 200 on the already formed diffraction pattern layer 200. This case requires that the top surface of the already formed diffraction pattern layer 200 is flat.
[0098] Another case is that a filling layer 500 is pre-formed on the top surface of the diffraction pattern layer 200 , and then a portion of the filling layer 500 is removed to form a flat support surface, and then a next diffraction pattern layer 500 is formed on the filling layer 500 .
[0099] According to some examples of the present application, the manufacturing method further includes: forming an isolation layer 300 between two adjacent diffraction pattern layers 200, see Figure 7 .
[0100] According to the above example, it is possible to effectively prevent the newly formed diffraction pattern layer 200 and other structures above from having adverse effects on the underlying structures, thereby improving the yield of the product.
[0101] According to some examples of the present application, the filling layer 500 is an organic glue or a transparent dielectric material.
[0102] When the filling layer 500 is made of organic glue, such as photoresist or embossing glue, it has a relatively low refractive index (refractive index is 1.4-2.0) and is in a liquid state in the initial state.
[0103] When the filling layer 500 is made of dielectric material, it includes silicon oxide, silicon nitride, titanium oxide, aluminum oxide, etc. The refractive index range of the material can be larger, for example, 1.4 to 2.4 or higher.
[0104] According to some examples of the present application, the method for forming the diffraction pattern layer 200 includes at least one of electron beam lithography, interference lithography, multiphoton lithography, scanning probe lithography, nanoimprinting, diffusion doping, ion implantation, reactive ion etching, inductively coupled plasma etching, ion beam etching, reactive ion beam etching and wet etching.
[0105] The manufacturing method provided in the embodiment of the present application does not limit the method for forming the diffraction pattern layer 200 , thereby improving the flexibility and freedom of product production.
[0106] According to some examples of the present application, the method for forming the isolation layer 300 includes at least one of spin coating, inkjet printing, screen printing, sol-gel method, thermal evaporation deposition, electron beam evaporation deposition, magnetron sputtering, chemical vapor deposition and atomic layer deposition.
[0107] It should be noted that the forming method and material of the protective layer 400 may be the same as those of the isolation layer 300 , and the forming method and material of the protective layer 400 are not exemplified one by one.
[0108] According to some examples of the present application, the method for forming the filling layer 500 includes at least one of spin coating, inkjet printing, screen printing, sol-gel method, thermal evaporation deposition, electron beam evaporation deposition, magnetron sputtering, chemical vapor deposition and atomic layer deposition.
[0109] For example, the formed diffraction pattern layer 200 can be filled by spin coating, inkjet printing, screen printing, or sol-gel method. The above filling method is suitable for the filling material is an organic material, similar to an imprint glue or a photoresist, and the material refractive index is relatively low, 1.4 to 2.0, and is adapted to the needs of filling a low refractive index grating with a similar refractive index, or a high refractive index grating with a large refractive index. The process cost is low, and the initial top surface may have a small fluctuation and be close to a flat shape. A flat top surface can be obtained by simple steps, such as using a flat imprint soft film for imprinting and curing, and directly obtaining a flat single-layer filling structure with easy-to-control thickness.
[0110] For another example, a thicker dielectric film can be formed by thermal evaporation deposition, electron beam evaporation deposition, magnetron sputtering, chemical vapor deposition, and atomic layer deposition, which can fill and overflow the grating gap to form a filling layer 500. The filling material here can be a low-refractive dielectric material such as silicon oxide 1.4, or a high-refractive material such as titanium oxide 2.4. The dielectric material has good reliability and may not require additional protection in other subsequent processes. In addition, it will be relatively stable and unaffected in reliability tests such as temperature, humidity, or ultraviolet light. This method requires a subsequent removal step to obtain a flat top surface.
[0111] According to some examples of the present application, N layers of diffraction pattern layers are formed on the substrate 100, and the N layers of diffraction pattern layers include a one-dimensional periodic structure, a two-dimensional periodic structure, a super lens or a super surface. For example, two layers of stacked diffraction pattern layers 200 are formed on the substrate 100 along the thickness direction, one of which can be designed as a one-dimensional periodic structure, and the other can be designed as a two-dimensional periodic structure. In other words, the two layers of diffraction pattern layers 200 can be different. Of course, the two layers of diffraction pattern layers 200 can also be the same.
