Two-dimensional vector volume holographic grating and its manufacturing equipment, manufacturing method, optical machine

Abstract

The present application relates to the field of near-eye display technology, and in particular to a two-dimensional vector volume holographic grating and its manufacturing equipment, manufacturing method, and optical machine. The manufacturing equipment of the two-dimensional vector volume holographic grating includes: a sample stage for fixing a holographic dry plate; a light emitting assembly for emitting exposure light; and a beam splitting exposure assembly located in the optical path of the exposure light and used to split the exposure light into a first light beam, a second light beam, a third light beam, and a fourth light beam, and to make the first light beam perpendicular to the first surface of the holographic dry plate, and to make the second light beam, the third light beam, and the fourth light beam respectively enter the second surface of the holographic dry plate at predetermined incident angles, and the orthographic projection of the second light beam on the holographic dry plate and the orthographic projection of the third light beam on the holographic dry plate are located on the same straight line and propagate in opposite directions, and the propagation direction of the orthographic projection of the fourth light beam on the holographic dry plate is perpendicular to the propagation direction of the orthographic projection of the second light beam on the holographic dry plate.

Description

Technical Field

[0001] The present application relates to the field of near-eye display technology, and in particular to a two-dimensional vector volume holographic grating and its manufacturing equipment, manufacturing method, and optical machine. Background Art

[0002] With the rapid development of AR near-eye display technology, the primary challenge facing near-eye display devices is how to reduce their size and weight while providing sufficient information and field of view, achieving lightweight devices and near-eye 3D rendering with high spatial and angular resolution. Diffractive devices, with their more powerful light field manipulation capabilities and thinner and lighter structures, are an effective way to address these issues and improve display performance.

[0003] Volume holographic waveguides utilize volume holographic gratings as light incoupling / decoupling devices. Compared to traditional arrayed waveguides that use geometric optical elements as light incoupling / decoupling devices, holographic waveguides can effectively reduce the thickness and weight of display systems. Two-dimensional pupil expansion technology utilizes the reflective array surface of an optical expansion waveguide to expand light entering the waveguide in two dimensions and then emit light outward to form an image.

[0004] However, the two-dimensional pupil-expanding holographic waveguide in related technologies is usually a three-grating (coupling grating, turning grating, and out-coupling grating) structure. This structure requires three exposures and has a complex process. In addition, the complexity of the three-grating structure makes the optical machine larger and more bulky, which is not conducive to the widespread application of two-dimensional pupil-expanding holographic waveguides. Summary of the Invention

[0005] In order to simplify the preparation process of a two-dimensional pupil-expanding volume holographic optical waveguide and realize the lightweight and thinning of the two-dimensional pupil-expanding volume holographic optical waveguide, the present application provides a two-dimensional vector volume holographic grating and its production equipment, production method, and optical machine.

[0006] The present application provides a two-dimensional vector volume holographic grating and its manufacturing equipment, manufacturing method, and optical machine using the following technical solutions:

[0007] A device for manufacturing a two-dimensional vector volume holographic grating, comprising:

[0008] Sample stage, used to fix the holographic dry plate;

[0009] A light emitting component, used for emitting exposure light;

[0010] A beam splitting exposure assembly is located in the optical path of the exposure light and is used to split the exposure light into a first beam, a second beam, a third beam, and a fourth beam, and to make the first beam perpendicular to the first surface of the holographic dry plate, and to make the second beam, the third beam, and the fourth beam respectively enter the second surface of the holographic dry plate at predetermined incident angles, and the orthographic projection of the second beam on the holographic dry plate and the orthographic projection of the third beam on the holographic dry plate are located on the same straight line and propagate in opposite directions, and the orthographic projection of the fourth beam on the holographic dry plate is perpendicular to the orthographic projection of the second beam on the holographic dry plate.

[0011] By adopting the above technical solution, the sample stage fixes the holographic plate, the light emitting assembly emits exposure light, and the beam splitting exposure assembly processes the exposure light to split it into a first beam, a second beam, a third beam, and a fourth beam. The first beam is incident perpendicularly on the first surface of the holographic plate, and the second, third, and fourth beams are incident on the second surface of the holographic plate at predetermined angles of incidence. The orthographic projection of the second beam on the holographic plate and the orthographic projection of the third beam on the holographic plate are located on the same straight line and propagate in opposite directions. The propagation direction of the orthographic projection of the fourth beam on the holographic plate is perpendicular to the propagation direction of the orthographic projection of the second beam on the holographic plate. In this way, the first and second beams interfere with each other to form a first grating propagating in the second direction, the first and third beams interfere with each other to form a second grating propagating in the third direction, and the first and fourth beams interfere with each other to form a third grating propagating in the fourth direction. The propagation direction of the first grating is opposite to that of the second grating, and the propagation direction of the third grating is perpendicular to that of the first grating. Ultimately, a two-dimensional vector volume holographic grating is produced.

[0012] Optionally, the beam splitting exposure assembly includes a beam splitting assembly and a reflecting assembly; the beam splitting assembly is used to split the exposure light into the first beam, the second beam, the third beam and the fourth beam, and the beam splitting assembly includes at least one and at most three beam splitters; the reflecting assembly includes a first reflecting assembly, a second reflecting assembly, a third reflecting assembly and a fourth reflecting assembly, the first reflecting assembly is used to reflect the first beam so that the first beam is incident vertically onto the first surface of the holographic dry plate, the second reflecting assembly is used to reflect the second beam so that the second beam is incident onto the second surface of the holographic dry plate at a second predetermined incident angle, the third reflecting assembly is used to reflect the third beam so that the third beam is incident onto the second surface of the holographic dry plate at a third predetermined incident angle, and the fourth reflecting assembly is used to reflect the fourth beam so that the fourth beam is incident onto the second surface of the holographic dry plate at a fourth predetermined incident angle.

