CN114527537B - Two-dimensional grating, forming method thereof, optical waveguide and near-to-eye display device - Google Patents
Two-dimensional grating, forming method thereof, optical waveguide and near-to-eye display device Download PDFInfo
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- CN114527537B CN114527537B CN202210214447.3A CN202210214447A CN114527537B CN 114527537 B CN114527537 B CN 114527537B CN 202210214447 A CN202210214447 A CN 202210214447A CN 114527537 B CN114527537 B CN 114527537B
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- 230000003287 optical effect Effects 0.000 title claims abstract description 36
- 238000000034 method Methods 0.000 title claims abstract description 20
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- 238000005530 etching Methods 0.000 claims description 3
- 238000009826 distribution Methods 0.000 abstract description 5
- 210000001747 pupil Anatomy 0.000 abstract description 4
- 238000010586 diagram Methods 0.000 description 8
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- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 2
- 238000005452 bending Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 230000004424 eye movement Effects 0.000 description 2
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- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 description 2
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/10—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type
- G02B6/12—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type of the integrated circuit kind
- G02B6/122—Basic optical elements, e.g. light-guiding paths
- G02B6/124—Geodesic lenses or integrated gratings
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
- G02B27/01—Head-up displays
- G02B27/0101—Head-up displays characterised by optical features
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/10—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type
- G02B6/12—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type of the integrated circuit kind
- G02B6/13—Integrated optical circuits characterised by the manufacturing method
- G02B6/136—Integrated optical circuits characterised by the manufacturing method by etching
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/10—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type
- G02B6/12—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type of the integrated circuit kind
- G02B2006/12166—Manufacturing methods
- G02B2006/12176—Etching
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Abstract
The embodiment of the invention relates to the field of optical devices and discloses a two-dimensional grating, a forming method thereof, an optical waveguide and near-to-eye display equipment. The two-dimensional grating can be etched on the optical waveguide according to the requirement of light coupling-out efficiency, the degree of freedom of adjustment of the two-dimensional grating in the diffraction optical waveguide can be improved on the premise of not increasing processing difficulty, the coupling-out efficiency distribution can be better controlled, and better exit pupil uniformity and field uniformity are realized.
Description
Technical Field
The embodiment of the invention relates to the technical field of optical devices, in particular to a two-dimensional grating, a forming method thereof, an optical waveguide and near-eye display equipment.
Background
Augmented reality (Augmented Reality, AR) technology is a technology of fusing virtual information and the real world with each other, and an augmented reality technology represented by augmented reality glasses is currently coming up in various industries, especially in the fields of security and industry, and greatly improves an information interaction mode. The optical display scheme in the current mature augmented reality technology is mainly divided into a prism scheme, a Birdbath scheme, a free-form surface scheme and a light guide (Lightguide) scheme, and the former three schemes have larger volumes, so that the application of the optical display scheme in the aspect of intelligent wearing, namely the aspect of augmented reality glasses is limited, and the light guide scheme is the optimal optical display scheme in the current augmented reality glasses.
The optical waveguide scheme is divided into a geometric waveguide scheme, a relief grating waveguide scheme and a volume holographic waveguide scheme, wherein the geometric waveguide scheme uses a coated semi-transparent half mirror of an array to achieve virtual information display, but the view field and the eye movement range of the scheme are limited, and an array lens brings a stripe effect to a picture, so that the geometric waveguide scheme cannot present an optimal display effect to human eyes. Volume holographic waveguide solutions are currently limited in mass production. The relief grating waveguide scheme is the most studied technical scheme at present due to the convenience of nano imprinting, and has the advantages of large field of view and large eye movement range.
The scheme of the present relief grating waveguide mainly comprises a one-dimensional grating-based optical waveguide scheme and a two-dimensional grating-based optical waveguide scheme, wherein the two-dimensional grating waveguide is divided into a coupling-in area and a coupling-out area, and the coupling-out area adopts a two-dimensional grating structure to achieve the functions of expansion and coupling-out.
