Diffraction enhanced optical waveguide device and method thereof

Abstract

A diffraction-enhanced optical waveguide device and method thereof. The diffraction-enhanced optical waveguide device comprises: a diffraction optical waveguide, wherein the diffraction optical waveguide is provided with an incoupling grating region and an outcoupling grating region, wherein the incoupling grating region is used to diffract image incident light to form first-order diffraction light coupled into the diffraction optical waveguide and zero-order diffraction light transmitted through the diffraction optical waveguide, and the outcoupling grating region is used to couple the coupled first-order diffraction light out of the diffraction optical waveguide to form image output light; and a light energy compensation component, wherein the light energy compensation component is stacked on the diffraction optical waveguide and is used to couple the zero-order diffraction light transmitted through the diffraction optical waveguide to form compensation output light superimposed with the image output light to compensate for the output light energy.

Description

Technical Field

[0001] The present invention relates to the field of augmented reality technology, and in particular to a diffraction enhanced optical waveguide device and method thereof. Background Art

[0002] Augmented reality, as a technology that seamlessly integrates virtual world information with real world information, projects pixels on a micro-projector into the human eye through an optical display screen, while allowing the user to see the real world through the optical display screen at the same time. The virtual content provided by the micro-projector and the real environment are superimposed on the same screen or space in real time to exist simultaneously, allowing users to experience the fusion of virtual and reality.

[0003] In order to realize augmented reality display solutions, optical waveguide technology is currently commonly used. That is, when the refractive index of the transmission medium is greater than the refractive index of the surrounding medium and the incident angle in the waveguide is greater than the critical angle of total reflection, the light can be totally reflected in the waveguide for leakage-free transmission. In this way, after the image light from the projector is coupled into the waveguide, the image light continues to propagate losslessly in the waveguide until it is coupled out by the subsequent structure. At present, the waveguides on the market are generally divided into geometric array waveguides and diffraction waveguides, among which diffraction waveguides are further divided into volume holographic waveguides and surface relief grating waveguides. Although the essence of diffraction waveguides is to couple the incident light into or out of the waveguide through a grating, the surface relief grating waveguide has obvious advantages among many solutions due to its extremely high design freedom and mass production brought by nanoimprint processing.

[0004] Specifically for diffractive waveguides used in augmented reality (AR waveguides), their technical parameters primarily include field of view (FOV), eye relief, and eyebox size. The FOV is typically expressed as a diagonal angle, such as 40°, which corresponds to a 16:9 aspect ratio of approximately 35° (H) x 20° (V). The viewing distance is typically around 20-25mm, which generally meets the wearing requirements of most users, including those wearing nearsighted or farsighted glasses. The size of the eyebox determines the range of free eye movement. A larger size reduces the likelihood of image loss, thus providing greater adaptability. The horizontal size of the eyebox needs to accommodate the human eye's exit pupil distance and allow for varying horizontal wearing distances. The vertical size of the eyebox needs to adapt to the user's vertical wearing distance. A size of 15mm (H) x 10mm (V) is generally considered sufficient for a basic user experience. AR waveguides are optimized for high efficiency and good uniformity. High efficiency aims to achieve higher brightness output under the same micro-projector input, making the image seen by the human eye bright enough. Uniformity includes FOV uniformity, that is, the full field of view image seen by the human eye has good brightness and color uniformity, and eyebox uniformity, that is, the brightness difference received by the human eye at different positions in the eyebox (or when worn by users with different pupil distances and nose bridge heights) is minimized, and good FOV uniformity is expected at different positions.

[0005] However, since AR near-eye display devices enable the human eye to observe images without affecting the observation of the real environment, that is, AR near-eye display is a superposition of virtual images and background light, the brightness of the image is actually a relative value, which results in images of the same brightness (i.e., the same outcoupling energy) being much better observed at night than during the day. Therefore, if the image energy (i.e., brightness) is too low, it will seriously affect the user experience during the day or outdoors. Although increasing the light source energy can increase the image brightness to a certain extent, it does not essentially solve the problem of low overall energy utilization (efficiency) of the AR optical waveguide. At the same time, increasing the light source energy will not only increase the wasted light energy, but also shorten the battery life of the device.

[0006] The efficiency of the waveguide is an important evaluation index of AR near-eye display performance, which directly affects the brightness of the image. However, the energy utilization efficiency of existing diffraction waveguides is relatively low. The root cause is that the diffraction efficiency of existing diffraction waveguides is too low, and the energy of useless orders is wasted. For example, Figure 1As shown, the existing diffraction optical waveguide 1P is usually provided with a one-dimensional coupling-in grating 11P and a two-dimensional coupling-out grating 12P. The one-dimensional coupling-in grating 11P diffracts the image light into ±1-order diffraction light and 0-order diffraction light (i.e., zero-order diffraction light). After coupling the ±1-order diffraction light into the existing diffraction optical waveguide 1P, the two-dimensional coupling-out grating 12P usually only diffracts the +1-order diffraction light (i.e., the first-order diffraction light) out of the existing diffraction optical waveguide 1P so that it can be received by the human eye and the corresponding image can be observed. In other words, the existing diffraction optical waveguide 1P only utilizes the energy of the first-order diffraction light, while the energy of the -1-order diffraction light and the zero-order diffraction light is wasted. In addition, as shown in FIG. Figure 2 As shown, the diffraction efficiency of the ±1st order diffraction light is less than 20% at various field angles, and most of the energy is concentrated in the zeroth order diffraction light. This causes the diffraction efficiency of the existing diffraction light waveguide 1P to be inevitably lower than 20%, making it difficult to meet users' high demands for image brightness. Summary of the Invention

[0007] An advantage of the present invention is that it provides a diffraction-enhanced light waveguide device and method thereof, which can effectively improve the light energy utilization efficiency of the light waveguide device and help to improve the image brightness of near-eye display.

[0008] Another advantage of the present invention is that it provides a diffraction-enhanced optical waveguide device and method thereof. In one embodiment of the present invention, the diffraction-enhanced optical waveguide device can utilize a light energy compensation component to compensate the diffraction efficiency of the optical waveguide device, thereby reducing the waste of zero-order diffraction light and improving the light energy utilization efficiency of the optical waveguide device.

[0009] Another advantage of the present invention is that it provides a diffraction-enhanced optical waveguide device and method thereof. In one embodiment of the present invention, the diffraction-enhanced optical waveguide device can increase the overall diffraction efficiency of the optical waveguide device by increasing the number of compensation waveguides in the optical energy compensation component, thereby improving the brightness of the image displayed near the eye.

[0010] Another advantage of the present invention is that it provides a diffraction-enhanced optical waveguide device and method thereof. In one embodiment of the present invention, the diffraction-enhanced optical waveguide device can optimize the uniformity of the optical waveguide device, allowing the user to see a full-field image with good uniformity.

[0011] Another advantage of the present invention is that it provides a diffraction-enhanced optical waveguide device and method thereof, wherein, in one embodiment of the present invention, the diffraction-enhanced optical waveguide device can optimize the uniformity of the optical waveguide device by using compensating waveguides of different thicknesses and / or refractive indices to improve the near-eye display quality.

[0012] Another advantage of the present invention is that it provides a diffraction-enhanced optical waveguide device and method thereof. In one embodiment of the present invention, the diffraction-enhanced optical waveguide device can optimize the uniformity of the optical waveguide device by varying the grating constant, grating depth, and / or duty cycle, thereby helping to improve the near-eye display quality and enhance the user's visual experience.

[0013] Another advantage of the present invention is that it provides a diffraction-enhanced optical waveguide device and method thereof. In one embodiment of the present invention, the diffraction-enhanced optical waveguide device can gradually reduce the grating constant in the optical energy compensation component from top to bottom, so that the outcoupling point position of the light is gradually shifted backward to compensate for the problem of low outcoupling energy at the rear, thereby improving image uniformity.

[0014] Another advantage of the present invention is that it provides a diffraction-enhanced optical waveguide device and method thereof. In one embodiment of the present invention, the diffraction-enhanced optical waveguide device can gradually increase the thickness of the compensation waveguide in the optical energy compensation component from top to bottom, so that the coupling point position of the light is gradually shifted backward to compensate for the problem of low rear coupling energy, thereby improving image uniformity.

[0015] Another advantage of the present invention is that it provides a diffraction-enhanced optical waveguide device and method thereof. In one embodiment of the present invention, the diffraction-enhanced optical waveguide device can optimize the uniformity of energy density by arranging waveguide layers of different thicknesses to modulate the total internal reflection period of each waveguide layer.

[0016] Another advantage of the present invention is that it provides a diffraction-enhanced optical waveguide device and method thereof. In one embodiment of the present invention, the diffraction-enhanced optical waveguide device can reasonably distribute the grating constants in the optical energy compensation component, so that the compensation waveguide can transmit images with different (or partial) field of view angles to obtain a complete image.

[0017] Another advantage of the present invention is that it provides a diffraction-enhanced optical waveguide device and method thereof. In one embodiment of the present invention, the diffraction-enhanced optical waveguide device can be divided into sub-regions by dividing the pupil expansion region and the outcoupling region on the waveguide. Each sub-region can be configured with or without a grating, or the gratings configured have different depths or duty cycles, so as to improve the color uniformity of the waveguide and enhance the user's visual experience.

[0018] Another advantage of the present invention is that it provides a diffraction-enhanced optical waveguide device and method thereof, wherein the present invention does not require expensive materials or complex structures to achieve the aforementioned objectives. Thus, the present invention successfully and effectively provides a solution that not only provides a diffraction-enhanced optical waveguide device and method thereof, but also increases the practicality and reliability of the diffraction-enhanced optical waveguide device and method thereof.