[0013] By adopting the above technical solution, the first light beam is incident perpendicularly on the first surface of the holographic dry plate using the first reflecting component, the second light beam is incident on the second surface of the holographic dry plate at a second predetermined incident angle using the second reflecting component, the third light beam is incident on the second surface of the holographic dry plate at a third predetermined incident angle using the third reflecting component, and the fourth light beam is incident on the second surface of the holographic dry plate at a fourth predetermined incident angle using the fourth reflecting component.

[0014] Optionally, the beam splitting assembly includes a first beam splitter, a second beam splitter and a third beam splitter; the first beam splitter is arranged in the light-emitting direction of the exposure light, and is used to split the exposure light into the first light beam and the first total light beam; the second beam splitter is arranged in the optical path of the first total light beam, and is used to split the first total light beam into the second light beam and the second total light beam; the third beam splitter is arranged in the optical path of the second total light beam, and is used to split the second total light beam into the third light beam and the fourth light beam.

[0015] By adopting the above technical solution, the exposure light is split into the first light beam, the second light beam, the third light beam and the fourth light beam by using the first beam splitter, the second beam splitter and the third beam splitter.

[0016] Optionally, the first beam splitter, the second beam splitter and the third beam splitter are sequentially located in the light-emitting direction of the exposure light;

[0017] The first reflective assembly includes a first reflective mirror, which is arranged on the optical path of the first light beam and is used to reflect the first light beam and make the first light beam vertically enter the first surface of the holographic dry plate;

[0018] The second reflective assembly includes a second reflective mirror, which is arranged on the optical path of the second light beam and is used to reflect the second light beam and make the second light beam enter the second surface of the holographic dry plate at the second preset incident angle;

[0019] The third reflective assembly includes a third reflective mirror, which is arranged on the optical path of the third light beam and is used to reflect the third light beam and make the third light beam enter the second surface of the holographic dry plate at the third preset incident angle;

[0020] The fourth reflective assembly includes a fourth reflective mirror, a fifth reflective mirror, and a sixth reflective mirror. The fourth reflective mirror, the fifth reflective mirror, and the sixth reflective mirror are used to sequentially reflect the fourth light beam and make the fourth light beam enter the second surface of the holographic dry plate at the fourth preset incident angle.

[0021] By adopting the above technical solution, the first light beam is incident perpendicularly onto the first surface of the holographic dry plate using the first reflecting mirror, the second light beam is incident onto the second surface of the holographic dry plate at a second predetermined angle of incidence using the second reflecting mirror, the third light beam is incident onto the second surface of the holographic dry plate at a third predetermined angle of incidence using the third reflecting mirror, and the fourth light beam is incident onto the second surface of the holographic dry plate at a fourth predetermined angle of incidence using the fourth, fifth, and sixth reflecting mirrors.

[0022] Optionally, the second preset incident angle is equal to the third preset incident angle.

[0023] By adopting the above technical solution, the grating formed after the interference exposure of the first light beam and the second light beam is completely symmetrical with the grating formed after the interference exposure of the first light beam and the second light beam.

[0024] Optionally, the light emitting component includes a first light emitting component, a second light emitting component and a third light emitting component, wherein the first light emitting component, the second light emitting component and the third light emitting component are parallel to each other and have the same light emitting direction;

[0025] The first light output assembly includes a first light source, a first collimator and a reflector, wherein the first collimator and the reflector are sequentially located on a light output path of the first light source, and the reflector is used to make the first light emitted by the first light source propagate along a first direction;

[0026] The second light emitting assembly includes a second light source, a second collimator and a second dichroic mirror, wherein the second collimator and the second dichroic mirror are sequentially located on a light emitting path of the second light source, the second dichroic mirror is located in the first direction of the reflector, and the second dichroic mirror is used to transmit the first light and allow the second light emitted by the second light source to propagate along the first direction;

[0027] The third light output assembly includes a third light source, a third collimator, and a third dichroic mirror. The third collimator and the third dichroic mirror are sequentially located on a light output path of the third light source. The third dichroic mirror is located in the first direction of the second dichroic mirror. The third dichroic mirror is configured to transmit the first light and the second light and cause the third light emitted by the third light source to propagate along the first direction. The first light, the second light, and the third light are combined into an exposure light beam at the third dichroic mirror and propagate in the first direction.

[0028] The first light source, the second light source, and the third light source 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.

[0029] By adopting the above technical solution, the color output of the light emitting component is achieved.

[0030] Optionally, the production equipment further includes a special-shaped prism and a light-guiding prism, wherein the light-guiding prism is configured to be attached to the first surface of the holographic dry plate, and the special-shaped prism is configured to be attached to the second surface of the holographic dry plate.

[0031] By adopting the above technical solution, while ensuring the incident angles of the first light beam, the second light beam, the third light beam and the fourth light beam, stray light is eliminated, thereby improving the quality and production yield of the two-dimensional vector volume holographic grating.