In the process of implementing the embodiments of the present invention, the inventors found that at least the following problems exist in the above related art: in the current optical waveguide scheme based on the two-dimensional grating structure, the two-dimensional grating structure used in the coupling-out area is generally in a cylindrical structure, a diamond structure and the like, and the adjustable parameters of the grating structures are less, so that the adjustment of the coupling-out efficiency of the two-dimensional grating is not facilitated, and the uniform coupling-out efficiency of the coupling-out area is not facilitated.
Disclosure of Invention
The embodiment of the application provides a two-dimensional grating, a forming method thereof, an optical waveguide and near-eye display equipment.
The aim of the embodiment of the invention is realized by the following technical scheme:
in order to solve the above-mentioned technical problem, in a first aspect, an embodiment of the present invention provides a two-dimensional grating, which includes a plurality of stripe structures with identical shapes protruding or recessed on a surface of a waveguide sheet, where the stripe structures are formed by copying and extending a repeating unit along one direction, and each of the stripe structures is identical and equidistantly disposed, and the stripe structures are defined by a first boundary line and a second boundary line, where the first boundary line and the second boundary line are different multiple curves.
In some embodiments, within the repeating unit, the first boundary line is a cusp-convex multiple curve and the second boundary line is a plano-convex multiple curve.
In some embodiments, within the repeating unit, the first boundary line is a plano-convex multiple curve and the second boundary line is a cusp-convex multiple curve.
In some embodiments, the period of the repeating unit along its replication extension is 200nm-2 μm.
In some embodiments, the height of the stripe-like structures raised or recessed relative to the waveguide sheet surface is less than 2 μm.
In some embodiments, the surface of the repeating unit is coated with a metal oxide film.
In some embodiments, the metal oxide film has a thickness of 10nm to 200nm.
In order to solve the above technical problem, in a second aspect, an embodiment of the present invention provides a method for forming a two-dimensional grating, including: according to the requirement on the light coupling-out efficiency, determining an optimization variable of the two-dimensional grating according to the first aspect, wherein the optimization variable comprises: the distance between the peak of the first boundary line and the peak of the second boundary line, the positions of the first boundary line and the second boundary line on the surface of the waveguide sheet, the curved surface type of the first boundary line and the second boundary line, the period of the repeating unit along the replication extending direction thereof, and/or the height of the stripe-like structure raised or recessed with respect to the surface of the waveguide sheet; and carrying out etching operation on the waveguide sheet according to the optimized variable to form the two-dimensional grating.
To solve the above technical problem, in a third aspect, an embodiment of the present invention provides an optical waveguide, including: a waveguide sheet; the coupling-in structure formed by the one-dimensional grating is arranged on the light inlet side of the waveguide sheet; the coupling-out structure constituted by the two-dimensional grating according to the first aspect is disposed on the light-emitting side of the waveguide sheet.
In order to solve the above technical problem, in a fourth aspect, an embodiment of the present invention further provides a near-eye display device, including: the optical waveguide of the third aspect.
Compared with the prior art, the invention has the beneficial effects that: different from the situation of the prior art, the embodiment of the invention provides a two-dimensional grating, a forming method thereof, an optical waveguide and near-to-eye display equipment, wherein the two-dimensional grating comprises a plurality of strip-shaped structures with the same shape, which are convexly or concavely arranged on the surface of a waveguide sheet, the strip-shaped structures are formed by copying and extending a repeating unit along one direction, the strip-shaped structures are identical and equidistantly arranged, the strip-shaped structures are defined by a first boundary line and a second boundary line, the first boundary line and the second boundary line are different multiple curves, the two-dimensional grating can be etched on the optical waveguide according to the requirement of light coupling-out efficiency, the degree of freedom of adjustment of the two-dimensional grating in the diffraction optical waveguide can be improved on the premise of not increasing processing difficulty, the coupling-out efficiency distribution can be better controlled, and better exit pupil uniformity and field uniformity are realized.
Drawings
One or more embodiments are illustrated by way of example and not limitation in the figures of the accompanying drawings, in which like references indicate similar elements/modules and steps, and in which the figures do not include the true to scale unless expressly indicated by the contrary reference numerals.
