Two-dimensional coupling-out grating, diffractive optical waveguide and near-eye display device

Abstract

The utility model provides a two-dimensional coupling-out grating, a diffraction optical waveguide and a near-to-eye display device, and relates to the technical field of diffraction optics, the two-dimensional coupling-out grating comprises a plurality of coupling-out grating units arranged in an array; wherein the coupling-out grating units are polygonal or elliptical, and the plurality of coupling-out grating units are used for enabling the diffracted light to be uniformly expanded, conducted and coupled out in a two-dimensional coupling-out grating area. According to the utility model, diffracted light is uniformly expanded, conducted and coupled out in a two-dimensional coupling-out grating area through the plurality of coupling-out grating units which are arranged in an array, so that exit pupil uniformity and view field uniformity of the diffracted optical waveguide are improved; and the coupling-out grating unit can change the structural shape, the parameter size and the like, so that the design and regulation freedom degree of the diffraction optical waveguide is increased.

Description

Technical Field

[0001] The utility model relates to the technical field of diffractive optics, and in particular to a two-dimensional output grating, a diffractive optical waveguide and a near-eye display device. Background Art

[0002] Augmented Reality (AR) technology is a technology that combines virtual information generated by a computer with the real world. An AR near-eye display device represented by AR glasses transmits the image of a microdisplay to the human eye through a series of optical imaging elements, and its perspective characteristic enables real scenes to be simultaneously projected into the human eye, greatly enhancing the real experience. Currently, relatively mature optical imaging solutions mainly include prisms, free-form surfaces, off-axis holographic lenses, array waveguides, volume holographic waveguides, diffractive optical waveguides, etc. Among them, diffractive optical waveguides mainly use lithography technology to fabricate surface relief gratings on the waveguide surface to achieve image coupling-in and coupling-out. They have a large field of view, light waveguide weight, and their process is compatible with the mature manufacturing technology of the semiconductor industry, with a high yield in mass production. Therefore, diffractive optical waveguides are a favored AR display optical imaging solution.

[0003] A two-dimensional diffractive optical waveguide adopts two regions: a one-dimensional coupling-in grating and a two-dimensional output grating. The output grating region has both the functions of expansion and output, but its pupil uniformity and field uniformity are a major challenge. During the propagation of the light beam in the output grating region, part of the light is continuously expanded and coupled out, so that in the direction far from the coupling-in grating, the intensity of the light beam passing through the output grating continuously decreases, resulting in a higher light output efficiency of the output grating on the side close to the coupling-in grating and a lower light output efficiency on the side far from the coupling-in grating, ultimately leading to pupil non-uniformity. To improve the pupil uniformity of the two-dimensional diffractive optical waveguide, one method is to partition the output grating region. The grating periods of different regions are the same, but the grating parameters are different (such as height, structure size, etc.), so as to adjust the output efficiency of different regions and achieve uniform light output in the entire output grating region. However, this method uses different grating parameters in different regions, increasing the processing difficulty and cost.

[0004] How to improve the pupil uniformity and field uniformity of diffractive optical waveguides is a technical problem that needs to be solved currently. Summary of the Utility Model

[0005] The utility model provides a two-dimensional output grating, a diffractive optical waveguide and a near-eye display device to solve the defects existing in the prior art.

[0006] The present utility model provides a two-dimensional output grating, which includes a plurality of output grating units arranged in an array; wherein, the output grating units are polygons or ellipses, and the plurality of output grating units are used to uniformly expand and conduct diffracted light in the two-dimensional output grating region and output it.

[0007] According to a two-dimensional output grating provided by the present utility model, the plurality of output grating units are used to generate three diffraction orders during the diffraction process, and the three diffraction orders include: (0,0)R diffraction order, (1,-1)R diffraction order, and (1,1)R diffraction order.

[0008] According to a two-dimensional output grating provided by the present utility model, the diffraction efficiency of the (0,0)R diffraction order is higher than that of the (1,-1)R diffraction order, and the diffraction efficiency of the (1,-1)R diffraction order is higher than that of the (1,1)R diffraction order.