[0032] A method for manufacturing a two-dimensional vector volume holographic grating, wherein the steps of the method are implemented using the manufacturing device described in any embodiment of the present application, and the method comprises:

[0033] Fix the holographic dry plate to be exposed;

[0034] emitting exposure light through the light emitting component of the manufacturing equipment;

[0035] The exposure light is split into a first light beam, a second light beam, a third light beam, and a fourth light beam by a beam splitting exposure assembly of the manufacturing equipment. The first light beam is incident perpendicularly onto the first surface of the holographic dry plate, and the second light beam, the third light beam, and the fourth light beam are incident onto the second surface of the holographic dry plate at predetermined angles of incidence, respectively. The orthographic projection of the second light beam on the holographic dry plate is aligned with the orthographic projection of the third light beam on the holographic dry plate and propagates in opposite directions. The orthographic projection of the fourth light beam on the holographic dry plate is perpendicular to the orthographic projection of the second light beam on the holographic dry plate.

[0036] The first light beam and the second light beam are exposed to interfere with each other to form a first grating propagating along the second direction, the first light beam and the third light beam are exposed to interfere with each other to form a second grating propagating along the third direction, and the first light beam and the fourth light beam are exposed to interfere with each other to form a third grating propagating along the fourth direction, thereby finally preparing a two-dimensional vector volume holographic grating; wherein, the second direction is opposite to the third direction, and the fourth direction is perpendicular to the second direction.

[0037] By adopting the above technical solution, the light emitting assembly emits exposure light, and the beam splitting exposure assembly processes the exposure light, so that the exposure light is divided into a first light beam, a second light beam, a third light beam, and a fourth light beam. The first light beam is incident perpendicularly on the first surface of the holographic plate, and the second light beam, the third light beam, and the fourth light beam are incident on the second surface of the holographic plate at predetermined angles of incidence. The orthographic projection of the second light beam on the holographic plate and the orthographic projection of the third light beam on the holographic plate are located on the same straight line and propagate in opposite directions. The propagation direction of the orthographic projection of the fourth light beam on the holographic plate is perpendicular to the propagation direction of the orthographic projection of the second light beam on the holographic plate. In this way, the first and second light beams interfere with each other to form a first grating propagating in the second direction, the first and third light beams interfere with each other to form a second grating propagating in the third direction, and the first and fourth light beams interfere with each other to form a third grating propagating in the fourth direction. The propagation direction of the first grating is opposite to that of the second grating, and the propagation direction of the third grating is perpendicular to that of the first grating. Finally, a two-dimensional vector volume holographic grating is produced.

[0038] A two-dimensional vector volume holographic grating is prepared using the manufacturing device described in any embodiment of the present application and adopting the manufacturing method described in any embodiment of the present application.

[0039] An optical machine includes the two-dimensional vector volume holographic grating described in the present application.

[0040] In summary, this application includes at least one of the following beneficial technical effects:

[0041] 1. Using a light emitting assembly to emit exposure light, and using a beam splitting exposure assembly to process the exposure light, the exposure light is split into a first light beam, a second light beam, a third light beam, and a fourth light beam. The first light beam is incident perpendicularly on the first surface of the holographic plate, and the second light beam, the third light beam, and the fourth light beam are incident on the second surface of the holographic plate at predetermined angles of incidence, respectively. The orthographic projection of the second light beam on the holographic plate and the orthographic projection of the third light beam on the holographic plate are coaxial and propagate in opposite directions. The orthographic projection of the fourth light beam on the holographic plate is perpendicular to the propagation direction of the orthographic projection of the second light beam on the holographic plate. In this way, the first and second light beams interfere with each other to form a first grating propagating in the second direction, the first and third light beams interfere with each other to form a second grating propagating in the third direction, and the first and fourth light beams interfere with each other to form a third grating propagating in the fourth direction. The propagation direction of the first grating is opposite to that of the second grating, and the propagation direction of the third grating is perpendicular to that of the first grating, thereby ultimately producing a two-dimensional vector volume holographic grating.

[0042] 2. The grating after the interference exposure of the first light beam and the second light beam is completely symmetrical with the grating after the interference exposure of the first light beam and the second light beam;

[0043] 3. Eliminate stray light and improve the quality and production yield of two-dimensional vector volume holographic grating. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 This is a schematic diagram of the first structure of the equipment for manufacturing the two-dimensional vector volume holographic grating in Example 1 of the present application.

[0045] Figure 2 This is a schematic diagram of the optical path of the two-dimensional vector volume holographic grating in Example 1 of the present application.

[0046] Figure 3 This is a second structural schematic diagram of the manufacturing equipment of the two-dimensional vector volume holographic grating in Example 2 of the present application.

[0047] Figure 4 This is a schematic diagram of the optical path of the two-dimensional vector volume holographic grating in Example 2 of the present application.

[0048] Figure 5 This is a flow chart of the method for manufacturing a two-dimensional vector volume holographic grating in Example 3 of the present application.

[0049] Description of reference numerals:

[0050] 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 collimator; 22. Second collimator; 23. Third collimator; 31. Reflector; 32. Second dichroic mirror; 33. Third dichroic mirror; 41. First beam splitter; 411. First light beam; 42. Second beam splitter; 421. Second light beam; 43. Third beam splitter; 431. Third light beam; 432. Fourth light beam; 51. First reflector; 52. Second reflector; 53. Third reflector; 54. Fourth reflector; 55. Fifth reflector; 56. Sixth reflector; 57. Seventh reflector; 58. Eighth reflector; 6. Special-shaped prism; 7. Light-guiding prism; 8. Holographic dry plate. DETAILED DESCRIPTION

[0051] The following is combined with Figure 1-5 This application is described in further detail.

