Two-dimensional vector body holographic grating waveguide, manufacturing method thereof and AR optical module

Abstract

The invention relates to an AR near-to-eye display technology, in particular to a two-dimensional vector body holographic grating waveguide and a manufacturing method thereof, an AR optical module and a manufacturing method, and the method comprises the steps: fixing a holographic plate to be exposed, and building a rectangular coordinate system with a second surface of the holographic plate as an XOY plane; dividing the same exposure light into a first light beam and a second light beam, enabling the first light beam to vertically irradiate the first surface of the holographic plate, and enabling the second light beam to irradiate the second surface of the holographic plate at a # imgabs0 # incident angle so as to form a volume holographic grating with a first grating component; enabling the first light beam to vertically irradiate the first surface of the holographic plate, and enabling the second light beam to irradiate the second surface of the holographic plate at a # imgabs1 # incident angle to form a volume holographic grating with a second grating component; wherein the propagation direction of the orthographic projection of the volume holographic grating vector of the first grating component on the second surface and the propagation direction of the orthographic projection of the volume holographic grating vector of the second grating component on the second surface are symmetric about the X axis.

Description

Technical Field

[0001] The present application relates to AR near-eye display technology, and in particular to a two-dimensional vector volume holographic grating waveguide and a manufacturing method thereof, and an AR optical module. Background Art

[0002] As a major feature of the current information display technology field, the development of augmented reality (AR) near-eye display technology carries people's beautiful vision of future information interaction methods, and has very broad application prospects in industrial production, security, education, military and other fields. Although AR technology is developing rapidly, compared with AR content and computer networks, the development of the most basic AR display devices is still lagging behind. AR display modules are large in size and weight, and the display quality cannot meet people's needs.

[0003] In order to solve the problems of heavy optical system components and limited exit pupil size, diffraction waveguide imaging technology has received widespread attention. This technology uses gratings as coupling components to couple the collimated and amplified image light into the waveguide through the diffraction effect of the grating, and transmits it to the grating at the coupling end by total reflection. Finally, the image light is diffracted out of the waveguide through the coupling grating and enters the human eye for imaging. Compared with near-eye imaging display solutions based on geometric optics principles such as prism solutions, free-form surface solutions, BB solutions, etc., the optical waveguide structure is lighter and thinner, with a thickness generally between 0.5mm and 2mm, which is almost the same as the thickness of common eyeglass lenses, and is closer to people's definition of AR glasses. In addition, the main advantages of optical waveguides include the ability to achieve exit pupil expansion through the continuous replication and output of light beams during waveguide transmission, thereby breaking the inverse relationship between exit pupil size and field of view in the Lagrange optical invariant formula and achieving a larger exit pupil range.

[0004] However, the two-dimensional pupil expansion technology of the related art is realized by using a three-grating (coupling grating, turning grating, and coupling grating) structure. This structure requires three exposures and has a complex process. In addition, the complex three-grating structure makes the optical machine larger and more bulky, which is not conducive to the widespread application of two-dimensional pupil expansion holographic waveguides. Summary of the invention

[0005] In order to optimize the manufacturing method of volume holographic optical waveguide and realize the lightweight and thinning of two-dimensional pupil expansion volume holographic optical waveguide, the present application provides a two-dimensional vector volume holographic grating waveguide and a manufacturing method thereof, and an AR optical module.

[0006] The present application provides a method for manufacturing a two-dimensional vector volume holographic grating waveguide using the following technical solution: A method for manufacturing a two-dimensional vector volume holographic grating waveguide, comprising: S1, fixing the holographic dry plate to be exposed, and establishing a rectangular coordinate system with the second surface of the holographic dry plate as the XOY plane; S2, dividing the same exposure light into a first light beam and a second light beam, and making the first light beam irradiate the first surface of the holographic dry plate vertically, while making the second light beam irradiating the second surface of the holographic dry plate at an incident angle to form a volume holographic grating having a first grating component; S3, making the first light beam irradiate the first surface of the holographic dry plate vertically, and making the second light beam irradiating the second surface of the holographic dry plate at an incident angle to form a volume holographic grating having a second grating component, thereby achieving a two-dimensional pupil expansion of the two-dimensional vector volume holographic grating waveguide; The propagation direction of the positive projection of the volume holographic grating vector of the first grating component on the second surface is symmetric about the X-axis with the propagation direction of the positive projection of the volume holographic grating vector forming the second grating component on the second surface.