[0009] According to a two-dimensional output grating provided by the present utility model, the diffraction efficiencies of the (1,-1)R diffraction order and the (1,1)R diffraction order are both less than 10%, so that the diffracted light uniformly expands and conducts in the two-dimensional output grating region in the horizontal and vertical directions.

[0010] According to a two-dimensional output grating provided by the present utility model, the plurality of output grating units are further used to generate a (2,0) reflection order and a (2,0) transmission order during the diffraction process.

[0011] According to a two-dimensional output grating provided by the present utility model, the diffraction efficiency of the (2,0) reflection order is higher than that of the (2,0) transmission order.

[0012] According to a two-dimensional output grating provided by the present utility model, the diffraction efficiencies of the (2,0) reflection order and the (2,0) transmission order are both less than 1%, so that the diffracted light is uniformly output and enters the human eye for imaging.

[0013] According to a two-dimensional output grating provided by the present utility model, the (2,0) reflection order is reflected and output perpendicular to the plane where the two-dimensional output grating is located, and the (2,0) transmission order is transmitted and output perpendicular to the plane where the two-dimensional output grating is located.

[0014] The present utility model further provides a diffractive optical waveguide, which includes: a waveguide substrate, a one-dimensional input grating disposed on the surface of the waveguide substrate, and the two-dimensional output grating as described in any one of the above.

[0015] Wherein, the one-dimensional coupling grating is configured to couple the incident light carrying image information into the waveguide substrate; and the two-dimensional output grating is configured to diffract the light that comes from the one-dimensional coupling grating and is conducted in the waveguide substrate in a total reflection manner, and couple it out for human eye imaging.

[0016] The present utility model further provides a near-eye display device, comprising: a micro display and the diffraction optical waveguide as described above; the micro display outputs incident light carrying image information.

[0017] For the two-dimensional output grating, diffraction optical waveguide and near-eye display device provided by the present utility model, the two-dimensional output grating includes a plurality of output grating units arranged in an array; wherein, the output grating unit is a polygon or an ellipse, and the plurality of output grating units are configured to uniformly expand and conduct and couple out the diffracted light in the two-dimensional output grating region. It can be seen that the present utility model enables the diffracted light to be uniformly expanded, conducted and coupled out in the two-dimensional output grating region through the plurality of output grating units arranged in an array, improving the pupil uniformity and field of view uniformity of the diffraction optical waveguide; and the output grating unit can change the structural shape, parameter size, etc., thereby increasing the design and regulation freedom of the diffraction optical waveguide. Description of the Drawings

[0018] In order to more clearly illustrate the technical solutions in the present utility model or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present utility model. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0019] Figure 1 It is a schematic diagram of the principle of the diffraction waveguide display device provided by the present utility model.

[0020] Figure 2 It is one of the structural schematic diagrams of the two-dimensional output grating provided by the present utility model.

[0021] Figure 3 It is one of the schematic diagrams of the pupil uniformity of the diffraction optical waveguide provided by the present utility model.

[0022] Figure 4 It is one of the schematic diagrams showing the variation of the diffraction efficiency of the two-dimensional output grating provided by the present utility model with the incident angle.

[0023] Figure 5 It is the second structural schematic diagram of the two-dimensional output grating provided by the present utility model.

[0024] Figure 6 It is the second schematic diagram of the pupil uniformity of the diffraction optical waveguide provided by the present utility model.

[0025] Figure 7 It is the second schematic diagram showing the variation of the diffraction efficiency of the two-dimensional output grating provided by the present utility model with the incident angle.

[0026] Figure 8 It is the third schematic structural diagram of the two-dimensional output grating provided by the present utility model.

[0027] Figure 9 It is the third schematic diagram showing the pupil uniformity of the diffractive optical waveguide provided by the present utility model.

[0028] Figure 10 It is the third schematic diagram showing the variation of the diffraction efficiency of the two-dimensional output grating provided by the present utility model with the incident angle.

[0029] Figure 11 It is the fourth schematic structural diagram of the two-dimensional output grating provided by the present utility model.

[0030] Figure 12 It is the fourth schematic diagram showing the pupil uniformity of the diffractive optical waveguide provided by the present utility model.

