WO2023284627A1 - 光学显示元件及光学设备 - Google Patents

光学显示元件及光学设备 Download PDF

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Publication number
WO2023284627A1
WO2023284627A1 PCT/CN2022/104451 CN2022104451W WO2023284627A1 WO 2023284627 A1 WO2023284627 A1 WO 2023284627A1 CN 2022104451 W CN2022104451 W CN 2022104451W WO 2023284627 A1 WO2023284627 A1 WO 2023284627A1
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WIPO (PCT)
Prior art keywords
display element
optical display
stripes
optical
element according
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Ceased
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PCT/CN2022/104451
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English (en)
French (fr)
Inventor
姚湛史
郭睿
李�根
孟培雯
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Huawei Technologies Co Ltd
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Huawei Technologies Co Ltd
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Priority to EP22841263.1A priority Critical patent/EP4357837A4/en
Publication of WO2023284627A1 publication Critical patent/WO2023284627A1/zh
Priority to US18/408,894 priority patent/US20240142775A1/en
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/01—Head-up displays
    • G02B27/0101—Head-up displays characterised by optical features
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B1/00—Optical elements characterised by the material of which they are made; Optical coatings for optical elements
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/01—Head-up displays
    • G02B27/017—Head mounted
    • G02B27/0172—Head mounted characterised by optical features
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/01—Head-up displays
    • G02B27/0179—Display position adjusting means not related to the information to be displayed
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/42—Diffraction optics, i.e. systems including a diffractive element being designed for providing a diffractive effect
    • G02B27/4205—Diffraction optics, i.e. systems including a diffractive element being designed for providing a diffractive effect having a diffractive optical element [DOE] contributing to image formation, e.g. whereby modulation transfer function MTF or optical aberrations are relevant
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/20—Filters
    • G02B5/28—Interference filters
    • G02B5/284—Interference filters of etalon type comprising a resonant cavity other than a thin solid film, e.g. gas, air, solid plates

Definitions

  • the embodiments of the present application relate to the field of optical technology, and in particular to an optical display element, an optical device, an augmented reality near-eye imaging system, a head-up display system, and a vehicle.
  • Augmented reality (augmented reality, AR) technology is a technology that integrates virtual information with real world information.
  • Physical information such as visual information, sound, or touch
  • space such as visual information, sound, or touch
  • AR technology has been widely used in augmented reality devices, such as AR glasses, which can project virtual images into human eyes and realize the superposition of virtual images and real images.
  • FIG. 1 is a schematic diagram of an AR near-eye imaging system, which can be divided into two parts: an optical projection system 101 and an optical display element 102 .
  • the augmented reality near-eye imaging system includes: an optical projection system 101 and an optical display element 102 .
  • the optical display element 102 is located in front of the user's eyes, and the optical display element 102 can not only transmit the external ambient light, but also reflect the light of the projection system to the human eye 103 .
  • the augmented reality near-eye imaging system uses a curved mirror 1021 as an optical display element to reflect and image the image source emitted by the optical projection system 101 into human eyes.
  • the curved reflector 1021 performs normal specular reflection on the working light, and an angle of about 45 degrees is formed between the tangent direction of the specular surface and the line of sight of the human eye looking straight ahead.
  • the reflective surface is semi-reflective and semi-transparent, showing a uniform wide-band response, that is, for all wavelengths in the visible light band, part of the light is reflected, and the remaining part of the light is transmitted.
  • the angle between the curved mirror 1021 and the line of sight of the human eye is about 45 degrees, so the imaging system will protrude a large volume forward when the user wears it, which is not conducive to the realization of a compact near-eye imaging system.
  • Embodiments of the present application provide an optical display element, an optical device augmented reality near-eye imaging system, a head-up display system, and a vehicle.
  • a resonant element and stripes are matched together to enhance the diffraction efficiency of a specific order.
  • an optical display element including: a plurality of stripes, the stripes are arc-shaped, and the bending directions of the stripes are the same , the stripes are used to reflect the working light of the optical display element, so that the working light forms an image; wherein, the stripes include: a plurality of resonant elements, and the working light generates a resonance effect in one or more of the resonant elements.
  • the grating structure has a micro-nano size and a small volume, which reduces the space occupation and realizes the miniaturization of the device.
  • combining resonant elements with fringes can enhance the diffraction efficiency of specific orders.
  • the resonant element can selectively improve the diffraction of working light, while keeping the diffraction of light in other bands at a low level, so as to achieve high reflectivity for the wavelength of working light and high transmittance for the wavelength of ambient light. Select properties.
  • the bending direction of the stripes is parallel to the surface of the optical display element. As a result, space for the optical display element can be saved.
  • the radius of curvature of at least one stripe is different from the radius of curvature of other stripes. Therefore, the non-uniform grating structure can be designed according to the incident angle, exit angle, and imaging requirements of the light, and can present different grating structures in different regions, so that the incident light can form first-order diffracted light after being diffracted by the grating, and the diffracted light along the It is emitted at the angle required by the optical system.
  • the radius of curvature of the stripes changes along one direction.
  • different diffraction responses can be presented in different regions, so that light entering different regions can achieve diffracted light coming out in different directions, which is beneficial for imaging.
  • the projection of the radius of curvature of the stripes on the optical display element along the incident direction of the working light gradually becomes larger.
  • incident light from different directions can be diffracted, which is beneficial to imaging.
  • the minimum curvature radius of the stripes is not less than 100 ⁇ m.
  • the uniformity of the diffraction efficiency of the fringes is better.
  • the distance between at least one pair of adjacent stripes is different from the distance between other adjacent stripes. Therefore, the non-uniform grating structure can be designed according to the incident angle, exit angle, and imaging requirements of the light, and can present different grating structures in different regions, so that the incident light can form first-order diffracted light after being diffracted by the grating, and the diffracted light along the It is emitted at the angle required by the optical system.
  • the distance between adjacent stripes varies along one direction.
  • different diffraction responses can be presented in different regions, so that light entering different regions can achieve diffracted light coming out in different directions, which is beneficial for imaging.
  • the projection of the distance between adjacent stripes on the optical display element gradually becomes smaller along the incident direction of the working light. In this way, diffracted light from incident light in different directions can be emitted, which is beneficial to imaging.
  • the distance between two adjacent stripes is greater than or equal to 1/4 of the wavelength of the working light and less than 10 times the wavelength of the working light.
  • the diffraction performance of the stripes on the working light can be guaranteed.
  • the angle between the incident direction of the working light and the normal direction of the plane where the stripes are located is greater than or equal to 40 degrees. Therefore, the optical display element can diffract light incident at a large oblique angle, making the structure of the optical system more compact.
  • the working light is converging after being reflected by the optical display element.
  • the projection light incident at a large angle obliquely can be diffracted by the grating and then reflected according to the angle required for imaging.