FIG. 1 is a schematic diagram of a two-dimensional grating according to an embodiment of the present invention;
FIG. 2 (a) is a top view of a single repeating unit of the two-dimensional grating shown in FIG. 1;
FIG. 2 (b) is a K-vector diagram of the two-dimensional grating of FIG. 1 according to an embodiment of the present invention;
FIG. 3 is a schematic diagram of another two-dimensional grating according to an embodiment of the present invention;
FIG. 4 (a) is a top view of a single repeating unit of the two-dimensional grating shown in FIG. 3;
FIG. 4 (b) is a K-vector diagram of the two-dimensional grating shown in FIG. 3;
FIG. 4 (c) is a diffraction efficiency profile of the two-dimensional grating shown in FIG. 3;
FIG. 5 is a top view of a single repeating unit of a two-dimensional grating according to a second embodiment of the present invention;
FIG. 6 is a top view of a single repeating unit of another two-dimensional grating provided by a second embodiment of the present invention;
fig. 7 is a flow chart of a method for forming a two-dimensional grating according to a third embodiment of the present invention;
fig. 8 is a schematic structural view of an optical waveguide according to a fourth embodiment of the present invention;
fig. 9 is a schematic structural diagram of a near-eye display device according to a fifth embodiment of the present invention.
Detailed Description
The present invention will be described in detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the present invention, but are not intended to limit the invention in any way. It should be noted that variations and modifications could be made by those skilled in the art without departing from the inventive concept. These are all within the scope of the present invention.
In order to make the objects, technical solutions and advantages of the present application more apparent, the present application will be further described in detail with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the present application.
It should be noted that, if not conflicting, the various features of the embodiments of the present invention may be combined with each other, which are all within the protection scope of the present application. In addition, while functional block division is performed in a device diagram and logical order is shown in a flowchart, in some cases, the steps shown or described may be performed in a different order than the block division in the device, or in the flowchart. Moreover, the words "first," "second," and the like as used herein do not limit the data and order of execution, but merely distinguish between identical or similar items that have substantially the same function and effect.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and/or" as used in this specification includes any and all combinations of one or more of the associated listed items.
In addition, the technical features of the embodiments of the present invention described below may be combined with each other as long as they do not collide with each other.
Specifically, embodiments of the present invention will be further described below with reference to the accompanying drawings; it should be understood that in the schematic structure of the two-dimensional grating and its repeating units, the shaded/black portions of the figure are the grating structures.
Example 1
The present embodiment provides a two-dimensional grating, please refer to fig. 1 and fig. 2 (a), wherein fig. 1 shows a structure of the two-dimensional grating provided by the present embodiment, fig. 2 (a) is a structure of a single repeating unit in the two-dimensional grating provided by the present embodiment, the two-dimensional grating includes a plurality of stripe structures with identical shapes protruding on a surface of a waveguide sheet, the stripe structures are formed by copying and extending the repeating unit along one direction (a direction of a dashed arrow in fig. 1), each stripe structure is identical and is equidistantly arranged, the stripe structures are defined by a first boundary line S1 and a second boundary line S2, and the first boundary line S1 and the second boundary line S2 are different multiple curves.
In the example shown in fig. 2 (a), the first boundary line S1 is a convex-shaped multiple curve and the second boundary line S2 is a plano-convex multiple curve within the repeating unit. The second boundary line S2 (plano-convex) in the vertical direction (i.e., the direction perpendicular to the arrow of the broken line in fig. 1 and the direction of the central axis l) corresponding to the peak of the first boundary line S1 (plano-convex) is also located at the peak position. Referring to fig. 2 (b), fig. 2 (b) is a K vector diagram of the two-dimensional grating shown in fig. 1, which shows the vector directions of partial diffraction orders of the two-dimensional grating.