[0007] By adopting the above technical solution, the holographic dry plate is exposed twice only by adjusting the relative angle between the exposure light and the holographic dry plate, and two grating components with different vector directions are obtained respectively, and the two grating components have grating vector components with the same direction on the X-axis and grating vector components with the same size and opposite directions on the Y-axis, and finally a composite two-dimensional vector volume holographic grating waveguide is obtained; the two-dimensional vector volume holographic grating waveguide prepared in this embodiment uses a reflective two-dimensional vector volume holographic grating composited with two volume holographic gratings with different grating vector directions as a coupling-in and coupling-out optical component, and the two-dimensional pupil expansion function can be completed only by coupling-in and coupling-out two grating areas, and the space utilization rate is extremely high, thereby greatly reducing the volume, weight and transmission distance of the waveguide. While reducing the volume and weight of the waveguide device, it also further reduces the loss and scattering of the light beam in the waveguide, thereby improving the final imaging effect.

[0008] In one embodiment of the present application, the propagation direction of the orthographic projection of the volume holographic grating vector of the first grating component on the second surface makes an angle θ with the X-axis direction, and an angle (π / 2-θ) with the Y-axis direction; the propagation direction of the orthographic projection of the volume holographic grating vector of the second grating component on the second surface makes an angle θ with the X-axis direction, and an angle (π / 2+θ) with the Y-axis direction; θ is greater than 0 and less than π / 2.

[0009] By adopting the above technical solution, a two-dimensional vector volume holographic grating waveguide is prepared, which propagates along the X-axis direction and expands the pupil along the positive direction of the Y-axis and the negative direction of the Y-axis.

[0010] In one embodiment of the present application, the specific steps of S2 include: The same exposure light is divided into a first light beam and a second light beam by using a beam splitter of a two-dimensional vector volume holographic grating waveguide manufacturing device; the first light beam is vertically irradiated to the first surface of the holographic dry plate by using a reflector of the two-dimensional vector volume holographic grating waveguide manufacturing device, and the second light beam is vertically irradiated to the first surface of the holographic dry plate by using a reflector of the two-dimensional vector volume holographic grating waveguide manufacturing device. The incident angle illuminates the second surface of the holographic dry plate.

[0011] In one embodiment of the present application, the specific steps of S1 include: Fixing the holographic dry plate on a stage of a manufacturing device for a two-dimensional vector volume holographic grating waveguide; An XOY rectangular coordinate system is established on the second surface of the holographic dry plate according to the propagation direction of the two-dimensional vector volume holographic grating waveguide.

[0012] In one embodiment of the present application, the step of fixing the holographic dry plate on a stage of a two-dimensional vector volume holographic grating waveguide manufacturing device comprises: The first surface of the holographic dry plate is bonded to the light-guiding prism of the stage, and the second surface of the holographic dry plate is bonded to the triangular prism of the stage; the holographic dry plate comprises a waveguide substrate and a photosensitive material layer, the first surface of the holographic dry plate is the surface where the waveguide substrate is located, and the second surface of the holographic dry plate is the surface where the photosensitive material layer is located.

[0013] In one embodiment of the present application, the step of establishing an XOY rectangular coordinate system on the second surface of the holographic dry plate according to the propagation direction of the two-dimensional vector volume holographic grating waveguide includes: A rectangular coordinate system is established with the propagation direction of the two-dimensional vector volume holographic grating waveguide as the X-axis direction, the direction perpendicular to the X-axis direction as the Y-axis direction, and the propagation starting point of the two-dimensional vector volume holographic grating waveguide as point O.