[0031] Figure 13 It is the fourth schematic diagram showing the variation of the diffraction efficiency of the two-dimensional output grating provided by the present utility model with the incident angle. Detailed implementation manners

[0032] To make the objectives, technical solutions and advantages of the present utility model clearer, the technical solutions in the present utility model will be clearly and completely described below with reference to the accompanying drawings in the present utility model. Apparently, the described embodiments are some but not all of the embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art without making creative efforts based on the embodiments in the present utility model fall within the protection scope of the present utility model.

[0033] The following combines with Figures 1-13 to describe the two-dimensional output grating, diffractive optical waveguide and near-eye display device of the present utility model.

[0034] It should be noted that, first, the principle of the diffractive waveguide display device will be described. Figure 1 It is the schematic diagram of the principle of the diffractive waveguide display device provided by the present utility model, as Figure 1As shown in the figure, the diffractive waveguide display device consists of a microdisplay 110 from which light carrying image information is output, and an optical waveguide sheet 100. The optical waveguide sheet 100 generally consists of a waveguide substrate 111, and an input grating 120 and an output grating 130 located on the surface of the waveguide substrate; the material of the waveguide substrate 111 can be glass, polymer or other materials transparent to visible light, in the form of a flat plate with smooth surfaces on both sides; the input grating 120 and the output grating 130 are located on the same surface or different surfaces of the waveguide substrate 111, and can be prepared by photolithography or nanoimprinting technology. The light 101 output by the microdisplay 110 is incident on the input grating 120 of the optical waveguide sheet 100 to generate diffracted light 102 through diffraction. The diffracted light 102 is conducted in the waveguide by total internal reflection towards the output grating 130. When it reaches the area of the output grating 130, diffraction occurs to generate diffracted light 103, 104 and 105 which are coupled out of the waveguide. Since the diffraction efficiency of the output grating 130 remains unchanged, the energy carried by the diffracted light gradually decreases during multiple diffractions. The energy carried by the coupled-out light 103, 104 and 105 will gradually decrease. The light 103, 104 and 105 are conducted towards the human eye and enter the human eye for imaging. When the human eye 140 observes from different areas of the eyebox, the brightness of the image seen will be different, resulting in uneven waveguide exit pupils and reduced field-of-view uniformity of different eyeboxes of the waveguide. Based on this, the present utility model proposes a two-dimensional output grating to improve the exit pupil uniformity and field-of-view uniformity of the diffractive optical waveguide.

[0035] Figure 2 is one of the structural schematic diagrams of the two-dimensional output grating provided by the present utility model, as Figure 2 shown, the two-dimensional output grating provided by the present utility model includes a plurality of output grating units arranged in an array; wherein, the output grating unit is a polygon or an ellipse, and the plurality of output grating units are used to uniformly expand the conduction and coupling out of the diffracted light in the two-dimensional output grating area.

[0036] It should be noted that the two-dimensional output grating 230 includes a plurality of output grating units arranged in an array, and the output grating unit is a polygon or an ellipse. The polygon can be, for example, a hexagon or an octagon, so as to uniformly expand the conduction and coupling out of the diffracted light in the two-dimensional output grating area.

[0037] In one embodiment, refer to Figure 2, the diffractive optical waveguide 200 includes a waveguide substrate and an input grating 220 and an output grating 230 disposed on the waveguide substrate. The input grating 220 is used to couple the input light from the microdisplay into the diffractive optical waveguide 200. The light coupled into the diffractive optical waveguide 200 is conducted to the area of the output grating 230 in a total reflection manner. After the light is conducted to the area of the output grating 230, diffraction occurs, and the light is coupled out of the diffractive optical waveguide 200 and enters the human eye for imaging, enabling the user to see the projection image of the microdisplay. The input grating 220 adopts grating structures such as one-dimensional rectangular gratings, tilted gratings, and blazed gratings; the output grating 230 includes a plurality of hexagonal structures 232 (i.e., the above-mentioned output grating units) arranged in an array.