In other embodiments, please refer to fig. 3 and fig. 4 (a), which show a two-dimensional grating having an inverse concave-convex structure as the two-dimensional grating shown in fig. 1 and fig. 2 (a), the two-dimensional grating includes a plurality of identically shaped stripe structures concavely arranged on the surface of the waveguide sheet, the stripe structures are formed by copying and extending the repeating units along one direction (the direction of the dashed arrow in fig. 3), each of the stripe structures is identical and equidistantly arranged, the stripe structures are defined by a first boundary line S1 and a second boundary line S2, and the first boundary line S1 and the second boundary line S2 are different multiple curves.
In the example shown in fig. 4 (a), the first boundary line S1 is a convex-shaped multiple curve and the second boundary line S2 is a plano-convex multiple curve within the repeating unit. And the second boundary line S2 (plano-convex) in the corresponding vertical direction (i.e., the direction perpendicular to the dashed arrow in fig. 3, the direction of the central axis l) at the peak of the first boundary line S1 (plano-convex) is also at the peak position. Referring to fig. 4 (b) and 4 (c), fig. 4 (b) is a K vector diagram of the two-dimensional grating shown in fig. 3, which shows the vector directions of partial diffraction orders of the two-dimensional grating; fig. 4 (c) shows a distribution of diffraction efficiency in a vector direction of a partial diffraction order when the two-dimensional grating shown in fig. 3 is used to realize extended propagation and coupling-out of a light beam in a coupling-out region, wherein R0, R1, R2, R3, R4, and R5 in fig. 4 (c) correspond to the forward order 0, the extended order 1, the extended order 2, the extended order 3, the extended order 4, and the return order 5 in fig. 4 (b), respectively.
Preferably, in the examples shown in fig. 2 (a) and 4 (a), in the repeating unit, the peak of the boundary line of the cusp type and the peak of the boundary line of the plano-convex type maintain corresponding consistency, that is, a point on the boundary line of the other plano-convex type in the vertical direction corresponding to a point where the boundary line of the cusp type is at the peak is also at the peak position; the repeating units are all axisymmetric patterns taking a central axis l as a symmetry axis.
In some embodiments, the repeat units have a period of 200nm-2 μm along their replication extension (as indicated by the dashed arrow in fig. 1 or 3). In some embodiments, the height of the stripe-like structures raised or recessed relative to the waveguide sheet surface is less than 2 μm.
In some embodiments, the surface of the repeating unit is coated with a metal oxide film. In some embodiments, the metal oxide film has a thickness of 10nm to 200nm, and the material for plating may be selected from, for example, titanium dioxide (TiO 2 ) And aluminum oxide (Al) 2 O 3 ) At least one of the metal oxides.
In this embodiment, by adjusting the distance d between the peak of the first boundary line S1 and the peak of the second boundary line S2, the positions of the first boundary line S1 and the second boundary line S2 on the surface of the waveguide sheet, the curved surface shapes of the first boundary line S1 and the second boundary line S2, the period of the repeating unit along the replication extending direction thereof, and/or the height of the protrusion or the depression of the stripe structure relative to the surface of the waveguide sheet, the adjustment of the K vector of the diffraction order of the two-dimensional grating can be realized, and the coupling-out efficiency is relatively uniform after the light beam propagates in the coupling-out region. It should be understood that the curved surface shape indicates a direction of curve bending, a bending amplitude, and the like, and for example, the curved surface shape may be a cusp shape, a plano-convex shape, and the like.
In the examples shown in fig. 2 (a) and 4 (a), the repeating units may be divided in such a manner that the boundary line has peaks and is axisymmetric, or in other embodiments, the repeating units may be divided in such a manner that the boundary line has valleys and is axisymmetric, or in other forms, and specifically, the repeating units may be arranged according to actual needs, without being limited to the embodiment of fig. 2 (a) and 4 (a) of the present invention.
Example two
The present embodiment provides a two-dimensional grating, please refer to fig. 5, in which the planar view structure of a single repeating unit of the two-dimensional grating provided in this embodiment includes a plurality of stripe structures with identical shapes protruding on the surface of the waveguide sheet, the stripe structures are formed by copying and extending the repeating unit along a direction, each stripe structure is identical and equidistantly disposed, the stripe structures are defined by a first boundary line S1 and a second boundary line S2, and the first boundary line S1 and the second boundary line S2 are different multiple curves.
