Optical waveguide structure and display device

Abstract

The application relates to a light guide wave structure and a display device, comprising a base layer, a first wave guide layer and a second wave guide layer, the base layer having a first surface and a second surface arranged oppositely; the first wave guide layer is arranged on the first surface of the base layer; the second wave guide layer is arranged on different regions of the first surface of the base layer with the first wave guide layer; or the second wave guide layer is arranged on the second surface of the base layer, and the second wave guide layer is configured to receive and conduct infrared light. Thus, by arranging the first wave guide layer and the second wave guide layer on different surfaces of the base layer or different regions of the same surface, the display light path of visible light and the eye movement tracking light path of infrared light are integrated on a single base layer, and the display light path and the infrared light path do not interfere with each other; the single base layer integration avoids problems such as polarization interference and optical imaging caused by adhesion; and the single base layer design reduces the number of base layers from two in the prior art to one, thereby reducing the overall thickness and weight of the structure, and achieving a light and thin design.

Description

Technical Field

[0001] This application relates to the field of optical components technology, and in particular to an optical waveguide structure and display device. Background Technology

[0002] Currently, augmented reality (AR) glasses, as the next generation of human-computer interaction terminals, typically employ diffractive waveguide structures in their core optical engines to achieve thinness and a large field of view (FOV). With increasing interaction demands, integrated eye-tracking functionality has become an industry standard, used for foveated rendering, gaze-based interaction, and user status monitoring.

[0003] Traditional eye-tracking systems typically employ independent infrared lens modules (including infrared light sources, lens groups, and image sensors), resulting in bulky lens frames. While attempts have been made to use infrared waveguides to replace lens modules and reduce size and weight, these solutions still require precise alignment between the independent infrared waveguide and the display waveguide. This alignment process must ensure that both are perfectly aligned with the image plane centered on the pupil, demanding high precision. Directly bonding and assembling the infrared and display waveguides can also lead to polarization interference, bonding stress deformation, and optical and structural defects. Summary of the Invention

[0004] Therefore, it is necessary to provide an optical waveguide structure and display device to address the aforementioned technical problems.

[0005] The first aspect of this application provides an optical waveguide structure, comprising:

[0006] The base layer has a first surface and a second surface that are arranged opposite to each other;

[0007] A first waveguide layer is disposed on the first surface of the base layer, and the first waveguide layer is configured to receive and conduct visible light;

[0008] A second waveguide layer is disposed in different regions of the first surface of the substrate, respectively, and the second waveguide layer is disposed on the side of the substrate away from the first waveguide layer. The second waveguide layer is configured to receive and transmit infrared light.

[0009] In one embodiment, the optical waveguide structure further includes:

[0010] A first refractive layer is disposed on the second surface of the base layer;

[0011] A first flattening layer is disposed on the side of the first waveguide layer away from the base layer;

[0012] The second refractive layer is disposed on the side of the first planarization layer away from the first waveguide layer;

[0013] A first anti-reflective layer is disposed on the side of the second refractive layer opposite to the first planarization layer.

[0014] In one embodiment, when the second waveguide layer is disposed on the second surface of the substrate, the first refractive layer is located between the second waveguide layer and the substrate.

[0015] In one embodiment, the optical waveguide structure further includes:

[0016] The second planarization layer is disposed on the side of the second waveguide layer away from the first refractive layer;

[0017] The third refractive layer is disposed on the side of the second planarization layer opposite to the second waveguide layer.

[0018] In one embodiment, the first waveguide layer includes a plurality of spaced first gratings, the second waveguide layer includes a plurality of spaced second gratings, and the period of the plurality of first gratings is less than the period of the plurality of second gratings.

[0019] The light emission angle of the second waveguide layer is smaller than the total internal reflection angle of the base layer.

[0020] In one embodiment, the optical waveguide structure further includes:

[0021] The first lens is disposed on the side of the first antireflective layer away from the base layer via an adhesive layer;

[0022] The second lens is disposed on the side of the third refractive layer away from the base layer via an adhesive layer.

[0023] In one embodiment, when the second waveguide layer and the first waveguide layer are respectively disposed in different regions of the first surface of the substrate, the first planarization layer is attached to the side of the first waveguide layer and the second waveguide layer away from the substrate.

