Optical waveguide device and display device

Abstract

The invention relates to an optical waveguide device and display equipment, and the device comprises a waveguide substrate which is provided with a first surface and a second surface which are arranged oppositely, the first surface is provided with a light incident region, and the second surface is provided with a light emergent region; wherein the waveguide substrate comprises an embossment grating which is located on the first surface and at least located in the light incident area; the waveguide substrate comprises a first refractive index gradient layer and a second refractive index gradient layer, and the second refractive index gradient layer is located on the side, away from the first surface, of the first refractive index gradient layer; in the direction parallel or perpendicular to the plane where the waveguide substrate is located, the refractive index of the first refractive index gradient layer in at least one direction gradually changes, and the refractive index of the second refractive index gradient layer in at least one direction gradually changes. The first refractive index gradient layer and the second refractive index gradient layer are different in at least one of a refractive index change value and a refractive index change direction. According to the invention, multi-view-angle light emitting can be realized.

Description

Technical Field

[0001] The present application relates to the field of optical waveguide technology, and in particular to an optical waveguide device and a display apparatus. Background Art

[0002] With the development of augmented reality technology, AR headsets, AR glasses, and in-vehicle AR HUDs are gaining recognition as next-generation computing and display platforms, leading to a growing number of manufacturers investing significant resources in their research and development. The key optical components of AR display devices are the optical engine that generates the image and the light transmission module that transmits the image to the eye. The light transmission module is the most critical component, directly impacting the size, image quality, and viewing comfort of the AR display device. Currently, optical waveguide devices are the industry's leading AR light transmission module.

[0003] However, in the prior art, there is a problem that optical waveguides are difficult to achieve multi-angle light emission. Summary of the Invention

[0004] Based on this, it is necessary to provide a new optical waveguide device and display device to address the problem in the prior art that optical waveguides are difficult to achieve multi-angle light emission.

[0005] According to a first aspect of the present application, there is provided an optical waveguide device, comprising:

[0006] The waveguide substrate has a first surface and a second surface disposed opposite to each other, wherein the first surface has a light entrance area and the second surface has a light exit area;

[0007] The waveguide substrate includes a relief grating located on the first surface and at least located in the light incident area;

[0008] The waveguide substrate comprises a first refractive index gradient layer and a second refractive index gradient layer, wherein the second refractive index gradient layer is located on a side of the first refractive index gradient layer away from the first surface;

[0009] In a direction parallel or perpendicular to the plane of the waveguide substrate, the refractive index of the first refractive index gradient layer gradually changes in at least one direction, and the refractive index of the second refractive index gradient layer gradually changes in at least one direction. The first refractive index gradient layer and the second refractive index gradient layer differ in at least one of the value of the refractive index change and the direction of the refractive index change.

[0010] In some embodiments, the light entrance area is located at one end of the first surface, and in a direction parallel to the plane where the waveguide substrate is located, the direction from the light entrance area to the end away from the light entrance area is a first direction, and the direction perpendicular to the first direction is a second direction;

[0011] The refractive index of the first graded refractive index layer and the second graded refractive index layer both gradually changes in the first direction or the second direction.

[0012] In some embodiments, the refractive index of one of the first graded refractive index layer and the second graded refractive index layer gradually increases in the first direction, and the refractive index of the other of the first graded refractive index layer and the second graded refractive index layer gradually decreases in the first direction.

[0013] In some embodiments, the refractive index of the first graded refractive index layer gradually increases in the first direction, and the refractive index of the second graded refractive index layer gradually decreases in the first direction.

[0014] In some embodiments, the refractive index of the first graded refractive index layer in the first direction gradually increases from 1.69 to 1.83, and the refractive index of the second graded refractive index layer in the first direction decreases from 1.9 to 1.83.

[0015] In some embodiments, the relief grating includes a plurality of grating protrusions arranged at intervals, and a grating recess located between two adjacent grating protrusions;

[0016] The light entrance area is located at one end of the first surface, and on a plane parallel to the waveguide substrate, a direction from the light entrance area to an end away from the light entrance area is a first direction;

[0017] The plurality of grating protrusions are spaced apart in the first direction, and the widths of the grating concavities gradually increase or decrease in the first direction.