[0052] The embodiments of the present application disclose a two-dimensional vector volume holographic grating and a manufacturing method, manufacturing equipment, and optical machine thereof.

[0053] Example 1

[0054] Reference Figure 1 and Figure 2This embodiment provides a device for fabricating a two-dimensional vector volume holographic grating. The device includes a sample stage, a light output assembly, and a beam splitting exposure assembly. The sample stage is used to secure a holographic dry plate 8; the light output assembly is used to emit exposure light; and the beam splitting exposure assembly, located in the optical path of the exposure light, splits the exposure light and projects the split light beams onto the holographic dry plate 8 for exposure.

[0055] Specifically, in this embodiment, the light emitting assembly includes a first light emitting assembly, a second light emitting assembly, and a third light emitting assembly. 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.

[0056] The first light emitting component includes a first light source 11, a first collimator 21 and a reflector 31. The first light source 11 is used to emit a first light ray 111. The first collimator 21 is located between the first light source 11 and the reflector 31. The first collimator 21 is used to collimate the first light ray 111 emitted by the first light source 11. The reflector is used to reflect the first light ray 111 collimated by the first collimator 21, so that the first light ray 111 propagates along a first direction.

[0057] The second light emitting component includes a second light source 12, a second collimator 22 and a second dichroic mirror 32. The second light source 12 is used to emit a second light 121. The second collimator 22 is located between the second light source 12 and the second dichroic mirror 32. The second collimator 22 is used to collimate the second light 121 emitted by the second light source 12. The second dichroic mirror 32 is located in the first direction of the reflector 31. The second dichroic mirror 32 is used to pass the first light 111, reflect the second light 121, and make the second light 121 propagate along the first direction.

[0058] The third light emitting assembly includes a third light source 13, a third collimator 23 and a third dichroic mirror 33. The third light source 13 is used to emit a third light 131. The third collimator 23 is located between the third light source 13 and the third dichroic mirror 33. The third collimator 23 is used to collimate the third light 131 emitted by the third light source 13. The third dichroic mirror 33 is located in the first direction of the second dichroic mirror 32. The third 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.

[0059] The first light source 11, the second light source 12, and the third light source 13 are each selected from 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 beam at the third dichroic mirror 33, and the exposure beam continues to propagate in the first direction.

[0060] In other embodiments, the light emitting component may also be arranged in other ways. As long as the light emitting component design can achieve high-quality colored light output, it is within the scope of protection of this application.

[0061] Specifically, the beam splitting exposure assembly includes a beam splitting assembly and a reflecting assembly. The beam splitting assembly is used to split the exposure light into a first beam 411, a second beam 421, a third beam 431, and a fourth beam 432. The reflecting assembly includes a first reflecting assembly, a second reflecting assembly, a third reflecting assembly, and a fourth reflecting assembly. The first reflecting assembly is used to reflect the first beam 411 so that the first beam 411 is incident perpendicularly onto the first surface of the holographic dry plate 8. The second reflecting assembly is used to reflect the second beam 421 so that the second beam 421 is incident onto the second surface of the holographic dry plate 8 at a second predetermined angle of incidence. The third reflecting assembly is used to reflect the third beam 431 so that the third beam 431 is incident onto the second surface of the holographic dry plate 8 at a third predetermined angle of incidence. The fourth reflecting assembly is used to reflect the fourth beam 432 so that the fourth beam 432 is incident onto the second surface of the holographic dry plate 8 at a fourth predetermined angle of incidence.

[0062] The beam splitting assembly includes a first beam splitter 41, a second beam splitter 42, and a third beam splitter 43. The first beam splitter 41 is used to split the exposure light emitted by the light output assembly into a first beam 411 and a first total beam. The second beam splitter 42 is provided on the optical path of the first total beam and is used to split the first total beam into a second beam 421 and a second total beam. The third beam splitter 43 is provided on the optical path of the second total beam and is used to split the second total beam into a third beam 431 and a fourth beam 432.

[0063] In this embodiment, the first beam splitter 41, the second beam splitter 42 and the third beam splitter 43 can be arranged as follows: Figure 1 and Figure 2 As shown, the second beam splitter 42 is located between the first beam splitter 41 and the third beam splitter 43, and the first beam splitter 41, the second beam splitter 42, and the third beam splitter 43 are sequentially located in the first direction. The first beam splitter 41, the second beam splitter 42, and the third beam splitter 43 can also be arranged in other ways, as long as the arrangement method of splitting the exposure light into the first beam 411, the second beam 421, the third beam 431, and the fourth beam 432 is satisfied, and the scope of protection of this embodiment is all the same.

[0064] Correspondingly, such as Figure 1 and Figure 2As shown, the first reflecting assembly includes a first reflecting mirror, which is arranged on the optical path of the first light beam 411 and is used to reflect the first light beam 411 so that the first light beam 411 is perpendicularly incident on the first surface of the holographic dry plate 8. The second reflecting assembly includes a second reflecting mirror, which is arranged on the optical path of the second light beam 421 and is used to reflect the second light beam 421 so that the second light beam 421 is incident on the second surface of the holographic dry plate 8 at a second preset angle of incidence. The third reflecting assembly includes a third reflecting mirror, which is arranged on the optical path of the third light beam 431 and is used to reflect the third light beam 431 so that the third light beam 431 is incident on the second surface of the holographic dry plate 8 at a third preset angle of incidence. The fourth reflecting assembly includes a fourth reflecting mirror, a fifth reflecting mirror, and a sixth reflecting mirror, which are used to sequentially reflect the fourth light beam 432 so that the fourth light beam 432 is incident on the second surface of the holographic dry plate 8 at the fourth preset angle of incidence.

