Segmented hybrid optical waveguide

Abstract

The utility model provides a segmented hybrid optical waveguide, which comprises a first part and a second part, the first part comprises a first layer structure and a second layer structure which are superposed along a first direction, the second layer structure is provided with a coupling-in area and a turning area, and the coupling-in area is used for coupling in light; the second part and the first part are spliced in the second direction, the second direction is perpendicular to the first direction, the thickness of the first part in the first direction is equal to that of the second part in the first direction, and the second part is provided with a coupling-out area. According to the utility model, the problem in the prior art that different structures of hybrid optical waveguides are suitable for large thickness differences is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of optical waveguides, in particular to a segmented hybrid optical waveguide. Background Art

[0002] Hybrid waveguides are a new type of optical component that combines the advantages of arrayed waveguides and surface-relief waveguides. They aim to provide a high-efficiency, low-light-leakage waveguide solution while also improving production efficiency and process feasibility issues in existing technologies.

[0003] Surface-relief waveguides utilize the diffraction properties of gratings to achieve light steering and color separation. However, when the grating area thickness is set too large, the total internal reflection step length of light in the waveguide increases, which in turn increases the pupil expansion step length. This ultimately leads to pupil separation during propagation, preventing light of different colors from simultaneously focusing at the pupil of the human eye. This causes color aliasing and reduced visual clarity, impacting the optical effect and visual experience.

[0004] Arrayed optical waveguides are favored for their high efficiency, color consistency, and low light leakage, making them particularly suitable for display modules in applications such as augmented reality (AR) and virtual reality (VR). However, when the optical splitter layer of an arrayed optical waveguide is too thin, more optical splitter layers must be added. The small distance between adjacent optical splitter layers prevents light from completing sufficient total internal reflection steps before reaching the next optical splitter layer. Consequently, the light cannot be effectively separated and guided during subsequent propagation, increasing process complexity and cost, and reducing product yield.

[0005] That is to say, in the prior art, the hybrid optical waveguide has the problem that the thickness applicable to different structures varies greatly. Utility Model Content

[0006] The main purpose of the utility model is to provide a segmented hybrid optical waveguide to solve the problem in the prior art that hybrid optical waveguides with different structures have relatively large differences in thickness.

[0007] To achieve the above-mentioned objectives, the present invention provides a segmented hybrid optical waveguide, comprising: a first portion, the first portion comprising a first layer structure and a second layer structure stacked along a first direction, the second layer structure having a coupling-in region and a turning region, the coupling-in region being used to couple light; a second portion, the second portion being spliced ​​with the first portion along a second direction, wherein the second direction is arranged perpendicular to the first direction, and the thickness of the first portion in the first direction is equal to the thickness of the second portion in the first direction, and the second portion having a coupling-out region.

[0008] Furthermore, the second part includes a plurality of light-splitting layers stacked in a direction away from the first part, and the light-splitting layers have light-splitting surfaces arranged obliquely relative to the second direction, and the light-splitting surfaces are used for coupling out light.

[0009] Furthermore, the first layer structure and the second layer structure are molecularly bonded, and the refractive index n of the second layer structure is base , the refractive index n of the first layer structure glass , the minimum incident angle α of light from the second layer structure to the first layer structure min Between: n base -n glass ≥ n base *(1- sin(α min )).

[0010] Furthermore, the first layer structure and the second layer structure are bonded together by bonding adhesive, and the refractive index n of the second layer structure is base , the refractive index n of the bonding adhesive glue , the minimum incident angle α of light from the second layer structure to the first layer structure min Between: n base -n glue ≥ n base *(1- sin(α min )).

[0011] Furthermore, a surface of the second layer structure close to the first layer structure has a coupling-in region, and a surface of the second layer structure away from the first layer structure has a plurality of turning grating regions to form a turning region.

[0012] Furthermore, a reflective surface is provided on the side of the second layer structure away from the second part, and the refractive index of the second layer structure is greater than the refractive index of the first layer structure, so that light is incident from the surface of the side of the first layer structure away from the second layer structure, is reflected by the reflective surface through the coupling entrance of the coupling area, and is then transmitted by total reflection within the second layer structure, and the angle θ1 between the reflective surface and the side surface of the second layer structure in the first direction satisfies: 25°<θ1<35°.

[0013] Furthermore, the second part includes a plurality of splitting layers stacked in a direction away from the first part, the splitting layers have splitting surfaces inclined relative to the second direction, the inclination angle β of the splitting surface is equal to the included angle θ1, and the thickness T of the second part, the included angle θ1, and the distance ∆d between two adjacent splitting surfaces satisfy: 0.90*T / tan(θ1)<∆d<1.10*T / tan(θ1).