[0018] In some embodiments, the relief grating includes a plurality of grating protrusions arranged at intervals, and a grating recess located between two adjacent grating protrusions;

[0019] The light entrance area is located at one end of the first surface, and on a plane parallel to the waveguide substrate, a direction from the light entrance area to an end away from the light entrance area is a first direction, and a direction perpendicular to the first direction is a second direction;

[0020] The plurality of grating protrusions are spaced apart in the first direction, and the grating protrusion includes a plurality of spaced apart first sub-protrusions and a first sub-recess between two adjacent first sub-protrusions in the second direction. In the second direction, at least one of the length of the first sub-protrusion and the length of the first sub-recess gradually increases or decreases.

[0021] In some embodiments, the waveguide substrate further includes a light guiding layer, which is located on a side of the first refractive index gradient layer away from the second refractive index gradient layer, has a fixed refractive index at each location, and has the first surface.

[0022] In some embodiments, further comprising:

[0023] A light emitting control component is located on a side of the light emitting area away from the first surface, and the surface of the light emitting control component away from the waveguide substrate is a light emitting surface, and the light emitting surface includes a first sub-portion and a second sub-portion. The light emitting control component is used to control the emission direction of light emitted from the light emitting area on the light emitting surface, and the light emitting control component can control the light emitting direction of the first sub-portion to be different from the light emitting direction of the second sub-portion.

[0024] According to a second aspect of the present application, there is provided a display device, comprising:

[0025] a display module, the display module being configured to emit image light; and

[0026] The optical waveguide device described in any one of the above items is configured to receive the image light.

[0027] In an embodiment of the present application, the image light or incident light enters the waveguide substrate in the light entrance area, and after the propagation direction of the image light or incident light is changed by the first refractive index gradient layer and the second refractive index gradient layer, it can be emitted from different areas of the second surface (emitted from different parts of the light exit area). Since the refractive index of the first refractive index gradient layer gradually changes in at least one direction in a direction parallel to or perpendicular to the plane of the waveguide substrate, and the refractive index of the second refractive index gradient layer gradually changes in at least one direction, the first refractive index gradient layer and the second refractive index gradient layer are different in at least one of the value of the refractive index change and the direction of the refractive index change, the image light or incident light can have different exit directions in different areas of the second surface (different parts of the light exit area), for example, the focal length of the first exit light in some areas is 20 meters (the exit is non-parallel light), for example, the focal length of the first exit light in some areas is 50 meters (the exit is non-parallel light), for example, the focal length of the first exit light in some areas is infinity (the exit is parallel light). BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments or exemplary embodiments of the present application, the drawings required for use in the description of the embodiments or exemplary embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0029] Figure 1 A schematic top view of an optical waveguide device provided in an embodiment of the present application.

[0030] Figure 2 This is a schematic diagram of a first cross-sectional structure of an optical waveguide device provided in an embodiment of the present application.

[0031] Figure 3 This is a schematic diagram of a second cross-sectional structure of an optical waveguide device provided in an embodiment of the present application.

[0032] Figure 4 This is a schematic diagram of a third cross-sectional structure of an optical waveguide device provided in an embodiment of the present application.

[0033] Figure 5 This is a schematic diagram of a fourth cross-sectional structure of an optical waveguide device provided in an embodiment of the present application.

[0034] Figure 6 This is a first schematic top view of a relief grating in an optical waveguide device provided in an embodiment of the present application.

[0035] Figure 7 This is a second schematic top view of a relief grating in an optical waveguide device provided in an embodiment of the present application.

[0036] Figure 1: Waveguide device 100; waveguide substrate 10; first surface 101; second surface 102; light entrance area 1011; light exit area 1021; relief grating 13; first refractive index gradient layer 11; second refractive index gradient layer 12; first direction X; second direction Y; incident light g11; first exit light g12; grating protrusion 131; grating recess 132; first sub-protrusion 1311; first sub-recess 1312; light guiding layer 14; light exit control component 20; light exit surface 201; first sub-portion 2011; second sub-portion 2012; third sub-portion 2013; first sub-exit light g131; second sub-exit light g132; third sub-exit light g133. DETAILED DESCRIPTION

[0037] To make the above-mentioned objects, features, and advantages of the present application more clearly understood, the specific embodiments of the present application are described in detail below with reference to the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the scope of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0038] In the description of this application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0039] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include at least one of such features. In the description of this application, if the term "plurality" appears, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0040] In this application, unless otherwise specified or limited, the terms "mounted," "connected," "connected," "fixed," etc., should be interpreted broadly. For example, these terms may refer to fixed connections, removable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediary; and internal communication between two components or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of these terms in this application based on the specific circumstances.