[0065] 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.

[0066] Figure 1 and Figure 2Only the application scenario where the beam splitting assembly includes three beam splitters is shown. In embodiments of the present invention, the beam splitting assembly may also include only one or two beam splitters. When the beam splitting assembly includes only one beam splitter, the beam splitter can simultaneously split the exposure light into a first beam 411, a second beam 421, a third beam 431, and a fourth beam 432. Accordingly, the first, second, third, and fourth reflective assemblies can be configured according to the propagation directions of the corresponding first, second, third, and fourth beams 411, 421, 431, and 432, respectively. Any configuration that ensures that the first beam 411 is incident perpendicularly onto the first surface of the holographic dry plate 8, the second beam 421 is incident at a second preset angle onto the second surface of the holographic dry plate 8, the third beam 431 is incident at a third preset angle onto the second surface of the holographic dry plate 8, and the fourth beam 432 is incident at a fourth preset angle onto the second surface of the holographic dry plate 8 is protected by the embodiments of the present application. When the beam splitting assembly includes only two beam splitters, one beam splitter can split the exposure light into the first beam 411 and the first total beam, and the other beam splitter can further split the first total beam into the second beam 421, the third beam 431, and the fourth beam 432. Alternatively, one beam splitter can split the exposure light into the first beam 411, the second beam 421, and the second total beam, and the other beam splitter can further split the second total beam into the third beam 431 and the fourth beam 432. Similarly, the first reflective assembly, the second reflective assembly, the third reflective assembly, and the fourth reflective assembly can be arranged according to the propagation directions of the corresponding first beam 411, the second beam 421, the third beam 431, and the fourth beam 432, respectively.

[0067] The second preset angle and the third preset angle are equal in magnitude. The orthographic projection of the second light beam 421 on the holographic dry plate 8 and the orthographic projection of the third light beam 431 on the holographic dry plate 8 are located on the same straight line and propagate in opposite directions. The magnitudes of the second, third, and fourth preset angles must all meet the following conditions:

[0068]

[0069] Wherein, θ is the size of any one of the second preset angle, the third preset angle, and the fourth preset angle; n is the refractive index of the waveguide substrate of the holographic dry plate 8, Prepare half the field of view of the optical machine for the holographic plate 8.

[0070] Furthermore, the apparatus for fabricating a two-dimensional vector volume holographic grating provided in this embodiment further includes a shaped prism 6. The shaped prism 6 includes a first surface, a second surface, a third surface, and a fourth surface. The first surface is configured to be in contact with the second surface of the holographic dry plate 8. The second surface is configured to receive a second light beam 421 and is perpendicular to the second light beam 421, so that the second light beam 421 can enter the second surface of the holographic dry plate 8 at a second predetermined angle of incidence. The third surface is configured to receive a third light beam 431 and is perpendicular to the third light beam 431, so that the third light beam 431 can enter the second surface of the holographic dry plate 8 at a third predetermined angle of incidence. The fourth surface is configured to receive a fourth light beam 432 and is perpendicular to the fourth light beam 432, so that the fourth light beam 432 can enter the second surface of the holographic dry plate 8 at a fourth predetermined angle of incidence.

[0071] Furthermore, the apparatus for fabricating a two-dimensional vector volume holographic grating provided in this embodiment also includes a light-guiding prism 7. The light-guiding prism 7 includes a light-incident surface, a light-exiting surface, and a bonding surface. The bonding surface is configured to mate with the first surface of the holographic dry plate 8. The light-incident surface is configured to receive the first light beam 411 and is perpendicular to the first light beam 411, thereby allowing the first light beam 411 to vertically enter the first surface of the holographic dry plate 8. The light-exiting surface is configured to emit stray light, thereby directing away excess stray light, thereby eliminating ghosting and improving the quality and manufacturing yield of the two-dimensional vector volume holographic grating. In this embodiment, the light-guiding prism 7 can be a parallelogram-shaped light-guiding prism 7 with an acute angle of 45°.

[0072] The implementation principle of the manufacturing device of the two-dimensional vector volume holographic grating provided in Example 1 of the present application is as follows:

[0073] The holographic dry plate 8 is fixed by the sample stage, and the exposure light is emitted by the light emitting component. The exposure light is processed by the beam splitting exposure component so that the exposure light is divided into a first light beam 411, a second light beam 421, a third light beam 431 and a fourth light beam 432. The first light beam 411 is vertically incident on the first surface of the holographic dry plate 8, and the second light beam 421, the third light beam 431 and the fourth light beam 432 are respectively incident on the second surface of the holographic dry plate 8 at predetermined incident angles. The orthographic projection of the second light beam 421 on the holographic dry plate 8 and the orthographic projection of the third light beam 431 on the holographic dry plate 8 are located on the same straight line and propagate in opposite directions. The orthographic projection of the fourth light beam 432 on the holographic dry plate 8 is located on the same straight line and propagates in opposite directions. The propagation direction of the orthographic projection of the light beam 432 on the holographic dry plate 8 is perpendicular to the propagation direction of the orthographic projection of the second light beam 421 on the holographic dry plate 8. In this way, the first light beam 411 and the second light beam 421 are exposed to interfere with each other to form a first grating propagating along the second direction, the first light beam 411 and the third light beam 431 are exposed to interfere with each other to form a second grating propagating along the third direction, and the first light beam 411 and the fourth light beam 432 are exposed to interfere with each other to form a third grating propagating along the fourth direction. The propagation direction of the first grating is opposite to that of the second grating, and the propagation direction of the third grating is perpendicular to that of the first grating. Finally, a two-dimensional vector volume holographic grating is prepared.