[0019] In order to achieve at least one of the above advantages or other advantages and purposes, the present invention provides a diffraction-enhanced optical waveguide device, comprising:

[0020] A diffraction optical waveguide, wherein the diffraction optical waveguide is provided with an incoupling grating region and an outcoupling grating region, wherein the incoupling grating region is used to diffract image incident light to form first-order diffraction light coupled into the diffraction optical waveguide and zero-order diffraction light passing through the diffraction optical waveguide, and the outcoupling grating region is used to couple the coupled first-order diffraction light out of the diffraction optical waveguide to form image output light; and

[0021] A light energy compensation component is stacked on the diffraction waveguide, and is used to couple the zero-order diffraction light passing through the diffraction waveguide to form a compensation output light superimposed with the image output light to compensate for the output light energy.

[0022] According to one embodiment of the present application, the optical energy compensation component includes N compensation optical waveguides stacked on each other, where N is greater than or equal to 1, and each of the compensation optical waveguides includes a waveguide substrate, a coupling element, and a coupling element, wherein the coupling element is arranged on the waveguide substrate to correspond to the coupling-in grating region, and is used to couple the zero-order diffraction light into the waveguide substrate, and the coupling element is arranged on the waveguide substrate to correspond to the coupling-out grating region, and is used to couple the coupled zero-order diffraction light out of the waveguide substrate to form the compensated output light.

[0023] According to an embodiment of the present application, the coupling-in element is an coupling-in grating structure formed on the waveguide substrate, and the coupling-out element is an coupling-out grating structure formed on the waveguide substrate.

[0024] According to one embodiment of the present application, the N compensation optical waveguides in the optical energy compensation component are stacked on the diffraction optical waveguide at intervals to form gaps between the diffraction optical waveguide and the optical energy compensation component and between two adjacent compensation optical waveguides in the optical energy compensation component.

[0025] According to one embodiment of the present application, the diffraction enhanced optical waveguide device further includes a gasket, which is arranged between the diffraction optical waveguide and the optical energy compensation component and between two adjacent compensation optical waveguides in the optical energy compensation component, so that the gap is an air gap.

[0026] According to one embodiment of the present application, the thickness and refractive index of the diffraction optical waveguide are equal to the thickness and refractive index of the compensation optical waveguide, and the grating constant, grating depth and duty cycle corresponding to the diffraction optical waveguide are equal to the grating constant, grating depth and duty cycle corresponding to the compensation optical waveguide.

[0027] According to an embodiment of the present application, thicknesses of the N compensation optical waveguides are different from each other and different from the thickness of the diffraction optical waveguide.

[0028] According to an embodiment of the present application, the thicknesses of the N compensation optical waveguides gradually increase in a direction away from the diffraction optical waveguide.

[0029] According to an embodiment of the present application, the grating constants corresponding to the N compensation optical waveguides are different from each other and are all different from the grating constant corresponding to the diffraction optical waveguide.

[0030] According to an embodiment of the present application, the grating constants corresponding to the diffraction optical waveguide and the N compensation optical waveguides are evenly distributed between 300 nm and 500 nm.

[0031] According to one embodiment of the present application, the grating constants corresponding to the diffraction optical waveguide and the N compensation optical waveguides are selected in sequence so that the diffraction optical waveguide and the N compensation optical waveguides transmit image light corresponding to different local field of view angles in sequence, wherein the union of the local field of view angles is the full field of view angle.

[0032] According to one embodiment of the present application, the coupling-in grating region is provided on at least one of the upper surface and the lower surface of the diffraction optical waveguide, the coupling-out grating region is provided on at least one of the upper surface and the lower surface of the diffraction optical waveguide, the coupling-in element of each of the compensation optical waveguides is provided on the upper surface and / or the lower surface of the waveguide substrate of the compensation optical waveguide, and the coupling-out element of each of the compensation optical waveguides is provided on the upper surface and / or the lower surface of the waveguide substrate of the compensation optical waveguide.

[0033] According to one embodiment of the present application, the lower surface of the diffraction optical waveguide is provided with the coupling-in grating region and the coupling-out grating region; the optical energy compensation component is stacked on the lower surface of the diffraction optical waveguide; for each supplementary optical waveguide except the last layer of compensation optical waveguide in the optical energy compensation component, the upper surface and lower surface of the waveguide substrate of the compensation optical waveguide are both provided with coupling-in elements and coupling-out elements; for the last layer of compensation optical waveguide in the optical energy compensation component, the coupling-in elements and coupling-out elements of the compensation optical waveguide are both arranged on the upper surface of the waveguide substrate of the compensation optical waveguide.

[0034] According to one embodiment of the present application, the diffraction-enhanced optical waveguide device, when the upper surface of the diffraction optical waveguide is provided with a coupling-in grating region and / or the coupling-out grating region, the diffraction-enhanced optical waveguide device further includes a protective substrate, wherein the protective substrate is attached to the upper surface of the diffraction optical waveguide and is located outside the coupling-in grating region and / or the coupling-out grating region.

[0035] According to one embodiment of the present application, the diffraction-enhanced optical waveguide device further includes a TiO2 film layer, wherein the TiO2 film layer is plated on the coupling-in grating region and the coupling-out grating region of the diffraction optical waveguide and the coupling-in grating structure and the coupling-out grating structure of the compensation optical waveguide.

[0036] According to one embodiment of the present application, the diffraction optical waveguide is further provided with a pupil expansion grating region, wherein the pupil expansion grating region is located between the coupling-in grating region and the coupling-out grating region, and is used to diffractively diffuse the first-order diffraction light coupled in through the coupling-in grating region, so that the diffused first-order diffraction light is transmitted to different positions of the coupling-out grating region.

[0037] According to an embodiment of the present application, the pupil expansion grating region is subdivided to form at least two pupil expansion grating sub-regions, wherein different pupil expansion grating sub-regions have different grating depths and / or duty cycles.

[0038] According to an embodiment of the present application, the pupil expansion grating region is subdivided to form at least two pupil expansion grating sub-regions, wherein some of the pupil expansion grating sub-regions in the pupil expansion grating region are provided with gratings to form discontinuous gratings.

[0039] According to an embodiment of the present application, the compensating optical waveguide further includes a pupil expansion element, wherein the pupil expansion element is a pupil expansion grating structure formed on the waveguide substrate.

[0040] According to an embodiment of the present application, the diffraction optical waveguide and the N compensation optical waveguides have different total reflection periods for light with the same viewing angle.

[0041] According to another aspect of the present application, the present application further provides a method for enhancing light energy diffraction, comprising the steps of:

[0042] diffracting the image incident light to form first-order diffracted light coupled into the diffraction waveguide and zero-order diffracted light passing through the diffraction waveguide;

[0043] diffracting the zero-order diffracted light passing through the diffraction waveguide to form a first-order diffracted light coupled into a compensation waveguide and a zero-order diffracted light passing through the compensation waveguide, wherein the compensation waveguide is stacked on the diffraction waveguide;

[0044] transmitting the first-order diffracted light by total reflection in the diffraction optical waveguide and the compensation optical waveguide respectively; and

[0045] The first-order diffracted light transmitted in the diffraction light waveguide and the compensation light waveguide is diffracted respectively to correspondingly form superimposed image output light and compensation output light to compensate for the output light energy.

[0046] According to an embodiment of the present application, the thickness, refractive index, grating constant, grating depth, and duty cycle of the diffraction optical waveguide and the compensation optical waveguide are reasonably selected to optimize image uniformity.

[0047] According to another aspect of the present application, the present application further provides a method for manufacturing a diffraction-enhanced optical waveguide device, comprising the steps of:

[0048] A diffraction optical waveguide is obtained, and grating structures are formed in the coupling-in grating region and the coupling-out grating region of the diffraction optical waveguide; wherein the grating structure in the coupling-in grating region is used to diffract image incident light to form first-order diffraction light coupled into the diffraction optical waveguide and zero-order diffraction light passing through the diffraction optical waveguide, and the grating structure in the coupling-out grating region is used to couple the coupled first-order diffraction light out of the diffraction optical waveguide to form image output light; and

[0049] A light energy compensation component is stacked on the diffraction waveguide, wherein the light energy compensation component is used to couple and transmit the zero-order diffraction light passing through the diffraction waveguide to form a compensation output light superimposed with the image output light to compensate the output light energy.

[0050] According to an embodiment of the present application, the step of obtaining a diffraction optical waveguide and forming a grating structure in an in-coupling grating region and an out-coupling grating region of the diffraction optical waveguide includes the steps of:

[0051] Manufacturing a master plate, wherein the master plate has grating structures to be transferred corresponding to the grating structures in the coupling-in grating region and the coupling-out grating region, respectively; and

[0052] The grating structures in the coupling-in grating region and the coupling-out grating region are formed on the surface of the diffraction optical waveguide by using the master plate through a nano-imprinting method.

[0053] Further objects and advantages of the present invention will be fully apparent from an understanding of the following description and accompanying drawings.

[0054] These and other objects, features and advantages of the present invention will be more fully understood from the following detailed description, accompanying drawings and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 A schematic diagram of the optical path of an existing optical waveguide device is shown.

[0056] Figure 2 A schematic diagram of the curve showing how the diffraction efficiency of each level of a one-dimensional grating changes with the field of view angle is shown.

[0057] Figure 3 FIG. 4 is a schematic structural diagram of a diffraction-enhanced optical waveguide device according to an embodiment of the present invention.