[0014] Furthermore, a coupling region is provided on a side of the second layer structure away from the second portion, and an angle θ2 between a surface where a coupling port of the coupling region is located and a side surface of the second layer structure in the first direction satisfies: 50°<θ2<70°.

[0015] Furthermore, a surface of the second layer structure away from the first layer structure has a plurality of turning grating regions to form a turning area.

[0016] Further, the second part includes a plurality of beam splitting layers stacked in a direction away from the first part. The beam splitting layer has a beam splitting surface inclined with respect to the second direction, and the inclination angle β of the beam splitting surface is half of the included angle θ2. The thickness T of the second part, the included angle θ2, and the distance ∆d between adjacent two beam splitting surfaces satisfy: 0.90*T / tan(θ2) < ∆d < 1.10*T / tan(θ2).

[0017] Further, one side surface of the second layer structure away from the first layer structure has a coupling-in region and a plurality of turning grating regions to form a turning region. The coupling-in port of the coupling-in region has a coupling-in grating to couple light into the second layer structure through the coupling-in grating.

[0018] Further, the plurality of turning grating regions include a first grating region to an Nth grating region arranged closer to the second part, where 3 < N < 8. The grating periods and grating line angles of the first grating region to the Nth grating region are the same, and the first-order diffraction efficiencies of the second grating region to the Nth grating region gradually increase. The first-order diffraction efficiency eff satisfies: 0.03 < eff < 0.77.

[0019] Further, the material of the beam splitting layer is the same as that of the second layer structure.

[0020] Further, along the direction away from the first part, the reflectivity of the beam splitting surface gradually increases. The minimum reflectivity among the reflectivities of all beam splitting surfaces satisfies: 0.02 < R min <0.14, and the maximum reflectivity among the reflectivities of all beam splitting surfaces satisfies: 0.13 < R max <0.35.

[0021] Further, the thickness t of the first layer structure glass satisfies: 0.2 mm < t glass < 5.0 mm.

[0022] [[ID=二十]]

[0021] Further, the thickness t of the second layer structure<00000,19>satisfies: 0.2 mm < t base < 5.0 mm.

[0023] Further, the thickness T of the second part satisfies: 0.4 < T < 10 mm.

[0024] Further, the refractive index n of the first layer structure glass satisfies: 1.5 < n glass < 2.2.

[0025] Applying the technical solution of the present invention, the segmented hybrid optical waveguide includes a first part and a second part, the first part includes a first layer structure and a second layer structure stacked along a first direction, the second layer structure has a coupling region and a turning region, and the coupling region is used to couple in light; the second part and the first part are spliced ​​and arranged along a second direction, wherein the second direction is arranged perpendicular to the first direction, and the thickness of the first part in the first direction is equal to the thickness of the second part in the first direction, and the second part has a coupling region.

[0026] The segmented hybrid optical waveguide of the present application is composed of two main components: a first portion and a second portion joined together along a second direction. The first portion guides light toward the second portion, while the second portion simultaneously couples light out of the segmented hybrid optical waveguide along the first direction. Light enters the coupling-in region from the second layer structure, where it expands the pupil and deflects the optical path through the turning region. After entering the second portion, the coupling-out region couples the light out. By limiting the thickness of the first and second portions in the first direction to be equal, processing and splicing them is facilitated while reducing light loss. Furthermore, since the applicable thicknesses of the second layer structure and the second portion differ significantly, the second layer structure, stacked on the first layer structure in the first direction, achieves uniform thickness between the first and second portions. This reduces light loss and allows both the second layer structure and the second portion to adopt thicknesses ideal for both processability and optical performance, achieving more efficient coupling-in and coupling-out. Furthermore, this design facilitates the integrated appearance and functional integration of the segmented hybrid optical waveguide, facilitating its use with other optical components. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The drawings constituting part of this application are provided to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are provided to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0028] Figure 1 The figure shows the appearance of the segmented hybrid optical waveguide according to the first embodiment of the present invention;

[0029] Figure 2 Shown Figure 1 Schematic diagram of the first and second parts of the segmented hybrid optical waveguide;

[0030] Figure 3 Shown Figure 1 Cross-sectional view of the segmented hybrid optical waveguide;

[0031] Figure 4 The figure shows the appearance of the segmented hybrid optical waveguide of the second embodiment of the present utility model;

[0032] Figure 5 Shown Figure 4 Schematic diagram of the first and second parts of the segmented hybrid optical waveguide;

[0033] Figure 6 Shown Figure 4 Cross-sectional view of the segmented hybrid optical waveguide;

[0034] Figure 7 The figure shows the appearance of the segmented hybrid optical waveguide of the third embodiment of the present invention;

[0035] Figure 8 Shown Figure 7 Schematic diagram of the first and second parts of the segmented hybrid optical waveguide;

[0036] Figure 9 Shown Figure 7 Cross-sectional view of the segmented hybrid optical waveguide;

[0037] Figure 10 A parameter diagram showing the cooperation between the segmented hybrid optical waveguide and the light source according to any optional embodiment of the present utility model is shown.