[0041] In this application, unless otherwise expressly specified or limited, if a first feature is described as being "above" or "below" a second feature, or similar descriptions, this may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, when a first feature is described as being "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is described as being "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0042] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only embodiment.

[0043] In the prior art, there is a problem that optical waveguides are difficult to achieve multi-angle light emission.

[0044] Based on the above problems, the present application provides a new optical waveguide device and a display apparatus.

[0045] See also Figures 1 to 7 . Figure 1 A schematic top view of an optical waveguide device provided in an embodiment of the present application. Figure 2 This is a schematic diagram of a first cross-sectional structure of an optical waveguide device provided in an embodiment of the present application. Figure 3 This is a schematic diagram of a second cross-sectional structure of an optical waveguide device provided in an embodiment of the present application. Figure 4 This is a schematic diagram of a third cross-sectional structure of an optical waveguide device provided in an embodiment of the present application. Figure 5 This is a schematic diagram of a fourth cross-sectional structure of an optical waveguide device provided in an embodiment of the present application.

[0046] Figure 6 This is a first schematic top view of a relief grating in an optical waveguide device provided in an embodiment of the present application. Figure 7 This is a second schematic top view of a relief grating in an optical waveguide device provided in an embodiment of the present application.

[0047] It should be noted that Figures 2 to 5 for Figure 1 The cross-sectional structure at the first dotted line D1-D1 in FIG. Figure 2 and Figure 3 The structure is the same, but Figure 3 The direction of light propagation is also indicated.

[0048] First, as Figures 1 to 7As shown, the present application provides an optical waveguide device 100, which includes a waveguide substrate 10. The waveguide substrate 10 has a first surface 101 and a second surface 102 disposed opposite to each other. The first surface 101 has a light entrance area 1011, and the second surface 102 has a light exit area 1021. The waveguide substrate 10 includes a relief grating 13 located on the first surface 101, at least in the light entrance area 1011. The waveguide substrate 10 includes a first graded refractive index layer 11 and a second graded refractive index layer 12, with the second graded refractive index layer 12 located on a side of the first graded refractive index layer 11 away from the first surface 101. In a direction parallel or perpendicular to the plane of the waveguide substrate 10, the refractive index of the first graded refractive index layer 11 gradually changes in at least one direction, and the refractive index of the second graded refractive index layer 12 gradually changes in at least one direction. The first graded refractive index layer 11 and the second graded refractive index layer 12 differ in at least one of the value of the refractive index change and the direction of the refractive index change.

[0049] For example, the relief grating 13 may be realized by machining a micro-nanoscale grating structure on the first surface 101 of the waveguide substrate 10 , but the present invention is not limited thereto.

[0050] For example, the refractive index of the first refractive index gradient layer 11 in at least one direction gradually changes in a direction parallel to or perpendicular to the plane of the waveguide substrate 10, which means that: in the direction parallel to the plane of the waveguide substrate 10, the refractive index of the first refractive index gradient layer 11 in one direction gradually increases, or the refractive index of the first refractive index gradient layer 11 in one direction gradually decreases; or, in the direction perpendicular to the plane of the waveguide substrate 10, the refractive index of the first refractive index gradient layer 11 in one direction gradually increases, or the refractive index of the first refractive index gradient layer 11 in one direction gradually decreases.

[0051] For example, the refractive index of the second refractive index gradient layer 12 in at least one direction gradually changes in a direction parallel to or perpendicular to the plane of the waveguide substrate 10, which means that: in the direction parallel to the plane of the waveguide substrate 10, the refractive index of the second refractive index gradient layer 12 in one direction gradually increases, or the refractive index of the second refractive index gradient layer 12 in one direction gradually decreases; or, in the direction perpendicular to the plane of the waveguide substrate 10, the refractive index of the second refractive index gradient layer 12 in one direction gradually increases, or the refractive index of the second refractive index gradient layer 12 in one direction gradually decreases.

[0052] For example, the change direction of the refractive index of the first graded refractive index layer 11 and the second graded refractive index layer 12 is parallel to or perpendicular to the plane of the waveguide substrate 10, for example Figure 2 The direction of change from left to right.

[0053] For example, the first surface 101 has a light entrance area 1011 , and the second surface 102 has a light exit area 1021 . Part of the second surface 102 may be the light exit area 1021 , or the entire second surface 102 may be the light exit area 1021 .