[0058] Figure 4 FIG. 1 is a schematic diagram showing an optical path of the diffraction-enhanced optical waveguide device according to the above embodiment of the present invention.

[0059] Figure 5 A schematic diagram showing the change of the diffraction efficiency of the diffraction enhanced optical waveguide device according to the above embodiment of the present invention is shown.

[0060] Figure 6 FIG. 4 is a schematic diagram of the k-space of the diffraction-enhanced optical waveguide device according to the above embodiment of the present invention.

[0061] Figure 7 A schematic diagram of the curve showing the change of diffraction angle with grating constant is shown.

[0062] Figure 8 A first variant implementation of the diffraction-enhanced optical waveguide device according to the above embodiment of the present invention is shown.

[0063] Figure 9 FIG. 4 is an exploded schematic diagram of the diffraction-enhanced optical waveguide device according to the first variant embodiment of the present invention.

[0064] Figure 10 FIG. 4 shows a k-space schematic diagram of the diffraction-enhanced optical waveguide device according to the first variant embodiment of the present invention.

[0065] Figure 11 A second variant implementation of the diffraction-enhanced optical waveguide device according to the above embodiment of the present invention is shown.

[0066] Figure 12 A third modified implementation of the diffraction-enhanced optical waveguide device according to the above embodiment of the present invention is shown.

[0067] Figure 13 FIG. 4 is a schematic diagram of the k-space of the diffraction-enhanced optical waveguide device according to the third variant embodiment of the present invention.

[0068] Figure 14 A fourth modified implementation of the diffraction-enhanced optical waveguide device according to the above embodiment of the present invention is shown.

[0069] Figure 15 A fifth modified implementation of the diffraction-enhanced optical waveguide device according to the above embodiment of the present invention is shown.

[0070] Figure 16 A sixth variation of the diffraction-enhanced optical waveguide device according to the above embodiment of the present invention is shown.

[0071] Figure 17A seventh variation of the diffraction-enhanced optical waveguide device according to the above embodiment of the present invention is shown.

[0072] Figure 18 FIG. 4 is an exploded schematic diagram of the diffraction-enhanced optical waveguide device according to the seventh variant embodiment of the present invention.

[0073] Figure 19 A schematic structural diagram of a near-eye display device according to an embodiment of the present application is shown, which is equipped with the diffraction-enhanced optical waveguide device according to the seventh variant embodiment of the present application.

[0074] Figure 20 An eighth modified implementation of the diffraction-enhanced optical waveguide device according to the above embodiment of the present invention is shown. DETAILED DESCRIPTION

[0075] The following description is intended to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are for illustrative purposes only, and those skilled in the art will readily appreciate other obvious variations. The basic principles of the present invention defined in the following description may be applied to other embodiments, variations, improvements, equivalents, and other technical solutions that do not depart from the spirit and scope of the present invention.

[0076] Those skilled in the art should understand that, in the disclosure of the present invention, the terms "longitudinal", "transverse", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like to indicate orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the above terms should not be understood as limiting the present invention.

[0077] In the present invention, the term "a" or "an" in the claims and the specification should be understood as "one or more." That is, in one embodiment, the number of an element may be one, while in another embodiment, the number of the element may be multiple. Unless the disclosure of the present invention clearly indicates that the number of the element is only one, the term "a" or "an" should not be understood as a unique or singular element, and the term "a" or "an" should not be understood as a limitation on the quantity.

[0078] In the description of the present invention, it should be understood that the terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance. In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through a medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0079] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0080] In order to improve the overall diffraction efficiency of a diffraction optical waveguide, the present application provides a diffraction enhanced optical waveguide device and method and equipment thereof, which can use the energy of zero-order diffracted light to compensate for the diffraction efficiency of the optical waveguide device, thereby reducing the energy waste of zero-order diffracted light. Specifically, Figure 3 and Figure 4 As shown, a diffraction-enhanced optical waveguide device 1 according to an embodiment of the present application is illustrated, wherein the diffraction-enhanced optical waveguide device 1 may include a diffraction optical waveguide 10 and a light energy compensation component 20. The diffraction optical waveguide 10 is provided with an incoupling grating region 11 and an outcoupling grating region 12, wherein the incoupling grating region 11 is used to diffract image incident light 1000 to form first-order diffraction light 1001 coupled into the diffraction optical waveguide 10 and zero-order diffraction light 1002 transmitted through the diffraction optical waveguide 10, and the outcoupling grating region 12 is used to couple the incoupling first-order diffraction light 101 out of the diffraction optical waveguide 10 to form image output light 1003. The light energy compensation component 20 is stacked on the diffraction optical waveguide 10 and is used to couple and transmit the zero-order diffraction light 1001 transmitted through the diffraction optical waveguide 10 to form compensation output light 1004 superimposed with the image output light 1003 to compensate for the output light energy.

[0081] More specifically, if Figure 3 and Figure 4As shown, the optical energy compensation component 20 includes N stacked compensation optical waveguides 200, where N is greater than or equal to 1. Each compensation optical waveguide 200 includes a waveguide substrate 21, a coupling element 22, and a coupling element 23. The coupling element 22 is disposed on the waveguide substrate 21 to correspond to the coupling-in grating region 11 of the diffraction optical waveguide 10, and the coupling element 23 is disposed on the waveguide substrate 21 to correspond to the coupling-out grating region 12 of the diffraction optical waveguide 10. The coupling element 22 is configured to continue diffracting the zero-order diffraction light 1002 to form diffracted light coupled into the waveguide substrate 21, and the coupling element 23 is configured to couple the coupled zero-order diffraction light 1002 out of the waveguide substrate 21 to form a compensation output light 1004, so that the coupled-out compensation output light 1004 is superimposed on the image output light 1003 to compensate for the output optical energy.

[0082] It is worth noting that, since the light energy compensation component 20 of the present application can convert the zero-order diffraction light 1002 not utilized by the diffraction optical waveguide 10 into the compensation output light 1004 to be superimposed with the image output light 1003 and received by the human eye, part or all of the zero-order diffraction light 1002 is also utilized by the diffraction-enhanced optical waveguide device 1. Therefore, the diffraction-enhanced optical waveguide device 1 of the present application not only utilizes the first-order diffraction light like the existing diffraction optical waveguide 1P, but also utilizes the zero-order diffraction light to reduce the energy waste of the zero-order diffraction light, so that the diffraction efficiency of the diffraction-enhanced optical waveguide device 1 can be compensated, thereby effectively improving the light energy utilization efficiency and helping to improve the image brightness of the near-eye display.

[0083] According to the above-described embodiments of the present application, the coupling-in grating region 11 of the diffractive optical waveguide 10 can be implemented as, but is not limited to, a region having a one-dimensional grating or a two-dimensional grating. It is understood that the one-dimensional grating can be implemented as, but is not limited to, a rectangular grating, a skewed grating, or a sawtooth grating, etc.; and the two-dimensional grating can also be replaced by a stack of multiple one-dimensional gratings.

[0084] Accordingly, the outcoupling grating region 12 of the diffraction waveguide 10 may also be implemented as, but not limited to, a one-dimensional grating or a two-dimensional grating. In particular, when the outcoupling grating region 12 is a two-dimensional grating, the outcoupling grating region 12 has both an outcoupling function and a pupil expansion function.

[0085] According to the above embodiments of the present application, Figure 3As shown, the coupling-in element 22 of the compensation optical waveguide 200 is preferably implemented as a coupling-in grating structure 220, and the coupling-out element 23 of the compensation optical waveguide 200 is preferably implemented as a coupling-out grating structure 230, so that both the coupling-in element 22 and the coupling-out element 23 couple in and couple out image light by diffraction. It is understandable that the coupling-in grating structure 220 and the coupling-out grating structure 230 can also be implemented as a one-dimensional grating or a two-dimensional grating, and the one-dimensional grating and the two-dimensional grating can be implemented as a relief grating or a volume holographic grating. Of course, in other examples of the present application, the coupling-in element 22 and the coupling-out element 23 can also be implemented as other forms of coupling structures such as a coupling-in prism and a semi-reflective semi-transparent film, which will not be described in detail in this application.

[0086] It is worth mentioning that for a one-dimensional grating, when diffracting light, it will produce at least three orders of diffraction light, namely 0-order diffraction light (i.e., zero-order diffraction light), +1-order diffraction light (i.e., first-order diffraction light), and -1-order diffraction light. The diffraction efficiency changes with the field of view, as shown in the figure. Figure 2 As shown. Figure 3 and Figure 4 As shown, taking the case where both the grating structure of the coupling-in grating region 11 and the coupling-in grating structure 220 are one-dimensional gratings, first, the image incident light 1000 is diffracted by the grating structure of the coupling-in grating region 11 of the diffraction waveguide 10 into a first-order diffraction light 1001 coupled into the diffraction waveguide 10 and a zero-order diffraction light 1002 that propagates along the original direction through the diffraction waveguide 10. At this time, the coupling-in diffraction efficiency of the grating structure of the coupling-in grating region 11 is η 0，+1 Then, the zero-order diffraction light 1002 is diffracted by the first coupling-in grating structure 221 of the first compensating optical waveguide 201 into the first-order diffraction light 1001 coupled into the first waveguide substrate 211 of the first compensating optical waveguide 201 and the zero-order diffraction light 1002 that propagates along the original direction through the first waveguide substrate 211. At this time, the coupling-in diffraction efficiency of the first compensating optical waveguide 201 (i.e., the first coupling-in grating structure 221) is η 0，0 ×η 1，+1 After that, by analogy, the coupling diffraction efficiency of the Nth compensation optical waveguide 20N (ie, the Nth coupling grating structure 22N) in the light energy compensation component 20 is η 0，0 ×η 1，0 …×η N，+1 .