[0014] In one embodiment of the present application, the specific steps of S3 include: Taking the Z axis perpendicular to the XOY plane and passing through the O point as the rotation axis, rotate the angle 2θ in the direction of the positive half axis of the X axis; wherein the θ is greater than 0 and less than π / 2.

[0015] By adopting the above technical solution, the double exposure procedure in this application can be achieved only by rotating the stage, and the operation is simple and easy to perform.

[0016] In one embodiment of the present application, the The size satisfies the following conditions: Wherein, n is the refractive index of the waveguide substrate of the holographic dry plate, Half field of view of the optical machine used for preparing holographic plates.

[0017] The present application also provides a two-dimensional vector volume holographic grating waveguide, which is prepared using the method for preparing the two-dimensional vector volume holographic grating waveguide described in any embodiment of the present application.

[0018] The present application also provides an AR optical module, including a micro-image source display, a collimating optical system, the two-dimensional vector volume holographic grating waveguide described in an embodiment of the present application, and a cover protective layer, wherein the collimating optical system, the two-dimensional vector volume holographic grating waveguide and the cover protective layer are sequentially located on the optical path of the micro-image source display; the collimating optical system is used to collimate and enlarge the image emitted by the micro-image source display; the two-dimensional vector volume holographic grating waveguide is used to perform two-dimensional pupil expansion imaging on the collimated and enlarged image; the cover protective layer is bonded to the two-dimensional vector volume holographic grating waveguide to seal and protect the surface of the two-dimensional vector volume holographic grating waveguide.

[0019] In summary, the present application includes at least one of the following beneficial technical effects: 1. The present application only adjusts the relative angle between the exposure light and the holographic dry plate, performs two exposure processes on the holographic dry plate, and obtains two grating components with different vector directions respectively, and the two grating components have grating vector components with the same direction on the X-axis and grating vector components with the same size and opposite directions on the Y-axis, so as to prepare a composite two-dimensional vector volume holographic grating waveguide; 2. The two-dimensional vector volume holographic grating waveguide prepared in this embodiment is a reflective two-dimensional vector volume holographic grating composited with two volume holographic gratings with different grating vector directions as an input and output optical component. The two-dimensional pupil expansion function can be completed only by coupling in and out of two grating areas, and the space utilization rate is extremely high, thereby greatly reducing the volume, weight and transmission distance of the waveguide. While reducing the volume and weight of the waveguide device, it also further reduces the loss and scattering of the light beam in the waveguide, thereby improving the final imaging effect; 3. Applying the two-dimensional vector volume holographic grating waveguide provided in the embodiment of the present application to an AR optical module and then to an AR wearable device will help the AR wearable device to achieve efficient, high-quality waveguide imaging with a large exit pupil and a large field of view, and at the same time help to reduce the size and weight of the AR wearable device. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a diagram of a manufacturing device for a two-dimensional vector volume holographic grating waveguide in Example 1 of the present application; Figure 2 It is a schematic diagram of the optical path for manufacturing the two-dimensional vector volume holographic grating waveguide in Example 1 of the present application; Figure 3 is a flow chart for manufacturing a two-dimensional vector volume holographic grating waveguide in Example 2 of the present application; Figure 4 is a schematic diagram of the volume holographic grating vectors of each grating component of the two-dimensional vector volume holographic grating in Example 2 of the present application in a three-dimensional coordinate system; Figure 5 It is a diagram of the simulation result of waveguide optical path transmission when the coupling-in and coupling-out grating regions in Example 2 of the present application have only the first grating component; Figure 6 It is a diagram of the simulation result of waveguide optical path transmission when the coupling-in and coupling-out grating regions in Example 2 of the present application have only the second grating component; Figure 7 This is a diagram of the simulation results of waveguide optical path transmission when the coupling-in and coupling-out grating regions in Example 2 of the present application simultaneously include the first grating component and the second grating component.