[0024] The optical waveguide structure also includes:

[0025] A second anti-reflective layer is disposed on the side of the first refractive layer that is away from the base layer;

[0026] The first lens is disposed on the side of the first antireflective layer away from the base layer via an adhesive layer;

[0027] The second lens is disposed on the side of the second antireflective layer away from the base layer via an adhesive layer.

[0028] In one embodiment, a transition region is provided between the first waveguide layer and the second waveguide layer, and the grating depth in the transition region smoothly transitions in the direction from the first waveguide layer to the second waveguide layer.

[0029] In one embodiment, the period of the first grating is 350nm to 450nm, the operating wavelength of the first grating is 400nm to 750nm, and the first grating is configured to produce a diffraction response only to the first polarized light.

[0030] The period of the second grating is 600nm to 900nm, the operating wavelength of the second grating is 850nm or 940nm, and the second grating is configured to produce a diffraction response only to the second polarized light.

[0031] The second aspect of this application provides a display device applied to the optical waveguide structure as described in the first aspect of this application.

[0032] This application provides a light guide wave structure and display device. By setting a single base layer as a common substrate, and arranging the first waveguide layer and the second waveguide layer on different surfaces of the base layer or different areas of the same surface, the visible light display light path and the infrared light eye-tracking light path are integrated on a single base layer, and the display light path and the infrared light path do not interfere with each other.

[0033] Therefore, by adopting this single-layer integrated architecture, the alignment of two independent layers through optical adhesive is avoided, thereby eliminating polarization interference and optical deformation caused by bonding, and effectively avoiding optical imaging problems such as ghosting and reduced contrast in the display image.

[0034] At the same time, the single-base design reduces the number of base layers from the traditional two to one, thereby reducing the overall thickness and weight, thus achieving a lightweight and thin design of the structure. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of a single-sided double-layer structure of an optical waveguide structure according to an embodiment of this application.

[0036] Figure 2 This is a schematic diagram of a single-sided double-layer structure of an optical waveguide structure according to an embodiment of this application after adding a lens.

[0037] Figure 3 The optical path diagram of a single-sided double-layer structure of an optical waveguide structure according to an embodiment of this application after adding a lens.

[0038] Figure 4 This is a schematic diagram of a single-sided, single-layer structure of an optical waveguide structure according to an embodiment of this application.

[0039] Figure 5 This is a side view of the transition zone after the base layer of a single-sided, single-layer optical waveguide structure in an embodiment of this application is combined with the first waveguide layer and the second waveguide layer.

[0040] Figure 6 This is a top view of the transition zone after the base layer of a single-sided, single-layer optical waveguide structure in an embodiment of this application is combined with the first waveguide layer and the second waveguide layer.

[0041] Figure 7 This is a schematic diagram of a single-sided, single-layer optical waveguide structure according to an embodiment of this application after adding a lens.

[0042] Figure 8 The optical path diagram of a single-sided, single-layer optical waveguide structure according to an embodiment of this application after adding a lens.

[0043] Figure 9 This is a schematic diagram of the polarization response of the first polarized light of a single-sided, single-layer structure of an optical waveguide structure according to an embodiment of this application.

[0044] Figure 10 This is a schematic diagram of the polarization response of a single-sided, single-layer structure of an optical waveguide structure according to an embodiment of this application.

[0045] Explanation of reference numerals in the attached figures:

[0046] 10. Base layer; 10a. First surface; 10b. Second surface; 20. First waveguide layer; 21. First grating; 30. Second waveguide layer; 31. Second grating; 40. First refractive layer; 50. First planarization layer; 60. Second refractive layer; 70. First antireflective layer; 80. Second planarization layer; 90. Third refractive layer; 100. Adhesive layer; 110. First lens; 120. Second lens; 130. Second antireflective layer; 140. Transition zone; 150. First polarized light; 160. Second polarized light. Detailed Implementation

[0047] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0048] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0049] like Figure 1 or Figure 4 As shown, this application embodiment provides an optical waveguide structure, including a base layer 10, a first waveguide layer 20, and a second waveguide layer 30. The base layer 10 has a first surface 10a and a second surface 10b disposed opposite to each other. The first waveguide layer 20 is disposed on the first surface 10a of the base layer 10 and is configured to receive and conduct visible light, and to form a display image. The second waveguide layer 30 is disposed on one side of the second surface 10b of the base layer 10 and is configured to receive and conduct infrared light, and to perform eye tracking.