[0074] Example 2

[0075] Please refer to Figure 3 and Figure 4 The same and similar examples between this embodiment and embodiment 1 are not repeated here. The difference lies in that the first reflective assembly includes a first reflective mirror, a seventh reflective mirror, and an eighth reflective mirror. The first reflective mirror, the seventh reflective mirror, and the eighth reflective mirror are used to sequentially reflect the first light beam 411 and finally make the first light beam 411 vertically enter the first surface of the holographic dry plate 8.

[0076] In Example 1, the optical path length of the first light beam 411 reaching the holographic dry plate 8 is shorter than the optical path length of the second light beam 421 reaching the holographic dry plate 8, shorter than the optical path length of the third light beam 431 reaching the holographic dry plate 8, and shorter than the optical path length of the fourth light beam 432 reaching the holographic dry plate 8. In Example 2, by adding a seventh reflector and an eighth reflector, the optical path length of the first light beam 411 is increased, and the optical path length differences between the first light beam 411 and the second light beam 421, the third light beam 431, and the fourth light beam 432 are reduced, thereby improving the quality and manufacturing yield of the two-dimensional vector volume holographic grating.

[0077] Example 3

[0078] Please refer to Figure 5 This embodiment provides a method for manufacturing a two-dimensional vector volume holographic grating. The method adopts the manufacturing equipment in embodiment 1 or embodiment 2 to implement the various steps of the method. The implementation method includes:

[0079] Step B1: Fix the holographic dry plate 8 to be exposed.

[0080] Specifically, a light-guiding prism 7 is attached to the first surface of a holographic dry plate 8, and a shaped prism 6 is attached to the second surface of the holographic dry plate 8. The holographic dry plate 8 comprises a waveguide substrate and a photosensitive material layer. The first surface of the holographic dry plate 8 is where the waveguide substrate resides, while the second surface of the holographic dry plate 8 is where the photosensitive material layer resides. The light-guiding prism 7, holographic dry plate 8, and shaped prism are secured to the sample stage of a two-dimensional vector volume holographic grating fabrication apparatus.

[0081] Step B2: emitting exposure light through the light emitting component of the manufacturing equipment.

[0082] Specifically, the first light source 11 of the light emitting assembly emits a first light 111, which is collimated by the first collimator 21 and then emitted to the reflector 31. The reflector 31 reflects the first light 111 so that the first light 111 propagates in the first direction; the second light source 12 of the light emitting assembly emits a second light 121, which is collimated by the second collimator 22 and then emitted to the second dichroic mirror 32. The second dichroic mirror 32 projects the first light 111, reflects the second light 121 and propagates in the second direction. The light 121 propagates in the first direction; the third light source 13 of the light emitting assembly emits a third light 131, which is collimated by the third collimator 23 and then emitted to the third dichroic mirror 33. The third dichroic mirror 33 projects the first light 111 and the second light 121, reflects the third light 131 and causes the third light 131 to propagate in the first direction; the first light 111, the second light 121 and the third light 131 are combined into an exposure beam at the third dichroic mirror 33 and propagate in the first direction.

[0083] Step B3: The exposure light is split into a first light beam 411, a second light beam 421, a third light beam 431, and a fourth light beam 432 by the beam splitting exposure assembly of the manufacturing equipment. The first light beam 411 is incident perpendicularly onto the first surface of the holographic dry plate 8, while the second light beam 421, the third light beam 431, and the fourth light beam 432 are incident upon the second surface of the holographic dry plate 8 at predetermined angles of incidence. The orthographic projection of the second light beam 421 and the orthographic projection of the third light beam 431 on the holographic dry plate 8 are colinear and propagate in opposite directions. The orthographic projection of the fourth light beam 432 on the holographic dry plate 8 propagates perpendicularly to the orthographic projection of the second light beam 421 on the holographic dry plate 8.

[0084] Specifically, the first beam splitter 41 of the beam splitting exposure assembly splits the exposure light into a first beam 411 and a first total beam. The first reflector reflects the first beam 411 and makes the first beam 411 vertically incident on the light incident surface of the light guide prism 7, and then vertically incident on the first surface of the holographic dry plate 8. The second beam splitter 42 splits the first total beam into a second beam 421 and a second total beam. The second reflector reflects the second beam 421 and makes the second beam 421 vertically incident on the first surface of the special-shaped prism 6, and then incident on the holographic dry plate 8 at a first preset incident angle. The second surface of the holographic plate 8 is formed by the second beam splitter 43; the third beam splitter 43 splits the second total light beam into a third light beam 431 and a fourth light beam 432; the third reflector reflects the third light beam 431 so that the third light beam 431 is incident perpendicularly on the second surface of the shaped prism 6 and then incident on the second surface of the holographic plate 8 at a third preset angle of incidence; the fourth reflector, the fifth reflector, and the sixth reflector sequentially reflect the fourth light beam 432 so that the fourth light beam 432 is incident perpendicularly on the third surface of the shaped prism 6 and then incident on the second surface of the holographic plate 8 at a fourth preset angle of incidence. The orthographic projection of the second light beam 421 on the holographic plate 8 and the orthographic projection of the third light beam 431 on the holographic plate 8 are colinear and propagate in opposite directions; the propagation direction of the orthographic projection of the fourth light beam 432 on the holographic plate 8 is perpendicular to the propagation direction of the orthographic projection of the second light beam 421 on the holographic plate 8; and the second preset angle of incidence is equal to the third preset angle of incidence. The second, third, and fourth preset angles all satisfy the following conditions:

[0085]

[0086] Wherein, θ is the size of any one of the second preset angle, the third preset angle, and the fourth preset angle; n is the refractive index of the waveguide substrate of the holographic dry plate 8, Prepare half the field of view of the optical machine for the holographic plate 8.