[0038] The above drawings include the following reference numerals:

[0039] 10. First part; 11. First layer structure; 12. Second layer structure; 13. Coupling region; 14. Coupling port; 15. Reflection surface; 16. Turning region; 17. Turning grating region; 171. First grating region; 18. Coupling grating; 20. Second part; 21. Outcoupling region; 22. Splitting layer; 23. Splitting surface. DETAILED DESCRIPTION

[0040] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0041] It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meaning as commonly understood by ordinary technicians in the technical field to which this application belongs.

[0042] In the present invention, unless otherwise specified, directional words such as "up, down, top, bottom" are usually used with reference to the directions shown in the drawings, or with reference to the components themselves in the vertical, perpendicular or gravity direction; similarly, for ease of understanding and description, "inside and outside" refer to the inside and outside relative to the outline of each component itself, but the above directional words are not used to limit the present invention.

[0043] In order to solve the problem in the prior art that different hybrid optical waveguide structures have relatively large differences in applicable thickness, the utility model provides a segmented hybrid optical waveguide.

[0044] like Figures 1 to 10 As shown, the segmented hybrid optical waveguide includes a first part 10 and a second part 20, the first part 10 includes a first layer structure 11 and a second layer structure 12 stacked along a first direction, the second layer structure 12 has a coupling region 13 and a turning region 16, and the coupling region 13 is used to couple light; the second part 20 is spliced ​​with the first part 10 along a second direction, wherein the second direction is perpendicular to the first direction, and the thickness of the first part 10 in the first direction is equal to the thickness of the second part 20 in the first direction, and the second part 20 has a coupling region 21.

[0045] The segmented hybrid optical waveguide of the present application is composed of two main components: a first portion 10 and a second portion 20, which are spliced ​​together along a second direction. The first portion 10 guides light toward the second portion 20. While the second portion 20 guides light along the second direction, it can also couple light out of the segmented hybrid optical waveguide along the first direction. Light enters the second layer structure 12 from the coupling-in region 13, where it passes through the turning region 16, expanding the pupil and turning the optical path. After entering the second portion 20, the coupling-out region 21 couples the light out. By limiting the thickness of the first and second portions 10, 20 in the first direction to be equal, processing and splicing them is facilitated while reducing light loss. Furthermore, since the applicable thicknesses of the second layer structure 12 and the second portion 20 differ significantly, the second layer structure 12, with the help of the first layer structure 11 stacked in the first direction, achieves a uniform thickness for the first and second portions 10, 20. This reduces light loss and allows both the second layer structure 12 and the second portion 20 to adopt thicknesses that are ideal for their processability and optical performance, achieving more efficient coupling-in and coupling-out. In addition, this design is conducive to the appearance and functional integration of the segmented hybrid optical waveguide, making it easy to use with other optical components.

[0046] like Figures 1 to 10As shown, the second part 20 includes a plurality of splitting layers 22 stacked in a direction away from the first part 10, and the splitting layers 22 have splitting surfaces 23 tilted relative to the second direction, and the splitting surfaces 23 are used to couple out light. The second part 20 receives the light transmitted from the first part 10, and the light is split once each time it passes through a splitting surface 23, that is, part of the light is transmitted and continues to be transmitted backward, and part of the light is reflected and coupled out of the second part 20 from the coupling area 21. By designing multiple splitting layers 22, the light is reflected and split multiple times in the second part 20, which improves the light utilization rate of the segmented hybrid optical waveguide and improves the brightness and contrast display of the segmented hybrid optical waveguide. At the same time, the splitting surface 23 tilted relative to the second direction optimizes the light path, reduces light scattering and energy loss, and can maintain a good display effect, especially in a strong light environment, greatly improving the practicality of outdoor and industrial applications.

[0047] Specifically, the material of the light-splitting layer 22 is the same as that of the second layer structure 12. The same material of the light-splitting layer 22 and the second layer structure 12 can avoid light transmission loss between different materials. Using the same material reduces the refractive index difference at the interface, reduces light reflection and scattering, and improves the light transmission efficiency of the segmented hybrid optical waveguide.