[0054] In the embodiments of this application, Figure 3 As shown, the image light or incident light g11 enters the waveguide substrate 10 in the light entrance area 1011, and after the propagation direction of the image light or incident light g11 is changed by the first refractive index gradient layer 11 and the second refractive index gradient layer 12, it can be emitted from different areas of the second surface 102 (emitted from different parts of the light exit area 1021). Since the refractive index of the first refractive index gradient layer 11 gradually changes in at least one direction in the direction parallel to or perpendicular to the plane of the waveguide substrate 10, and the refractive index of the second refractive index gradient layer 12 gradually changes in at least one direction, the first refractive index gradient layer 11 gradually changes in at least one direction. The refractive index gradient layer 11 and the second refractive index gradient layer 12 are different in at least one of the value of the refractive index change and the direction of the refractive index change, so that the image light or the incident light g11 can have different exit directions in different areas of the second surface 102 (different parts of the light exit area 1021), for example, the focal length of the first exit light g12 in some areas is 20 meters (the exit is non-parallel light), for example, the focal length of the first exit light g12 in some areas is 50 meters (the exit is non-parallel light), for example, the focal length of the first exit light g12 in some areas is infinity (the exit is parallel light).

[0055] In some embodiments, the light entrance area 1011 is located at one end of the first surface 101. In a direction parallel to the plane of the waveguide substrate 10, the direction from the light entrance area 1011 to the end away from the light entrance area 1011 is the first direction X, and the direction perpendicular to the first direction X is the second direction Y. The refractive index of the first refractive index gradient layer 11 and the second refractive index gradient layer 12 both gradually changes in the first direction X or the second direction Y.

[0056] For example, Figure 1 As shown, the light entrance area 1011 is located at the left end of the first surface 101 , the direction from the left end to the right end is the first direction X, and the vertical direction is the second direction Y. The second direction Y is parallel to the plane where the waveguide substrate 10 is located.

[0057] For example, Figures 2 to 5 As shown, the light entrance area 1011 is located at the left end of the first surface 101 , and the direction from the left end to the right end is the first direction X, and the direction perpendicular to the desktop or paper is the second direction Y. The first direction X and the second direction Y are parallel to the plane of the waveguide substrate 10 .

[0058] In some embodiments, the refractive index of one of the first and second graded refractive index layers 11 and 12 in the first direction X gradually increases, and the refractive index of the other of the first and second graded refractive index layers 11 and 12 in the first direction X gradually decreases.

[0059] For example, in some embodiments, the refractive index of the first graded refractive index layer 11 in the first direction X gradually increases, and the refractive index of the second graded refractive index layer 12 in the first direction X gradually decreases.

[0060] For example, in some other embodiments, the refractive index of the first graded refractive index layer 11 in the first direction X gradually decreases, and the refractive index of the second graded refractive index layer 12 in the first direction X gradually increases.

[0061] For example, the refractive index of the first refractive index gradient layer 11 in the first direction X can be gradually increased or decreased, and the refractive index of the second refractive index gradient layer 12 in the first direction X can be gradually decreased or increased according to the application scenario of the optical waveguide device 100 and user needs.

[0062] For example, the refractive index of one of the first refractive index gradient layer 11 and the second refractive index gradient layer 12 in the first direction X gradually increases, and the refractive index of the other of the first refractive index gradient layer 11 and the second refractive index gradient layer 12 in the first direction X gradually decreases, so that the image light or incident light g11 can have different exit directions in different areas along the first direction X on the second surface 102, for example, the focal length of the first exit light g12 in some areas in the first direction X is 20 meters (the exit is non-parallel light), for example, the focal length of the first exit light g12 in some areas in the first direction X is 50 meters (the exit is non-parallel light), for example, the focal length of the first exit light g12 in some areas in the first direction X is infinity (the exit is parallel light).

[0063] In some embodiments, the refractive index of the first graded refractive index layer 11 in the first direction X gradually increases, and the refractive index of the second graded refractive index layer 12 in the first direction X gradually decreases.

[0064] In some embodiments, the refractive index of the first graded refractive index layer 11 in the first direction X gradually increases from 1.69 to 1.83, and the refractive index of the second graded refractive index layer 12 in the first direction X decreases from 1.9 to 1.83.