In the example shown in fig. 5, in the repeating unit, the first boundary line S1 is a plano-convex multiple curve, and the second boundary line S2 is a cusp-convex multiple curve. The first boundary line S1 (plano-convex type) in the vertical direction (i.e., the direction of the central axis l in fig. 5) corresponding to the peak of the second boundary line S2 (plano-convex type) is also located at the peak position. In other embodiments, referring to fig. 6, a single repeating unit of a two-dimensional grating is shown with an inverse concave-convex structure as that of the single repeating unit of the two-dimensional grating shown in fig. 5, where the two-dimensional grating includes a plurality of stripe structures with identical shapes concavely arranged on a surface of a waveguide sheet, the stripe structures are formed by copying and extending the repeating unit along one direction, and each stripe structure is identical and equidistantly arranged, and the stripe structures are defined by a first boundary line S1 and a second boundary line, where the first boundary line S1 and the second boundary line S2 are different multiple curves.
In the example shown in fig. 6, in the repeating unit, the first boundary line S1 is a plano-convex multiple curve, and the second boundary line S2 is a cusp-convex multiple curve, and specifically, the convexities of the first boundary line S1 and the second boundary line S2 may be set according to actual needs, which is not limited by the embodiment of the present invention.
Preferably, in the examples shown in fig. 5 and 6, the repeating units are each in an axisymmetric pattern having the central axis l as the symmetry axis.
In the examples shown in fig. 5 and 6, the first boundary line S1 (plano-convex) in the vertical direction (the direction of the central axis l in fig. 5 and 6) corresponding to the peak of the second boundary line S2 (cusp-convex) is also located at the peak position; preferably, in some other embodiments, the peak of the borderline of the cusp-type and the peak of the borderline of the plano-type maintain a corresponding consistency, i.e. the point on the borderline of the other plano-type in the vertical direction corresponding to the point at the peak of the borderline of the cusp-type is also at the peak position.
The two-dimensional gratings of the examples shown in fig. 5 and 6 each have the same K vector direction as the two-dimensional grating of the embodiment shown in fig. 3; which is used to achieve an extended propagation of the light beam in the outcoupling area and a distribution of diffraction efficiencies in the vector direction of the partial diffraction orders that is slightly different from the two-dimensional grating shown in fig. 3.
In some embodiments, the period of the repeating unit along its replication extension (direction perpendicular to the central axis l in fig. 5 and 6) is 200nm-2 μm. In some embodiments, the height of the stripe-like structures raised or recessed relative to the waveguide sheet surface is less than 2 μm.
In some embodiments, the surface of the repeating unit is coated with a metal oxide film. In some embodiments, the metal oxide film has a thickness of 10nm to 200nm, and the material for plating may be selected from, for example, titanium dioxide (TiO 2 ) And aluminum oxide (Al) 2 O 3 ) At least one of the metal oxides.
In this embodiment, by adjusting the distance d between the peak of the first boundary line S1 and the peak of the second boundary line S2, the positions of the first boundary line S1 and the second boundary line S2 on the surface of the waveguide sheet, the curved surface shapes of the first boundary line S1 and the second boundary line S2, the period of the repeating unit along the replication extending direction thereof, and/or the height of the protrusion or the depression of the stripe structure relative to the surface of the waveguide sheet, the adjustment of the K vector of the diffraction order of the two-dimensional grating can be realized, and the coupling-out efficiency is relatively uniform after the light beam propagates in the coupling-out region.
In the examples shown in fig. 5 and 6, the repeating units are divided in the case where the boundary line has a peak and is axisymmetric, and in other embodiments, the repeating units may be divided in the case where the boundary line has a trough and is axisymmetric, or may be divided in other forms, and specifically, may be set according to actual needs, which is not limited to the embodiment of fig. 5 and 6 of the present invention.