[0021] Description of reference numerals: 11. First light source; 111. First light ray; 12. Second light source; 121. Second light ray; 13. Third light source; 131. Third light ray; 21. First collimation system; 22. Second collimation system; 23. Third collimation system; 31. Reflector; 32. First dichroic mirror; 33. Second dichroic mirror; 41. Beam splitter; 42. First reflector; 43. First light beam; 51. Second reflector; 52. Third reflector; 53. Second light beam; 6. Triangular prism; 7. Light guide prism; 8. Holographic dry plate. DETAILED DESCRIPTION

[0022] The following is combined with Figure 1-7 This application is described in further detail.

[0023] The embodiments of the present application disclose a two-dimensional vector volume holographic grating waveguide and a manufacturing method thereof, and an AR optical module.

[0024] Example 1 Reference Figure 1 This embodiment provides a two-dimensional vector volume holographic grating waveguide manufacturing device, which includes: a stage, a light emitting component and a beam splitting exposure component. The stage is used to fix the holographic dry plate 8; the light emitting component is used to emit an exposure beam; the beam splitting exposure component is located on the optical path of the exposure beam, and is used to split the exposure beam and project the split light beam onto the holographic dry plate 8 to perform exposure processing on the holographic dry plate 8.

[0025] Specifically, the stage includes a triangular prism 6 and a light-guiding prism 7, and the holographic dry plate 8 to be exposed is sandwiched between the triangular prism 6 and the light-guiding prism 7. The light-guiding prism 7 includes a light-incident surface, a light-emitting surface, and a bonding surface. The bonding surface is configured to be bonded to the first surface of the holographic dry plate 8, the light-incident surface is configured to be parallel to and opposite to the bonding surface, and the light-emitting surface is configured to emit stray light. In this embodiment, the light-guiding prism 7 is preferably a parallelogram light-guiding prism with an acute angle of 45°. The triangular prism 6 also includes a light-incident surface and a bonding surface. The bonding surface is configured to be bonded to the second surface of the holographic dry plate 8, and the light-incident surface is configured to be connected to the bonding surface at an acute angle. The stage is rotatable and adjustable.

[0026] It should be noted that the holographic dry plate 8 includes a waveguide substrate and a photosensitive material layer. The first surface of the holographic dry plate 8 is the surface where the waveguide substrate is located, and the second surface of the holographic dry plate 8 is the surface where the photosensitive material layer is located.

[0027] Specifically, the light emitting assembly includes a first light emitting assembly, a second light emitting assembly and a third light emitting assembly, and the first light emitting assembly, the second light emitting assembly and the third light emitting assembly are parallel to each other and have the same light emitting direction. The first light emitting assembly includes a first light source 11, a first collimation system 21 and a reflector 31, the first light source 11 is used to emit a first light ray 111, the first collimation system 21 is located between the first light source 11 and the reflector 31, the first collimation system 21 is used to collimate the first light ray 111 emitted by the first light source 11, and the reflector 31 is used to reflect the first light ray 111 collimated by the first collimation system 21, so that the first light ray 111 propagates along a first direction. The second light emitting component includes a second light source 12, a second collimation system 22 and a first dichroic mirror 32. The second light source 12 is used to emit a second light 121. The second collimation system 22 is located between the second light source 12 and the first dichroic mirror 32. The second collimation system 22 is used to collimate the second light 121 emitted by the second light source 12. The first dichroic mirror 32 is located in the first direction of the reflector 31. The first dichroic mirror 32 is used to transmit the first light 111, reflect the second light 121 and make the second light 121 propagate along the first direction. The third light emitting component includes a third light source 13, a third collimating system 23 and a second dichroic mirror 33. The third light source 13 is used to emit a third light 131. The third collimating system 23 is located between the third light source 13 and the second dichroic mirror 33. The third collimating system 23 is used to collimate the third light 131 emitted by the third light source 13. The second dichroic mirror 33 is located in the first direction of the first dichroic mirror 32. The second dichroic mirror 33 is used to transmit the first light 111 and the second light 121, reflect the third light 131 and make the third light 131 propagate along the first direction. The first light source 11, the second light source 12, and the third light source 13 are respectively selected from one of a red light source, a green light source and a blue light source and are different from each other. The first light 111, the second light 121 and the third light 131 are combined into an exposure light beam at the second dichroic mirror 33, and the exposure light beam continues to propagate in the first direction. In other embodiments, the light emitting component can also be arranged in other ways. As long as the light emitting component design that can achieve high-quality color light beam output is within the scope of protection of this application.

