Grating structure manufacturing system
By combining an integrated mask assembly and a spectroscopic guide assembly, the problem that traditional methods are difficult to simultaneously produce diffraction structures is solved, and low-cost and efficient grating structure preparation is achieved.
Patent Information
- Application Number
- CN202422273288.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-14
- Publication Date
- 2025-09-09
- Estimated Expiration
- 2034-09-14
AI Technical Summary
Traditional methods make it difficult to simultaneously produce coupling-in and coupling-out diffraction structures with different structural functions, and the production difficulty and cost are high.
An integrated mask assembly is used, including a first grating phase mask and a second grating phase mask. The laser beam is divided into a first beam and a second beam by a beam splitting guide assembly, and the first beam and the second beam are incident on the mask assembly with different optical paths, forming grating structures with different periods.
It is possible to simultaneously prepare grating structures with different periods during a single exposure process, reducing the difficulty and cost of production.
Smart Images
Figure CN223320614U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of grating production, and in particular to a system for producing a variable-period grating structure. Background Art
[0002] Augmented Reality (AR) is a display technology that captures real-world image information in real time and combines virtual information and images with the displayed image information. AR display devices based on AR technology are expected to become the next generation of information interaction terminals after personal computers and smartphones, with a wide range of application scenarios.
[0003] Diffractive waveguide modules are the core modules of AR display devices and are typically required to be lightweight, efficient, and mass-producible. However, diffractive waveguide modules typically include in-coupling and out-coupling diffraction structures with distinct structural functions. Traditional manufacturing methods make it difficult to simultaneously produce these diffraction structures, or the manufacturing process is difficult and costly. Utility Model Content
[0004] The present application provides a grating structure production system, comprising: a light source assembly for emitting a first light beam and a second light beam, the first light beam and the second light beam propagating along different optical paths; a mask assembly, the mask assembly being an integrated structure, comprising a first grating phase mask and a second grating phase mask, the first grating phase mask and the second grating phase mask having different grating periods, the first grating phase mask being located on the propagation path of the first light beam and being used to diffract the first light beam to form a first exposure beam; the second grating phase mask being located on the propagation path of the second light beam and being used to diffract the second light beam to form a second exposure beam; an exposure substrate for carrying an exposure material, the first exposure beam and the second exposure beam being incident on different positions of the exposure substrate respectively, so as to form grating structures with different periods at different positions of the exposure material when the exposure material is placed on the exposure substrate.
[0005] In at least one embodiment of the present application, the light source assembly includes a laser light source and a beam splitting and guiding assembly. The laser light source is used to emit a laser beam. The beam splitting and guiding assembly is arranged on the optical path of the laser beam and is used to split the laser beam to form the first beam and the second beam.
[0006] In at least one embodiment of the present application, the spectroscopic guiding component is also used to guide the first light beam to be incident on the first grating phase mask at a first Littrow angle, and to guide the second light beam to be incident on the second grating phase mask at a second Littrow angle; the first exposure beam is formed by the interference of the 0th order diffraction light and the -1st order diffraction light of the first light beam, and the second exposure beam is formed by the interference of the 0th order diffraction light and the -1st order diffraction light of the second light beam.
[0007] In at least one embodiment of the present application, the spectroscopic guiding component includes a spectrometer and a reflector; the spectrometer is located in the optical path of the laser beam, and is used to reflect part of the laser beam as the first beam, and to transmit another part of the laser beam as the second beam, and the reflector is used to reflect the second beam to the second grating phase mask.
[0008] In at least one embodiment of the present application, the grating structure fabrication system further includes a first beam shaping element, which is located in the optical path of the first beam and is used to adjust the spot size of the first beam incident on the first grating phase mask; and / or the grating structure fabrication system includes a second beam shaping element located in the optical path of the second beam, which is used to adjust the spot size of the second beam incident on the second grating phase mask.
[0009] In at least one embodiment of the present application, the grating structure manufacturing system also includes a first grayscale mask, which is located on the optical path of the first light beam. The first grayscale mask is used to modulate the light intensity distribution of the first light beam so that the first light beam after light intensity modulation is incident on the first grating phase mask. The first grayscale mask includes multiple partitions with different transmittances or has a gradient transmittance as a whole.