[0065] For example, after verified material selection, the refractive index of the first refractive index gradient layer 11 in the first direction X is set to gradually increase from 1.69 to 1.83, and the refractive index of the second refractive index gradient layer 12 in the first direction X is reduced from 1.9 to 1.83. This can well adjust the emission direction of the image light or incident light g11 in different areas of the second surface 102 along the first direction X, and can well meet the needs of the display device.

[0066] In some embodiments, as Figure 6 As shown, the relief grating 13 includes a plurality of spaced grating protrusions 131 and a grating recess 132 located between two adjacent grating protrusions 131; the light entrance area 1011 is located at one end of the first surface 101, and on a plane parallel to the above-mentioned waveguide substrate 10, the direction from the light entrance area 1011 to the end away from the light entrance area 1011 is a first direction X; the plurality of grating protrusions 131 are spaced apart in the first direction X, and the width of the grating recess 132 gradually increases or decreases in the first direction X.

[0067] For example, the grating protrusions 131 are ridges of the grating, and the grating depressions 132 are valleys of the grating.

[0068] For example, multiple grating protrusions 131 are arranged at intervals in the first direction X, and in the first direction X, the width of the grating recess 132 gradually increases or decreases, that is, the relief grating 13 adopts a gradient design in the first direction X, which can improve the coupling efficiency in the first direction X, and can cover different wavelength bands and incident angle conditions in the first direction X.

[0069] In some embodiments, as Figure 7 As shown, the relief grating 13 includes a plurality of spaced grating protrusions 131 and a grating recess 132 located between two adjacent grating protrusions 131. A light entrance area 1011 is located at one end of the first surface 101. On a plane parallel to the waveguide substrate 10, the direction from the light entrance area 1011 toward one end away from the light entrance area 1011 is a first direction X, and a direction perpendicular to the first direction X is a second direction Y. The plurality of grating protrusions 131 are spaced apart in the first direction X. Each grating protrusion 131 includes a plurality of spaced first sub-protrusions 1311 in the second direction Y, and a first sub-recess 1312 located between two adjacent first sub-protrusions 1311. In the second direction Y, at least one of the lengths of the first sub-protrusions 1311 and the lengths of the first sub-recesses 1312 gradually increases or decreases.

[0070] For example, in the second direction Y, at least one of the length of the first sub-protrusion 1311 and the length of the first sub-recess 1312 gradually increases or gradually decreases, that is, the relief grating 13 adopts a gradient design in the second direction Y, which can improve the coupling efficiency in the second direction Y, and can cover different wavelength bands and incident angle conditions in the second direction Y.

[0071] In some embodiments, as Figure 5 As shown, the waveguide substrate 10 further includes a light guiding layer 14 , which is located on a side of the first refractive index gradient layer 11 away from the second refractive index gradient layer 12 . The refractive index of the light guiding layer 14 at various locations is a fixed value, and the light guiding layer 14 has a first surface 101 .

[0072] For example, Figure 5 As shown, the light guiding layer 14 is located on the side of the first refractive index gradient layer 11 away from the second refractive index gradient layer 12. The refractive index of the light guiding layer 14 at each position is a fixed value. The light guiding layer 14 has a first surface 101. The light guiding layer 14 serves to transmit the incident light g11 as evenly as possible to various areas of the waveguide substrate 10, and then modulate the emission direction and angle of the first output light g12 through the first refractive index gradient layer 11 and the second refractive index gradient layer 12.

[0073] For example, Figure 5 As shown, the light guide layer 14, the first refractive index gradient layer 11 and the second refractive index gradient layer 12 are stacked in sequence.

[0074] In some embodiments, as Figure 4 and Figure 5 As shown, the optical waveguide device 100 also includes a light emitting control component 20, which is located on the side of the light emitting area 1021 away from the first surface 101. The surface of the light emitting control component 20 away from the waveguide substrate 10 is the light emitting surface 201. The light emitting surface 201 includes a first sub-portion 2011 and a second sub-portion 2012. The light emitting control component 20 is used to control the emission direction of light emitted from the light emitting area 1021 on the light emitting surface 201, and the light emitting control component 20 can control the light emitting direction of the first sub-portion 2011 to be different from the light emitting direction of the second sub-portion 2012.

[0075] For example, the light control component 20 is a dynamic light coupling control module. The light control component 20 can be an electrically controlled liquid crystal box, a thermo-induced deformation unit or a MEMS light control module, which is not limited here.