[0028] Specifically, the beam splitting exposure assembly includes a beam splitter 41, a first reflector 42, a second reflector 51, and a third reflector 52. The beam splitter 41 is used to split the exposure light into a first beam 43 and a second beam 53. The first reflector 42 is used to reflect the first beam 43 and inject the first beam 43 vertically into the first surface of the holographic dry plate 8. The second reflector 51 and the third reflector 52 work together to reflect the second beam 53 and inject the second beam 53 at an incident angle. The radiation is directed onto the second surface of the holographic dry plate 8. The size needs to meet the following conditions: Wherein, n is the refractive index of the waveguide substrate of the holographic dry plate 8, Prepare the half field of view of the optical machine for the holographic plate 8 to be used.

[0029] Example 2 Please refer to Figure 3 This embodiment provides a method for manufacturing a two-dimensional vector volume holographic grating waveguide. The manufacturing device in Embodiment 1 can be used to implement the steps of the method. The method includes: Step S1, fixing the holographic dry plate 8 to be exposed, and establishing a rectangular coordinate system with the second surface of the holographic dry plate 8 as the XOY plane.

[0030] Specifically, the first surface of the holographic dry plate 8 is bonded to the light-guiding prism 7, and the second surface of the holographic dry plate 8 is bonded to the triangular prism 6; the holographic dry plate 8 includes a waveguide substrate and a photosensitive material layer, the first surface of the holographic dry plate 8 is the surface where the waveguide substrate is located, and the second surface of the holographic dry plate 8 is the surface where the photosensitive material layer is located.

[0031] On the second surface of the holographic dry plate 8, a rectangular coordinate system is established with the propagation direction of the two-dimensional vector volume holographic grating waveguide as the X-axis direction, the Y-axis direction perpendicular to the X-axis direction, and the propagation starting point of the two-dimensional vector volume holographic grating waveguide as point O.

[0032] Step S2: Split the same exposure light into a first light beam 43 and a second light beam 53, and make the first light beam 43 irradiate the first surface of the holographic dry plate 8 vertically, while making the second light beam 53 The incident angle irradiates the second surface of the holographic dry plate 8 to form a volume holographic grating having a first grating component; wherein the propagation direction of the positive projection of the volume holographic grating vector of the first grating component on the second surface has an angle θ with the X-axis direction and an angle (π / 2-θ) with the Y-axis direction.

[0033] Specifically, the exposure light is emitted by the light emitting component of the manufacturing equipment; the exposure light is divided into a first light beam 43 and a second light beam 53 by the beam splitting exposure component; the first reflector 42, the second reflector 51 and the third reflector 52 are adjusted so that the first light beam 43 is reflected by the first reflector 42 and then vertically enters the first surface of the holographic dry plate 8, so that the second light beam 53 is reflected by the second reflector 51 and the third reflector 52 and then vertically enters the first surface of the holographic dry plate 8. The incident angle illuminates the second surface of the holographic dry plate 8, and ensures that the propagation direction of the positive projection of the volume holographic grating vector of the first grating component formed after exposure on the second surface is at an angle θ with the X-axis direction and at an angle (π / 2-θ) with the Y-axis direction.