[0048] like Figures 1 to 10 As shown, the reflectivity of the light splitting surface 23 gradually increases in the direction away from the first portion 10, and the minimum reflectivity among the reflectivities of all the light splitting surfaces 23 satisfies: 0.02 <R min <0.14, the maximum reflectivity among the reflectivities of all the light-splitting surfaces 23 satisfies: 0.13 <R max <0.35. When the light passes through the second part 20, the reflectivity on the splitter surface 23 increases as the light propagation path increases. When the light enters from the coupling region 13, the light energy gradually decreases as the light passes through the multiple splitter surfaces 23 for reflection and splitting. By gradually increasing the reflectivity of the splitter surface 23, the loss of light energy can be compensated, so that the intensity of the light coupled out from different positions remains consistent, thereby providing a consistent brightness and color effect at different receiving positions. By limiting R min Within a certain range, it is possible to avoid ineffective light splitting due to too low a reflectivity, and to avoid setting the minimum reflectivity too high, which will result in too little light energy distribution in the subsequent light path after excessive light splitting, thus affecting the brightness uniformity. max Within a certain range, proper splitting and outcoupling of light inside the segmented hybrid optical waveguide is ensured while avoiding excessive energy loss and unnecessary internal scattering, thereby improving the optical efficiency and image quality of the segmented hybrid optical waveguide.

[0049] Example 1

[0050] like Figures 1 to 3 As shown, the segmented hybrid optical waveguide includes a first part 10 and a second part 20. The first part 10 includes a first-layer structure 11 and a second-layer structure 12 stacked along a first direction. The second-layer structure 12 has a light-coupling region 13 and a turning region 16. The light-coupling region 13 is used for coupling light. The second part 20 is spliced with the first part 10 along a second direction, where the second direction is perpendicular to the first direction, and the thickness of the first part 10 in the first direction is equal to the thickness of the second part 20 in the first direction. The second part 20 has a light-output region 21.

[0051] As Figures 1 to 3 shown, on the side surface of the second-layer structure 12 close to the first-layer structure 11, there is a light-coupling region 13, and on the side surface of the second-layer structure 12 far from the first-layer structure 11, there are multiple turning grating regions 17 to form a turning region 16. Light enters the second-layer structure 12 from the light-coupling port 14. After propagating to the turning grating region 17 on the turning region 16, the light is restricted to be transmitted within the second-layer structure 12, ensuring the light-coupling efficiency and improving the light management ability of the segmented hybrid optical waveguide. Specifically, the multiple turning grating regions 17 include a first grating region 171 to an Nth grating region arranged towards the second part 20, where 3 < N < 8. The grating periods and grating line angles of the first grating region 171 to the Nth grating region are the same, and the first-order diffraction efficiencies of the second grating region to the Nth grating region gradually increase. The first-order diffraction efficiency eff satisfies: 0.03 < eff < 0.77. The turning grating region 17 is designed to be multiple. The grating periods and grating line angles of each partition are the same, but the first-order diffraction efficiencies of different partitions will gradually increase to ensure that the energy distribution of the light after diffraction at different positions is uniform, avoiding inconsistencies in the picture brightness and color. By controlling eff within a reasonable range, the gradient diffraction efficiency not only improves the light utilization rate of the segmented hybrid optical waveguide but also provides a smoother and more natural transition effect in the display of gradient colors and brightness, enhancing the visual performance of the segmented hybrid optical waveguide.

[0052] As Figures 1 to 3 shown, on the side of the second-layer structure 12 far from the second part 20, there is a reflecting surface 15. The refractive index of the second-layer structure 12 is greater than that of the first-layer structure 11, so that light is incident from the side surface of the first-layer structure 11 far from the second-layer structure 12, reflected by the reflecting surface 15 after passing through the light-coupling port 14 of the light-coupling region 13, and then undergoes total internal reflection transmission within the second-layer structure 12. The included angle θ1 between the reflecting surface 15 and the side surface of the second-layer structure 12 in the first direction satisfies: 25° < θ1 < 35°.