[0087] Step B4: The first light beam 411 and the second light beam 421 are exposed to interfere with each other to form a first grating propagating along the second direction; the first light beam 411 and the third light beam 431 are exposed to interfere with each other to form a second grating propagating along the third direction; the first light beam 411 and the fourth light beam 432 are exposed to interfere with each other to form a third grating propagating along the fourth direction, and a two-dimensional vector volume holographic grating is finally prepared; wherein, the second direction is opposite to the third direction, and the fourth direction is perpendicular to the second direction.

[0088] Example 4

[0089] This embodiment provides a two-dimensional vector volume holographic grating, which is manufactured using the manufacturing equipment in Example 1 or Example 2 and the manufacturing method in Example 3.

[0090] Example 5

[0091] This embodiment provides an optical engine, which includes the two-dimensional vector volume holographic grating in Example 3.

[0092] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A device for manufacturing a two-dimensional vector volume holographic grating, characterized in that: include: A sample stage is used for fixing a holographic dry plate (8), wherein a first surface of the holographic dry plate (8) is a surface on which a waveguide substrate is located; A light emitting component, used for emitting exposure light; The beam splitting exposure component is located on the optical path of the exposure light and is used to split the exposure light into a first light beam (411), a second light beam (421), a third light beam (431) and a fourth light beam (432), and to make the first light beam (411) vertically incident on the first surface of the holographic dry plate (8), and to make the second light beam (421), the third light beam (431) and the fourth light beam (432) incident on the second surface of the holographic dry plate (8) at a second preset incident angle, a third preset incident angle and a fourth preset incident angle respectively, and the second light beam (421) is incident on the second surface of the holographic dry plate (8) at a second preset incident angle, a third preset incident angle and a fourth preset incident angle respectively. The orthographic projection of the light beam (421) on the holographic dry plate (8) and the orthographic projection of the third light beam (431) on the holographic dry plate (8) are located on the same straight line and have opposite propagation directions; the propagation direction of the orthographic projection of the fourth light beam (432) on the holographic dry plate (8) is perpendicular to the propagation direction of the orthographic projection of the second light beam (421) on the holographic dry plate (8); the second preset incident angle is equal to the third preset incident angle, and the second preset incident angle, the third preset incident angle, and the fourth preset incident angle all need to meet the following conditions: Wherein, θ is the size of any one of the second preset incident angle, the third preset incident angle, and the fourth preset incident angle; n is the refractive index of the waveguide substrate of the holographic dry plate (8), The half field angle of the optical machine to which the holographic dry plate (8) is to be applied; and A special-shaped prism (6) includes a first surface, a second surface, a third surface, and a fourth surface. The first surface is configured to be in contact with the second surface of a holographic dry plate (8); the second surface is configured to receive a second light beam (421) and is perpendicular to the second light beam (421), so that the second light beam (421) can be incident on the second surface of the holographic dry plate (8) at a second preset angle of incidence; the third surface is configured to receive a third light beam (431) and is perpendicular to the third light beam (431), so that the third light beam (431) can be incident on the second surface of the holographic dry plate (8) at a third preset angle of incidence; and the fourth surface is configured to receive a fourth light beam (432) and is perpendicular to the fourth light beam (432), so that the fourth light beam (432) can be incident on the second surface of the holographic dry plate (8) at a fourth preset angle of incidence.

2. The production equipment according to claim 1, characterized in that The beam splitting exposure component comprises a beam splitting component and a reflection component; the beam splitting component is used to split the exposure light into the first light beam (411), the second light beam (421), the third light beam (431) and the fourth light beam (432); the beam splitting component comprises 1 to 3 beam splitters; the reflection component comprises a first reflection component, a second reflection component, a third reflection component and a fourth reflection component; the first reflection component is used to reflect the first light beam (411) so that the first light beam (411) is vertically incident on the first surface of the holographic dry plate (8); the second reflection component is used to reflect the second light beam (421); the third reflection component is used to reflect the third light beam (431); and the fourth reflection component is used to reflect the fourth light beam (432).

3. The production equipment according to claim 2, characterized in that The beam splitting assembly comprises a first beam splitter (41), a second beam splitter (42) and a third beam splitter (43); the first beam splitter (41) is arranged in the light-emitting direction of the exposure light, and is used to split the exposure light into the first light beam (411) and a first total light beam; the second beam splitter (42) is arranged in the optical path of the first total light beam, and is used to split the first total light beam into the second light beam (421) and the second total light beam; the third beam splitter (43) is arranged in the optical path of the second total light beam, and is used to split the second total light beam into the third light beam (431) and the fourth light beam (432).