[0076] For example, Figure 4 and Figure 5 As shown, the light guide layer 14, the first refractive index gradient layer 11, the second refractive index gradient layer 12, and the light control component 20 are stacked in sequence. Figure 4 , Figure 5The direction of light propagation is also indicated.

[0077] For example, Figure 5 As shown, after the first emergent light g12 enters the light-emerging control component 20, it emerges from the light-emerging surface 201. Different parts of the light-emerging surface 201 can emit light with different propagation directions. For example, a first sub-emergent light g131 is emitted from the first sub-part 2011, a second sub-emergent light g132 is emitted from the second sub-part 2012, and a third sub-emergent light g133 is emitted from the third sub-part 2013. The emission directions of the light emitted from different parts of the light-emerging surface 201 can be controlled by the light-emerging control component 20. 0 modulation or control, the emission direction of light emitted from different parts of the light-emitting surface 201 can be modulated to be different by the light-emitting control component 20, for example, the focal length of the first sub-emitting light g131 emitted from the first sub-part 2011 is 20 meters (the emission is non-parallel light), for example, the focal length of the second sub-emitting light g132 emitted from the second sub-part 2012 is 50 meters (the emission is non-parallel light), for example, the focal length of the third sub-emitting light g133 emitted from the third sub-part 2013 is infinity (the emission is parallel light).

[0078] For example, in the above embodiment, a first refractive index gradient layer 11 and a second refractive index gradient layer 12 are provided in the optical waveguide device 100 to modulate the first emergent light g12, but the emergent angle of the first emergent light g12 may not necessarily perfectly meet the needs of the display device and the user, and the emergent angle of the emergent light cannot be dynamically adjusted according to the needs of the display device and the user.

[0079] For example, Figure 5 As shown, on the first hand, through the setting of the light-emitting control component 20, the light emitted from the light-emitting surface 201 is made to more perfectly match the display device and user needs (for example, the light beam output direction and angle can be adjusted according to the observation angle or the eye position), for example, the first sub-emitting light g131 emitted from the first sub-portion 2011 is more perfectly matched with the focal length of 20 meters, for example, the second sub-emitting light g132 emitted from the second sub-portion 2012 is more perfectly matched with the focal length of 50 meters, for example, the third sub-emitting light g133 emitted from the third sub-portion 2013 is more perfectly matched with the focal length of infinity. Secondly, through the setting of the light control component 20, dynamic adjustment of the emitted light is also achieved. The light control component 20 can control the light emission direction of the first sub-part 2011 to be different from the light emission direction of the second sub-part 2012. The light control component 20 can control the light emission direction of the first sub-part 2011 to be different at different times. For example, at a certain moment, the light control component 20 can control the first sub-emitting light g131 emitted from the first sub-part 2011 to have a focal length of 20 meters. For example, at another moment, the light control component 20 can control the first sub-emitting light g131 emitted from the first sub-part 2011 to have a focal length of 25 meters.

[0080] It should be noted that, in some embodiments, the diffraction efficiency, wavefront control capability and light coupling range of the light beam can be effectively improved by setting the relief grating 13, the first refractive index gradient layer 11 and the second refractive index gradient layer 12. The design of the first refractive index gradient layer 11 and the second refractive index gradient layer 12 can further optimize the efficiency of specific diffraction orders, improve the light beam control capability in the optical waveguide, and reduce the angle limitation caused by the fixed structure, thereby achieving multi-angle light coupling and high uniformity output. In addition, the setting of the first refractive index gradient layer 11 and the second refractive index gradient layer 12 can effectively form the dual functions of optical path deflection and focusing, thereby improving the light coupling efficiency and viewing angle uniformity.

[0081] It should be noted that in some embodiments, the plurality of grating protrusions 131 are spaced apart in the first direction X, and the width of the grating recesses 132 gradually increases or decreases in the first direction X; or in the second direction Y, at least one of the length of the first sub-protrusions 1311 and the length of the first sub-recesses 1312 gradually increases or decreases. The relief grating 13 employs a gradual change design, such that the equivalent refractive index of the relief grating 13 gradually changes, for example, the equivalent refractive index of the relief grating 13 gradually changes from 1.4 to 1.6.