[0038] Figure 3 is one of the schematic diagrams of the exit pupil uniformity of the diffractive optical waveguide provided by the present invention. Figure 4 is one of the schematic diagrams of the diffraction efficiency of the two-dimensional output grating provided by the present invention changing with the incident angle. In combination with Figure 3 and Figure 4 further explanation is made.

[0039] Based on the above embodiments, in this embodiment, the plurality of output grating units are used to generate three diffraction orders during the diffraction process. The three diffraction orders include: (0,0)R diffraction order, (1,-1)R diffraction order, and (1,1)R diffraction order.

[0040] Based on the above embodiments, in this embodiment, the diffraction efficiency of the (0,0)R diffraction order is higher than the diffraction efficiency of the (1,-1)R diffraction order, and the diffraction efficiency of the (1,-1)R diffraction order is higher than the diffraction efficiency of the (1,1)R diffraction order.

[0041] Based on the above embodiments, in this embodiment, the diffraction efficiencies of the (1,-1)R diffraction order and the (1,1)R diffraction order are both less than 10%, so that the diffracted light is uniformly expanded and conducted in the horizontal and vertical directions in the two-dimensional output grating area.

[0042] Based on the above embodiments, in this embodiment, the plurality of output grating units are further used to generate a (2,0) reflection order and a (2,0) transmission order during the diffraction process.

[0043] Based on the above embodiments, in this embodiment, the diffraction efficiency of the (2,0) reflection order is higher than the diffraction efficiency of the (2,0) transmission order.

[0044] Based on the above embodiments, in this embodiment, the diffraction efficiencies of the (2,0) reflection order and the (2,0) transmission order are both less than 1%, so that the diffracted light is uniformly coupled out and enters the human eye for imaging.

[0045] Based on the above embodiments, in this embodiment, the (2,0) reflection order is reflected and coupled out perpendicular to the plane where the two-dimensional output grating is located, and the (2,0) transmission order is transmitted and coupled out perpendicular to the plane where the two-dimensional output grating is located.

[0046] Specifically, the output grating unit 232 enables the diffracted light to be more evenly expanded, conducted, and coupled out in the area of the output grating 230. As Figure 4 shown, three diffraction orders, namely (0,0)R, (1,-1)R, and (1,1)R, will be generated. The efficiencies of the three diffraction orders are approximately 95%, approximately 6%, and approximately 2% respectively. The efficiencies of the (1,-1)R and (1,1)R diffracted lights are very low (<10%), indicating that the diffracted light can be effectively expanded along the horizontal and vertical directions. In addition, there are also lights of two diffraction orders, namely the (2,0) reflection order and the (2,0) transmission order, which are reflected and transmitted perpendicular to the plane of the grating respectively. As Figure 4 shown, which represents the variation of the diffraction efficiency with the incident angle. It can be seen that as the incident angle changes, the efficiency value of the (2,0) reflection order is about 0.15%, and the efficiency value of the (2,0) transmission order is about 0.1%. This indicates that both the reflection and transmission orders can couple out the diffractive waveguide into the human eye for imaging with a very low diffraction efficiency (<1%). Thus, more light energy can be expanded and conducted in the diffractive waveguide, making the pupil uniformity of the diffractive waveguide better. As Figure 3 shown.

[0047] In another embodiment, Figure 5 is the second structural schematic diagram of the two-dimensional output grating provided by the present utility model. Refer to Figure 5 , the diffractive optical waveguide 300 includes a waveguide substrate and an input grating 320 and an output grating 330 disposed on the waveguide substrate. The input grating 320 is used to couple the input light from the microdisplay into the diffractive optical waveguide 300. The light coupled into the diffractive optical waveguide 300 is conducted to the area of the output grating 330 in a total reflection manner. After the light is conducted to the area of the output grating 330, it is diffracted and coupled out of the diffractive optical waveguide 300 and enters the human eye for imaging, enabling the user to see the projection image of the microdisplay. The input grating 320 adopts grating structures such as one-dimensional rectangular gratings, tilted gratings, and blazed gratings; the output grating 330 includes a plurality of hexagonal structures 332 (i.e., the above-mentioned output grating units) arranged in an array.