4. The production equipment according to claim 3, characterized in that The first beam splitter (41), the second beam splitter (42), and the third beam splitter (43) are sequentially located in the light-emitting direction of the exposure light; The first reflecting component comprises a first reflecting mirror, the first reflecting mirror being arranged on the optical path of the first light beam (411) and being used for reflecting the first light beam (411); The second reflecting component comprises a second reflecting mirror, which is arranged on the optical path of the second light beam (421) and is used to reflect the second light beam (421); The third reflecting assembly comprises a third reflecting mirror, which is arranged on the optical path of the third light beam (431) and is used to reflect the third light beam (431); The fourth reflecting assembly includes a fourth reflecting mirror, a fifth reflecting mirror and a sixth reflecting mirror, and the fourth reflecting mirror, the fifth reflecting mirror and the sixth reflecting mirror are used to reflect the fourth light beam (432) in sequence.

5. The production equipment according to claim 1, characterized in that The light emitting assembly includes a first light emitting assembly, a second light emitting assembly and a third light emitting assembly, wherein 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 component comprises a first light source (11), a first collimator (21) and a reflector (31), wherein the first collimator (21) and the reflector (31) are sequentially located on a light emitting path of the first light source (11), and the reflector (31) is used to cause a first light ray (111) emitted by the first light source (11) to propagate along a first direction; The second light emitting component comprises a second light source (12), a second collimator (22) and a second dichroic mirror (32), wherein the second collimator (22) and the second dichroic mirror (32) are sequentially located on a light emitting path of the second light source (12), the second dichroic mirror (32) is located in the first direction of the reflector (31), and the second dichroic mirror (32) is used to transmit the first light (111) and to allow the second light (121) emitted by the second light source (12) to propagate along the first direction; The third light emitting component comprises a third light source (13), a third collimator (23) and a third dichroic mirror (33); the third collimator (23) and the third dichroic mirror (33) are sequentially located on the light emitting path of the third light source (13); the third dichroic mirror (33) is located in the first direction of the second dichroic mirror (32); the third dichroic mirror (33) is used to transmit the first light (111) and the second light (121), and to make the third light (131) emitted by the third light source (13) propagate along the first direction; the first light (111), the second light (121) and the third light (131) are combined into an exposure light beam at the third dichroic mirror (33) and propagate in the first direction; the first light source (111), the second light source (121) and the third light source (131) 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.

6. The production equipment according to any one of claims 1 to 5, characterized in that: The manufacturing equipment further comprises a light-guiding prism (7), and the light-guiding prism (7) is configured to be attached to the first surface of the holographic dry plate (8).

7. A method for manufacturing a two-dimensional vector volume holographic grating, characterized in that: The steps of the production method are implemented using the production equipment according to any one of claims 1 to 6, and the production method includes: Fixing a holographic dry plate (8) to be exposed, wherein the first surface of the holographic dry plate (8) is the surface where the waveguide substrate is located; emitting exposure light through the light emitting component of the manufacturing equipment; The exposure light is divided into a first light beam (411), a second light beam (421), a third light beam (431) and a fourth light beam (432) by a beam splitting exposure component of the manufacturing equipment, and the first light beam (411) is vertically incident on the first surface of the holographic dry plate (8), and the second light beam (421), the third light beam (431) and the fourth light beam (432) are incident on the second surface of the holographic dry plate (8) at a second preset incident angle, a third preset incident angle and a fourth preset incident angle respectively; the orthographic projection of the second light beam (421) on the holographic dry plate (8) and the orthographic projection of the third light beam (431) on the holographic dry plate (8) are located on the same straight line and propagate in opposite directions, and the propagation direction of the orthographic projection of the fourth light beam (432) on the holographic dry plate (8) is vertical to the propagation direction of the orthographic projection of the second light beam (421) on the holographic dry plate (8); The first light beam (411) and the second light beam (421) are exposed and interfered to form a first grating propagating along the second direction, the first light beam (411) and the third light beam (431) are exposed and interfered to form a second grating propagating along the third direction, and the first light beam (411) and the fourth light beam (432) are exposed and interfered to form a third grating propagating along the fourth direction, thereby finally preparing a two-dimensional vector volume holographic grating; wherein, the second direction and the third direction are opposite, and the fourth direction is perpendicular to the second direction; the second preset incident angle and the third preset incident angle are equal in magnitude, and the magnitudes of the second preset incident angle, the third preset incident angle, and the fourth preset incident angle all need to meet the following conditions: Wherein, θ is the size of any one of the second preset incident angle, the third preset incident angle, and the fourth preset incident angle; n is the refractive index of the waveguide substrate of the holographic dry plate (8), The half field angle of the optical machine to which the holographic dry plate (8) is to be applied; and A special-shaped prism (6) is provided, wherein the special-shaped prism (6) comprises a first surface, a second surface, a third surface and a fourth surface, wherein the first surface is arranged to be in contact with the second surface of a holographic dry plate (8); the second surface is arranged to receive a second light beam (421) and is perpendicular to the second light beam (421), so that the second light beam (421) can be incident on the second surface of the holographic dry plate (8) at a second preset incident angle; the third surface is arranged to receive a third light beam (431) and is perpendicular to the third light beam (431), so that the third light beam (431) can be incident on the second surface of the holographic dry plate (8) at a third preset incident angle; and the fourth surface is arranged to receive a fourth light beam (432) and is perpendicular to the fourth light beam (432), so that the fourth light beam (432) can be incident on the second surface of the holographic dry plate (8) at a fourth preset incident angle.

8. A two-dimensional vector volume holographic grating, characterized in that: The two-dimensional vector volume holographic grating is manufactured using the manufacturing equipment according to any one of claims 1 to 6 and the manufacturing method according to claim 7.

9. An optical machine, characterized in that: The optical engine includes the two-dimensional vector volume holographic grating described in claim 8.

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