[0034] in, The size satisfies the following conditions: Wherein, n is the refractive index of the waveguide substrate of the holographic dry plate 8, Prepare the half field of view of the optical machine for the holographic plate 8 to be used.

[0035] The size of θ satisfies: greater than 0 and less than π / 2.

[0036] Step S3: Make the first light beam 43 irradiate the first surface of the holographic dry plate 8 vertically, and make the second light beam 53 The incident angle irradiates the second surface of the holographic dry plate 8 to form a volume holographic grating having a second grating component, thereby realizing the two-dimensional pupil expansion of the two-dimensional vector grating waveguide; wherein the propagation direction of the positive projection of the volume holographic grating vector of the second grating component on the second surface has an angle θ with the X-axis direction and an angle (π / 2+θ) with the Y-axis direction.

[0037] Specifically, the Z axis perpendicular to the XOY plane and passing through the point O is used as the rotation axis, and the stage is rotated by an angle of 2θ in the direction of the positive half axis of the X axis, so that the second light beam 53 is still reflected by the second reflector 51 and the third reflector 52. The incident angle illuminates the second surface of the holographic dry plate 8, and makes the propagation direction of the positive projection of the volume holographic grating vector of the second grating component on the second surface have an angle θ with the X-axis direction and an angle (π / 2+θ) with the Y-axis direction; at the same time, the first light beam 43 is still vertically incident on the first surface of the holographic dry plate 8 after being reflected by the first reflector 42.

[0038] Reference Figure 4 , the volume holographic grating vector of the first grating component is The volume holographic grating vector of the second grating component is but, The grating vector components having the positive half-axis direction of the X-axis and the positive half-axis direction of the Y-axis; similarly, The grating vector has components in the positive half-axis direction of the X axis and the negative half-axis direction of the Y axis. and All must satisfy the Bragg formula of volume holographic grating: Among them, λ 0 is the wavelength in vacuum, Λ 0 is the grating period, is the incident angle of the second light beam relative to the holographic dry plate 8, n HOE is the refractive index of the grating medium of the holographic dry plate 8.

[0039] Then, the grating periods of the synthesized composite two-dimensional vector volume holographic grating in the X direction and the Y direction are: The composite two-dimensional vector volume holographic grating formed by combining the first grating component and the second grating component simultaneously has grating vector components in three directions: the positive half axis of the X-axis, the positive half axis of the Y-axis, and the negative half axis of the Y-axis, thereby realizing the two-dimensional pupil expansion of the two-dimensional vector volume holographic grating waveguide.

[0040] In order to further verify the effectiveness of the manufacturing method of this embodiment, the waveguide light path transmission when the coupling-in and coupling-out grating regions of this embodiment have only the first grating component, only the second grating component, and a composite reflective two-dimensional vector volume holographic grating is simulated. Please refer to Figures 5 to 7 .

[0041] From the simulation results of the waveguide optical path transmission, it can be seen that when there is only the first grating component, the light transmitted in the waveguide medium propagates along the X-axis direction while expanding the pupil to the right along the positive half axis of the Y-axis and coupling out into the detector (human eye); when there is only the second grating component, the light transmitted in the waveguide medium propagates along the X-axis direction while expanding the pupil to the left along the negative half axis of the Y-axis and coupling out into the detector (human eye); when there is a composite reflective two-dimensional vector volume holographic grating, the light transmitted in the waveguide medium propagates along the X-axis direction while propagating in the directions of the positive and negative half axes of the Y-axis and coupling out into the detector (human eye). This proves that the two-dimensional vector volume holographic grating waveguide provided in this embodiment only uses two grating components to achieve the two-dimensional pupil expansion function of the waveguide display system.