[0050] Specifically, the base layer 10 is a glass or plastic substrate with a high refractive index. The first waveguide layer 20 is a display waveguide layer, which can transmit light visible to the human eye and present a clearly visible AR virtual image. The second waveguide layer 30 is an infrared waveguide layer, which can transmit infrared light invisible to the human eye, so as to track the human eye's gaze point by changing the refraction angle of the infrared light.

[0051] Therefore, the optical waveguide structure, by sharing the same substrate 10 for the first waveguide layer 20 used for display imaging and the second waveguide layer 30 used for infrared eye tracking, replaces the traditional structural design that requires bonding and aligning the first waveguide layer 20 and the second waveguide layer 30. It also eliminates unnecessary bonding between the first waveguide layer 20, the second waveguide layer 30 and the substrate 10, thereby reducing problems such as polarization interference at the interface and deformation of the substrate and / or the first waveguide layer 20 and the second waveguide layer 30 caused by bonding. Simultaneously, while ensuring imaging performance, by integrating the first waveguide layer 20 and the second waveguide layer 30 on one or both sides of a single substrate 10 using different configurations, the overall weight of the optical waveguide structure is reduced, thus achieving a lightweight structural design.

[0052] like Figure 1 or Figure 4As shown, in some embodiments, the optical waveguide structure further includes a first refractive layer 40, a first planarization layer 50, a second refractive layer 60, and a first antireflection layer 70. The first refractive layer 40 is disposed on the second surface 10b of the base layer 10; the first planarization layer 50 is disposed on the side of the first waveguide layer 20 opposite to the base layer 10; the second refractive layer 60 is disposed on the side of the first planarization layer 50 opposite to the first waveguide layer 20; and the first antireflection layer 70 is disposed on the side of the second refractive layer 60 opposite to the first planarization layer 50.

[0053] Specifically, the first refractive layer 40 is imprinted on the surface of the base layer 10, and the first refractive layer 40 serves as an optical barrier layer. The first refractive layer 40 can effectively prevent light from penetrating it and leaking to the outside, while providing optical isolation for the first waveguide layer 20.

[0054] The first planarization layer 50 is disposed between the first waveguide layer 20 and the second refractive layer 60, and covers the first grating 21 of the first waveguide layer 20. Thus, the first planarization layer 50 can flatten the small undulations formed by the first grating 21, so that the installation of the second refractive layer 60 will not affect the refraction effect of the first grating 21 on light.

[0055] Understandably, the second refractive layer 60 also serves as an optical barrier layer, with a refractive index of 1.1 to 1.25. Therefore, the second refractive layer 60 can constrain the total internal reflection light within the first waveguide layer 20, thereby reducing light leakage and improving the transmission efficiency of the displayed light.

[0056] The first anti-reflective layer 70 is used to eliminate surface reflections on the outer side of the base layer 10, so as to prevent stray light from entering the human eye and interfering with the viewing of the image.

[0057] like Figure 1 and Figure 4 As shown, the first waveguide layer 20 and the second waveguide layer 30 can be disposed on one or both sides of the base layer 10 to form a single-sided double-layer structure or a single-sided single-layer structure.

[0058] like Figure 2 and Figure 3 As shown, in some embodiments, an optical waveguide structure with a single-sided double-layer structure is formed by disposing the first waveguide layer 20 and the second waveguide layer 30 on both sides of the base layer 10.

[0059] When the second waveguide layer 30 is further disposed on one side of the second surface 10b of the base layer 10, a first refractive layer 40 is also disposed between the second waveguide layer 30 and the base layer 10. Here, the first refractive layer 40 serves as an interlayer, and the first refractive layer 40 is made of an ultra-low refractive index material with a refractive index of 1.1 to 1.25. By setting the first refractive layer 40, the total internal reflection efficiency of the second waveguide layer 30 can be effectively increased, and stray light that may exist in the base layer 10 can be prevented from interfering with the infrared optical path, thus ensuring the purity of the infrared light signal that the second waveguide layer 30 can receive.

[0060] Specifically, the single-sided double-layer optical waveguide structure further includes a second planarization layer 80 and a third refractive layer 90. The second planarization layer 80 is disposed on the side of the second waveguide layer 30 opposite to the first refractive layer 40; the third refractive layer 90 is disposed on the side of the second planarization layer 80 opposite to the second waveguide layer 30. The second planarization layer 80 is used to fill the grooves of the second grating 31 of the second waveguide layer 30 with a low-refractive-index resin material to ensure total internal reflection. Furthermore, the second planarization layer 80 enables bubble-free optical bonding and isolates external contaminants such as moisture.