Example III
The present embodiment provides a method for forming a two-dimensional grating, please refer to fig. 7, which shows a flow of the method for forming a two-dimensional grating provided in the present embodiment, the method includes:
step S11: according to the requirement for light coupling-out efficiency, the optimization variables of the two-dimensional grating according to the first or second embodiment are determined,
wherein the optimization variables include: the distance between the peak of the first boundary line and the peak of the second boundary line, the positions of the first boundary line and the second boundary line on the surface of the waveguide sheet, the curved surface type of the first boundary line and the second boundary line, the period of the repeating unit along the replication extending direction thereof, and/or the height of the stripe-like structure protruding or recessed with respect to the surface of the waveguide sheet.
Step S12: and carrying out etching operation on the waveguide sheet according to the optimized variable to form the two-dimensional grating.
By way of example, the method for forming a two-dimensional grating according to the present embodiment may optimize the dimensional parameters in the structure of the two-dimensional grating as shown in the example shown in fig. 4 (b) and fig. 4 (c) according to the diffraction efficiency requirement of the optical waveguide required by the user, so as to obtain the actual manufacturing parameters of the two-dimensional grating, that is, the optimization variables of the two-dimensional grating. Thus, the recessed portion, i.e., the black portion in fig. 1 and 2 (a), is etched on the optical waveguide substrate according to the obtained optimization variables to form a two-dimensional grating as in the first embodiment.
Example IV
The present embodiment provides an optical waveguide, please refer to fig. 8, which illustrates a structure of the optical waveguide provided in the present embodiment, and the optical waveguide 10 includes: a waveguide sheet 11; a coupling-in structure 12 composed of a one-dimensional grating, disposed on the light-incident side of the waveguide sheet 11; the coupling-out structure 13, which is constituted by a two-dimensional grating as described in the first embodiment or the second embodiment, is arranged on the light-emitting side of the waveguide sheet 11.
The coupling-in structure 12 may be a rectangular grating, an oblique grating, a trapezoidal grating, an echelle grating, a holographic grating or other one-dimensional gratings, and specifically, the coupling-in structure 12 may diffractively couple the projection light of the optical machine into the waveguide sheet 11 to propagate in a total reflection direction toward the coupling-out structure 13, and may be set according to practical needs.
The coupling-out structure 13 is formed by a two-dimensional grating as described in the first embodiment or the second embodiment, which is easy to process and is beneficial to adjusting the coupling-out efficiency, specifically, please refer to the first embodiment or the second embodiment and the drawings thereof, which will not be described in detail herein, the coupling-out area 13 can diffuse and propagate light, and couple part of the light out of the waveguide substrate 11 into human eyes, thereby realizing pupil expansion display.
Example five
An embodiment of the present invention provides a near-eye display device, please refer to fig. 9, which illustrates a structure of the near-eye display device provided by the embodiment of the present invention, where the near-eye display device 100 includes: the optical waveguide 10 as described in embodiment four.
In the near-eye display device 100 provided by the embodiment of the invention, the optical waveguide 10 adopts the two-dimensional grating as the coupling-out structure, which is shown in the first embodiment or the second embodiment of the invention, and the two-dimensional grating has more optimized variables, so that multi-parameter regulation and control can be performed to realize the adjustment of diffraction efficiency.
The embodiment of the invention provides a two-dimensional grating, a forming method thereof, an optical waveguide and near-to-eye display equipment, wherein the two-dimensional grating comprises a plurality of strip-shaped structures with the same shape, wherein the strip-shaped structures are convexly or concavely arranged on the surface of a waveguide sheet, the strip-shaped structures are formed by copying and extending repeated units along one direction, the strip-shaped structures are identical and are equidistantly arranged, the strip-shaped structures are defined by a first boundary line and a second boundary line, and the first boundary line and the second boundary line are different multiple curves. The two-dimensional grating can be etched on the optical waveguide according to the requirement of light coupling-out efficiency, the degree of freedom of adjustment of the two-dimensional grating in the diffraction optical waveguide can be improved on the premise of not increasing processing difficulty, the coupling-out efficiency distribution can be better controlled, and better exit pupil uniformity and field uniformity are realized.