  • the projection of the imaged eye box area on the plane where the optical display element is located is located inside the optical display element. Therefore, images can be imaged inside the optical display element.
  • the optical display element is integrated with an aberration correction function. Therefore, the optical display element integrates the aberration correction function, so that the AR near-eye display system can avoid the use of the aberration correction lens group in the front optical path, further reducing the volume and weight of the system.
  • the optical display element has different optical powers for the incident working light in two mutually orthogonal directions along the surface of the optical display element.
  • the astigmatism problem of the optical system can be alleviated, so that the AR near-eye display system can avoid the use of aberration correction lens groups in the front optical path, reducing the volume and weight of the system.
  • the distance between the image formed by the working light and the optical element is greater than or equal to 5 cm.
  • imaging can be performed at an appropriate position.
  • the stripes include: convex stripes and concave stripes arranged adjacently.
  • the diffraction function of the fringes is realized.
  • the convex stripes are composed of multiple resonant elements. Therefore, the convex stripes are directly composed of resonant elements, without special molding of the convex stripes, and the manufacturing process is simpler.
  • multiple resonant elements are arranged on the convex stripes. Therefore, a resonant element can be arranged on the grating structure, and higher diffraction efficiency can be realized.
  • multiple resonant elements are arranged in the concave stripes.
  • a resonant element can be arranged on the grating structure, and by matching the resonant element with the grating convex stripes, higher diffraction efficiency can be achieved without increasing the complexity of the process.
  • the stripes include: a plurality of resonant elements arranged at intervals, and the distance between adjacent resonant elements of each stripe is less than or equal to twice the working wavelength.
  • the resonance mode of the resonant element is any one or more of Mie resonance, guided mode resonance GMR, continuum bound state BIC resonance or whispering gallery mode WGM.
  • the resonance phenomenon of a single resonant element can be utilized.
  • the stripes include: a plurality of resonant elements arranged continuously.
  • the resonance mode of the resonant element is any one or several of guided mode resonance GMR and continuum bound state BIC resonance.
  • the resonant element can achieve a resonant effect with a higher quality factor.
  • the height of the resonance element is less than 1 ⁇ m. Thereby, higher transparency is ensured, and the process is simple.
  • the cross-sectional shape of the resonant element includes a circle, a rectangle, a cross, a T shape, or a trapezoid. Therefore, the resonant element has a flexible shape and is suitable for various working scenarios.
  • the optical display element includes multiple sub-regions, the multiple sub-regions are located on the same plane, and there are blank areas between adjacent sub-regions.
  • the transparency of the optical display element is increased, and the ambient light transmittance of the stripes can be increased.
  • the optical display element includes a plurality of sub-regions, and the plurality of sub-regions are stacked along a direction perpendicular to a plane where the stripes are located.
  • the optical display elements in each sub-region correspond to one working light wavelength, and the optical display elements in multiple sub-regions have at least two working light wavelengths. Therefore, the fringes of different sub-regions have different wavelength selectivities, so that the fringes of the multiple sub-regions can diffract multiple wavelengths.
  • the working light wavelengths of the included multiple sub-regions include three colors: red, green, and blue. In this way, color diffraction imaging is realized.
  • the radian of each stripe is smaller than ⁇ .
  • the uniformity of the diffraction efficiency of the fringes is better.
  • an optical device which includes: an optical projection system, and the above-mentioned optical display element; wherein, the optical projection system is used to generate working light and display the working light to the optical display element; the optical display element is used to reflect the working light to human eyes. Therefore, the optical device adopts the above-mentioned optical display element, has a more compact structure, and has a higher diffraction efficiency for working light.
  • the projection of the optical projection system on the optical display element is located in the bending direction of the stripes, and the direction of the radius of curvature of the stripes points to the direction of the optical projection system on the optical display element. Displays the shadow cast on the component.
  • the light emitted by the optical projection system can be reflected to human eyes through the optical display element.
  • an augmented reality near-eye imaging system is provided, and the augmented reality near-eye imaging system includes the above-mentioned optical device. Therefore, the thickness of the stripes is only in the micro-nano scale, and its volume can be ignored.
  • a head-up display system is provided, and the head-up display system includes the above-mentioned optical device.
  • the size of the head-up display system can be reduced.
  • a vehicle is provided, and the vehicle includes the above-mentioned head-up display system. As a result, the vehicle space occupied by the head-up display system can be reduced.
  • FIG. 1 is a schematic diagram of an AR near-eye imaging system
  • FIG. 2 is a schematic diagram of another AR near-eye imaging system
  • Fig. 3 is a schematic structural diagram of an optical display element provided by an embodiment of the present application.
  • Fig. 4a is a kind of partial enlarged view of place A in Fig. 3;
  • Fig. 4b is another kind of partial enlarged view of place A in Fig. 3;
  • Fig. 4c is another kind of partial enlarged view of place A in Fig. 3;
  • Fig. 4d is another partial enlarged view of A place in Fig. 3;
  • Fig. 4e is another kind of partial enlarged view of place A in Fig. 3;
  • FIG. 5 is a schematic diagram of the working state of the resonant element provided by the embodiment of the present application.
  • FIG. 6 is a cross-sectional view of a resonant element provided in an embodiment of the present application.
  • FIG. 7 is a working state diagram of the AR near-eye display system provided in Example 1.
  • Example 8 is a schematic diagram of wavelength selection performed by an optical display element in Example 1;
  • FIG. 9 is a schematic diagram of an imaging result of an optical display element provided in Example 1.
  • Fig. 10 is a schematic structural diagram of another optical display element provided by the embodiment of the present application.
  • Fig. 11 is a schematic structural diagram of another optical display element provided by the embodiment of the present application.
  • Fig. 12 is a perspective view of the optical display element shown in Fig. 11;
  • FIG. 13 is a schematic diagram of a working state of a head-up display system provided in Example 2.
  • FIG. 14 is a schematic diagram of a working state of a beam collimating element provided in Example 3.
  • Fig. 15 is a schematic diagram of a working state of a beam focusing element provided in Example 4.
  • first”, second, etc. are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of indicated technical features.
  • a feature defined as “first”, “second”, etc. may expressly or implicitly include one or more of that feature.
  • plural means two or more.
  • An embodiment of the present application provides an optical device, which includes but is not limited to a head-up display (HUD, head-up display), a virtual reality (VR, virtual reality) system, an augmented reality (augmented reality, AR) near-eye imaging system, Optical filters, optical phase plates, spatial optical communications, etc.
  • HUD head-up display
  • VR virtual reality
  • AR augmented reality
  • Optical filters optical phase plates, spatial optical communications, etc.
  • This application takes the optical device as an AR near-eye imaging system as an example for illustration.
  • the AR near-eye display system includes: an optical projection system 101 and an optical display element 102 .
  • the optical display element 102 is located in front of the eyes of the user.
  • the optical display element 102 can not only transmit the external ambient light, but also reflect the light of the projection system to the human eye 103 .