[0061] The third refractive layer 90 serves as a protective layer and the outermost barrier layer of the second waveguide layer 30. On the one hand, it can strictly confine infrared light within the second waveguide layer 30 to improve energy transfer efficiency. On the other hand, it also protects the second grating 31, preventing it from directly contacting the outer layer and reducing the possibility of damage to the second grating 31.

[0062] Understandably, the third refractive layer 90 also serves as an optical barrier layer, and its refractive index is the same as that of the first refractive layer 40, which is 1.1 to 1.25.

[0063] More specifically, the first waveguide layer 20 includes a first grating 21, and the second waveguide layer 30 includes a second grating 31, wherein the period of the first grating 21 in the first waveguide layer 20 is less than the period of the second grating 31 in the second waveguide layer 30. In this embodiment, the period of the first grating 21 is 350nm to 450nm; and the period of the second grating 31 is 600nm to 950nm.

[0064] Meanwhile, the structural density of the first grating 21 is greater than that of the second grating 31. The first grating 21 operates at a short wavelength of 400nm to 750nm, while the second grating 31 operates at a long wavelength of 850nm or 940nm. Furthermore, the light emission angle of the second waveguide layer 30 is designed to be smaller than the total internal reflection angle of the base layer 10.

[0065] Therefore, since the wavelength of infrared light is longer than that of visible light, the second grating 31 requires a larger grating period to effectively diffract infrared light. When visible light transmitted in the first waveguide layer 20 passes through the base layer 10 and enters the second waveguide layer 30 due to scattering and other reasons, the grating period and orientation of the second grating 31 are set for infrared light, and its light emission angle is designed to be smaller than the total internal reflection angle of the base layer 10. Therefore, the visible light will not diffract at the second grating 31, but will be directly transmitted out, thus completely eliminating the possibility of visible light producing ghosting on the second grating 31, and significantly improving the purity of the displayed image.

[0066] More specifically, the grating structures of the first waveguide layer 20 and the second waveguide layer 30 can both be single-layer or multi-layer grating stack structures to meet different diffraction efficiency bandwidth requirements. Furthermore, the first grating 21 of the first waveguide layer 20 and the second grating 31 of the second waveguide layer 30 can be integrally imprinted on the first surface 10a and the second surface 10b of the base layer 10 using a double-sided nanoimprinting process to ensure manufacturing precision and eliminate the need for secondary alignment.

[0067] It is understandable that the grating period is the center distance between two adjacent repeating microstructure units on the grating structure, that is, the pitch between two adjacent repeating microstructure units. If the density of microstructure units on the grating is higher, the period is smaller; if the density of microstructure units is lower, the period is larger.

[0068] In one embodiment, the optical waveguide structure further includes a first lens 110 and a second lens 120. The first lens 110 is disposed on the side of the first antireflective layer 70 away from the base layer 10 via an adhesive layer 100; the second lens 120 is disposed on the side of the third refractive layer 90 away from the base layer 10 via an adhesive layer 100.

[0069] It is understandable that the adhesive layer 100 can be an optically transparent adhesive. This optically transparent adhesive is a substrate-free double-sided optical tape with a light transmittance greater than 92% and a refractive index of less than or equal to 1.48. In an optical waveguide structure, it can seamlessly, damagelessly, and without reflection adhere a lens with optical power to a designated position. Furthermore, using it to adhere the lens to the designated position will not introduce additional imaging problems such as ghosting or image quality degradation.

[0070] Furthermore, the first lens 110 and the second lens 120 form a positive-negative cancellation lens group. For example, the first lens 110 is a +2.0D positive lens, and the second lens 120 is a -2.0D negative lens. When they are superimposed, the overall optical power is zero, ensuring that the observation of the real external field of vision is completely distortion-free. At the same time, by replacing the first lens 110 and the second lens 120 with different optical powers, it is possible to adapt to nearsighted or farsighted users and adjust the imaging distance of augmented reality virtual images.

[0071] like Figures 5 to 7 In some embodiments, an optical waveguide structure with a single-sided, single-layer structure formed by disposing the first waveguide layer 20 and the second waveguide layer 30 on the same surface of the base layer 10 is used as an example.