[0048] Figure 6 is the second schematic diagram of the pupil uniformity of the diffractive optical waveguide provided by the present utility model. The pupil uniformity of the output grating unit 332 can be referred to Figure 6 . Figure 7 is the second schematic diagram of the variation of the diffraction efficiency of the two-dimensional output grating provided by the present utility model with the incident angle. The diffraction efficiency of the output grating unit 332 is as Figure 7As shown, the diffracted light of (1, -1)R and (1, 1)R levels is conducted in the waveguide with very low efficiency, thereby improving the pupil uniformity and field-of-view uniformity of the diffractive optical waveguide.

[0049] In yet another embodiment, Figure 8 is the third schematic diagram of the structure of the two-dimensional output grating provided by the present utility model. Refer to Figure 8 , the diffractive optical waveguide 400 includes a waveguide substrate and an input grating 420 and an output grating 430 disposed on the waveguide substrate. The input grating 420 is used to couple the input light from the microdisplay into the diffractive optical waveguide 400. The light coupled into the diffractive optical waveguide 400 is conducted to the output grating 430 region in a total reflection manner. After the light is conducted to the output grating 430 region, it is diffracted and coupled out of the diffractive optical waveguide 400 and enters the human eye for imaging, enabling the user to see the projected image of the microdisplay. The input grating 420 adopts grating structures such as one-dimensional rectangular gratings, tilted gratings, and blazed gratings; the output grating 430 includes a plurality of elliptical structures 432 (i.e., the above-mentioned output grating units) arranged in an array.

[0050] Figure 9 is the third schematic diagram of the pupil uniformity of the diffractive optical waveguide provided by the present utility model. The pupil uniformity of the output grating unit 432 can be referred to Figure 9 . Figure 10 is the third schematic diagram of the diffraction efficiency of the two-dimensional output grating provided by the present utility model changing with the incident angle. The diffraction efficiency of the output grating unit 432 is as Figure 10 shown. The diffracted light of (1, -1)R and (1, 1)R levels is conducted in the waveguide with very low efficiency, thereby improving the pupil uniformity and field-of-view uniformity of the diffractive optical waveguide.

[0051] In still another embodiment, Figure 11 is the fourth schematic diagram of the structure of the two-dimensional output grating provided by the present utility model. Refer to Figure 11 , the diffractive optical waveguide 500 includes a waveguide substrate and an input grating 520 and an output grating 530 disposed on the waveguide substrate. The input grating 520 is used to couple the input light from the microdisplay into the diffractive optical waveguide 500. The light coupled into the diffractive optical waveguide 500 is conducted to the output grating 530 region in a total reflection manner. After the light is conducted to the output grating 530 region, it is diffracted and coupled out of the diffractive optical waveguide 500 and enters the human eye for imaging, enabling the user to see the projected image of the microdisplay. The input grating 520 adopts grating structures such as one-dimensional rectangular gratings, tilted gratings, and blazed gratings; the output grating 530 includes a plurality of octagonal structures 532 (i.e., the above-mentioned output grating units) arranged in an array.

[0052] Figure 12Figure 4 shows the pupil uniformity of the diffractive optical waveguide provided by the present utility model. For the pupil uniformity of the output grating unit 532, please refer to Figure 12 . Figure 13 Figure 4 shows the variation of the diffraction efficiency of the two-dimensional output grating provided by the present utility model with the incident angle. The diffraction efficiency of the output grating unit 532 is as shown in Figure 13 . The diffracted light of the (1, -1)R and (1, 1)R orders is conducted in the waveguide with very low efficiency, thereby improving the pupil uniformity and field-of-view uniformity of the diffractive optical waveguide.

[0053] The above is the description of the two-dimensional output grating provided by the present utility model. It can be seen from the above description that according to the two-dimensional output grating provided by the present utility model, it includes a plurality of output grating units arranged in an array; wherein, the output grating unit is a polygon or an ellipse, and the plurality of output grating units are used to uniformly expand and conduct and output the diffracted light in the two-dimensional output grating region. It can be seen that the present utility model enables the diffracted light to be uniformly expanded and conducted and output in the two-dimensional output grating region through a plurality of output grating units arranged in an array, and the diffracted light of the (1, -1)R and (1, 1)R orders is conducted in the waveguide with very low efficiency, improving the pupil uniformity and field-of-view uniformity of the diffractive optical waveguide; and the output grating unit can change the structural shape and parameter size, etc., thereby increasing the design and regulation freedom of the diffractive optical waveguide.