[0087] In summary, without considering the energy loss of absorption and reflection, the coupling diffraction efficiency of the diffraction-enhanced optical waveguide device 1 of the present application is the superposition of the N+1 times coupling diffraction efficiency, that is, the coupling diffraction efficiency η of the diffraction-enhanced optical waveguide device 1 is sum =η 0，+1 +η 0，0 ×η 1，+1+…+η 0，0 ×η 1，0 …×η N，+1 , where η 0，+1 and η 0，0 are the +1st order diffraction efficiency and the zeroth order diffraction efficiency of the coupled grating region 11 respectively; η N，+1 and η N，0 are respectively the +1-order diffraction efficiency and the zero-order diffraction efficiency of the N-th coupling-in grating structure 22N, where N≥1.

[0088] It is worth noting that when the grating structure of the in-coupling grating region 11 is identical to the grating structure of the in-coupling grating structure 220, that is, all +1-order diffraction efficiencies are identical and all zero-order diffraction efficiencies are also identical, the in-coupling diffraction efficiency of the diffraction-enhanced optical waveguide device 1 is simplified to:

[0089]

[0090] Among them, η sum The coupling diffraction efficiency of the diffraction-enhanced optical waveguide device 1 is η +1 is the +1-order diffraction efficiency; η0 is the zero-order diffraction efficiency.

[0091] Since the +1st order diffraction efficiency η of the one-dimensional grating +1 Usually less than 20%, so the +1st order diffraction efficiency η +1 = 10% as an example, the coupling diffraction efficiency function of the diffraction enhanced optical waveguide device 1 of the present application is obtained as follows Figure 5 As shown in the figure, it can be seen that the theoretical diffraction efficiency of the diffraction-enhanced optical waveguide device 1 increases with the number of layers of the optical energy compensation component 20 (i.e., the number N of waveguide substrates 21). Generally, selecting one to three waveguide substrates 21 (i.e., N=1, 2, or 3) can achieve a relatively objective increase in diffraction efficiency without making the structure of the diffraction-enhanced optical waveguide device 1 too complicated.

[0092] Similarly, analysis of the outcoupling region of the diffraction-enhanced optical waveguide device 1 reveals that the outcoupling diffraction efficiency of the diffraction-enhanced optical waveguide device 1 also increases with the number of layers of the light energy compensation component 20. Since the outcoupling compensated output light 1004 and the image output light 1003 are superimposed on each other and directly observed by the human eye, increases in both the incoupling and outcoupling diffraction efficiencies of the diffraction-enhanced optical waveguide device 1 improve image brightness. In other words, the diffraction-enhanced optical waveguide device 1 of the present application can achieve improved outcoupling image brightness without increasing the power consumption of the light source.

[0093] According to the above embodiments of the present application, Figure 3As shown, the N compensation optical waveguides 200 in the optical energy compensation component 20 are preferably stacked at intervals on the diffraction optical waveguide 10 to form gaps 300 between the diffraction optical waveguide 10 and the optical energy compensation component 20 and between two adjacent compensation optical waveguides 200 in the optical energy compensation component 20, so as to ensure that the diffracted light coupled into the diffraction optical waveguide 10 or the compensation optical waveguide 200 can be transmitted by total reflection in the diffraction optical waveguide 10 or the compensation optical waveguide 200.

[0094] Preferably, if Figure 3 As shown, the diffraction enhanced optical waveguide device 1 may further include N groups of spacers 30, wherein the N groups of spacers 30 are respectively arranged between the diffraction optical waveguide 10 and the optical energy compensation component 20 and between adjacent compensation optical waveguides 200 in the optical energy compensation component 20, so that the gap 300 is implemented as an air gap, thereby ensuring that the total reflection conditions of the diffraction optical waveguide 10 and the compensation optical waveguide 200 are easily satisfied.

[0095] More preferably, if Figure 3 and Figure 4 As shown, the spacers 30 are implemented as gaskets 31, and each set of gaskets 31 is correspondingly disposed at the end positions between the diffractive optical waveguide 10 and the optical energy compensation component 20, or at the end positions between adjacent waveguide substrates 21 in the optical energy compensation component 20, so that the gap 300 corresponds to the area between the coupling-in grating region 11 and the coupling-out grating region 12, thereby preventing the spacers 30 from affecting the total internal reflection conditions of the diffractive optical waveguide 10 and the compensation optical waveguide 200. Of course, in other examples of the present application, the spacers 30 can also be replaced by a transparent adhesive layer, disposed at the edge of the optical waveguide, to ensure that the gap 300 is implemented as an air gap.

[0096] Of course, in other embodiments, the gap 300 can also be implemented as a glue layer gap. It is only necessary to ensure that the refractive index of the transparent glue layer is less than the refractive index of the diffraction optical waveguide 10 and the waveguide substrate 21, and the total reflection conditions of the diffraction optical waveguide 10 and the compensation optical waveguide 200 are met. This application will not elaborate on this.

[0097] Most preferably, the thickness of the spacer 31 is between 5um and 100um, so that the height of the gap 300 is between 5um and 100um.

[0098] It is worth noting that in one example of this application, Figure 4 As shown, the thickness and refractive index of the N compensation optical waveguides 200 in the optical energy compensation assembly 20 can be the same and equal to the thickness and refractive index of the diffraction optical waveguide 10. Preferably, the thickness of the diffraction optical waveguide 10 is between 300 μm and 1.5 mm, and the refractive index is between 1.5 and 1.9.

[0099] In addition, if Figure 4As shown, the grating constant, grating depth, and duty cycle of the coupling-in grating structure 220 and the coupling-out grating structure 230 in the optical energy compensation component 20 can be the same and equal to the grating constant, grating depth, and duty cycle of the coupling-in grating region 11 and the coupling-out grating region 12 of the diffraction optical waveguide 10, so that the image output light 1003 and the compensation output light 1004 coupled out by the diffraction-enhanced optical waveguide device 1 are aligned and superimposed, thereby improving the diffraction efficiency of the diffraction-enhanced optical waveguide device 1.

[0100] Of course, in other examples of the present application, the thicknesses and refractive indices of the N compensation optical waveguides 200 in the optical energy compensation component 20 may also be different, and not equal to the thickness and refractive index of the diffraction optical waveguide 10; at the same time, the grating constants, grating depths, and duty cycles of the coupling-in grating structure 220 and the coupling-out grating structure 230 in the optical energy compensation component 20 may also be different, and not equal to the grating constants, grating depths, and duty cycles of the coupling-in grating region 11 and the coupling-out grating region 12 of the diffraction optical waveguide 10, but it is necessary that the grating periods corresponding to the N compensation optical waveguides 200 and the diffraction optical waveguide 10 all satisfy the total reflection condition and the coupling-out condition.

[0101] It is worth noting that the grating constant of the diffraction-enhanced optical waveguide device 1 of the present application can be in the range of 200 nm to 700 nm. In addition, the grating depth of the diffraction-enhanced optical waveguide device 1 can be in the range of 30 nm to 500 nm.

[0102] Preferably, the grating constants corresponding to the optical waveguide layers in the diffraction-enhanced optical waveguide device 1 are different from each other and are evenly distributed between 300 nm and 500 nm.

[0103] For example, for an image light source with a wavelength of 515 nm and a waveguide with a refractive index of 1.72, its k-domain diagram is as follows: Figure 6 As shown, the k 11 、k 12 、k 13 、k 21 、k 22 and k 23 Represents different grating vectors, and the figure shows the extreme positions of two sets of grating vectors, so that the corresponding field angle light is just within the k-domain ring that can be effectively coupled out. It can be obtained that the grating constant value range at this time is preferably implemented as 340nm to 430nm.

[0104] It is worth noting that since the grating constant is related to the transmission of light inside the waveguide, the present application can control the diffraction angle or total reflection angle of light in the waveguide by selecting an appropriate grating constant. For example, Figure 7 The relationship between the diffraction angle and the grating constant is shown by Figure 7It can be seen that as the grating constant (i.e., grating period) increases, the diffraction angle gradually decreases, causing the total internal reflection period to gradually decrease, while the energy density gradually increases. Therefore, the grating constants corresponding to the diffraction waveguide 10 and the N compensation waveguides 200 in the diffraction-enhanced optical waveguide device 1 of the present application can be different, so that the image output light 1003 and the compensation output light 1004 coupled out of the diffraction-enhanced optical waveguide device 1 can be misaligned and superimposed. This improves the diffraction efficiency of the diffraction-enhanced optical waveguide device 1 while also achieving a balance in the energy density coupled out of the diffraction-enhanced optical waveguide device 1.

[0105] Attachment Figures 8 to 10 A first variant implementation of the diffraction-enhanced optical waveguide device 1 according to the above-mentioned embodiment of the present application is shown, wherein the grating constants corresponding to the N compensating optical waveguides 200 in the diffraction-enhanced optical waveguide device 1 can all be greater than the grating constant corresponding to the diffraction optical waveguide 10, and the grating constants corresponding to the N compensating optical waveguides 200 gradually increase from top to bottom, so that the diffraction angle thereof gradually decreases from top to bottom, so as to achieve a total reflection period in each layer of the waveguide gradually decreasing from top to bottom, thereby achieving optimization of energy density uniformity.