[0042] The implementation principle of the method for manufacturing the two-dimensional vector volume holographic grating waveguide provided in Example 2 of the present application is as follows: by rotating the stage, the holographic dry plate is exposed twice to obtain two grating components with different grating vector directions respectively, and the two grating components have grating vector components in the same direction on the X-axis and grating vector components with the same size and opposite directions on the Y-axis, and finally a composite two-dimensional vector volume holographic grating waveguide is obtained; the two-dimensional vector volume holographic grating waveguide prepared in this embodiment is a reflective two-dimensional vector volume holographic grating composited with two volume holographic gratings with different grating vector directions as a coupling-in and coupling-out optical component, and the two-dimensional pupil expansion function can be completed by coupling-in and coupling-out two grating areas, with extremely high space utilization, thereby greatly reducing the volume, weight and transmission distance of the waveguide, while reducing the volume and weight of the waveguide device, it also further reduces the loss and scattering of the light beam in the waveguide, thereby improving the final imaging effect.

[0043] Example 3 This embodiment provides a two-dimensional vector volume holographic grating waveguide, which is prepared by using the preparation method of Example 2 using the preparation equipment of Example 1.

[0044] Example 4 This embodiment provides an AR optical module, which includes a micro-image source display, a collimating optical system, a two-dimensional vector volume holographic grating waveguide in Example 3, and a cover plate protective layer, wherein the collimating optical system, the two-dimensional vector volume holographic grating waveguide and the cover plate protective layer are sequentially located on the optical path of the micro-image source display. The micro-image source display includes but is not limited to Micro-OLED, Micro-LED, LCOS, DMD, LBS, etc.; the collimating optical system is used to collimate and magnify the image emitted by the micro-image source display; the two-dimensional vector volume holographic grating waveguide is used to perform two-dimensional pupil expansion imaging on the collimated and magnified image; the cover plate protective layer is bonded to the two-dimensional vector volume holographic grating waveguide by a dispensing technology, and is used to seal and protect the surface of the two-dimensional vector volume holographic grating waveguide.

[0045] This embodiment applies the two-dimensional vector volume holographic grating waveguide in Example 3 to an AR optical module, and then to an AR wearable device, which helps the AR wearable device to achieve efficient, high-quality waveguide imaging with a large exit pupil and a large field of view, and at the same time helps to reduce the size and weight of the AR wearable device.

[0046] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A method for manufacturing a two-dimensional vector volume holographic grating waveguide, characterized in that: include: S1, fixing a holographic dry plate (8) to be exposed, and establishing a rectangular coordinate system with the second surface of the holographic dry plate (8) as an XOY plane; S2, dividing the same exposure light into a first light beam (43) and a second light beam (53), and making the first light beam (43) irradiate the first surface of the holographic dry plate (8) vertically, and making the second light beam (53) irradiating the second surface of the holographic dry plate (8) at an incident angle to form a volume holographic grating having a first grating component; S3, making the first light beam (43) irradiate the first surface of the holographic dry plate (8) vertically, and making the second light beam (53) The incident angle irradiates the second surface of the holographic dry plate (8) to form a volume holographic grating having a second grating component, thereby realizing a two-dimensional pupil expansion of the two-dimensional vector volume holographic grating waveguide; The propagation direction of the orthographic projection of the volume holographic grating vector of the first grating component on the second surface is symmetric with the propagation direction of the orthographic projection of the volume holographic grating vector of the second grating component on the second surface about the X-axis.

2. The method for manufacturing a two-dimensional vector volume holographic grating waveguide according to claim 1, characterized in that: The angle between the propagation direction of the orthographic projection of the volume holographic grating vector of the first grating component on the second surface and the X-axis direction is θ, and the angle between the propagation direction of the orthographic projection of the volume holographic grating vector of the second grating component on the second surface and the X-axis direction is θ, and the angle between the propagation direction of the orthographic projection of the volume holographic grating vector of the second grating component on the second surface and the Y-axis direction is (π / 2+θ); θ is greater than 0 and less than π / 2.