[0072] The first waveguide layer 20 and the second waveguide layer 30 are respectively disposed in different regions of the first surface 10a of the base layer 10. At this time, the first planarization layer 50 is attached to the side of the first waveguide layer 20 and the second waveguide layer 30 away from the base layer 10. The optical waveguide structure also includes a second anti-reflection layer 130, a first lens 110 and a second lens 120. The second anti-reflection layer 130 is disposed on the side of the first refractive layer 40 away from the base layer 10; the first lens 110 is disposed on the side of the first anti-reflection layer 70 away from the base layer 10 via an adhesive layer 100; and the second lens 120 is disposed on the side of the second anti-reflection layer 130 away from the base layer 10 via an adhesive layer 100.

[0073] like Figure 8 As shown, in this embodiment, the optical waveguide structure adopts a design architecture that integrates the first waveguide layer 20 and the second waveguide layer 30 in sections on a single surface of a monolithic substrate 10. This allows the first waveguide layer 20 and the second waveguide layer 30 to undergo a single nanoimprinting process on the first surface 10a of the substrate 10, fabricating the first waveguide layer 20 and the second waveguide layer 30 in different regions of the same plane. For example, the first waveguide layer 20 for display is arranged in the central field of view, while the second waveguide layer 30 for infrared tracking surrounds or partially surrounds the periphery of the first waveguide layer 20. Furthermore, since the double-sided structure is eliminated, double-sided alignment is unnecessary, reducing the manufacturing process difficulty and making the device thinner and lighter. In addition, the first planarization layer 50 can cover and planarize the first grating 21 of the first waveguide layer 20 and the second grating 31 of the second waveguide layer 30 in one step, thereby simplifying the film structure of the entire optical waveguide structure.

[0074] Specifically, in order to suppress diffraction noise and scattered stray light caused by the structural abrupt change at the interface between the first waveguide layer 20 and the second waveguide layer 30, a transition region 140 is defined between the first waveguide layer 20 and the second waveguide layer 30. The first waveguide layer 20 includes a first grating 21, and the second waveguide layer 30 includes a second grating 31. The grating depths of the first grating 21 and the second grating 31 within the transition region 140 smoothly transition in the direction from the first waveguide layer 20 to the second waveguide layer 30.

[0075] Therefore, by setting the transition zone 140, light waves will not form hard boundaries and undergo Fresnel diffraction when they encounter the junction of the first grating 21 and the second grating 31, thus avoiding the appearance of messy diffracted light, which will appear as ghosting, halo or severe stray light in the eyes of the user. This ensures the purity and contrast of the image presented to the user, while achieving complete crosstalk-free operation between the two light paths.

[0076] like Figure 9 As shown, in an optional embodiment, to address potential optical crosstalk caused by same-side partitioning, the first grating 21 of the first waveguide layer 20 is configured to generate a diffraction response only to the first polarized light 150; the second grating 31 of the second waveguide layer 30 is configured to generate a diffraction response only to the second polarized light 160. For example, the visible light emitted by the display screen is the first polarized light 150, which is TE (Transverse Electric) polarized light with an electric field perpendicular to the incident plane or parallel to the grating lines. Furthermore, the period, duty cycle, and depth of the grating structure of the first grating 21 are designed to achieve high diffraction efficiency only for the first polarized light 150.

[0077] like Figure 10 As shown, the infrared light emitted by the infrared illumination source is second-polarized light 160, which is TM (Transverse Magnetic) polarized light with a magnetic field perpendicular to the incident plane. Furthermore, the grating structure of the second grating 31 can only achieve high diffraction efficiency for the second-polarized light 160.

[0078] Therefore, by physically isolating light of different polarizations as described above, the occurrence of cross-diffraction and crosstalk between visible light at the second grating 31 and infrared light at the first grating 21 is prevented.

[0079] One embodiment of this application also provides a display device, which includes the waveguide structure of any of the above embodiments. It is understood that the display device may be augmented reality glasses, a head-mounted display device, etc.

[0080] Specifically, the display device integrates the integrated light guide waveguide structure, which also includes an external IR LED emitting module, an RGB display light source, and a CMOS receiving module coupled to the second waveguide layer 30 at the rear end.

[0081] In practical applications, the optical waveguide structure used in this display device can first couple visible light from the display light source into the first waveguide layer 20, and then cause total internal reflection at the interface between the first waveguide layer 20 and the surrounding dielectric layer, and finally be exported to the human eye to form a virtual image.