[0053] In this embodiment, after light enters the coupling port 14 from the surface of the first structure 11 facing away from the second structure 12, the reflective surface 15 reflects the light coupled from the coupling port 14 into the interior of the second structure 12. The higher refractive index of the second structure 12 than that of the first structure 11 facilitates total internal reflection of the light within the second structure 12, allowing the light to propagate through the second structure 12 without leaking into the first structure 11 until it enters the second portion 20. If θ1 is too small, the light reflected by the reflective surface 15 will be less likely to be totally reflected by the surface of the second structure 12, resulting in ineffective transmission to the second portion 20. If θ1 is too large, the space left for the coupling region 13 is too small, hindering the coupling of light into the second structure 12 and affecting the coupling efficiency of the segmented hybrid optical waveguide. Limiting the angle θ1 to a reasonable range enables effective light coupling and transmission, reduces light loss during transmission, ensures the stability and clarity of image information during long-distance transmission, and provides a more natural and smooth visual experience.

[0054] like Figures 1 to 3 As shown, the second portion 20 includes multiple splitter layers 22 stacked in a direction away from the first portion 10. The splitter layers 22 have splitter surfaces 23 inclined relative to the second direction. The inclination angle β of the splitter surfaces 23 is equal to the included angle θ1. The thickness T of the second portion 20, the included angle θ1, and the spacing ∆d between adjacent splitter surfaces 23 satisfy the following conditions: 0.90*T / tan(θ1)<∆d<1.10*T / tan(θ1). The second portion 20 is composed of multiple splitter layers 22 stacked in a direction away from the first portion, thereby achieving light outcoupling at different locations. In addition, by limiting the range of the spacing ∆d between adjacent splitter surfaces 23, the efficiency and effectiveness of light propagation between the splitter layers 22 are ensured. Precise spacing ensures uniformity in the light energy outcoupling from the splitter surfaces 23, improving the uniformity of image display at different receiving locations, effectively avoiding hotspots and dark spots in the display, and providing a more detailed and realistic display effect. By controlling ∆d to maintain a certain proportional relationship with T and θ1, it is possible to ensure that the light transmitted from the first portion 10 to the second portion 20 is not deflected, and the transmitted image is guaranteed to be complete and not offset.

[0055] Optionally, the thickness t of the second layer structure 12 base Meet: 0.2mm <t base<5.0 mm. When light travels in the second layer structure 12, it needs to contact the grating to undergo diffraction. If the second layer structure 12 is too thick, the total reflection step before the light reaches the grating will increase, and the difference in the number of times different wavelengths of light contact the grating will increase, resulting in pupil separation, that is, light of different colors cannot be focused at the same position, affecting color consistency. If the second layer structure 12 is too thin, it is difficult to meet the physical size requirements of the grating or the process processing limitations. By setting t base within a reasonable range, taking into account the processability of the second layer structure 12 and good optical effects, reducing the difference in the number of times different wavelengths of light contact the grating is beneficial to maintaining the color consistency of the outgoing light.

[0056] Optionally, the thickness T of the second part 20 satisfies: 0.4 < T < 10 mm. If T is too thin, more splitting layers 22 need to be stacked to achieve the required splitting effect, resulting in a long processing process flow and a low yield rate. If T is too thick, it may lead to a reduction in light transmission efficiency or optical path distortion. By setting T within a reasonable range, comprehensively considering the control of the pupil separation phenomenon, the improvement of the coupling-out efficiency, and the simplification of the production process to improve the yield rate, the processability and optical effects of the second part 20 can be taken into account.

[0057] Optionally, the thickness t glass of the first layer structure 11 satisfies: 0.2 mm < t glass <5.0 mm. By setting t glass within a reasonable range and coordinating with the thickness of the second layer structure 12, making the stacked first layer structure 11 and second layer structure 12 equal to the thickness of the second part 20 can not only take into account the processability of each structure but also retain the working thickness applicable to the first part 10 and the second part 20.

[0058] Optionally, the refractive index n glass of the first layer structure 11 satisfies: 1.5 < n glass <2.2. By setting n glass within a reasonable range, controlling the propagation characteristics of light in the segmented hybrid optical waveguide, including total reflection conditions, diffraction angles, and the reflection effect of the splitting layer 22, can reduce the critical angle of total reflection, making it easier for light to propagate in the waveguide, and at the same time increasing the diffraction efficiency of the grating.

[0059] Specifically, Figure 1 the segmented hybrid optical waveguide of Example 1 is described. The first layer structure 11 and the second layer structure 12 are bonded by bonding glue. Among them, θ1 = 29°, T = 1.5 mm, ∆d = 2.711 mm, t base = 0.75 mm, t glass = 0.75 mm, n base = 1.84, n glue=1.25, such as Figure 10 As shown, the angle component θ of the H direction before the light enters the segmented hybrid optical waveguide H =13.15°, the number of the light-splitting layers 22 is 8, and the refractive index R of the i-th light-splitting layer in the direction away from the first portion 10 is i They are R1=R2=0.087, R3=R4=0.11, R5=R6=0.16, and R7=R8=0.2 respectively.