[0112] It should be noted that, for the multiple diffraction pattern layers 200, each diffraction pattern layer 200 may be the same or different, and the present application does not limit this. Each diffraction pattern layer 200 may be stacked in sequence according to a preset order.
[0113] In addition, for each diffraction pattern layer 200, it can include one or more combinations of a one-dimensional periodic structure, a two-dimensional periodic structure, a superlens and a supersurface, and can be specifically designed according to needs, which is not limited in the embodiments of the present application.
[0114] In a specific example of the present application, the diffractive optical structure includes a substrate 100 and three diffractive pattern layers 200, and the structure formed by the substrate 100 can be seen in FIG. Figure 7 ; Its production method comprises the following steps:
[0115] Step 1, providing a substrate 100;
[0116] Step 2: forming an isolation layer 300 on the substrate 100, forming a first diffraction pattern layer 200 on the isolation layer 300, and forming a protective layer 400 on the diffraction pattern layer 200;
[0117] Step 3, forming a filling layer 500 on the protective layer 400 formed in step 2, using the filling layer 500 to fill the gaps in the first diffraction pattern layer 200 and to form a support surface of a set thickness on a side of the diffraction pattern layer 200 away from the substrate 100; then removing part of the filling layer 500 to obtain a flat surface of the filling layer 500;
[0118] Step 4, forming an isolation layer 300 on the filling layer 500 formed in step 3, and then repeating step 3, wherein a second diffraction pattern layer 200 is formed, and a protective layer 400 and a filling layer 500 are sequentially formed on the diffraction pattern layer 200;
[0119] Step 5: After step 4, an isolation layer 300 is formed on the formed filling layer 500, and then step 3 is repeated again, wherein a third diffraction pattern layer 200 is formed, and a protective layer 400 and a filling layer 500 are sequentially formed on the diffraction pattern layer 200;
[0120] Finally, we got Figure 7 The diffractive optical structure is shown.
[0121] See also Figure 7 The formed diffraction optical structure includes a substrate 100 and three diffraction pattern layers 200 arranged on the substrate 100; wherein an isolation layer 300 is arranged between the substrate 100 and the first diffraction pattern layer 200, and an isolation layer 300 is arranged between the first diffraction pattern layer 200 and the second diffraction pattern layer 200, and between the second diffraction pattern layer 200 and the third diffraction pattern layer 200, and a protective layer 400 and a filling layer 500 are sequentially formed on each diffraction pattern layer 200. The isolation layer 300 and the protective layer 400 are both used to protect the underlying structure layer that has been formed, and the filling layer 500 is used to provide a support plane for a newly formed diffraction pattern layer 200.
[0122] According to an embodiment of the present application, a diffractive optical structure is provided, and the diffractive optical structure is manufactured using the manufacturing method described above.
[0123] According to one embodiment of the present application, a diffractive optical structure is provided. Figure 7 The diffractive optical structure includes a substrate 100 and N diffraction pattern layers arranged on the substrate 100, wherein N≥2.
[0124] In one example, see Figure 7 The diffractive optical structure includes a substrate 100 and three diffraction pattern layers arranged on the substrate 100.
[0125] According to another embodiment of the present application, a light guide device is provided. Figure 8 The light-guiding device comprises a substrate 1 and a coupling-in element 2 and a coupling-out element 3 arranged on the substrate 1; wherein the coupling-in element 2 and / or the coupling-out element 3 adopt the diffractive optical structure as described above.
[0126] The light guiding device is, for example, an optical waveguide element.
[0127] Optionally, a turning element is further provided on the substrate 1, the turning element is located between the coupling-in element and the coupling-out element, the turning element is used to receive light from the coupling-in element, and the coupling-out element is used to receive light from the turning grating. The turning element may also adopt the diffraction optical structure as described above.
[0128] According to another embodiment of the present application, a near-eye optical system is provided, wherein the near-eye optical system comprises the light guide device as described above.
[0129] The near-eye optical system can be used in an AR optical device, for example.
[0130] According to one embodiment of the present application, a head-mounted display device is also provided.
[0131] The head mounted display device comprises a housing and the near-eye optical system as described above.
[0132] The head mounted display device includes AR smart glasses or AR smart helmets, etc., which is not limited in the embodiments of the present application.