[0082] It should be noted that, in some embodiments, the first refractive index gradient layer 11, the second refractive index gradient layer 12, and the light output control component 20 are stacked in sequence to form a mechanism for elastically adjusting the light output direction. The angle and mode of the output light can be dynamically adjusted according to an external control signal, corresponding to user eye tracking or scene changes, and the application flexibility is greatly improved.

[0083] It should be noted that, in some embodiments, the optical waveguide device 100 can couple multi-mode outputs, and the optical waveguide can be switched to support virtual and real overlap or high-resolution holographic projection, which can be applied to different head-mounted or vehicle-mounted scenarios.

[0084] It should be noted that in some embodiments, the output light angle can be adjusted to meet different viewing angles. The first and second refractive index gradient layers 11, 12 improve the beam guidance efficiency within the optical waveguide, effectively reducing losses. The introduction of the light output control component 20 (dynamic light coupling control module) enables the device to be used with an eye-tracking system, automatically aligning the device with the observer's visual axis, providing a highly accurate and immersive display experience. The multimodal output structure design supports both AR and holographic display modes, making it suitable for head-mounted displays, in-vehicle displays, and near-eye holographic projection, demonstrating broad application potential.

[0085] It should be noted that 1) this application achieves multi-viewing angles, with a dual-layer refractive index gradient control area (first refractive index gradient layer 11 and second refractive index gradient layer 12). By adjusting the propagation path and angle of light through changes in refractive index, light beams with different incident angles can be guided to different exit directions, achieving multi-viewing angle output. 2) This application implements an asymmetric light guide channel design. The refractive index gradient area (first refractive index gradient layer 11 and second refractive index gradient layer 12) adopts a laterally asymmetric design. Light beams at different positions or incident angles will be guided to different directions due to changes in refractive index, thereby supporting multi-viewing angle display. 3) The present application realizes variable-focus light output and sets a light output control component 20. By changing the refractive index or shape of the coupling structure, the angle and phase of the output light beam are dynamically adjusted to achieve focal length change (zoom) or light output angle adjustment; the combination with the refractive index gradient zone (the first refractive index gradient layer 11 and the second refractive index gradient layer 12) improves the focusing ability. The refractive index gradient zone has a lens effect, which can focus the light beam in the waveguide; when the dynamic module (light output control component 20) is adjusted, combined with the lens effect, the light output focus or viewing angle can be changed to achieve a variable-focus effect. 4) The synergistic effect of different structures enhances the application scenarios. The refractive index gradient zone (the first refractive index gradient layer 11 and the second refractive index gradient layer 12) provides static optical path control, and the dynamic light coupling module (light output control component 20) realizes real-time angle or focal length adjustment. The combination of the two can realize multi-view output and variable focus display, improving display flexibility and immersion; it is suitable for AR glasses, vehicle-mounted HUD, aerial holographic displays and other fields, and can be dynamically adjusted according to different viewing angles or focal length requirements to improve display effects and user experience.

[0086] It should be noted that the first and second graded refractive index layers 11, 12 can be fabricated using a photochemical method, using a photosensitive polymer or a light-variable material, such as a photochromic polymer, and controlling the light intensity through an exposure mask to form a transverse or longitudinal refractive index gradient. The first and second graded refractive index layers 11, 12 can also be fabricated using an ion exchange method, using a glass material (such as soda glass) immersed in a high-temperature salt solution for ion exchange. Controlling the diffusion time and temperature can form a stable longitudinal refractive index gradient. The first and second graded refractive index layers 11, 12 can also be fabricated using a multilayer coating method, using vacuum coating technology (such as an optical coating machine) to deposit layers of high and low refractive index materials (such as SiO2 and TiO2) to achieve precise refractive index gradient control.

[0087] It should be noted that the gradual change in the refractive index of the first and second graded refractive index layers 11, 12 in a direction parallel to the plane of the waveguide substrate 10 can be achieved through photochemical methods. The gradual change in the refractive index of the first and second graded refractive index layers 11, 12 in a direction perpendicular to the plane of the waveguide substrate 10 can be achieved through ion exchange or multilayer coating methods.

[0088] Secondly, based on the same inventive concept, the present application also provides a display device, including: a display module, the display module is used to emit image light; and any one of the above-mentioned light waveguide devices 100, the light waveguide device 100 is used to receive image light.

[0089] For example, the display device may be augmented reality (AR) glasses, a vehicle-mounted HUD display, or an aerial holographic display, but is not limited thereto.