[0060] like Figure 2 As shown, the first layer structure 11 and the second layer structure 12 are bonded together by bonding adhesive, and the refractive index n of the second layer structure 12 is base , the refractive index n of the bonding adhesive glue , the minimum incident angle α of light from the second layer structure 12 to the first layer structure 11 min Between: n base -n glue ≥n base *(1- sin(α min By using a bonding adhesive with an appropriate refractive index, light reflection at the interface can be effectively reduced, improving the overall performance of the hybrid optical waveguide. This provides a more comfortable and long-lasting wearing experience, especially during extended use.

[0061] Specifically, α min satisfy:

[0062] Formula (1);

[0063] Formula (1) can achieve efficient transmission of light, reduce light loss during transmission, ensure the stability and clarity of light during long-distance transmission, and provide a more natural and smooth visual experience.

[0064] Optionally, the segmented hybrid optical waveguide provided in this embodiment can be used in AR glasses.

[0065] Example 2

[0066] like Figures 4 to 6 , which describes the second embodiment of the present application, which differs from the first embodiment in the light coupling method and the bonding method of the first layer structure 11 and the second layer structure 12.

[0067] like Figures 4 to 6As shown, a coupling region 13 is provided on a side of the second layer structure 12 away from the second portion 20, and a surface of the second layer structure 12 away from the first layer structure 11 has multiple turning grating regions 17 to form a turning region 16. The second portion 20 includes multiple beam splitting layers 22 stacked in a direction away from the first portion 10, and the beam splitting layers 22 have beam splitting surfaces 23 arranged obliquely relative to the second direction.

[0068] Specifically, the angle θ2 between the surface of the coupling port 14 of the coupling region 13 and a side surface of the second layer structure 12 in the first direction satisfies the following: 50° < θ2 < 70°. By controlling θ2 within a reasonable range, the initial propagation direction of the coupled light is directly affected, allowing the light to form a preset incident angle with the turning region 16 upon entering the second layer structure 12. This ensures that during subsequent propagation, the light forms a sufficiently large incident angle with the turning region 16 to achieve total internal reflection, thereby preventing premature light leakage and avoiding energy loss caused by light failure due to excessively large angles or light propagation over a long distance within the second layer structure 12 due to excessively small angles.

[0069] Specifically, the inclination angle β of the splitter surface 23 is half the angle θ2. The thickness T of the second portion 20, the angle θ2, and the spacing ∆d between adjacent splitter surfaces 23 satisfy the following conditions: 0.90*T / tan(θ2)<∆d<1.10*T / tan(θ2). Designing the inclination angle β to be half the angle θ2 ensures that the light propagation path in the first portion 10 matches the path in the second portion 20, preventing light deviation or scattering caused by sudden changes in the optical path. If the spacing between adjacent splitter layers 22 is too small, the splitter layers 22 must be arranged very densely to meet the requirements for light outcoupling to the receiving end, increasing the number of times the splitter layers 22 are stacked, which is detrimental to production yield and cost control. If the spacing between adjacent splitter layers 22 is too large, light requires multiple reflections to be coupled out, which increases optical loss within the segmented hybrid optical waveguide and reduces image quality. By controlling 0.90*T / tan(θ2)<∆d<1.10*T / tan(θ2), a reasonable spacing between the splitter layers 22 is ensured, while the total number of splitter layers 22 is reduced, which greatly reduces the complexity and cost of production and processing, and also reduces the scattering of light between the splitter layers 22, thereby improving the display clarity.

[0070] Where, θ2=60°, T=1.5mm, ∆d=2.8mm, t base =0.8mm, t glass =0.7mm, n base =2.0, n glass =1.51,θ H =13.15°, the number of the light-splitting layers 22 is 9, and the refractive index R of the i-th light-splitting layer in the direction away from the first portion 10 isi They are R1=R2=R3=0.05, R4=R5=0.73, R6=R7=0.116, and R8=R9=0.2 respectively.

[0071] Specifically, α min satisfy:

[0072] Formula (2);

[0073] According to formula (2), light enters the second layer structure 12 directly from the outside. This method generally provides higher coupling efficiency and avoids light scattering and energy loss caused by reflection from the reflective surface. Efficient refractive coupling is crucial for enhancing display brightness and ensuring high definition.