[0106] For example, Figure 8 and Figure 9As shown, the coupling-in grating region 11 and the coupling-out grating region 12 of the diffraction-enhanced optical waveguide 10 of the diffraction-enhanced optical waveguide device 1 are provided with grating structures with matched grating vectors, and the optical energy compensation component 20 of the diffraction-enhanced optical waveguide device 1 includes a first compensation optical waveguide 201 and a second compensation optical waveguide 202, that is, N=2, wherein the first compensation optical waveguide 201 is provided with a first coupling-in grating structure 221 and a first coupling-out grating structure 231 with matched grating vectors at positions corresponding to the coupling-in grating region 11 and the coupling-out grating region 12 on the first waveguide substrate 211, and the second compensation optical waveguide 202 is provided with a second coupling-in grating structure 222 and a second coupling-out grating structure 232 at positions corresponding to the coupling-in grating region 11 and the coupling-out grating region 12 on the second waveguide substrate 212. The grating structure of the in-coupling grating region 11, the first in-coupling grating structure 221, and the second in-coupling grating structure 222 are all implemented as one-dimensional relief gratings; the grating structure of the out-coupling grating region 12, the first out-coupling grating structure 231, and the second out-coupling grating structure 232 are all implemented as two-dimensional relief gratings. Specifically, the grating constants of the in-coupling grating region 11 and the out-coupling grating region 12 are 360 ​​nm, the grating constants of the first in-coupling grating structure 221 and the first out-coupling grating structure 231 are 390 nm, and the grating constants of the second in-coupling grating structure 222 and the second out-coupling grating structure 232 are 420 nm. Furthermore, for monochromatic light with a wavelength of 515 nm, the parameters of the diffraction waveguide 10, the first compensation waveguide 201, and the second compensation waveguide 202 in the diffraction-enhanced optical waveguide device 1 are sufficient to display images at full viewing angles.

[0107] In this way, Figure 8As shown, when the image incident light 1000 reaches the coupling-in grating region 11 of the diffraction optical waveguide 10, the image incident light 1000 will be diffracted by the grating structure in the coupling-in grating region 11 into a first-order diffraction light 1001a that propagates by total reflection in the diffraction optical waveguide 10 and a zero-order diffraction light 1002 that continues to propagate downward to reach the first compensation optical waveguide 201; thereafter, the zero-order diffraction light 1002 will be diffracted by the first coupling-in grating structure 221 into a first-order diffraction light 1001b that propagates by total reflection in the first compensation optical waveguide 201. and the zero-order diffraction light 1002 that continues to propagate downward to reach the second compensation optical waveguide 202. Finally, the zero-order diffraction light 1002 will be diffracted by the second incoupling grating structure 222 into the first-order diffraction light 1001c that propagates by total reflection in the second compensation optical waveguide 202 and the zero-order diffraction light 1002 that continues to propagate downward to reach the second compensation optical waveguide 202. At the same time, the first-order diffraction light 1001a that propagates by total reflection in the diffraction optical waveguide 10 is coupled out by the outcoupling grating region 12 to form image output light 1003. The first-order diffraction lights 1001b and 1001c that propagate by total reflection in the first and second compensation optical waveguides 201 and 202 are coupled out by the first and second outcoupling grating structures 231 and 232, respectively, to form compensation output light 1004. This allows the compensation output light 1004 and the image output light 1003 to overlap and reach the human eye at the same time, thereby achieving high-efficiency image display.

[0108] It is worth noting that Figure 10 As shown in FIG. 1 , the k-domain diagram corresponding to the diffraction-enhanced optical waveguide device 1 according to this variant embodiment of the present application is illustrated, wherein the grating vectors ka, kb, and kc correspond to the diffraction waveguide 10, the first compensating optical waveguide 201, and the second compensating optical waveguide 203, respectively. Since the grating constants corresponding to the diffraction waveguide 10, the first compensating optical waveguide 201, and the second compensating optical waveguide 203 are different, the total internal reflection angle of the light in each layer of the optical waveguide is different, wherein the diffraction angle of the first-order diffracted light 1001a is the largest, the diffraction angle of the first-order diffracted light 1001b is the second largest, and the diffraction angle of the first-order diffracted light 1001c is the smallest. In this way, since the outcoupling energy of the diffraction-enhanced optical waveguide device 1 is the synthesis of the outcoupling energies corresponding to each layer of optical waveguide, the difference in energy density of light emitted from each layer of optical waveguide in the diffraction-enhanced optical waveguide device 1 will be homogenized after synthesis, thereby achieving optimization of image uniformity.

[0109] It is worth mentioning that in the second variant embodiment of the present application, Figure 11As shown, the grating constants corresponding to the N compensating optical waveguides 200 in the diffraction-enhanced optical waveguide device 1 can also be smaller than the grating constant corresponding to the diffraction optical waveguide 10, and the grating constants corresponding to the N compensating optical waveguides 200 gradually decrease from top to bottom, so that their diffraction angles gradually increase from top to bottom. In other words, the grating constants corresponding to the grating structure in the coupling-in grating region 11, the first coupling-in grating structure 221, ..., the Nth coupling-in grating structure 22N in the diffraction-enhanced optical waveguide device 1 gradually decrease, so that their corresponding diffraction angles θ0, θ1, ..., θ N As the total reflection period in each layer of the optical waveguide in the diffraction-enhanced optical waveguide device 1 gradually increases with the diffraction angle from top to bottom, the outcoupling point of the light gradually moves backward in the outcoupling region from top to bottom, thereby improving the diffraction efficiency while also compensating for the outcoupling energy behind the outcoupling region, thereby improving the uniformity of the image. It is understandable that after each light is coupled out of the outcoupling region, the energy of the remaining light transmitted in the waveguide will decrease, resulting in a sequential decrease in the energy coupled out of the outcoupling region each time. However, the diffraction-enhanced optical waveguide device 1 of the present application can compensate for the outcoupling energy behind the outcoupling region, thereby improving the uniformity of the image.

[0110] It is understood that, in another example of the present application, the grating constants corresponding to the diffraction waveguide 10 and the N compensating waveguides 200 in the diffraction-enhanced optical waveguide device 1 can be randomly selected within a certain range, and this application will not elaborate on this. Of course, in other examples of the present application, other parameters of the diffraction-enhanced optical waveguide device 1 can also be adjusted, as long as the total reflection angles of light with the same field of view in each layer of the optical waveguide in the diffraction-enhanced optical waveguide device 1 are different, and the purpose of improving image uniformity can still be achieved.

[0111] In addition, the diffraction-enhanced optical waveguide device 1 of the present application can also optimize FOV uniformity by setting different grating depths and / or duty cycles for the diffraction optical waveguide 10 and the N compensating optical waveguides 200. Of course, the diffraction-enhanced optical waveguide device 1 of the present application can also achieve modulation of the total internal reflection period in each waveguide layer by setting different thicknesses and / or refractive indices for the diffraction optical waveguide 10 and the N compensating optical waveguides 200, thereby optimizing energy density uniformity.

[0112] For example, in the third variant embodiment of the present application, Figure 12As shown, the thicknesses corresponding to the N compensating optical waveguides 200 in the diffraction-enhanced optical waveguide device 1 are all greater than the thickness corresponding to the diffraction optical waveguide 10, and the thicknesses corresponding to the N compensating optical waveguides 200 gradually increase from top to bottom, so that their total internal reflection period gradually increases from top to bottom. In other words, the thicknesses d0, d1, ..., dN corresponding to the diffraction optical waveguide 10, the first compensating optical waveguide 201, ..., the Nth compensating optical waveguide 20N in the diffraction-enhanced optical waveguide device 1 are N Gradually increases, so that the total reflection period in each layer of the optical waveguide in the diffraction enhanced optical waveguide device 1 gradually increases. Therefore, the outcoupling point position of the light will gradually move backward from top to bottom in the outcoupling area, while still being able to improve the diffraction efficiency, it can also compensate for the outcoupling energy behind the outcoupling area, thereby improving the uniformity of the image. It can be understood that the thickness of the N compensation optical waveguides 201, ... 20N gradually increases in the direction away from the diffraction optical waveguide 10. Of course, in other examples of the present application, the thickness corresponding to the diffraction optical waveguide 10 and the N compensation optical waveguides 200 in the diffraction enhanced optical waveguide device 1 can also be randomly selected within a certain range, and this application will not go into details.

[0113] In the above embodiment, the diffraction waveguide and the N compensating waveguides have different total reflection periods for light with the same field of view angle. By modulating the total reflection period in each waveguide layer, energy density uniformity is optimized. Modulation of the total reflection period can be achieved by modulating the total reflection angle (diffraction angle) and / or the waveguide thickness. Specifically, modulation of the total reflection period can be achieved by modulating at least one of the grating constant of the waveguide-coupled grating structure, the waveguide thickness, and the waveguide refractive index.

[0114] It is worth mentioning that when the grating constants corresponding to the diffraction optical waveguide 10 and the N compensation optical waveguides 200 in the diffraction enhanced optical waveguide device 1 can only partially meet the total reflection condition and the outcoupling condition, the k-domain diagram thereof is as follows: Figure 13 As shown, since the full field of view angle cannot meet the total reflection condition, the obtained image will have a perspective loss. In order to obtain a complete image, the diffraction-enhanced optical waveguide device 1 of the present application can reasonably allocate the grating constants corresponding to each layer of optical waveguides. That is, by appropriately selecting the grating constants corresponding to each layer of optical waveguides, each layer of optical waveguides can transmit image light of different (or partial) field of view angles. In this way, the images transmitted by each layer of optical waveguides are combined to obtain a complete image, which helps to improve the uniformity of FOV in optical waveguide devices with a large field of view angle.