[0054] The present utility model also provides a diffractive optical waveguide, including: a waveguide substrate, a one-dimensional input grating disposed on the surface of the waveguide substrate, and the two-dimensional output grating as described in any one of the above;

[0055] wherein, the one-dimensional input grating is used to couple the incident light carrying image information into the waveguide substrate; the two-dimensional output grating is used to diffract the light that comes from the one-dimensional input grating and is conducted in the waveguide substrate in a total reflection manner, and output it for human eye imaging.

[0056] The present utility model also provides a near-eye display device, including: a microdisplay and the diffractive optical waveguide as described above; the microdisplay outputs the incident light carrying image information.

[0057] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place, or may be distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. Those of ordinary skill in the art can understand and implement it without creative labor.

[0058] Through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on such an understanding, the essence of the above technical solution, or the part that contributes to the prior art, can be embodied in the form of a software product. The computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A two-dimensional outcoupling grating, characterized in that: It comprises a plurality of outcoupling grating units arranged in an array; wherein the outcoupling grating units are polygonal or elliptical, and the plurality of outcoupling grating units are used to make the diffracted light evenly expand, conduct and couple out in a two-dimensional outcoupling grating area.

2. The two-dimensional outcoupling grating according to claim 1, characterized in that: The multiple out-coupling grating units are used to generate three diffraction orders during the diffraction process, and the three diffraction orders include: (0,0)R diffraction order, (1,-1)R diffraction order and (1,1)R diffraction order.

3. The two-dimensional outcoupling grating according to claim 2, characterized in that: The diffraction efficiency of the (0,0)R diffraction order is higher than the diffraction efficiency of the (1,-1)R diffraction order, and the diffraction efficiency of the (1,-1)R diffraction order is higher than the diffraction efficiency of the (1,1)R diffraction order.

4. The two-dimensional outcoupling grating according to claim 3, characterized in that: The diffraction efficiency of the (1,-1)R diffraction order and the diffraction efficiency of the (1,1)R diffraction order are both less than 10%, so that the diffracted light is evenly expanded and transmitted in the two-dimensional outcoupling grating area in the horizontal and vertical directions.

5. The two-dimensional outcoupling grating according to claim 1, characterized in that: The plurality of outcoupling grating units are further configured to generate a (2,0) reflection order and a (2,0) transmission order during a diffraction process.

6. The two-dimensional outcoupling grating according to claim 5, characterized in that: The diffraction efficiency of the (2,0) reflection order is higher than the diffraction efficiency of the (2,0) transmission order.

7. The two-dimensional outcoupling grating according to claim 6, characterized in that: The diffraction efficiency of the (2,0) reflection order and the diffraction efficiency of the (2,0) transmission order are both less than 1%, so that the diffracted light is evenly coupled out and enters the human eye for imaging.

8. The two-dimensional outcoupling grating according to claim 5, characterized in that: The (2,0) reflection order is reflectively coupled out perpendicularly to the plane where the two-dimensional coupling grating is located, and the (2,0) transmission order is transmittance coupled out perpendicularly to the plane where the two-dimensional coupling grating is located.

9. A diffractive optical waveguide, characterized in that: include: A waveguide substrate, a one-dimensional coupling-in grating arranged on a surface of the waveguide substrate, and a two-dimensional coupling-out grating as claimed in any one of claims 1 to 8; The one-dimensional coupling-in grating is used to couple the incident light carrying image information into the waveguide substrate; the two-dimensional coupling-out grating is used to diffract the light from the one-dimensional coupling-in grating and transmitted in the waveguide substrate by total reflection, and couple it out to the human eye for imaging.

10. A near-eye display device, characterized in that: include: A microdisplay and a diffractive optical waveguide as claimed in claim 9; The microdisplay outputs incident light that carries image information.

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