[0090] For example, when the display device is augmented reality (AR) glasses, the projection angle can be adjusted in real time according to the user's line of sight to enhance the user experience and image stability.

[0091] For example, when the display device is a vehicle-mounted HUD display, the light output control component 20 can be used to adjust the output position to accommodate the different viewing angles required by the driver and passengers.

[0092] For example, when the display device is an aerial holographic display, it can be combined with multimodal output technology to support functions such as floating images, virtual and real overlap, and depth control.

[0093] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0094] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. An optical waveguide device, characterized in that include: The waveguide substrate has a first surface and a second surface disposed opposite to each other, wherein the first surface has a light entrance area and the second surface has a light exit area; The waveguide substrate includes a relief grating located on the first surface and at least located in the light incident area; The waveguide substrate comprises a first refractive index gradient layer and a second refractive index gradient layer, wherein the second refractive index gradient layer is located on a side of the first refractive index gradient layer away from the first surface; In a direction parallel or perpendicular to the plane of the waveguide substrate, the refractive index of the first refractive index gradient layer gradually changes in at least one direction, and the refractive index of the second refractive index gradient layer gradually changes in at least one direction. The first refractive index gradient layer and the second refractive index gradient layer differ in at least one of the value of the refractive index change and the direction of the refractive index change.

2. The optical waveguide device according to claim 1, wherein The light entrance area is located at one end of the first surface, and in a direction parallel to the plane where the waveguide substrate is located, the direction from the light entrance area to the end away from the light entrance area is a first direction, and the direction perpendicular to the first direction is a second direction; The refractive index of the first graded refractive index layer and the second graded refractive index layer both gradually changes in the first direction or the second direction.

3. The optical waveguide device according to claim 2, wherein The refractive index of one of the first graded refractive index layer and the second graded refractive index layer gradually increases in the first direction, and the refractive index of the other of the first graded refractive index layer and the second graded refractive index layer gradually decreases in the first direction.

4. The optical waveguide device according to claim 3, wherein The refractive index of the first graded refractive index layer gradually increases in the first direction, and the refractive index of the second graded refractive index layer gradually decreases in the first direction.

5. The optical waveguide device according to claim 4, wherein The refractive index of the first graded refractive index layer in the first direction gradually increases from 1.69 to 1.83, and the refractive index of the second graded refractive index layer in the first direction decreases from 1.9 to 1.

83.

6. The optical waveguide device according to claim 1, wherein The relief grating includes a plurality of grating protrusions arranged at intervals, and a grating depression located between two adjacent grating protrusions; The light entrance area is located at one end of the first surface, and on a plane parallel to the waveguide substrate, a direction from the light entrance area to an end away from the light entrance area is a first direction; The plurality of grating protrusions are spaced apart in the first direction, and the widths of the grating concavities gradually increase or decrease in the first direction.

7. The optical waveguide device according to claim 1, wherein The relief grating includes a plurality of grating protrusions arranged at intervals, and a grating depression located between two adjacent grating protrusions; The light entrance area is located at one end of the first surface, and on a plane parallel to the waveguide substrate, a direction from the light entrance area to an end away from the light entrance area is a first direction, and a direction perpendicular to the first direction is a second direction; The plurality of grating protrusions are spaced apart in the first direction, and the grating protrusion includes a plurality of spaced apart first sub-protrusions and a first sub-recess between two adjacent first sub-protrusions in the second direction. In the second direction, at least one of the length of the first sub-protrusion and the length of the first sub-recess gradually increases or decreases.

8. The optical waveguide device according to claim 1, wherein The waveguide substrate further includes a light guiding layer, which is located on a side of the first refractive index gradient layer away from the second refractive index gradient layer. The refractive index of each portion of the light guiding layer is a fixed value, and the light guiding layer has the first surface.

9. The optical waveguide device according to claim 1, wherein Also includes: A light emitting control component is located on a side of the light emitting area away from the first surface, and the surface of the light emitting control component away from the waveguide substrate is a light emitting surface, and the light emitting surface includes a first sub-portion and a second sub-portion. The light emitting control component is used to control the emission direction of light emitted from the light emitting area on the light emitting surface, and the light emitting control component can control the light emitting direction of the first sub-portion to be different from the light emitting direction of the second sub-portion.

10. A display device, characterized in that: include: A display module, the display module being used to emit image light; as well as The optical waveguide device according to any one of claims 1 to 9, wherein the optical waveguide device is configured to receive the image light.

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