[0010] In at least one embodiment of the present application, the grating structure manufacturing system also includes a second grayscale mask, which is located on the optical path of the second light beam. The second grayscale mask is used to modulate the light intensity distribution of the second light beam so that the second light beam after light intensity modulation is incident on the second grating phase mask. The second grayscale mask includes multiple partitions with different transmittances or has a gradient transmittance as a whole.
[0011] In at least one embodiment of the present application, the first grayscale mask is rectangular, having a first side and a second side relatively arranged, and the transmittance of the grayscale mask gradually increases from the first side to the second side; or the grayscale mask is circular, and the transmittance of the grayscale mask gradually increases from the circumference to the center of the circle.
[0012] In at least one embodiment of the present application, the second grayscale mask is rectangular, having a first side and a second side relatively arranged, and the transmittance of the second grayscale mask gradually increases from the first side to the second side; or the grayscale mask is circular, and the transmittance of the grayscale mask gradually increases from the circumference to the center of the circle.
[0013] In at least one embodiment of the present application, the light source assembly is further configured to emit a third light beam, wherein a propagation optical path of the third light beam is different from those of the first and second light beams. The mask assembly further comprises a third grating phase mask, wherein a grating period of the third grating phase mask is different from those of the first and second grating phase masks. The third grating phase mask is located on the propagation optical path of the third light beam and is configured to diffract the third light beam to form a third exposure beam corresponding to the third light beam.
[0014] In the above-mentioned grating structure production system, the light source component is used to emit the first light beam and the second light beam, and the mask component includes an integrated first grating phase mask and a second grating phase mask. The first grating phase mask and the second grating phase mask can respectively diffract the first light beam and the second light beam to generate a first exposure beam and a second exposure beam. The first grating phase mask and the second grating phase mask have different grating periods. After the first exposure beam and the second exposure beam irradiate the exposure material, a single exposure can be achieved to simultaneously prepare the first grating structure and the second grating structure with different periods. In addition, the preparation process of the grating structure production system 1 is simple and the preparation cost is low. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 This is a diagram of the optical path structure of the grating structure manufacturing system according to an embodiment of the present application.
[0016] Figure 2 for Figure 1 Schematic diagram of the effect of the middle mask assembly on the first light beam and the second light beam.
[0017] Figure 3 To utilize Figure 1 Schematic diagram of the grating structure produced by the grating structure production system.
[0018] Figure 4 This is a diagram of the optical path structure of a grating structure manufacturing system in a modified embodiment of the present application.
[0019] Figure 5 for Figure 4 Schematic diagram of the transmittance design of the first grayscale mask.
[0020] Figure 6 Schematic diagram of the transmittance design of the first grayscale mask in a modified embodiment of the present application.
[0021] Figure 7 Schematic diagram of the transmittance design of the first grayscale mask in another modified embodiment of the present application.
[0022] Figure 8 Schematic diagram of a grating structure fabricated using a grating structure fabrication system according to another embodiment of the present application.
[0023] Description of main component symbols
[0024]
[0025] The following specific implementation methods will further illustrate the present application in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION
[0026] The embodiments of the present application provide a grating structure manufacturing system, which can simultaneously form at least a first grating structure and a second grating structure with different periods while reducing the manufacturing difficulty and cost.
[0027] See also Figure 1 The grating structure manufacturing system 1 of this embodiment includes a light source assembly 10, an exposure substrate 20, and a mask assembly 30. The light source assembly 10 is used to emit a first light beam L11 and a second light beam L12. The first light beam L11 and the second light beam L12 propagate along different optical paths. The mask assembly 30 is used to diffract the first light beam L11 to generate a first exposure light beam L21 (see FIG. Figure 2 ), and is also used to diffract the second light beam L12 to generate a second exposure light beam L22 (see Figure 2 The exposure substrate 20 is used to support the exposure material 2. The first exposure beam L21 and the second exposure beam L22 are respectively incident on different positions of the exposure substrate 20, so as to form two grating structures with different periods at different positions of the exposure material 2 when the exposure material 2 is placed on the exposure substrate 20.