  • the optical display element 102 provided by the embodiment of the present application is shown in FIG. 3 , and the optical display element 102 includes a plurality of stripes 1020 , for example.
  • the optical display element 102 further includes the substrate 1024 on which the stripes 1020 are disposed.
  • the embodiment of the present application does not limit the material of the base 1024 .
  • the material of the substrate 1024 includes but not limited to silicon oxide, silicon nitride, titanium oxide, silicon, polymer, metal and so on.
  • the stripes 1020 can use the same material as the base 1024 , or can use a material different from the base 1024 .
  • the embodiment of the present application does not limit the shape of the stripes 1020 .
  • the stripes 1020 are arc-shaped, and the bending direction of the stripes 1020 is parallel to the plane of the optical display element 102 .
  • the bending directions of the stripes 1020 are the same, and the stripes 1020 are used for reflecting the working light of the optical display element 102 and transmitting ambient light.
  • the same bending direction of the stripes 1020 means that the arc opening directions of each stripe are the same.
  • the arc opening direction of the stripes in FIG. 3 is indicated by the arrow, and the arc opening direction is rightward.
  • the "same" in the same bending direction is a qualitative rather than a quantitative description.
  • the above-mentioned stripes 1020 are, for example, diffraction gratings, which can exhibit periodic structural changes or refractive index changes on a near-wavelength scale, and can perform periodic spatial modulation on the amplitude or phase of incident light.
  • Diffraction gratings can reflect incident light at one or several specific angles. Different reflection angles correspond to specific diffraction orders.
  • the angle of the zero-order diffracted light of the grating is symmetrical to the incident light angle with respect to the normal line of the grating surface, and has nothing to do with the grating period.
  • the angle of high-order diffracted light (1st order or above) is not symmetrical with the angle of incident light, which belongs to abnormal angle reflection, and the angle of such reflection is related to the grating period.
  • Diffraction gratings have a simple working principle and compact size, and have been widely used in spectral measurement, optical communication and other fields.
  • ⁇ i is the incident angle
  • ⁇ m is the diffraction angle with the diffraction order m
  • ⁇ is the wavelength of the incident light
  • d is the distance between adjacent fringes of the grating.
  • the distance between adjacent stripes of the grating refers to the distance between centers of adjacent stripes.
  • the diffraction angle of the first-order diffracted light is equal to the incident angle, which belongs to symmetrical reflection and has nothing to do with the grating period.
  • the diffraction angle is ⁇ 1 ) and the incident angle ( ⁇ i ) of the incident light is asymmetrical with respect to the grating surface normal
  • the structural parameters of the grating depend on the wavelength of the working light and the requirements of the optical system on the deflection direction of the light.
  • the stripes 1020 can be based on the incident angle, exit angle, and imaging requirements of the near-eye imaging system.
  • the designed non-uniform grating structure can present different grating structures in different regions, such as different spacing between the stripes 1020 and changes in the radius of curvature of the stripes 1020 .
  • the spacing between the stripes and the radius of curvature of the stripes 1020 can be determined according to the requirements of the optical system on the incident and outgoing angles of the light, so that the incident light can form high-order diffracted rays after being diffracted by the grating, and the diffracted rays can form high-order diffracted rays along the optical path.
  • the stripes are placed in front of people's eyes, and the projected light of a specific wavelength band incident at various angles can be diffracted and enter the human eye at a specific angle, so that the light enters the human eye and forms an image.
  • the thickness of the grating is only micro-nano scale, its volume is small, which realizes the miniaturization of the device.
  • the AR display system has the concept of an eyebox, within which the human eye can observe clear images.
  • the projection of the eye box area on the plane of the optical display element is located inside the optical display element.
  • the aberration correction function can be integrated after the grating is designed. It should be noted that aberrations usually exist in AR near-eye display systems, and if the aberrations are not corrected, the visual experience will be reduced. Especially in the off-axis AR near-eye display system, the astigmatism phenomenon is relatively serious, resulting in blurred images.
  • the astigmatism problem of the optical system can be alleviated by designing the arrangement of the period and direction of the grating so that the optical display element has different optical powers in two mutually orthogonal directions (such as x and y directions). This enables the AR near-eye display system to avoid the use of aberration correction lens groups in the front optical path, reducing the volume and weight of the system.
  • the embodiment of the present application does not limit the specific radius of curvature of the stripes 1020 .
  • the radius of curvature of at least one stripe 1020 is different from the radius of curvature of other stripes 1020 .
  • the non-uniform grating structure can be designed according to the incident angle, exit angle, and imaging requirements of the light, and can present different grating structures in different regions, so that the incident light can form first-order diffracted light after being diffracted by the grating, and the diffracted light along the It is emitted at the angle required by the optical system.
  • the radius of curvature of the stripes 1020 changes along one direction.
  • the radius of curvature of the stripes 1020 varies uniformly along one direction, for example, the radius of curvature of the stripes 1020 in FIG. 3 varies uniformly along the left and right directions.
  • different diffractive responses can be exhibited in different regions.
  • the changing direction of the radius of curvature of the fringe 1020 in different regions is different, and different diffraction responses can be presented in different regions, so that light entering different regions can achieve diffracted light coming out in different directions, which is beneficial for imaging.
  • the embodiment of the present application does not limit the distance between two adjacent stripes 1020 .
  • the distance between at least two adjacent stripes 1020 is different from the distance between other adjacent stripes 1020 .
  • the non-uniform grating structure can be designed according to the incident angle, exit angle, and imaging requirements of the light, and can present different grating structures in different regions, so that the incident light can form first-order diffracted light after being diffracted by the grating, and the diffracted light along the It is emitted at the angle required by the optical system.
  • the distance between adjacent stripes 1020 varies along one direction. In some embodiments, the distance between adjacent stripes 1020 varies uniformly along one direction. For example, the distance between adjacent stripes 1020 in FIG. 3 varies uniformly along the left-right direction. Thus, different diffractive responses can be exhibited in different regions.
  • the distances between adjacent stripes 1020 in different regions change in different directions, and different diffraction responses can be presented in different regions, so that light entering different regions can achieve diffracted light in different directions, which is beneficial to imaging .
  • the embodiment of the present application does not limit the structure of the stripes 1020 .
  • the stripes 1020 include, for example, convex stripes 1022 and concave stripes 1023 arranged adjacent to each other.
  • the convex stripes 1022 may be convex ribs formed on the surface of the substrate 1024, and the concave stripes 1023 may be grooves formed on the surface of the substrate.
  • the optical display element 102 includes a substrate 1024, a surface of the substrate 1024 is formed with a plurality of convex stripes 1022, and the plurality of convex stripes 1022 are spaced apart from each other. It is set that concave stripes 1023 are formed between two adjacent convex stripes 1022, and multiple concave stripes 1023 are formed between the plurality of convex stripes 1022.