It should be noted that the above-described apparatus embodiments are merely illustrative, and the units described as separate units may or may not be physically separate, and units shown as units may or may not be physical units, may be located in one place, or may be distributed over a plurality of network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment.
From the above description of embodiments, it will be apparent to those skilled in the art that the embodiments may be implemented by means of software plus a general purpose hardware platform, or may be implemented by hardware. Those skilled in the art will appreciate that all or part of the processes implementing the methods of the above embodiments may be implemented by a computer program for instructing relevant hardware, where the program may be stored in a computer readable storage medium, and the program may include processes of the embodiments of the methods described above when executed. The storage medium may be a magnetic disk, an optical disk, a Read-Only Memory (ROM), a random access Memory (Random Access Memory, RAM), or the like.
Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention, and are not limiting; the technical features of the above embodiments or in the different embodiments may also be combined within the idea of the invention, the steps may be implemented in any order, and there are many other variations of the different aspects of the invention as described above, which are not provided in detail for the sake of brevity; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the invention.
Claims (8)
1. A two-dimensional grating is characterized by comprising a plurality of strip-shaped structures with the same shape, which are convexly or concavely arranged on the surface of a waveguide sheet, wherein the strip-shaped structures are formed by copying and extending a repeating unit along one direction, the strip-shaped structures are identical and are equidistantly arranged,
the strip-like structure is defined by a first borderline and a second borderline, the first borderline and the second borderline being different multiple curves,
in the repeating unit, the first boundary line may be a convex-shaped multiple curve and the second boundary line may be a plano-convex multiple curve, or the first boundary line may be a plano-convex multiple curve and the second boundary line may be a convex-shaped multiple curve.
2. The two-dimensional grating according to claim 1, wherein,
the period of the repeating unit along the replication extension direction thereof is 200nm-2 μm.
3. A two-dimensional grating according to claim 2, wherein,
the height of the strip-shaped structures protruding or recessed relative to the surface of the waveguide sheet is less than 2 μm.
4. A two-dimensional grating according to claim 3,
and the surface of the repeating unit is plated with a metal oxide film.
5. The two-dimensional grating according to claim 4, wherein,
the thickness of the metal oxide film is 10nm-200nm.
6. A method of forming a two-dimensional grating, comprising:
according to the requirements for light outcoupling efficiency, an optimization variable of the two-dimensional grating according to any of the claims 1-5 is determined,
wherein the optimization variables include: the distance between the peak of the first boundary line and the peak of the second boundary line, the positions of the first boundary line and the second boundary line on the surface of the waveguide sheet, the curved surface type of the first boundary line and the second boundary line, the period of the repeating unit along the replication extending direction thereof, and/or the height of the stripe-like structure raised or recessed with respect to the surface of the waveguide sheet;
and carrying out etching operation on the waveguide sheet according to the optimized variable to form the two-dimensional grating.
7. An optical waveguide, comprising:
a waveguide sheet;
the coupling-in structure formed by the one-dimensional grating is arranged on the light inlet side of the waveguide sheet;
a coupling-out structure consisting of a two-dimensional grating as claimed in any one of claims 1-5, arranged on the light exit side of the waveguide sheet.