[0028] The light source assembly 10 includes a laser light source 11, a spatial filter 12, a lens 13, and a beam splitting and guiding assembly 14. The laser light source 11 is used to emit a laser beam L0. In this embodiment, the laser light source 11 is a laser, and the laser beam L0 is an ultraviolet laser with a wavelength of 320nm-460nm (including the endpoint values). The spatial filter 12 is located between the laser light source 11 and the lens 13, and is used to filter out high-frequency noise in the light beam emitted by the laser light source 11. The lens 13 is a convex lens, which is used to converge and collimate the light beam emitted by the spatial filter 12 to emit the above-mentioned laser beam L0, that is, the laser beam L0 is a collimated ultraviolet laser beam.
[0029] In this embodiment, the beam splitting and guiding assembly 14 includes a beam splitter 141 and a reflector 142. The beam splitter 141 is used to reflect a portion of the laser beam L0 from the lens 13 as a first beam L11, and to transmit another portion of the laser beam L0 from the lens 13 as a second beam L12. The reflection and transmission ratio of the beam splitter 141 is, for example, 1:1. The first beam L11 propagates along a first optical path to the mask assembly 30, and the second beam L12 propagates along a second optical path different from the first optical path to the mask assembly 30.
[0030] The mask assembly 30 is an integrated structure, comprising a first grating phase mask 32 and a second grating phase mask 33. In one embodiment, the mask assembly 30 further comprises a substrate 31, on which the first grating phase mask 32 and the second grating phase mask 33 are disposed. The substrate 31 is a light-transmitting substrate, allowing the first light beam L11 and the second light beam L12 to penetrate the substrate 31 as much as possible and be utilized by the first grating phase mask 32 and the second grating phase mask 33, thereby minimizing light loss of the first light beam L11 and the second light beam L12 after passing through the substrate 31. This helps improve diffraction efficiency.
[0031] The substrate 31 has a first surface 311 facing away from the spectroscopic guiding component 14 and a second surface 312 facing the spectroscopic guiding component 14. That is, the first surface 311 and the second surface 312 are spaced apart and arranged opposite to each other. The substrate 31 is a solid structure as a whole, and the first surface 311 and the second surface 312 are continuous flat surfaces. The first grating phase mask 32 and the second grating phase mask 33 are spaced apart and arranged on the first surface 311. The first grating phase mask 32 and the second grating phase mask 33 have different grating periods. The first grating phase mask 32 and the second grating phase mask 33 of the embodiment of the present application can be surface relief gratings, volume holographic gratings, polarization volume holographic gratings, etc.
[0032] In a modified embodiment of the present application, one of the first grating phase mask 32 and the second grating phase mask 33 may be located on the first surface 311 of the substrate 31, while the other may be located on the second surface 312 of the substrate 31. In another modified embodiment of the present application, the mask assembly 30 is an entire planar structure, wherein a portion of the planar structure is patterned to form a grating pattern and serves as the first grating phase mask 32, while another portion of the planar structure is patterned to form a grating pattern and serves as the second grating phase mask 33. That is, in this modified embodiment, the mask assembly 30 is also a one-piece structure.
[0033] See also Figure 2The first grating phase mask 32 is used to receive and diffract the first light beam L11. After the first light beam L11 is diffracted by the first grating phase mask 32, it generates 0-order diffraction light L111 and -1-order diffraction light L112. The 0-order diffraction light L111 and the -1-order diffraction light L112 interfere with each other in the light field superposition area to generate the first exposure light beam L21. When the first exposure light beam L21 is irradiated on the exposure material 2, an interference pattern is formed, so that an exposure pattern can be formed on the substrate. Figure 3 A first grating structure 301 is shown.
[0034] Please refer to Figure 2 The second grating phase mask 33 is used to receive and diffract the second light beam L12. After the second light beam L12 is diffracted by the second grating phase mask 33, it generates a 0th order diffraction light L121 and a -1st order diffraction light L122. The 0th order diffraction light L121 and the -1st order diffraction light L122 interfere with each other in the light field superposition area to generate a second exposure light beam L22. When the second exposure light beam L22 is irradiated on the exposure material 2, an interference pattern is formed, so that an exposure pattern can be formed on the substrate. Figure 3 The second grating structure 202 is shown.