[0133] The specific implementation methods of the light-guiding device, near-eye optical system and head-mounted display device of the embodiments of the present application can refer to the various embodiments of the method for manufacturing the diffractive optical structure mentioned above, and therefore have at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be repeated here one by one.
[0134] The above embodiments focus on the differences between the various embodiments. As long as the different optimization features between the various embodiments are not contradictory, they can be combined to form a better embodiment. Considering the simplicity of the text, they will not be repeated here.
[0135] Although some specific embodiments of the present application have been described in detail by way of example, it should be understood by those skilled in the art that the above examples are only for illustration, not for limiting the scope of the present application. It should be understood by those skilled in the art that the above embodiments may be modified without departing from the scope and spirit of the present application. The scope of the present application is defined by the appended claims.
Claims
1. A method for manufacturing a diffractive optical structure, characterized in that: include: Step S1, providing a substrate; Step S2, forming a single-layer diffraction pattern layer on the substrate; Step S3, making the side of the formed diffraction pattern layer away from the substrate obtain a flat surface; Step S4, forming a next diffraction pattern layer on the diffraction pattern layer; Repeat step S3 and step S4 to form N diffraction pattern layers on the substrate, where N≥2.
2. The method for manufacturing a diffractive optical structure according to claim 1, characterized in that: The step S2 comprises: forming an isolation layer on the substrate, wherein the isolation layer is a transparent insulating material; and The single-layer diffraction pattern layer is formed on the isolation layer.
3. The method for manufacturing a diffractive optical structure according to claim 1 or 2, characterized in that: The step S2 further comprises: A protective layer covering the surface of the diffraction pattern layer is formed on the substrate.
4. The method for manufacturing a diffractive optical structure according to claim 3, characterized in that: The step S3 comprises: forming a filling layer on the diffraction pattern layer, wherein the filling layer is used to fill the gaps in the diffraction pattern layer and / or to form a supporting surface with a set thickness on a side of the diffraction pattern layer away from the substrate; and A portion of the filling layer is removed so that the filling layer has a flat surface.
5. The method for manufacturing a diffractive optical structure according to claim 4, characterized in that: The step S4 includes: forming a next diffraction pattern layer on the filling layer.
6. The method for manufacturing a diffractive optical structure according to claim 1, characterized in that: The manufacturing method further includes: forming an isolation layer between two adjacent diffraction pattern layers.
7. The method for manufacturing a diffractive optical structure according to claim 4, characterized in that: The filling layer is organic glue or a transparent dielectric material.
8. The method for manufacturing a diffractive optical structure according to claim 1, characterized in that: The method for forming the diffraction pattern layer includes at least one of electron beam lithography, interference lithography, multiphoton lithography, scanning probe lithography, nanoimprinting, diffusion doping, ion implantation, reactive ion etching, inductively coupled plasma etching, ion beam etching, reactive ion beam etching and wet etching.
9. The method for manufacturing a diffractive optical structure according to claim 2 or 6, characterized in that: The method for forming the isolation layer includes at least one of spin coating, inkjet printing, screen printing, sol-gel method, thermal evaporation deposition, electron beam evaporation deposition, magnetron sputtering, chemical vapor deposition and atomic layer deposition.
10. The method for manufacturing a diffractive optical structure according to claim 4, characterized in that: The method for forming the filling layer includes at least one of spin coating, inkjet printing, screen printing, sol-gel method, thermal evaporation deposition, electron beam evaporation deposition, magnetron sputtering, chemical vapor deposition and atomic layer deposition.
11. The method for manufacturing a diffractive optical structure according to claim 1, characterized in that: The N diffraction pattern layers include a one-dimensional periodic structure, a two-dimensional periodic structure, a super lens or a super surface.
12. A diffractive optical structure, characterized in that: The method is prepared according to any one of claims 1 to 11.
13. A diffractive optical structure, characterized in that: It comprises a substrate and N diffraction pattern layers arranged on the substrate, wherein N≥2.
14. A light guide device, characterized in that: include: A substrate, and an in-coupling element and an out-coupling element disposed on the substrate; The coupling-in element and / or the coupling-out element adopts the diffractive optical structure as claimed in claim 12 or 13.
15. A near-eye optical system, characterized in that: include: A light guiding device as claimed in claim 14.
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