[0115] It can be understood that, assuming the full field of view is FOV, the diffraction optical waveguide transmits the image light of the field of view angle FOV0, the first layer of compensation optical waveguide 201 transmits the image light of the field of view angle FOV1, the second layer of compensation optical waveguide 202 transmits the image light of the field of view angle FOV2, ..., the Nth layer of compensation optical waveguide 20N transmits the image light of the field of view angle FOV N The image light is transmitted, then FOV0, FOV1, FOV2, ..., FOV N For example, in the fourth variant implementation of the present application, Figure 14 As shown, the grating constants corresponding to the diffraction optical waveguide 10, the first compensation optical waveguide 201, ..., the Nth compensation optical waveguide 20N in the diffraction enhanced optical waveguide device 1 are preferably selected in sequence, so that the optical waveguides of each layer in the diffraction enhanced optical waveguide device 1 sequentially receive the image light F0, F1, ..., F corresponding to the gradually decreasing field angles. N Therefore, the diffraction-enhanced optical waveguide device 1 enables the human eye to observe a complete image. It can be understood that the zero-order diffraction light corresponding to the image light with a larger field of view angle is still transmitted by the compensation optical waveguide 200, so that the position of its corresponding coupling point is staggered. While still improving the diffraction efficiency, it can also achieve a uniform outcoupling energy distribution, thereby improving the uniformity of the image.

[0116] It is worth noting that in the above-described embodiments and various examples of the present application, the coupling-in grating structure 220 and the coupling-out grating structure 230 of the optical energy compensation component 20 are preferably formed on the upper surface of the waveguide substrate 21, so that the coupling-in grating structure 220 and the coupling-out grating structure 230 are located within corresponding gaps 300 to prevent the coupling-in grating structure 220 and the coupling-out grating structure 230 from directly contacting the outside world, thereby protecting the optical surfaces of the gratings. However, the coupling-in grating region 11 and the coupling-out grating region 12 of the present application are formed on the upper surface of the diffraction waveguide 10, so that the grating on the diffraction waveguide 10 is in direct contact with the outside world, which makes the optical surfaces of the gratings easily damaged.

[0117] To solve this problem, Figure 15As shown, a fifth variant embodiment of the diffraction-enhanced optical waveguide device 1 according to the above-mentioned embodiment of the present application is illustrated, wherein the diffraction-enhanced optical waveguide device 1 may further include a protective substrate 40, wherein the protective substrate 40 is made of a light-transmitting material and is attached to the upper surface of the diffraction optical waveguide 10 and is located outside the coupling-in grating region 11 and the coupling-out grating region 12 to prevent the coupling-in grating region 11 and the coupling-out grating region 12 from direct contact with the outside, thereby protecting the optical surfaces of the gratings from damage. It is understood that in other examples of the present application, the coupling-in grating structure 220 and / or the coupling-out grating structure 230 may also be formed on the lower surface of the waveguide substrate 21. In this case, the protective substrate 40 may also be attached to the lower surface of the compensation optical waveguide 200 to protect the optical surfaces of the coupling-in grating structure 220 and / or the coupling-out grating structure 230 from damage.

[0118] In particular, Figure 16 A sixth variant embodiment of the diffraction-enhanced optical waveguide device 1 according to the above-mentioned embodiment of the present application is shown, wherein the diffraction-enhanced optical waveguide device 1 may further include a TiO2 film layer 50, wherein the TiO2 film layer 50 is coated on the coupling-in grating region 11 and the coupling-out grating region 12 of the diffraction optical waveguide 10, as well as the coupling-in grating structure 220 and the coupling-out grating structure 230 in the optical energy compensation component 20, to further enhance the diffraction efficiency of the diffraction-enhanced optical waveguide device 1 while protecting the grating structure from damage.

[0119] It is worth noting that, although the diffraction-enhanced optical waveguide device 1 according to the above-mentioned embodiment and its variant embodiments of the present application uses the example in which the diffraction optical waveguide 10 is provided with only the coupling-in grating region 11 and the coupling-out grating region 12, and the corresponding compensation optical waveguide 20 is also provided with only the coupling-in grating structure 220 and the coupling-out grating structure 230 to illustrate the features and advantages of the present application, in other examples of the present application, the diffraction optical waveguide 10 may be further provided with a pupil expansion grating region, and the corresponding compensation optical waveguide 20 may also further include a pupil expansion element.

[0120] Specifically, attached Figure 17 and Figure 18A seventh variant embodiment of the diffraction-enhanced optical waveguide device 1 according to the above-described embodiment of the present application is shown, wherein the diffraction optical waveguide 10 may further include a pupil expansion grating region 13, wherein the pupil expansion grating region 13 is located between the coupling-in grating region 11 and the coupling-out grating region 12, and is used to diffractively diffuse the first-order diffracted light 1001 coupled in through the coupling-in grating region 11, so that the diffused first-order diffracted light 1001 is transmitted to different positions of the coupling-out grating region 12, and then coupled out of the diffraction optical waveguide 10 by the coupling-out grating region 12. This helps to improve the uniformity of the coupling-out energy density while eliminating image vignetting. Correspondingly, the compensating optical waveguide 20 may also further include a pupil expansion element 24, and the pupil expansion element 24 is located between the coupling-in element 22 and the coupling-out element 23 to perform the pupil expansion function.

[0121] Preferably, the pupil expansion element 24 is implemented as a pupil expansion grating structure 240 formed on the waveguide substrate 21. More preferably, the grating structure in the pupil expansion grating region 13 and the pupil expansion grating structure 240 are both implemented as one-dimensional gratings. Of course, in other examples of the present application, the grating structure in the pupil expansion grating region 13 and the pupil expansion grating structure 240 can also be implemented as, but not limited to, two-dimensional gratings.

[0122] For example, Figure 18 As shown, the diffraction-enhanced optical waveguide device 1 includes a diffraction optical waveguide 10 and a compensation optical waveguide 200. The coupling-in, coupling-out, and pupil expansion grating regions 11, 12, 13 and the coupling-in, coupling-out, and pupil expansion grating structures 220, 230, 240 are all implemented as one-dimensional relief gratings. The grating vector directions of the coupling-in, coupling-out, and pupil expansion grating regions 11, 12, 13 (or the coupling-in, coupling-out, and pupil expansion grating structures 220, 230, 240) are 0°, 120°, and -120°, respectively. The grating constant of the diffraction optical waveguide 10 is 380 nm, and the grating constant of the compensation optical waveguide 200 is 440 nm. It can be understood that in other examples of the present application, the grating vector directions of the coupling-in, coupling-out and pupil expansion grating regions 11, 12, 13 (or the coupling-in, coupling-out and pupil expansion grating structures 220, 230, 240) can also be set according to other angles, such as 0°, 135° and -90°, etc.

[0123] Preferably, if Figure 17 and Figure 18As shown, the pupil expansion grating region 13 can be subdivided to form at least two pupil expansion grating sub-regions 130, wherein different pupil expansion grating sub-regions 130 can have different grating depths and / or duty cycles to improve the color uniformity of the light waveguide. Of course, in other examples of the present application, different pupil expansion grating sub-regions 130 can also be provided with or without gratings to form continuous gratings or discontinuous gratings. It can be understood that continuous grating means that every position (such as the pupil expansion sub-region) within a region (such as the pupil expansion region) is arranged with a grating, while discontinuous grating means that a portion of the positions within a region are arranged with a grating, but another portion is not arranged with a grating.

[0124] Similarly, the pupil expansion grating structure 240 can also be subdivided according to the pupil expansion grating area 13. In addition, the outcoupling grating area 12 and the outcoupling grating structure 23 can also be subdivided, which will not be described in detail in this application.

[0125] For example, Figure 17 and Figure 18 As shown, the pupil expansion grating region 13 is subdivided into three parts, namely, a first pupil expansion grating sub-region 131, a second pupil expansion grating sub-region 132, and a third pupil expansion grating sub-region 133. The first pupil expansion grating sub-region 131, the second pupil expansion grating sub-region 132, and the third pupil expansion grating sub-region 133 have different grating depths and duty cycles. The outcoupling grating region 12 is also subdivided into three parts, namely, a first outcoupling grating sub-region 121, a second outcoupling grating sub-region 122, and a third outcoupling grating sub-region 123. The first outcoupling grating sub-region 121, the second outcoupling grating sub-region 122, and the third outcoupling grating sub-region 123 have different grating depths and duty cycles.

[0126] Similarly, the pupil expansion grating structure 240 and the outcoupling grating structure 230 are also subdivided into three parts. It is worth noting that the regional subdivision method here is only illustrative. To further improve uniformity, each grating area can be subdivided into more sub-areas, and some sub-areas can be selected from all sub-areas for grating setting, thereby obtaining a non-continuous grating distribution.

[0127] Preferably, if Figure 17As shown, the coupling-in grating region 11 and the coupling-out grating region 12 of the diffraction waveguide 10 are formed on the lower surface of the diffraction waveguide 10, and the compensation waveguide 200 of the optical energy compensation assembly 20 is also stacked on the lower surface of the diffraction waveguide 10, so that the coupling-in grating region 11 and the coupling-out grating region 12 are located within the gap 300 between the diffraction waveguide 10 and the compensation waveguide 200. Simultaneously, the coupling-in grating structure 220 and the coupling-out grating structure 230 of the compensation waveguide 200 are correspondingly formed on the upper surface of the waveguide substrate 21. Thus, the optical surface of the grating in the diffraction-enhanced optical waveguide device 1 is not in direct contact with the outside world, thereby eliminating the process step of attaching the protective substrate 40, reducing the overall thickness of the device and saving manufacturing costs.