[0035] Please refer to Figure 2 In this embodiment, the first light beam L11 is at the first Littrow angle The light is incident on the first grating phase mask 32. The first grating phase mask 32 is a blazed grating with a first Littrow angle of is equal to the blaze angle of the first grating phase mask 32. The light energy of the first light beam L11 after diffraction by the first grating phase mask 32 is concentrated in the 0th order diffraction light and the -1st order diffraction light. The second grating phase mask 33 is incident on the second grating phase mask 33. The second grating phase mask 33 is a blazed grating with a second Littrow angle of is equal to the blaze angle of the second grating phase mask 33. The light energy of the second light beam L12 after diffraction by the second grating phase mask 33 is also concentrated in the 0th order diffraction light and the -1st order diffraction light.
[0036] The first Littrow angle mentioned above and the second Littrow angle The calculation formula is:
[0037] (1)
[0038] in is the wavelength of the incident light (the first light beam L11 or the second light beam L12), is the period of the first grating phase mask 32 or the second grating phase mask 33.
[0039] The interference pattern period generated by the first exposure beam L21 and the second exposure beam L22 is:
[0040] (2)
[0041] In this embodiment, the exposure material 2 is a photoresist. When the first exposure beam L21 and the second exposure beam L22 irradiate the exposure material 2, the areas of the exposure material 2 irradiated by the first exposure beam L21 and the second exposure beam L22 respectively record the interference patterns irradiated by the first exposure beam L21 and the second exposure beam L22, so that the exposed exposure material 2 forms a first grating structure 301 and a second grating structure 302 after being immersed in a developer (see FIG. Figure 3 The first grating structure 301 and the first grating phase mask 32 have the same grating period, and the second grating structure 302 and the second grating phase mask 33 have the same grating period. The substrate 201 is a semiconductor material, such as silicon, silicon oxide, silicon nitride, silicon oxynitride, or quartz glass.
[0042] See also Figure 3 In this embodiment, the grating structure manufacturing system 1 is used to manufacture the coupling-in grating and the coupling-out grating on the optical waveguide in the AR glasses 3. Figure 3 In the embodiment, the first grating structure 301 is an outcoupling grating, and the second grating structure 302 is an incoupling grating. The surfaces of the first grating structure 301 and the second grating structure 302 for receiving light beams are defined as light-receiving surfaces. In this embodiment, the light-receiving surface area of the first grating structure 301 is larger than the light-receiving surface area of the second grating structure 302.
[0043] The second grating structure 302 is used to receive and diffract image light from the microdisplay. The image light emitted by the second grating structure 302 is transmitted along the optical waveguide to the first grating structure 301. The first grating structure 301 is used to couple the image light out to the human eye, allowing the human eye to observe the AR image.
[0044] Please refer to Figure 1 In this embodiment, the grating structure fabrication system 1 further includes a first beam shaping element 41 and a second beam shaping element 42. The first beam shaping element 41 is located between the beam splitter 141 and the mask assembly 30 and in the optical path of the first light beam L11. The first beam shaping element 41 is configured to expand or contract the first light beam L11 to adjust the spot size of the first light beam L11 on the first grating phase mask 32. The second beam shaping element 42 is located between the reflector 142 and the mask assembly 30 and in the optical path of the second light beam L12. The second beam shaping element 42 is configured to expand or contract the second light beam L12 to adjust the spot size of the second light beam L12 on the second grating phase mask 33.
[0045] The structures of the first beam shaping element 41 and the second beam shaping element 42 can be the same or different. In this embodiment, the first beam shaping element 41 and the second beam shaping element 42 can be Kepler beam expanders. In other embodiments of the present application, the grating structure fabrication system 1 may not include the first beam shaping element 41 and the second beam shaping element 42. In other embodiments of the present application, the grating structure fabrication system 1 may also include only one of the first beam shaping element 41 and the second beam shaping element 42.