  • the optical display element 102 includes a substrate 1024, a surface of the substrate 1024 is formed with a plurality of concave stripes 1023, and the plurality of concave stripes 1023 are arranged at intervals, Convex stripes 1022 are formed between two adjacent concave stripes 1023 , and multiple convex stripes 1022 are formed between the plurality of concave stripes 1023 .
  • the stripe 1020 includes: a plurality of resonant elements 10221 , and the resonant elements 10221 are arranged according to the outline of the stripe 1020 .
  • the resonant element 10221 is used to limit the light field of the working light, and the resonant wavelength of the resonant element 10221 is within the working light band of the optical display element 102 .
  • the resonant element 10221 has a resonant cavity, and the resonant cavity can make light of a specific wavelength generate a resonance effect therein.
  • the resonant cavity can select the input light of a specific wavelength through the resonance effect, and enhance its interaction with the optical display element, thereby enhancing the reflection efficiency of the optical display element for the input light of a specific wavelength, while the reflection efficiency of input light of other wavelengths remain at a low level.
  • the embodiment of the present application does not limit the specific material of the resonant element.
  • the resonance element 10221 is made of dielectric materials.
  • the material of the resonant element 10221 includes but not limited to dielectric materials such as silicon nitride, titanium oxide, silicon, silicon oxide, polymer, metal, etc.
  • the resonant element 10221 can use the same material as the substrate 1024, or can use the same material as the substrate 1024 different materials.
  • the optical display element includes a resonant element 10221 that has an optical resonance effect on a specific wavelength band, which can enhance the reflection efficiency of working light, while keeping the reflection of light in other wavelength bands at a low level. It can achieve high reflectivity for working light and high transmittance for light in other wavelength bands at the same time.
  • the grating in the embodiment of the present application has resonance Effect, it can diffract a narrow range of wavelengths, while the diffraction effect of other wavelengths is weak, so the dispersion phenomenon is weak, which can reduce the image blur caused by the dispersion characteristics of the grating itself.
  • the resonant element 10221 is disposed on the surface of the substrate 1024 , and a plurality of resonant elements 10221 are arranged in an arc shape to form the convex stripes 1022 in the stripes 1020 . Therefore, the convex stripes are directly composed of the resonant elements, and there is no need to specially form the convex stripes on the substrate, and the preparation process is simpler.
  • the substrate 1024 is provided with concave stripes 1023 and convex stripes 1022 , and the resonant element 10221 can be arranged on the convex stripes 1022 .
  • matching the resonant element with the fringe can enhance the diffraction efficiency of a specific order.
  • the resonant element 10221 and the convex stripes 1022 can enhance the high-order diffraction efficiency of the working light, so that the high-order diffraction efficiency of the working light is higher than the zero-order diffraction efficiency.
  • the substrate 1024 is provided with concave stripes 1023 and convex stripes 1022 , and the resonant element 10221 can be arranged in the concave stripes 1023 .
  • a resonant element can be arranged on the grating structure, and by matching the resonant element with the grating convex stripes, higher diffraction efficiency can be achieved without increasing the complexity of the process.
  • the substrate 1024 is provided with concave stripes 1023 and convex stripes 1022
  • the resonant element 10221 is provided on the convex stripes 1022 and in the concave stripes 1023 , for example.
  • the resonant element can be arranged on the grating structure, and the application range is wider.
  • the embodiment of the present application does not limit the shape of the resonant element.
  • the resonant element 10221 is a cylinder, and its cross section is, for example, a circle as shown in (a) of FIG. 6 . It should be noted that the cross-sectional shape of the resonant element 10221 is the projection of the resonant element 10221 on the xy plane.
  • the cross-sectional shape of the resonant element 10221 can be a rectangle as shown in (b) in FIG. 6, a cross as shown in (c) in FIG. The T-shape shown, or the trapezoid shown in (e) in Figure 6.
  • the shape of the resonant element is flexible.
  • the embodiment of the present application does not limit the size of the resonant element.
  • the height of the resonant element 10221 along the z direction is, for example, less than 1 ⁇ m.
  • the optical display element can be ensured to have higher transparency, and the process is simple.
  • the resonance mode of the optical resonance generated by the resonant element 10221 can be Mie Mie resonance, guided-mode resonance (GMR, guided-mode resonance), continuum bound state (BIC, bound states in the continuum) resonance, whispering gallery mode (WGM , whispering gallery mode) etc.
  • GMR guided-mode resonance
  • BIC continuum bound state
  • WGM whispering gallery mode
  • the resonant elements 10221 forming the same stripe are arranged at intervals, and the distance between adjacent resonant elements 10221 in the same stripe should be less than or equal to twice the wavelength of the working light.
  • a single element can resonate to the working light wavelength, and the resonance mode of the resonant element is any one or several of Mie resonance, guided mode resonance GMR, continuum bound state BIC resonance or whispering gallery mode WGM.
  • the resonance strength of the resonance element can be increased, contributing to higher diffraction efficiency.
  • the resonant elements 10221 forming the same stripe may be arranged continuously. At this time, multiple identical resonant elements 10221 interact with the confined light fields to generate resonance for the wavelength of the working light.
  • the resonant mode of the resonant element is any one of guided mode resonance (GMR) and continuum bound state BIC resonance. or several. As a result, the confining effect of the structure on the light field can be increased to form a resonance effect with a higher quality factor.
  • each resonant element 10221 along the radius of curvature direction of the stripe is smaller than the distance between adjacent stripes in this area.
  • optical display element provided by the embodiment of the present application will be specifically described below with reference to examples.
  • Fig. 7 is a working state diagram of the AR near-eye display system provided in Example 1.
  • the AR near-eye display system includes: an optical projection system 101 and an optical display element 102 .
  • the optical display element 102 is located in front of the eyes of the user.
  • the optical projection system 101 includes at least: a light-emitting element
  • the light-emitting element may be an organic light-emitting diode (Organic Light-Emitting Diode, OLED) display screen
  • OLED Organic Light-Emitting Diode
  • the light-emitting element can also be a micron light-emitting diode (micro LED) display screen.
  • the optical projection system 101 further includes, for example, aberration correcting optical elements and dispersion correcting optical elements.
  • the optical display element 102 includes: a base 1024 , and stripes 1020 disposed on the base 1024 .
  • the stripes 1020 are placed in front of people's eyes, which can not only transmit external ambient light, but also diffract the projected light from the optical projection system 101 into the human eye 103 at a specific angle, so that the light enters the human eye and forms an image.
  • the spacing between the stripes and the radius of curvature of the stripes 1020 can be determined according to the requirements of the optical system on the incident and outgoing angles of the light, so that the incident light can form a first-order diffracted light after being diffracted by the grating, and the diffracted light along the It is emitted at the angle required by the optical system.