[0074] like Figure 5 As shown, the first layer structure 11 and the second layer structure 12 are connected by molecular bonding, and the refractive index n of the second layer structure 12 is base , the refractive index n of the first layer structure 11 glass , the minimum incident angle α of light from the second layer structure 12 to the first layer structure 11 min Between: n base -n glass ≥ n base *(1- sin(α min The molecular bonding not only ensures the structural strength of the segmented hybrid optical waveguide but also provides a smoother bonding surface between the first and second layers 11, 12. This optimizes light transmission efficiency between the different materials and prevents excessive light loss during transmission. By controlling the aforementioned refractive index relationship, light is effectively confined within the second layer 12 and undergoes total internal reflection as it propagates from the second layer 12 toward the first layer 11, achieving both optical path deflection and pupil expansion.

[0075] Example 3

[0076] like Figures 7 to 9 , which describes the third embodiment of the present application, which differs from the first embodiment in that the light coupling region 13 is set and the bonding method of the first layer structure 11 and the second layer structure 12 is different.

[0077] Specifically, the second layer structure 12 has a coupling region 13 and multiple turning grating regions 17 on the side of the surface away from the first layer structure 11 to form a turning region 16. The coupling port 14 of the coupling region 13 has a coupling grating 18, so that light can be coupled into the second layer structure 12 through the coupling grating 18. The coupling region 13 is located on the surface of the second layer structure 12 away from the first layer structure 11. Light can directly enter the interior of the second layer structure 12 through the coupling grating 18 of the coupling port 14. The coupling grating 18 can ensure efficient coupling of light, reduce light scattering during the coupling process, and improve the energy efficiency and display quality of the segmented hybrid optical waveguide. When the turning region 16 subsequently propagates and processes light, light of different wavelengths will produce different diffraction angles when contacting the turning grating region 17 due to the different grating periods and grating line angles. The diffraction effect of the turning grating region 17 realizes the splitting and directional turning of light.

[0078] It should be noted that the coupling grating 18 can be a diffraction grating in the form of a blazed grating, a straight tooth grating, a slanted tooth grating, etc., to match the larger projection port of the projection optical machine. The choice depends on the required coupling efficiency and optical path requirements.

[0079] Where, β=35°, T=10mm, ∆d=14.2mm, t base =1mm, t glass =9mm, n base =2.0, n glass =1.51, the number of the light-splitting layers 22 is 9, and the refractive index R of the i-th light-splitting layer in the direction away from the first part 10 is i They are R1=R2=R3=0.05, R4=R5=0.73, R6=R7=0.116, and R8=R9=0.2 respectively.

[0080] Optionally, the segmented hybrid optical waveguide provided in this embodiment can be used in large scenes such as vehicle-mounted HUD. The thickness t of the first layer structure 11 is glass The 9mm setting matches the requirements of large-scale applications such as vehicle HUD. glass It not only provides sufficient structural support, but also reduces light scattering caused by insufficient thickness, and improves the stability and quality of optical coupling.

[0081] Obviously, the embodiments described above are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0082] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, tasks, devices, components and / or combinations thereof.

[0083] It should be noted that the terms "first," "second," and the like in the specification and claims of this application and the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein.

[0084] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A segmented hybrid optical waveguide, characterized in that: include: A first part (10), the first part (10) comprising a first layer structure (11) and a second layer structure (12) stacked along a first direction, the second layer structure (12) having a coupling region (13) and a turning region (16), the coupling region (13) being used for coupling light; A second part (20), wherein the second part (20) and the first part (10) are spliced ​​and arranged along a second direction, wherein the second direction is arranged perpendicular to the first direction, and the thickness of the first part (10) in the first direction is equal to the thickness of the second part (20) in the first direction, and the second part (20) has a coupling-out region (21).

2. The segmented hybrid optical waveguide according to claim 1, wherein: The second part (20) comprises a plurality of light-splitting layers (22) stacked in a direction away from the first part (10), the light-splitting layers (22) having a light-splitting surface (23) arranged obliquely relative to the second direction, and the light-splitting surface (23) is used for coupling out the light.

3. The segmented hybrid optical waveguide according to claim 1, wherein: The first layer structure (11) and the second layer structure (12) are molecularly bonded, and the refractive index n of the second layer structure (12) is base , the refractive index n of the first layer structure (11) glass , the minimum incident angle α of the light from the second layer structure (12) to the first layer structure (11) min Between: n base -n glass ≥n base *(1- sin(α min ));or The first layer structure (11) and the second layer structure (12) are bonded together by bonding adhesive, and the refractive index n of the second layer structure (12) is base , the refractive index n of the bonding adhesive glue , the minimum incident angle α of the light from the second layer structure (12) to the first layer structure (11) min Between: n base -n glue ≥n base *(1- sin(α min )).