[0046] See also Figure 4 In a modified embodiment of the present application, the grating structure fabrication system 1 further includes a first grayscale mask 51 and a second grayscale mask 52. The first grayscale mask 51 is located between the first beam shaping element 41 and the mask assembly 30 and in the optical path of the first light beam L11. It is used to adjust the amount of light incident on the first grating phase mask 32 after beam shaping of the first light beam L11, thereby adjusting the duty cycle of the generated first grating structure 301. The second grayscale mask 52 is located between the second beam shaping element 42 and the mask assembly 30 and in the optical path of the second light beam L12. It is used to adjust the amount of light incident on the second grating phase mask 33 after beam shaping of the second light beam L12, thereby adjusting the duty cycle of the generated second grating structure 302.
[0047] See also Figure 5 In at least one embodiment of the present application, the first grayscale mask 51 is an overall rectangular thin plate structure, comprising three sequentially connected rectangular sub-areas: sub-areas 511, 512, and 513. Sub-areas 511, 512, and 513 have different transmittances. The transmittance is consistent throughout sub-area 511, the transmittance is consistent throughout sub-area 512, and the transmittance is consistent throughout sub-area 513. Sub-area 512 is connected between sub-areas 511 and 513, and the transmittance of sub-area 512 is greater than the transmittance of sub-area 511 and less than the transmittance of sub-area 513.
[0048] In other embodiments of the present application, the transmittance of the first grayscale mask 51 is gradient.
[0049] See also Figure 6 In at least one embodiment of the present application, the first grayscale mask 51 is a rectangular thin plate structure as a whole, having a first side 514 and a second side 515 that are relative and parallel, and the transmittance of the first grayscale mask 51 gradually increases from the first side 514 to the second side 515.
[0050] See also Figure 7 In at least one embodiment of the present application, the first grayscale mask 51 is a circular thin plate structure as a whole, and the transmittance of the first grayscale mask 51 gradually increases from the circumference to the center of the circle.
[0051] The second grayscale mask 52 may also be selected from Figure 5-Figure 7 The structures of the first grayscale mask 51 and the second grayscale mask 52 may be the same or different, depending on the structures of the first grating structure 201 and the second grating structure 202 to be formed.
[0052] The grayscale mask design offers significant flexibility. By providing the first grayscale mask 51 and the second grayscale mask 52 in the grating structure fabrication system 1, the duty cycles of the first grating structure 301 and the second grating structure 302 can be flexibly designed to be gradient or partitioned. In other embodiments of the present application, the grating structure fabrication system 1 may include only one of the first grayscale mask 51 and the second grayscale mask 52.
[0053] The following combination Figure 4 The process of manufacturing a grating structure by the grating structure manufacturing system 1 according to an embodiment of the present application is described below:
[0054] The laser light source 11 emits a laser beam L0 , the spatial filter 12 filters out high-frequency noise in the laser beam L0 , and the lens 13 collimates the laser beam L0 emitted by the spatial filter 12 and then emits it.
[0055] The beam splitter 141 reflects a portion of the laser beam L0 to form a first beam L1 , and transmits another portion of the laser beam L0 to form a second beam L2 .
[0056] The first beam shaper 41 shapes the first beam L11 and adjusts the spot size of the first beam L11. The first grayscale mask 51 adjusts the transmitted light intensity of the shaped first beam L11 (i.e., the light intensity of the first beam L11 after passing through the first grayscale mask 51). The reflector 142 deflects the propagation direction of the second beam L12 so that the second beam L12 and the first beam L11 exit from the same side. The second beam shaper 42 shapes the second beam L12 and adjusts the spot size of the second beam L12. The second grayscale mask 52 adjusts the transmitted light intensity of the shaped second beam L12 (i.e., the light intensity of the second beam L12 after passing through the second grayscale mask 52).
[0057] The first light beam L11 has a first Littrow angle After the first light beam L11 is incident on the first grating phase mask 32 and diffracted by the first light beam L11, the 0th order diffracted light and the -1st order diffracted light of the first light beam L11 interfere to form the first exposure light beam L21. The light beam L12 is incident on the second grating phase mask 33 . After the second grating phase mask 33 diffracts the second light beam L12 , the 0th order diffracted light and the −1st order diffracted light of the second light beam L12 interfere with each other to form a second exposure light beam L22 .