  • the projection of the optical projection system 101 on the plane of the optical display element 102 is, for example, located in the bending direction of the stripes 1020 . That is, the center of curvature of the stripe 1020 and the projection position of the projection system 101 on the plane of the optical display element 102 are located on the same side of the stripe 1020, for example, both are located on the right side of the stripe 1020, and the radius of curvature of the stripe 1020 points to the projection system 101 on the same side of the stripe 1020.
  • the projection position of the optical display element 102 plane is, for example, located in the bending direction of the stripes 1020 . That is, the center of curvature of the stripe 1020 and the projection position of the projection system 101 on the plane of the optical display element 102 are located on the same side of the stripe 1020, for example, both are located on the right side of the stripe 1020, and the radius of curvature of the stripe 1020 points to the projection system 101 on the same side of the stripe 1020
  • the overall profile of stripes 1020 is shown in FIG. 7 .
  • the overall outline of the stripes 1020 presents a curved and gradual shape, that is, the distance between the stripes and the radius of curvature of the stripes 1020 gradually change with different spatial positions.
  • the overall outline of the stripes 1020 is curved, and the plurality of stripes 1020 are approximately in the shape of concentric rings, the radius of curvature of the stripes 1020 is parallel to the surface of the substrate 1024, and the radius of curvature of the stripes 1020 and the distance between the stripes gradually change along one direction.
  • the plurality of stripes 1020 are approximately in the shape of concentric rings, which means that the stripes may not be arranged strictly according to the concentric rings, and errors are allowed.
  • the radius of curvature of the stripe 1020 and the spacing between adjacent stripes change, wherein, as shown in Figure 7, the radius of curvature of the stripe 1020 and the distance between adjacent stripes
  • the pitch varies uniformly in the left-right direction.
  • the projection of the distance between adjacent stripes 1020 on the optical display element 102 along the incident direction of the working light gradually decreases, that is, the distance between adjacent stripes 1020 gradually increases from left to right. , that is, the spatial arrangement of the stripes 1020 becomes sparse.
  • the projection of the radius of curvature of the stripes 1020 on the optical display element 102 along the incident direction of the working light gradually becomes larger, that is, the radius of curvature of the stripes 1020 gradually decreases from left to right, that is, the curvature of the grating becomes larger.
  • the variation range of the spacing between the stripes 1020 is directly related to the wavelength of light used during operation.
  • the distance between adjacent stripes 1020 is greater than or equal to 1/4 of the wavelength of the light and less than or equal to 10 times the wavelength of the working light.
  • the diffraction performance of the stripes on the working light is ensured.
  • the minimum radius of curvature of the grating is not less than 100 ⁇ m, and the radian of each stripe is less than ⁇ .
  • the direction of the radius of curvature of the stripes 1020 also changes gradually.
  • the direction in which the radius of curvature of the stripe 1020 points to the center of curvature presents a change in the direction of lower right-right-upper right.
  • the angle corresponding to each arc included in the curved gradient grating is less than 180 degrees.
  • the incident angle of the working light is not less than 40 degrees, that is, the angle between the incident direction of the working light and the normal direction of the surface where the stripes 1020 are located should not be less than 40 degrees. Therefore, the optical display element can diffract light incident at a large oblique angle, making the structure of the optical system more compact.
  • the distance between the image formed by the working light and the optical element is greater than or equal to 5 cm.
  • imaging can be performed at an appropriate position.
  • the working light converges after being reflected by the optical display element.
  • the stripe 1020 structure in each area can make the projected light incident at a large angle obliquely pass through the grating to form first-order diffracted light, and the first-order diffracted light is reflected according to the angle required for imaging and enters the human eye or other Imaging in the optical imaging system.
  • the projection of the imaged eye box area on the plane where the optical display element is located is located inside the optical display element.
  • the projected light incident at a large oblique angle can be diffracted by the grating, reflected at the angle required for imaging, and imaged inside the optical display element.
  • the thickness of the optical display element is only on the micro-nano scale, its structure is compact, and it occupies a small space. It is used in the AR near-eye system, which can realize the miniaturization of the system, and is easy to use and carry.
  • the arrangement of the period and direction of the grating can be designed so that the optical display element has different light intensity in two mutually orthogonal directions (such as the x and y directions).
  • the focal power can integrate aberration correction (such as correctable pixels) and other functions to alleviate the astigmatism problem of the optical system, so that the AR near-eye display system can avoid the use of aberration correction lens groups in the front optical path, reducing the size and weight of the system.
  • the stripes 1020 include: a plurality of adjacent concave stripes 1023 and convex stripes 1022 .
  • the convex stripes 1022 are composed of a plurality of resonant elements 10221 arranged, and the plurality of convex stripes 1022 are arranged at intervals.
  • a concave stripe 1023 is formed between two adjacent convex stripes 1022, and a concave stripe 1023 is formed between the plurality of convex stripes 1022.
  • a plurality of concave stripes 1023 is formed between two adjacent convex stripes 1022.
  • the resonant element 10221 is in the shape of a cylinder.
  • the height of the resonant element 10221 along the z direction is, for example, less than 1 ⁇ m.
  • the resonant elements 10221 forming the same stripe are arranged at intervals, and the distance between adjacent resonant elements 10221 in the same stripe should be less than or equal to twice the wavelength of the working light.
  • the resonant element adopts Mie resonance, for example.
  • FIG. 8 is a schematic diagram of wavelength selection performed by an optical display element in Example 1.
  • the abscissa is the wavelength
  • the ordinate is the reflectance.
  • the optical display element has a higher reflectance for light whose wavelength is in the L1 band of the working light, and has a higher reflectance for the light whose working frequency is in the L1 band of the working light.
  • the ambient light L2 outside the range has a low reflectance.
  • the optical display element utilizes the resonance phenomenon to enhance the reflection of incident light of a specific wavelength band, realizes wavelength selectivity, and enhances the reflection efficiency of working light, while keeping the reflection of ambient light of other bands at a low level .
  • FIG. 9 is a schematic diagram of an imaging result of an optical display element provided in Example 1.
  • the wavelength of the projected working light used in the experiment is 525nm
  • the material of the stripes 1020 is silicon nitride
  • the material of the substrate 1024 is quartz.
  • the device structure in the visible light band is transparent, and the environment behind the fringes can be observed while realizing diffraction imaging.
  • the angle of incidence of the incident light is about 45 degrees.
  • clear images can be produced by diffracting the working light through the fringes.
  • optical display element provided in this example can be realized based on a mature semiconductor micro-nano manufacturing process, which is less difficult to manufacture and easier to achieve mass production.
  • the optical display element can be composed of stable materials, and the performance under different environmental conditions remains consistent without the problem of volume shrinkage.
  • the optical display element provided in this example adopts the non-uniform structural fringes with a curved and gradual overall outline to diffract the incident light of the optical system to form high-order diffracted light, so that the diffracted light in each area can follow the required direction of the optical system. Angle of light emitted.
  • the thickness of the stripes is only in the micro-nano scale, and its volume can be ignored.