[0082] Meanwhile, infrared light reflected from the cornea after being illuminated by an external infrared light source is coupled into the second waveguide layer 30 and conducted therein until it is finally transmitted to the CMOS image sensor (not shown in the figure) at the back end for eye-tracking analysis. When the infrared and visible light signals are conducted separately on the upper and lower surfaces or the same surface of the same substrate 10, they do not interfere with each other, thus preventing polarization interference and effectively avoiding optical imaging problems such as ghosting and reduced contrast in the displayed image.

[0083] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0084] It should be noted that if a component is described as "fixed to" or "set on" another component, it can be directly on the other component or there may be an intervening component. If a component is described as "connected to" another component, it can be directly connected to the other component or there may be an intervening component.

[0085] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. An optical waveguide structure, characterized in that, include: The base layer (10) has a first surface (10a) and a second surface (10b) disposed opposite to each other. A first waveguide layer (20) is disposed on the first surface (10a) of the base layer (10), and the first waveguide layer (20) is configured to receive and conduct visible light; The second waveguide layer (30) and the first waveguide layer (20) are respectively disposed in different regions of the first surface (10a) of the base layer (10); or the second waveguide layer (30) is disposed on the side of the base layer (10) away from the first waveguide layer (20), and the second waveguide layer (30) is configured to receive and conduct infrared light.

2. The optical waveguide structure according to claim 1, characterized in that, The optical waveguide structure also includes: A first refractive layer (40) is disposed on the second surface (10b) of the base layer (10). The first planarization layer (50) is disposed on the side of the first waveguide layer (20) away from the base layer (10); The second refractive layer (60) is disposed on the side of the first planarization layer (50) away from the first waveguide layer (20); A first anti-reflective layer (70) is disposed on the side of the second refractive layer (60) away from the first planarization layer (50).

3. The optical waveguide structure according to claim 2, characterized in that, When the second waveguide layer (30) is disposed on the second surface (10b) of the base layer (10), the first refractive layer (40) is located between the second waveguide layer (30) and the base layer (10).

4. The optical waveguide structure according to claim 3, characterized in that, The optical waveguide structure also includes: The second planarization layer (80) is disposed on the side of the second waveguide layer (30) away from the first refractive layer (40); The third refractive layer (90) is disposed on the side of the second planarization layer (80) away from the second waveguide layer (30).

5. The optical waveguide structure according to claim 3, characterized in that, The first waveguide layer (20) includes a plurality of spaced first gratings (21), and the second waveguide layer (30) includes a plurality of spaced second gratings (31), wherein the period between the plurality of first gratings (21) is less than the period between the second gratings (31); The light emission angle of the second waveguide layer (30) is smaller than the total internal reflection angle of the base layer (10).

6. The optical waveguide structure according to claim 4, characterized in that, The optical waveguide structure also includes: The first lens (110) is disposed on the side of the first antireflective layer (70) away from the base layer (10) via an adhesive layer (100); The second lens (120) is disposed on the side of the third refractive layer (90) away from the base layer (10) via an adhesive layer (100).

7. The optical waveguide structure according to claim 2, characterized in that, When the second waveguide layer (30) and the first waveguide layer (20) are respectively disposed in different regions of the first surface (10a) of the base layer (10), the first planarization layer (50) is attached to the side of the first waveguide layer (20) and the second waveguide layer (30) away from the base layer (10); The optical waveguide structure also includes: The second anti-reflective layer (130) is disposed on the side of the first refractive layer (40) away from the base layer (10); The first lens (110) is disposed on the side of the first antireflective layer (70) away from the base layer (10) via an adhesive layer (100); The second lens (120) is disposed on the side of the second antireflective layer (130) away from the base layer (10) via an adhesive layer (100).

8. The optical waveguide structure according to claim 7, characterized in that, A transition region (140) is provided between the first waveguide layer (20) and the second waveguide layer (30), and the grating depth in the transition region (140) is smoothly transitioned in the direction from the first waveguide layer (20) to the second waveguide layer (30).

9. The optical waveguide structure according to claim 5, characterized in that, The period of the first grating (21) is 350nm to 450nm, the operating wavelength of the first grating (21) is 400nm to 750nm, and the first grating (21) is configured to produce a diffraction response only to the first polarized light (150); The period of the second grating (31) is 600nm to 900nm, the operating wavelength of the second grating (31) is 850nm or 940nm, and the second grating (31) is configured to produce a diffraction response only to the second polarized light (160).

10. A display device, characterized in that, Includes the optical waveguide structure as described in any one of claims 1 to 9.

Images