[0058] The exposure material 2 is irradiated with the first exposure beam L21 and the second exposure beam L22 at the same time to expose the exposure material 2, wherein the vertical distance between one end of the first grating phase mask 32 and the second grating phase mask 33 emitting the first exposure beam L21 and the second exposure beam L22 and the photoresist layer 202 is on the order of several millimeters, so that the first exposure beam L21 and the second exposure beam L22 can form a larger interference pattern in the photoresist layer 202.
[0059] The exposed material 2 is placed in a developer to form a first grating structure 301 and a second grating structure 302 on the photoresist layer 202. The first grating structure 301 and the first grating phase mask 32 have the same grating period, and the second grating structure 302 and the second grating phase mask 33 have the same grating period.
[0060] The above describes the structure and manufacturing method of the grating structure manufacturing system 1 of the embodiment of the present application, taking the simultaneous manufacturing of the coupling-in grating and the coupling-out grating on the waveguide of the AR glasses 3 as an example. In other embodiments of the present application, the grating structure manufacturing system 1 is applied to other scenarios of manufacturing grating structures.
[0061] In other embodiments of the present application, the beam splitting and guiding assembly 14 is used to split the laser beam L0 into multiple (or greater than three) beams, for example, into a first beam, a second beam, and a third beam; the mask assembly 30 includes multiple (or greater than three) grating phase masks, for example, a first grating phase mask, a second grating phase mask, and a third grating phase mask; and the grating structure fabrication system 1 is used to simultaneously fabricate multiple (or greater than three) grating structures, for example, a first grating structure, a second grating structure, and a third grating structure. The number of beams and grating phase masks is equal to and corresponds to the number of grating structures to be fabricated. That is, each beam is incident on a corresponding grating phase mask, and the exposure beam formed after diffraction by the grating phase mask irradiates the exposure material 2, forming a corresponding grating structure. Among the multiple grating phase masks, at least two grating phase masks have different grating patterns. That is, among the multiple grating phase masks, some of the grating phase masks may have the same grating patterns, while some of the grating phase masks may have different grating patterns.
[0062] See for example Figure 8In at least one embodiment of the present application, the AR display device 4 includes three light sources: red, green, and blue. The AR display device 4 includes a first coupling-in grating 401, a first coupling-out grating 402, a second coupling-in grating 403, a second coupling-out grating 404, a third coupling-in grating 405, and a third coupling-out grating 406. The first coupling-in grating 401 and the first coupling-out grating 402 are respectively used to couple in and out red light, the second coupling-in grating 403 and the second coupling-out grating 404 are respectively used to couple in and out green light, and the third coupling-in grating 405 and the third coupling-out grating 406 are respectively used to couple in and out blue light.
[0063] Grating structure production system 1 is used to simultaneously produce Figure 8 401, first coupling-in grating 402, second coupling-in grating 403, second coupling-out grating 404, third coupling-in grating 405, and third coupling-out grating 406. In this modified embodiment, the beam splitting and guiding assembly 14 is used to split the laser beam L0 into six beams, and the grating structure fabrication system 1 includes six grating phase masks arranged at intervals to form six exposure beams to expose the exposure material 2.
[0064] In summary, the grating structure production system 1 of the embodiment of the present application, through a close-range (on the order of several millimeters) holographic exposure process, utilizes an integrated mask assembly 30 to achieve a single exposure to simultaneously prepare at least two grating structures of multiple periods, and the production process of the grating structure production system 1 is simple and the production cost is low.
[0065] Those skilled in the art should recognize that the above embodiments are only used to illustrate the present application and are not used to limit the present application. As long as they are within the spirit of the present application, appropriate changes and modifications to the above embodiments are within the scope of protection claimed in the present application.