3. The method for manufacturing a two-dimensional vector volume holographic grating waveguide according to claim 2, characterized in that: The specific steps of S2 include: Using a beam splitting exposure component of a two-dimensional vector volume holographic grating waveguide manufacturing device to split the same exposure light into a first light beam (43) and a second light beam (53); The first light beam (43) is used to vertically illuminate the first surface of the holographic dry plate (8) by using a reflector of a two-dimensional vector volume holographic grating waveguide manufacturing device, and the second light beam (53) is used to vertically illuminate the first surface of the holographic dry plate (8) The incident angle illuminates the second surface of the holographic dry plate (8).

4. The method for manufacturing a two-dimensional vector volume holographic grating waveguide according to claim 1, characterized in that: The specific steps of S1 include: Fixing the holographic dry plate (8) on a stage of a two-dimensional vector volume holographic grating waveguide manufacturing device; An XOY rectangular coordinate system is established on the second surface of the holographic dry plate (8) according to the propagation direction of the two-dimensional vector volume holographic grating waveguide.

5. The method for manufacturing a two-dimensional vector volume holographic grating waveguide according to claim 4, characterized in that: The step of fixing the holographic dry plate (8) on the stage of the manufacturing equipment of the two-dimensional vector volume holographic grating waveguide comprises: laminating the first surface of the holographic dry plate (8) with the light-guiding prism (7) of the stage, and laminating the second surface of the holographic dry plate (8) with the triangular prism (6) of the stage; the holographic dry plate (8) comprises a waveguide substrate and a photosensitive material layer, the first surface of the holographic dry plate (8) is the surface where the waveguide substrate is located, and the second surface of the holographic dry plate (8) is the surface where the photosensitive material layer is located.

6. The method for manufacturing a two-dimensional vector volume holographic grating waveguide according to claim 4, characterized in that: The step of establishing an XOY rectangular coordinate system on the second surface of the holographic dry plate (8) in the propagation direction of the two-dimensional vector volume holographic grating waveguide comprises: A rectangular coordinate system is established with the propagation direction of the two-dimensional vector volume holographic grating waveguide as the X-axis direction, the direction perpendicular to the X-axis direction as the Y-axis direction, and the propagation starting point of the two-dimensional vector volume holographic grating waveguide as point O.

7. The method for manufacturing a two-dimensional vector volume holographic grating waveguide according to claim 6, characterized in that: The specific steps of S3 include: With the Z axis perpendicular to the XOY plane and passing through the O point as the rotation axis, the stage is rotated by an angle of 2θ in the direction of the positive half axis of the X axis; wherein θ is greater than 0 and less than π / 2.

8. The method for manufacturing a two-dimensional vector volume holographic grating waveguide according to claim 1, characterized in that: Said The size satisfies the following conditions: Wherein, n is the refractive index of the waveguide substrate of the holographic dry plate (8), A half field of view of an optical machine for preparing a holographic plate (8).

9. A two-dimensional vector volume holographic grating waveguide, characterized in that: The two-dimensional vector volume holographic grating waveguide is prepared by the method for preparing the two-dimensional vector volume holographic grating waveguide according to any one of claims 1 to 8.

10. An AR optical module, characterized in that: include: A micro-image source display, a collimating optical system, the two-dimensional vector volume holographic grating waveguide as claimed in claim 9, and a cover plate protective layer, wherein the collimating optical system, the two-dimensional vector volume holographic grating waveguide and the cover plate protective layer are sequentially located on the optical path of the micro-image source display; the collimating optical system is used to collimate and enlarge the image emitted by the micro-image source display; the two-dimensional vector volume holographic grating waveguide is used to perform two-dimensional pupil expansion imaging on the collimated and enlarged image; the cover plate protective layer is bonded to the two-dimensional vector volume holographic grating waveguide to seal and protect the surface of the two-dimensional vector volume holographic grating waveguide.

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