[0128] More preferably, the thickness of the compensation optical waveguide 200 is greater than that of the diffraction optical waveguide 10, so that the light energy decays more slowly in the compensation optical waveguide 200, thereby achieving energy compensation at the rear end of the outcoupling region, and ultimately achieving the purpose of further optimizing uniformity.

[0129] It is worth noting that the diffraction optical waveguide 10 and the N compensating optical waveguides in the diffraction enhanced optical waveguide device 1 of the present application can all transmit red, green and blue image lights, which enables the diffraction enhanced optical waveguide device 1 to achieve improved image brightness and optimized color uniformity.

[0130] It should be noted that the diffraction-enhanced optical waveguide device provided in this application has an incoupling grating region formed on at least one of its upper and lower surfaces, and an outcoupling grating region formed on at least one of its upper and lower surfaces. In other words, the incoupling grating region and / or the outcoupling grating region can be formed on both the upper and lower surfaces of the diffraction optical waveguide.

[0131] It is understood that grating diffraction can occur in two situations: transmission diffraction and reflection diffraction. When the grating structure in the coupling-in grating region on the upper surface of the diffraction waveguide diffracts the image light into the diffraction waveguide, it primarily utilizes the first-order transmission diffraction light generated by diffraction. When the lower surface of the diffraction waveguide is also provided with a coupling-in grating region, the zero-order transmission diffraction light 1002 is diffracted again upon reaching the coupling-in grating region. At least a certain order of reflected diffraction light can be coupled into the diffraction waveguide and transmitted by total reflection in the diffraction waveguide to the coupling-out grating region before being coupled out. This allows further utilization of the reflected diffraction light of this order to improve the light energy utilization rate of the diffraction-enhanced optical waveguide device.

[0132] Similarly, the grating structure in the outcoupling grating region on the upper surface of the diffraction waveguide couples the diffracted light within the diffraction waveguide to a target region (e.g., the orbital region) primarily through transmission diffraction outcoupling. When the lower surface of the diffraction waveguide also includes an outcoupling grating region, the diffracted light within the diffraction waveguide can be reflected and coupled out to the target region (e.g., the orbital region), thereby improving the light energy utilization efficiency of the diffraction-enhanced optical waveguide device.

[0133] For example, in the eighth variant embodiment of the present application, as Figure 20 As shown, the top and bottom surfaces of the diffraction waveguide 10 are provided with an in-coupling grating region 11 and an out-coupling grating region 12. Furthermore, the compensation waveguide 200 in the optical energy compensation assembly 20 is also stacked on the bottom surface of the diffraction waveguide 10, such that the in-coupling grating region 11 and the out-coupling grating region 12 are located within a gap 300 between the diffraction waveguide 10 and the compensation waveguide 200. Furthermore, the in-coupling grating structure 220 and the out-coupling grating structure 230 in the compensation waveguide 200 are correspondingly formed on the top surface of the waveguide substrate 21. In this way, the diffracted light propagating by total reflection in the diffraction optical waveguide 10 can be coupled out by the upper and lower grating structures to form the image output light 1003; the order diffracted light propagating by total reflection in the first to Nth compensation optical waveguides 201 and 20N is coupled out by the first to Nth coupling grating structures to form the compensation output light 1004, so that the compensation output light 1004 and the image output light 1003 are superimposed and reach the human eye at the same time, thereby realizing high-efficiency display of the image.

[0134] Of course, similar to the diffraction waveguide of the diffraction-enhanced optical waveguide device provided in the present application, the compensating waveguide of the diffraction-enhanced optical waveguide device provided in the present application has a coupling element provided on at least one of its upper and lower surfaces at a position corresponding to the coupling-in grating region, and a coupling-out element provided on at least one of its upper and lower surfaces at a position corresponding to the coupling-in grating region. This can further improve the light energy utilization efficiency of the diffraction-enhanced optical waveguide device.

[0135] In addition, when the diffraction waveguide is formed with a pupil expansion grating region, the pupil expansion grating region can be provided on the upper surface and / or lower surface of the diffraction waveguide. A pupil expansion element is provided on at least one of the upper and lower surfaces of the compensation waveguide at a position corresponding to the pupil expansion grating region.

[0136] For example, in another modified embodiment of the present application, the lower surface of the diffraction optical waveguide 10 is provided with a coupling-in grating region 11 and a coupling-out grating region 12, and the compensation optical waveguide 200 in the optical energy compensation component 20 is also stacked on the lower surface of the diffraction optical waveguide 10, so that the coupling-in grating region 11 and the coupling-out grating region 12 are located in the gap between the diffraction optical waveguide 10 and the compensation optical waveguide 200. At the same time, the coupling-in grating structure and the coupling-out grating structure 230 of the compensation optical waveguides other than the compensation optical waveguide 20N in the compensation optical waveguide 200 are correspondingly formed on the upper and lower surfaces of the waveguide substrate, and the coupling-in grating structure and the coupling-out grating structure of the last layer of compensation optical waveguide 20N are formed on the upper surface of the waveguide substrate. In this way, on the one hand, the light energy utilization rate of the diffraction enhanced optical waveguide device can be improved, and the grating structures of the diffraction enhanced optical waveguide device are not exposed on the outer surface, and no additional design is required to protect the grating structure exposed on the outer surface. According to another aspect of the present application, as Figure 19 As shown, the present application further provides a near-eye display device, wherein the near-eye display device may include an optical machine 71 for projecting image incident light, a device body 70, and the above-mentioned diffraction-enhanced optical waveguide device 1, wherein the optical machine 71 and the diffraction-enhanced optical waveguide device 1 are correspondingly arranged on the device body 70, so that the image incident light provided by the optical machine 71 is compensated and coupled out by the diffraction-enhanced optical waveguide device 1 and is received by the user's eyes to see the corresponding image.

[0137] More specifically, if Figure 19 As shown, a near-eye display device body 70 may include a beam portion 72 and a pair of temple portions 73, wherein the temple portions 73 extend rearward from the left and right sides of the beam portion 72 to form the device body 70 having a spectacle frame structure. The diffraction-enhanced optical waveguide device 1 is disposed below the beam portion 72 to serve as a spectacle lens for near-eye display.

[0138] It is worth noting that in one example of this application, Figure 19 As shown, the coupling grating region 11 of the diffraction enhanced optical waveguide 10 in the diffraction enhanced optical waveguide device 1 is located on the upper part of the first waveguide layer 11 to correspond to the beam portion 72 of the device body 70; at this time, the optical engine 71 is suitable for being installed on the beam portion 72 of the device body 70, so that when the user wears the near-eye display device, the optical engine 71 is correspondingly located near the user's forehead, which helps to reserve a larger installation space for the optical engine 71.

[0139] According to another aspect of the present application, an embodiment of the present application further provides a method for enhancing light energy diffraction, which may include the steps of:

[0140] S110: diffracting the image incident light to form a first-order diffracted light coupled into the diffraction waveguide and a zero-order diffracted light passing through the diffraction waveguide;

[0141] S120: diffracting the zero-order diffracted light passing through the diffraction waveguide to form a first-order diffracted light coupled into a compensation waveguide and a zero-order diffracted light passing through the compensation waveguide, wherein the compensation waveguide is stacked on the diffraction waveguide;

[0142] S130: transmitting the first-order diffracted light by total reflection in the diffraction optical waveguide and the compensation optical waveguide respectively; and

[0143] S140: diffracting the first-order diffracted light transmitted in the diffraction light waveguide and the compensation light waveguide respectively to correspondingly form superimposed image output light and compensation output light to compensate for the output light energy.

[0144] It is worth noting that, preferably, in the light energy diffraction enhancement method of the present application, the thickness, refractive index, grating constant, grating depth and duty cycle corresponding to the diffraction optical waveguide and the compensation optical waveguide are reasonably selected to optimize the uniformity of the image.

[0145] According to another aspect of the present application, an embodiment of the present application further provides a method for manufacturing a diffraction-enhanced optical waveguide device, which may include the steps of:

[0146] S210: Obtain a diffraction optical waveguide, and form grating structures in an in-coupling grating region and an out-coupling grating region of the diffraction optical waveguide; wherein the grating structure in the in-coupling grating region is used to diffract image incident light to form first-order diffraction light coupled into the diffraction optical waveguide and zero-order diffraction light passing through the diffraction optical waveguide, and the grating structure in the out-coupling grating region is used to couple the coupled first-order diffraction light out of the diffraction optical waveguide to form image output light; and

[0147] S220: Overlaying a light energy compensation component on the diffraction waveguide, wherein the light energy compensation component is used to couple and transmit the zero-order diffraction light passing through the diffraction waveguide to form a compensation output light superimposed with the image output light to compensate for the output light energy.

[0148] For example, in one example of the present application, step S210 of the method for manufacturing the diffraction-enhanced optical waveguide device may include the following steps:

[0149] S211: manufacturing a master plate, wherein the master plate has a grating structure to be transferred corresponding to the in-coupling grating region and the out-coupling grating region; and

[0150] S212: Using a nanoimprint method, a motherboard is used to form an in-coupling grating region and an out-coupling grating region on the surface of the diffraction waveguide.

[0151] It is worth noting that according to the above-described embodiment of the present application, in step S211 of the method for manufacturing the diffraction-enhanced optical waveguide device, the motherboard may be manufactured using an etching process. For example, the etching process may include, but is not limited to, laser direct writing, electron beam direct writing, mask lithography, and dual-beam interference exposure.