Claims
1. A grating structure manufacturing system, characterized in that: include: A light source assembly is configured to emit a first light beam and a second light beam, wherein the first light beam and the second light beam propagate along different light paths; a mask assembly having an integrated structure and comprising a first grating phase mask and a second grating phase mask, wherein the first grating phase mask and the second grating phase mask have different grating periods, the first grating phase mask being located in the propagation path of the first light beam and being configured to diffract the first light beam to form a first exposure beam; and the second grating phase mask being located in the propagation path of the second light beam and being configured to diffract the second light beam to form a second exposure beam; An exposure substrate is used to carry an exposure material, and the first exposure beam and the second exposure beam are respectively incident on different positions of the exposure substrate to form grating structures with different periods at different positions of the exposure material when the exposure material is placed on the exposure substrate.
2. The grating structure fabrication system according to claim 1, wherein: The light source assembly includes a laser light source and a beam splitting and guiding assembly. The laser light source is used to emit a laser beam. The beam splitting and guiding assembly is arranged on the optical path of the laser beam and is used to split the laser beam to form the first beam and the second beam.
3. The grating structure fabrication system according to claim 2, wherein: The beam splitting and guiding assembly is further configured to guide the first light beam to be incident on the first grating phase mask at a first Littrow angle, and guide the second light beam to be incident on the second grating phase mask at a second Littrow angle; The first exposure beam is formed by interference of 0th order diffraction light and -1st order diffraction light of the first beam, and the second exposure beam is formed by interference of 0th order diffraction light and -1st order diffraction light of the second beam.
4. The grating structure fabrication system according to claim 2, wherein: The light splitting and guiding assembly includes a light splitter and a reflector; The spectrometer is located on the optical path of the laser beam, and is used to reflect part of the laser beam as the first beam and to transmit another part of the laser beam as the second beam. The reflector is used to reflect the second beam to the second grating phase mask.
5. The grating structure fabrication system according to claim 4, wherein: The grating structure manufacturing system further includes a first beam shaping element, which is located on the optical path of the first light beam and is used to adjust the spot size of the first light beam incident on the first grating phase mask; and / or The grating structure manufacturing system includes a second beam shaping element located on the optical path of the second light beam, and the second beam shaping element is used to adjust the spot size of the second light beam incident on the second grating phase mask.
6. The grating structure fabrication system according to claim 1, wherein: The grating structure manufacturing system also includes a first grayscale mask, which is located on the optical path of the first light beam. The first grayscale mask is used to modulate the light intensity distribution of the first light beam so that the first light beam after light intensity modulation is incident on the first grating phase mask. The first grayscale mask includes multiple partitions with different transmittances or has a gradient transmittance as a whole.
7. The grating structure fabrication system according to claim 6, wherein: The grating structure production system also includes a second grayscale mask, which is located on the optical path of the second light beam. The second grayscale mask is used to modulate the light intensity distribution of the second light beam so that the second light beam after light intensity modulation is incident on the second grating phase mask. The second grayscale mask includes multiple partitions with different transmittances or has a gradient transmittance as a whole.
8. The grating structure fabrication system according to claim 7, wherein: When the second grayscale mask has a gradient transmittance as a whole: The second grayscale mask is rectangular, having a first side and a second side opposite to each other, and the light transmittance of the grayscale mask gradually increases from the first side to the second side; or The second grayscale mask is circular, and the light transmittance of the grayscale mask gradually increases from the circumference to the center of the circle.
9. The grating structure manufacturing system according to claim 6, wherein: When the first grayscale mask has a gradually changing transmittance as a whole: The first grayscale mask is rectangular, having a first side and a second side opposite to each other, and the light transmittance of the grayscale mask gradually increases from the first side to the second side; or The first grayscale mask is circular, and the light transmittance of the grayscale mask gradually increases from the circumference to the center of the circle.
10. The grating structure fabrication system according to claim 1, wherein: The light source assembly is also used to emit a third light beam, and the propagation path of the third light beam is different from the propagation paths of the first light beam and the second light beam. The mask assembly also includes a third grating phase mask, and the grating period of the third grating phase mask is different from the grating period of the first grating phase mask and the second grating phase mask. The third grating phase mask is located on the propagation path of the third light beam and is used to diffract the third light beam to form an exposure beam corresponding to the third light beam.