4. The segmented hybrid optical waveguide according to claim 1, wherein: A surface of the second layer structure (12) close to the first layer structure (11) has a coupling region (13), and a surface of the second layer structure (12) away from the first layer structure (11) has a plurality of turning grating regions (17) to form the turning region (16).

5. The segmented hybrid optical waveguide according to claim 4, characterized in that: A reflecting surface (15) is provided on a side of the second layer structure (12) away from the second portion (20), and the refractive index of the second layer structure (12) is greater than the refractive index of the first layer structure (11), so that the light is incident from the surface of the side of the first layer structure (11) away from the second layer structure (12), passes through the coupling port (14) of the coupling region (13), is reflected by the reflecting surface (15), and is then transmitted in the second layer structure (12) by total reflection, and an angle θ1 between the reflecting surface (15) and a side surface of the second layer structure (12) in the first direction satisfies: 25°<θ1<35°.

6. The segmented hybrid optical waveguide according to claim 5, characterized in that: The second part (20) includes a plurality of light-splitting layers (22) stacked in a direction away from the first part (10), the light-splitting layer (22) having a light-splitting surface (23) inclined relative to the second direction, the inclination angle β of the light-splitting surface (23) being equal to the included angle θ1, and the thickness T of the second part (20), the included angle θ1, and the spacing ∆d between two adjacent light-splitting surfaces (23) satisfying the following conditions: 0.90*T / tan(θ1)<∆d<1.10*T / tan(θ1).

7. The segmented hybrid optical waveguide according to claim 1, wherein: A coupling region (13) is provided on a side of the second layer structure (12) away from the second portion (20), and an angle θ2 between a surface where a coupling port (14) of the coupling region (13) is located and a surface of one side of the second layer structure (12) in the first direction satisfies the following: 50°<θ2<70°.

8. The segmented hybrid optical waveguide according to claim 7, wherein: A surface of the second layer structure (12) on one side away from the first layer structure (11) has a plurality of turning grating regions (17) to form the turning area (16).

9. The segmented hybrid optical waveguide according to claim 7, wherein: The second part (20) includes a plurality of beam splitting layers (22) stacked in a direction away from the first part (10). The beam splitting layers (22) have beam splitting surfaces (23) inclined with respect to the second direction. The inclination angle β of the beam splitting surface (23) is half of the included angle θ2. The thickness T of the second part (20), the included angle θ2, and the spacing ∆d between two adjacent beam splitting surfaces (23) satisfy: 0.90*T / tan(θ2) < ∆d < 1.10*T / tan(θ2).

10. The segmented hybrid optical waveguide according to claim 1, wherein: One side surface of the second layer structure (12) away from the first layer structure (11) has the coupling-in region (13) and a plurality of turning grating regions (17) to form the turning region (16). The coupling-in port (14) of the coupling-in region (13) has a coupling-in grating (18) to couple the light into the second layer structure (12) through the coupling-in grating (18).

11. The segmented hybrid optical waveguide according to claim 4, 8 or 10, characterized in that: The plurality of turning grating regions (17) includes a first grating region (171) to an Nth grating region arranged closer to the second part (20), where 3 < N < 8. The grating periods and grating line angles of the first grating region (171) to the Nth grating region are the same. The first-order diffraction efficiencies of the second grating region to the Nth grating region gradually increase. The first-order diffraction efficiency eff satisfies: 0.03 < eff < 0.

77.

12. The segmented hybrid optical waveguide according to claim 2, 6 or 9, characterized in that: The material of the beam splitting layer (22) is the same as the material of the second layer structure (12).

13. The segmented hybrid optical waveguide according to claim 2, 6 or 9, characterized in that: In a direction away from the first part (10), the reflectivity of the light splitting surface (23) gradually increases, and the minimum reflectivity among the reflectivities of all the light splitting surfaces (23) satisfies: 0.02 <R min <0.14, the maximum reflectivity among the reflectivities of all the light-splitting surfaces (23) satisfies: 0.13 <R max <0.

35.

14. The segmented hybrid optical waveguide according to claim 1, wherein The thickness t of the first layer structure (11) glass Meet: 0.2mm <t glass <5.0 mm; and / or The thickness t of the second layer structure (12) base Meet: 0.2mm <t base <5.0 mm; and / or the thickness T of the second part (20) satisfies: 0.4 < T < 10 mm; and / or The refractive index n of the first layer structure (11) is glass Satisfaction: 1.5 <n glass <2.2.

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