  • the fringe of the present invention can integrate aberration correction function, so that the AR near-eye display system can avoid the use of aberration correction lens group in the front optical path, reducing the volume and weight of the system.
  • the embodiment of the present application does not limit the distribution position of the stripes 1020 on the substrate 1024 .
  • the optical display element includes a region (one surface of the substrate 1024), and the stripes 1020 are distributed in the region.
  • the optical display element includes a plurality of sub-areas, and the stripes 1020 are distributed in the sub-areas.
  • the multiple sub-regions are located on the same plane, and there is no grating structure between adjacent sub-regions.
  • the plurality of sub-regions are stacked in a direction perpendicular to the plane where the stripes are located.
  • the optical display elements in each sub-region correspond to one working light wavelength
  • the optical display elements in multiple sub-regions have at least two working light wavelengths. Therefore, the fringes of different sub-regions have different wavelength selectivities, so that the fringes of the multiple sub-regions can diffract multiple wavelengths.
  • the working light wavelengths of the included multiple sub-regions include three colors of red, green and blue. In this way, color diffraction imaging is realized.
  • optical display element 102 includes multiple sub-regions in FIG. 10 , FIG. 11 and FIG. 12 .
  • FIG. 10 is a schematic structural diagram of another optical display element provided by an embodiment of the present application. As shown in FIG. 10 , the difference between this example and the stripes 1020 in FIG. 7 is that the stripes in this embodiment are only distributed in a part of the structure of the substrate 1024 , and not completely distributed on the surface of the structure of the substrate 1024 .
  • the optical display element 102 includes a plurality of sub-regions S0 located on the same plane (XY plane shown in FIG. 10 ), and adjacent sub-regions S0 are blank regions 10201 .
  • the subregion S0 is, for example, a rectangle, and the structural surface of the substrate 1024 is divided into a plurality of subregions S0 by a series of mutually perpendicular parallel lines, and these subregions S0 are divided into two spatial dimensions (from left to right and from top to bottom) ) are periodically repeated, presenting a rectangular grid structure.
  • the stripes 1020 are distributed in these separated sub-regions S0, and the stripes 1020 can realize the diffraction function.
  • the part between the adjacent sub-regions S0 is blank, and there is no grating structure distribution.
  • the grating structure in this embodiment is only distributed in a part of the substrate 1024 structure, which increases the transparency of the optical display element and can increase the ambient light transmittance of the stripes.
  • grating structures corresponding to different working wavelengths can be designed in different sub-regions (for example, different sub-regions correspond to red, green and blue working lights of different wavelengths), so that the entire stripe can Diffraction at multiple wavelengths to achieve color diffraction imaging.
  • the optical display element includes a first sub-region S1 , a second sub-region S2 , and a third sub-region S3 located on the same layer.
  • the working wavelength of the first sub-region S1 is red
  • the working wavelength of the second sub-region S2 is green
  • the working wavelength of the third sub-region S3 is blue.
  • Fig. 11 is a front view of another optical display element provided by the embodiment of the present application.
  • FIG. 12 is a top view of another optical display element provided by an embodiment of the present application.
  • the optical display element includes a plurality of sub-regions (the first sub-region S1, the second sub-region S2, and the third sub-region S3), and the plurality of sub-regions are along the plane perpendicular to the stripes.
  • the direction (z direction) is stacked, and each sub-region includes: a base, and stripes set on the base.
  • stripes corresponding to different working wavelengths can be designed in different sub-regions (for example, different sub-regions correspond to red, green, and blue three colors of working light with different wavelengths), so that the entire stripe can be used for multiple Diffraction at each wavelength to achieve color diffraction imaging.
  • stripes of different layers have different wavelength selectivities, so that the multilayer stripes can diffract multiple wavelengths.
  • the optical display element includes: a first sub-region S1 , a second sub-region S2 , and a third sub-region S3 located in different layers.
  • the working wavelength of the first sub-region S1 is red
  • the working wavelength of the second sub-region S2 is green
  • the working wavelength of the third sub-region S3 is blue.
  • the optical display element can be used in an AR near-eye system, and in other embodiments, the optical display element can also be used in a head-up display (HUD) system.
  • HUD head-up display
  • HUD head-up display
  • FIG. 13 is a schematic diagram of a working state of a head-up display system provided in Example 2.
  • the head-up display system includes: an optical projection system 101 and an optical display element 102 .
  • the optical display element 102 is located in front of the eyes of the user.
  • the optical display element 102 includes: a base 1024 and stripes 1020 disposed on the base 1024 .
  • the stripes 1020 are placed in front of people's eyes, which can not only transmit external ambient light, but also diffract the projected light from the optical projection system 101 to enter the human eye 103 at a specific angle, so that the light enters the human eye and forms an image.
  • the main difference between this embodiment and the AR near-eye display system is the size of the stripes 1020 , and the width of the optical display element 102 of the HUD system is usually more than 10 cm.
  • the application scenario of the head-up display (HUD) system is in the vehicle application, for example, it can be installed on the front windshield of the car instead of being worn directly in front of people's eyes.
  • the optical display element can also be used as a beam focusing element or a beam collimating element.
  • Fig. 14 is a schematic diagram of a working state of a beam collimating element provided in Example 3.
  • the fringe parameters can be set so that the light emitted from the same point outside the device and incident on different areas of the fringe is diffracted by the local grating, and all exit in the same direction. Parallel light is formed to achieve beam collimation.
  • Fig. 15 is a schematic diagram of a working state of a beam focusing element provided in Example 4.
  • the fringe parameters can be set so that the light incident on different areas of the fringe in the same direction is diffracted by the local grating, and is reflected towards a spatial position point outside the device to form a focus light, so as to achieve beam focusing.
  • Both the light beam focusing function and the light beam collimating function of the optical display element can be realized by adjusting the parameters of the stripes, and the overall outline of the stripes is curved and gradual, within the scope described in Embodiment 1.
  • the distance between adjacent stripes and the radius of curvature of the stripes can be determined according to the wavelength of light used by the optical system and the requirements for the input and output angles of the light.
  • the optical display elements of the present application all generate projections, which are seen by human eyes. It should be noted that the optical display element of the present application can not only be applied to optical bands, such as visible light bands, infrared bands, ultraviolet bands, etc., but also can be used in terahertz, microwave, radio and other fields, all of which belong to the scope of protection of this application .