[0152] Those skilled in the art will appreciate that the embodiments of the present invention described above and shown in the accompanying drawings are intended to be illustrative only and are not intended to limit the present invention. The objectives of the present invention have been fully and effectively achieved. The functional and structural principles of the present invention have been demonstrated and illustrated in the embodiments. Any variations or modifications may be made to the embodiments of the present invention without departing from the principles described.

Claims

1. A diffraction-enhanced optical waveguide device, characterized in that: include: A diffraction optical waveguide, wherein the diffraction optical waveguide is provided with an incoupling grating region and an outcoupling grating region, wherein the incoupling grating region is used to diffract image incident light to form first-order diffraction light coupled into the diffraction optical waveguide and zero-order diffraction light passing through the diffraction optical waveguide, and the outcoupling grating region is used to couple the coupled first-order diffraction light out of the diffraction optical waveguide to form image output light; and a light energy compensation component, wherein the light energy compensation component is stacked on the diffraction light waveguide and is used to couple the zero-order diffraction light passing through the diffraction light waveguide to form a compensation output light superimposed with the image output light to compensate for the output light energy; The optical energy compensation component includes N compensation optical waveguides stacked on each other, where N is greater than or equal to 1; The thicknesses of the N compensation optical waveguides gradually increase in a direction away from the diffraction optical waveguide.

2. The diffraction-enhanced optical waveguide device according to claim 1, wherein: Each of the compensating optical waveguides includes a waveguide substrate, a coupling element, and a coupling element, wherein the coupling element is arranged on the waveguide substrate to correspond to the coupling-in grating region, and is used to couple the zero-order diffraction light into the waveguide substrate, and the coupling-out element is arranged on the waveguide substrate to correspond to the coupling-out grating region, and is used to couple the coupled zero-order diffraction light out of the waveguide substrate to form the compensating output light.

3. The diffraction-enhanced optical waveguide device according to claim 2, wherein: The coupling-in element is an coupling-in grating structure formed on the waveguide substrate, and the coupling-out element is an coupling-out grating structure formed on the waveguide substrate.

4. The diffraction-enhanced optical waveguide device according to claim 2, wherein: The N compensation optical waveguides in the optical energy compensation component are stacked on the diffraction optical waveguide at intervals to form gaps between the diffraction optical waveguide and the optical energy compensation component and between two adjacent compensation optical waveguides in the optical energy compensation component.

5. The diffraction-enhanced optical waveguide device according to claim 4, wherein: The diffraction enhanced optical waveguide device further includes a spacer, which is provided between the diffraction optical waveguide and the optical energy compensation component and between two adjacent compensation optical waveguides in the optical energy compensation component, so that the gap is an air gap.

6. The diffraction-enhanced optical waveguide device according to claim 3, wherein: The refractive index of the diffraction optical waveguide is equal to the refractive index of the compensation optical waveguide, and the grating constant, grating depth and duty cycle corresponding to the diffraction optical waveguide are equal to the grating constant, grating depth and duty cycle corresponding to the compensation optical waveguide.

7. The diffraction-enhanced optical waveguide device according to any one of claims 2 to 5, wherein: The thicknesses of the N compensation optical waveguides are different from each other and are all different from the thickness of the diffraction optical waveguide.

8. The diffraction-enhanced optical waveguide device according to claim 3, wherein: The grating constants corresponding to the N compensation optical waveguides are different from each other and are all different from the grating constant corresponding to the diffraction optical waveguide.

9. The diffraction-enhanced optical waveguide device according to claim 8, wherein: The grating constants corresponding to the diffraction optical waveguide and the N compensation optical waveguides are evenly distributed between 300 nm and 500 nm.

10. The diffraction-enhanced optical waveguide device according to claim 3, wherein: The grating constants corresponding to the diffraction optical waveguide and the N compensation optical waveguides are selected in sequence so that the diffraction optical waveguide and the N compensation optical waveguides transmit image light corresponding to different local field of view angles in sequence, wherein the union of the local field of view angles is the full field of view angle.

11. The diffraction-enhanced optical waveguide device according to claim 2, wherein: The coupling-in grating region is provided on at least one of the upper surface and the lower surface of the diffraction optical waveguide, and the coupling-out grating region is provided on at least one of the upper surface and the lower surface of the diffraction optical waveguide. The coupling-in element of each compensation optical waveguide is provided on the upper surface and / or the lower surface of the waveguide substrate of the compensation optical waveguide, and the coupling-out element of each compensation optical waveguide is provided on the upper surface and / or the lower surface of the waveguide substrate of the compensation optical waveguide.

12. The diffraction-enhanced optical waveguide device according to claim 11, wherein: The lower surface of the diffraction optical waveguide is provided with the coupling-in grating region and the coupling-out grating region; the light energy compensation component is stacked on the lower surface of the diffraction optical waveguide; For each supplementary optical waveguide in the optical energy compensation component except for the last layer of compensation optical waveguide, the upper surface and the lower surface of the waveguide substrate of the compensation optical waveguide are both provided with coupling elements and coupling elements; For the last layer of compensation optical waveguide in the optical energy compensation component, the coupling-in element and the coupling-out element of the compensation optical waveguide are both arranged on the upper surface of the waveguide substrate of the compensation optical waveguide.

13. The diffraction-enhanced optical waveguide device according to claim 11, wherein: When the upper surface of the diffraction optical waveguide is provided with a coupling-in grating region and / or the coupling-out grating region, the diffraction-enhanced optical waveguide device further includes a protective substrate, wherein the protective substrate is attached to the upper surface of the diffraction optical waveguide and is located outside the coupling-in grating region and / or the coupling-out grating region.

14. The diffraction-enhanced optical waveguide device according to claim 3, wherein: It further includes a TiO2 film layer, wherein the TiO2 film layer is plated on the coupling-in grating region and the coupling-out grating region of the diffraction optical waveguide and the coupling-in grating structure and the coupling-out grating structure of the compensation optical waveguide.

15. The diffraction-enhanced optical waveguide device according to claim 1, wherein: The diffraction light waveguide is further provided with a pupil expansion grating region, wherein the pupil expansion grating region is located between the coupling-in grating region and the coupling-out grating region, and is used to diffractively diffuse the first-order diffracted light coupled in through the coupling-in grating region, so that the diffused first-order diffracted light is transmitted to different positions of the coupling-out grating region.

16. The diffraction-enhanced optical waveguide device according to claim 15, wherein: The pupil expansion grating region is subdivided to form at least two pupil expansion grating sub-regions, wherein different pupil expansion grating sub-regions have different grating depths and / or duty cycles.

17. The diffraction-enhanced optical waveguide device according to claim 15, wherein: The pupil expansion grating region is subdivided into at least two pupil expansion grating sub-regions, wherein some of the pupil expansion grating sub-regions in the pupil expansion grating region are provided with gratings to form a discontinuous grating.

18. The diffraction-enhanced optical waveguide device according to claim 14, wherein: The compensating optical waveguide further includes a pupil expansion element, wherein the pupil expansion element is a pupil expansion grating structure formed on the waveguide substrate.

19. The diffraction-enhanced optical waveguide device according to any one of claims 2 to 5, wherein: The diffraction optical waveguide and the N compensation optical waveguides have different total reflection periods for light with the same viewing angle.

20. A method for enhancing light energy diffraction, used for controlling the diffraction-enhanced optical waveguide device according to any one of claims 1 to 19, characterized in that: Including steps: diffracting the image incident light to form first-order diffracted light coupled into the diffraction waveguide and zero-order diffracted light passing through the diffraction waveguide; diffracting the zero-order diffracted light passing through the diffraction waveguide to form a first-order diffracted light coupled into a compensation waveguide and a zero-order diffracted light passing through the compensation waveguide, wherein the compensation waveguide is stacked on the diffraction waveguide; transmitting the first-order diffracted light by total reflection in the diffraction optical waveguide and the compensation optical waveguide respectively; as well as The first-order diffracted light transmitted in the diffraction light waveguide and the compensation light waveguide is diffracted respectively to correspondingly form superimposed image output light and compensation output light to compensate for the output light energy.

21. The method for enhancing light energy diffraction according to claim 20, wherein: The thickness, refractive index, grating constant, grating depth and duty cycle of the diffraction optical waveguide and the compensation optical waveguide are reasonably selected to optimize the uniformity of the image.

22. A method for manufacturing a diffraction-enhanced optical waveguide device, for manufacturing the diffraction-enhanced optical waveguide device according to any one of claims 1 to 19, characterized in that: Including steps: A diffraction optical waveguide is obtained, and grating structures are formed in an in-coupling grating region and an out-coupling grating region of the diffraction optical waveguide; the grating structure in the in-coupling grating region is used to diffract image incident light to form first-order diffraction light coupled into the diffraction optical waveguide and zero-order diffraction light passing through the diffraction optical waveguide, and the grating structure in the out-coupling grating region is used to couple the coupled first-order diffraction light out of the diffraction optical waveguide to form image output light; and A light energy compensation component is stacked on the diffraction waveguide, wherein the light energy compensation component is used to couple and transmit the zero-order diffraction light passing through the diffraction waveguide to form a compensation output light superimposed with the image output light to compensate the output light energy.

23. The method for manufacturing a diffraction-enhanced optical waveguide device according to claim 22, wherein: The step of obtaining a diffraction light waveguide and forming a grating structure in the coupling-in grating region and the coupling-out grating region of the diffraction light waveguide comprises the steps of: Manufacturing a master plate, wherein the master plate has grating structures to be transferred corresponding to the grating structures in the coupling-in grating region and the coupling-out grating region, respectively; and The grating structures in the coupling-in grating region and the coupling-out grating region are formed on the surface of the diffraction optical waveguide by using the master plate through a nano-imprinting method.

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