8. A near-eye display device, comprising: the optical waveguide of claim 7.
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Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109459813A (en) * | 2018-12-26 | 2019-03-12 | 上海鲲游光电科技有限公司 | A kind of planar optical waveguide based on two-dimensional grating |
| CN209167585U (en) * | 2018-12-26 | 2019-07-26 | 上海鲲游光电科技有限公司 | A kind of planar optical waveguide based on two-dimensional grating |
| US10557994B1 (en) * | 2018-09-24 | 2020-02-11 | Facebook Technologies, Llc | Waveguide grating with spatial variation of optical phase |
| CN111103655A (en) * | 2020-01-10 | 2020-05-05 | 深圳珑璟光电技术有限公司 | Hexagonal columnar structure for diffraction optical waveguide |
| CN211577479U (en) * | 2020-01-10 | 2020-09-25 | 深圳珑璟光电科技有限公司 | Hexagonal columnar structure for diffraction optical waveguide |
| CN111812760A (en) * | 2020-08-06 | 2020-10-23 | 深圳珑璟光电技术有限公司 | Grating structure, optical waveguide and near-to-eye display system |
| CN213042024U (en) * | 2020-08-06 | 2021-04-23 | 深圳珑璟光电科技有限公司 | Grating, optical waveguide and near-to-eye display system |
| CN112965157A (en) * | 2021-03-15 | 2021-06-15 | 深圳珑璟光电技术有限公司 | Two-dimensional grating, optical waveguide and AR glasses |
| CN113156581A (en) * | 2021-05-27 | 2021-07-23 | Oppo广东移动通信有限公司 | Diffractive waveguide device, near-to-eye display apparatus and method of manufacture |
| CN214409370U (en) * | 2021-03-15 | 2021-10-15 | 深圳珑璟光电技术有限公司 | Two-dimensional grating, optical waveguide and AR glasses |
| CN215813431U (en) * | 2021-08-25 | 2022-02-11 | 宁波舜宇奥来技术有限公司 | Optical waveguide structure and near-eye display |
| CN114137655A (en) * | 2020-09-04 | 2022-03-04 | 宁波舜宇光电信息有限公司 | Optical waveguide device for AR apparatus, method of manufacturing the same, and AR apparatus |
-
2022
- 2022-03-07 CN CN202210214447.3A patent/CN114527537B/en active Active
Patent Citations (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10557994B1 (en) * | 2018-09-24 | 2020-02-11 | Facebook Technologies, Llc | Waveguide grating with spatial variation of optical phase |
| CN113325507A (en) * | 2018-12-26 | 2021-08-31 | 上海鲲游光电科技有限公司 | Planar optical waveguide based on two-dimensional grating |
| CN209167585U (en) * | 2018-12-26 | 2019-07-26 | 上海鲲游光电科技有限公司 | A kind of planar optical waveguide based on two-dimensional grating |
| CN109459813A (en) * | 2018-12-26 | 2019-03-12 | 上海鲲游光电科技有限公司 | A kind of planar optical waveguide based on two-dimensional grating |
| CN111103655A (en) * | 2020-01-10 | 2020-05-05 | 深圳珑璟光电技术有限公司 | Hexagonal columnar structure for diffraction optical waveguide |
| CN211577479U (en) * | 2020-01-10 | 2020-09-25 | 深圳珑璟光电科技有限公司 | Hexagonal columnar structure for diffraction optical waveguide |
| CN111812760A (en) * | 2020-08-06 | 2020-10-23 | 深圳珑璟光电技术有限公司 | Grating structure, optical waveguide and near-to-eye display system |
| CN213042024U (en) * | 2020-08-06 | 2021-04-23 | 深圳珑璟光电科技有限公司 | Grating, optical waveguide and near-to-eye display system |
| CN114137655A (en) * | 2020-09-04 | 2022-03-04 | 宁波舜宇光电信息有限公司 | Optical waveguide device for AR apparatus, method of manufacturing the same, and AR apparatus |
| CN112965157A (en) * | 2021-03-15 | 2021-06-15 | 深圳珑璟光电技术有限公司 | Two-dimensional grating, optical waveguide and AR glasses |
| CN214409370U (en) * | 2021-03-15 | 2021-10-15 | 深圳珑璟光电技术有限公司 | Two-dimensional grating, optical waveguide and AR glasses |
| CN113156581A (en) * | 2021-05-27 | 2021-07-23 | Oppo广东移动通信有限公司 | Diffractive waveguide device, near-to-eye display apparatus and method of manufacture |
| CN215813431U (en) * | 2021-08-25 | 2022-02-11 | 宁波舜宇奥来技术有限公司 | Optical waveguide structure and near-eye display |
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Denomination of invention: A two-dimensional grating and its formation method, optical waveguide and near eye display device Granted publication date: 20240130 Pledgee: Bank of Shanghai Limited by Share Ltd. Shenzhen branch Pledgor: Long optoelectronics Co.,Ltd. Registration number: Y2024980019924 |