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Abstract

一种光学显示元件（102）、光学设备、增强现实近眼成像系统、抬头显示系统及车辆。光学设备可以是光学滤波器、光学相位片、空间光通信设备。光学显示元件（102）包括多道条纹（1020），条纹（1020）呈弧线形状，且条纹（1020）的弯曲方向相同，用于对光学显示元件（102）的工作光进行反射，使得工作光成像。其中，条纹（1020）包括多个谐振元件（10221），工作光在其中一个或多个谐振元件（10221）中产生谐振效应。光栅结构为微纳尺寸，体积较小，减小了空间占用，实现了设备的小型化。同时，采用谐振元件可以选择性提高工作光的衍射效率，实现对工作光波长的高反射率，实现波长选择特性。

Description

光学显示元件及光学设备
“本申请要求于2021年07月13日提交国家知识产权局、申请号为202110790671.2、发明名称为光学显示元件及光学设备的中国专利申请的优先权，其全部内容通过引用结合在本申请中”。
技术领域
本申请实施例涉及光学技术领域，尤其涉及一种光学显示元件、光学设备、增强现实近眼成像系统、抬头显示系统及车辆。
背景技术
增强现实(augmented reality，AR)技术是一种将虚拟信息与真实世界信息相融合的技术，增强现实技术的目标是在屏幕上将虚拟世界套在现实世界，并进行互动，可以将真实世界的时间空间范围内的很难体验到的实体信息(比如视觉信息、声音、或触觉等)通过电脑等模拟仿真后再叠加，将虚拟信息应用到真实世界。目前，增强现实技术已广泛应用在增强现实装置中，比如AR眼镜，能够将虚拟图像投影到人眼之中，实现虚拟图像与真实图像的叠加。
图1为一种AR近眼成像系统示意图，该系统可分为两大部分：光学投影系统101和光学显示元件102。
如图1所示，该增强现实近眼成像系统包括：光学投影系统101和光学显示元件102。其中，光学显示元件102位于用户的眼前，光学显示元件102既可以透射外部的环境光，也可以反射投影系统的光到人眼103。
在一些实施例中，如图2所示，该增强现实近眼成像系统使用了曲面反射镜1021作为光学显示元件，将光学投影系统101发射的图像源反射并成像到人眼中。其中曲面反射镜1021对工作光线进行普通的镜面反射，镜面切线方向与人眼平视前方的视线之间呈现大约45度角。同时，反射面是半反半透型的，呈现均匀的宽波段响应，即对于可见光波段的所有波长，都是一部分光被反射，剩下的一部分光被透射。
曲面反射镜1021与人眼平视前方的视线之间呈现大约45度的夹角，因此使用者在佩戴时成像系统要往前凸出很大一块体积，不利于实现体积紧凑的近眼成像系统。
发明内容
本申请实施例提供一种光学显示元件、光学设备增强现实近眼成像系统、抬头显示系统及车辆，将谐振元件与条纹搭配在一起，以增强特定阶数的衍射效率。
为达到上述目的，本申请实施例采用如下技术方案：本申请实施例的第一方面，提供一种光学显示元件，包括：多道条纹，该条纹呈弧线形状，且该条纹的弯曲方向相同，该条纹用于对该光学显示元件的工作光进行反射，使得该工作光成像；其中，该条纹包括：多个谐振元件，该工作光在一个或多个该谐振元件中产生谐振效应。由此，光栅结构为微纳尺寸，体积较小，减小了空间占用，实现了设备的小型化。同时，将谐振元件与条纹搭配在一起，可以增强特定阶数的衍射效率。该谐振元件可以 选择性提高工作光的衍射，而对其他波段的光的衍射保持在较低的水平，实现对工作光波长的高反射率，以及实现对环境光波长的高透射率，实现波长选择特性。
一种可选的实现方式中，该条纹的弯曲方向与该光学显示元件的表面平行。由此，可以节省光学显示元件的空间。
一种可选的实现方式中，至少1道条纹的曲率半径和其他条纹的曲率半径不同。由此，可以根据光线入射角度、出射角度，以及成像需求而设计的非均匀光栅结构，可以在不同区域呈现不同的光栅结构，使得入射光线经过光栅衍射后可以形成一阶衍射光线，衍射光线沿着光学系统所需要的角度发射出来。
一种可选的实现方式中，该条纹的曲率半径沿一个方向变化。由此，可在不同区域呈现不同的衍射响应，导致光进入不同区域可以实现不同方向的衍射光出来，有利于成像。
一种可选的实现方式中，所述条纹的曲率半径沿着工作光入射的方向在光学显示元件上的投影逐渐变大。由此，可以将不同方向的入射光衍射光出来，有利于成像。
一种可选的实现方式中，所述条纹的最小曲率半径不小于100μm。由此，使得条纹的衍射效率均匀性更好。
一种可选的实现方式中，至少一对相邻条纹之间的距离与其他相邻条纹的之间的距离不同。由此，可以根据光线入射角度、出射角度，以及成像需求而设计的非均匀光栅结构，可以在不同区域呈现不同的光栅结构，使得入射光线经过光栅衍射后可以形成一阶衍射光线，衍射光线沿着光学系统所需要的角度发射出来。
一种可选的实现方式中，相邻条纹之间的距离沿一个方向均变化。由此，可在不同区域呈现不同的衍射响应，导致光进入不同区域可以实现不同方向的衍射光出来，有利于成像。
一种可选的实现方式中，相邻条纹之间的距离沿着工作光入射的方向在光学显示元件上的投影逐渐变小。由此，可以将不同方向的入射光的衍射光出来，有利于成像。
一种可选的实现方式中，相邻两道条纹之间的距离大于或等于工作光波长的1/4，且小于工作光波长的10倍。由此，可保证条纹对工作光的衍射性能。
一种可选的实现方式中，该工作光的入射方向与该条纹所在平面的法线方向的夹角大于或等于40度。由此，该光学显示元件可对大角度倾斜入射的光进行衍射，使得光系统结构更加紧凑。
一种可选的实现方式中，所述工作光经光学显示元件反射后呈收敛状。由此，可以使得以大角度倾斜入射的投射光线经过光栅衍射后按照成像所需要的角度反射出来。
一种可选的实现方式中，所述工作光经光学显示元件反射后，成像的眼盒区域在光学显示元件所在平面的投影位于光学显示元件内部。由此，可以在光学显示元件内部成像。
一种可选的实现方式中，该光学显示元件集成有像差矫正功能。由此，光学显示元件集成像差矫正功能，使得AR近眼显示系统可以避免在前端光路使用像差矫正透镜组，进一步减小系统体积和重量。
一种可选的实现方式中，所述光学显示元件对入射的工作光在沿着光学显示元件表面的两个相互正交的方向上具有不同的光焦度。由此，可以缓解光系统的像散问题，使得AR近眼显示系统可以避免在前端光路使用像差矫正透镜组，减小系统体积和重量。
一种可选的实现方式中，所述工作光形成的像与光学元件之间的距离大于或等于5cm。由此，可以在合适的位置成像。
一种可选的实现方式中，该条纹包括：邻接设置的凸条纹和凹条纹。由此，实现了条纹的衍射功能。
一种可选的实现方式中，该凸条纹由多个该谐振元件组成。由此，凸条纹直接由谐振元件组成，无需专门成型凸条纹，制备工艺更简单。
一种可选的实现方式中，该凸条纹上设有多个该谐振元件。由此，可以在光栅结构上设置谐振元件，可实现更高的衍射效率。
一种可选的实现方式中，该凹条纹中设有多个该谐振元件。由此，可以在光栅结构上设置谐振元件，通过谐振元件与光栅凸条纹搭配，可在不增加工艺复杂度的条件下实现更高的衍射效率。
一种可选的实现方式中，该条纹包括：多个间隔排布的谐振元件，每道条纹的相邻谐振元件之间的距离小于或等于工作波长的2倍。由此，可以提高谐振强度，有助于产生更高的衍射效率。
一种可选的实现方式中，该谐振元件的谐振方式为米氏共振、导模共振GMR、连续体束缚态BIC共振或回音壁模式WGM中的任意一种或几种。由此，可以利用单个谐振元件的谐振现象。
一种可选的实现方式中，该条纹包括：多个连续排布的谐振元件。由此，可增加结构对光场的限制作用，形成更高品质因子的谐振效果。
一种可选的实现方式中，该谐振元件的谐振方式为导模共振GMR、连续体束缚态BIC共振中的任意一种或几种。由此，谐振元件可以达到更高品质因子的谐振效果。
一种可选的实现方式中，该谐振元件的高度小于1μm。由此，确保更高的透明度，且工艺简单。
一种可选的实现方式中，该谐振元件的截面形状包括圆形、矩形、十字形、T字形、或梯形。由此，谐振元件形状灵活，适用于多种工作场景。
一种可选的实现方式中，该光学显示元件包括多个子区域，该多个子区域位于同一平面，且相邻子区域之间为空白区域。由此，增加了光学显示元件透明度，可以增加条纹的环境光透过率。
一种可选的实现方式中，该光学显示元件包括多个子区域，该多个子区域沿垂直于条纹所在平面的方向层叠设置。
一种可选的实现方式中，每个子区域的光学显示元件对应一个工作光波长，多个子区域的光学显示元件至少具有两个工作光波长。由此，不同子区域的条纹具有不同的波长选择性，使得该多个子区域的条纹可以实现对多个波长进行衍射。
一种可选的实现方式中，所包括的多个子区域的工作光波长包括红、绿、蓝三种 颜色。由此，实现彩色的衍射成像。
一种可选的实现方式中，每道该条纹的弧度小于π。由此，使得条纹的衍射效率均匀性更好。
本申请实施例的第二方面，提供一种光学设备，该光学设备包括：光学投影系统，以及如上所述的光学显示元件；其中，该光学投影系统用于产生工作光，并将该工作光射向该光学显示元件；该光学显示元件用于将该工作光反射至人眼。由此，该光学设备采用上述光学显示元件，结构更紧凑，且对工作光的衍射效率更高。
一种可选的实现方式中，所述光学投影系统在所述光学显示元件上的投影位于所述条纹的弯曲方向上，且所述条纹的曲率半径方向指向所述光学投影系统在所述光学显示元件上的投影。由此，可以将光学投影系统发出的光通过光学显示元件反射至人眼。
本申请实施例的第三方面，提供一种增强现实近眼成像系统，该增强现实近眼成像系统包括如上所述的光学设备。由此，条纹的厚度只在微纳尺度，其体积可以忽略不计。
本申请实施例的第四方面，提供一种抬头显示系统，该抬头显示系统包括如上所述的光学设备。由此，可以减小抬头显示系统尺寸。
本申请实施例的第五方面，提供一种车辆，该车辆包括如上所述的抬头显示系统。由此，可以减小抬头显示系统占用的车辆空间。
附图说明
图1为一种AR近眼成像系统示意图；
图2为另一种AR近眼成像系统示意图；
图3为本申请实施例提供的一种光学显示元件的结构示意图；
图4a为图3中A处的一种局部放大图；
图4b为图3中A处的另一种局部放大图；
图4c为图3中A处的另一种局部放大图；
图4d为图3中A处的另一种局部放大图；
图4e为图3中A处的另一种局部放大图；
图5为本申请实施例提供的谐振元件的工作状态示意图；
图6为本申请实施例提供的谐振元件的横截面图；
图7为示例一提供的AR近眼显示系统的工作状态图；
图8为示例一中的光学显示元件进行波长选择的示意图；
图9为示例一提供的光学显示元件的成像结果示意图；
图10为本申请实施例提供的另一种光学显示元件的结构示意图；
图11为本申请实施例提供的另一种光学显示元件的结构示意图；
图12为图11所示的光学显示元件的立体图；
图13为示例二提供的一种抬头显示系统的工作状态示意图；
图14为示例三提供的一种光束准直元件的工作状态示意图；
图15为示例四提供的一种光束聚焦元件的工作状态示意图。
具体实施方式
为了使本申请的目的、技术方案和优点更加清楚，下面将结合附图对本申请作进一步地详细描述。
以下，术语“第一”、“第二”等仅用于描述目的，而不能理解为指示或暗示相对重要性或者隐含指明所指示的技术特征的数量。由此，限定有“第一”、“第二”等的特征可以明示或者隐含地包括一个或者更多个该特征。在本申请的描述中，除非另有说明，“多个”的含义是两个或两个以上。
此外，本申请中，“上”、“下”等方位术语是相对于附图中的部件示意置放的方位来定义的，应当理解到，这些方向性术语是相对的概念，它们用于相对于的描述和澄清，其可以根据附图中部件所放置的方位的变化而相应地发生变化。
本申请实施例提供一种光学设备，该光学设备包括但不限于抬头显示(HUD，head-up display)、虚拟现实(VR，virtual reality)系统、增强现实(augmented reality，AR)近眼成像系统、光学滤波器、光学相位片、空间光通信等。
本申请以该光学设备为AR近眼成像系统为例进行说明。
如图1所示，AR近眼显示系统包括：光学投影系统101和光学显示元件102。其中，光学显示元件102位于用户的眼前。光学显示元件102既可以透射外部的环境光，也可以反射投影系统的光到人眼103。
本申请实施例提供的光学显示元件102如图3所示，该光学显示元件102例如包括多道条纹1020。
在一些实施例中，如图4a所示，该光学显示元件102还包括该基底1024，条纹1020设置在基底1024上。
本申请实施例对基底1024的材质不做限制。该基底1024的材质包括但不限于氧化硅、氮化硅、氧化钛、硅、聚合物、金属等。其中，条纹1020可以采用和基底1024相同的材料，也可以采用和基底1024不同的材料。
本申请实施例对条纹1020的形状不做限制。在一些实施例中，所述条纹1020呈弧线形状，所述条纹1020的弯曲方向与所述光学显示元件102的平面平行。
如图3所示，所述条纹1020的弯曲方向相同，所述条纹1020用于对所述光学显示元件102的工作光进行反射，并透射环境光。
需要说明的是，条纹1020的弯曲方向相同指的是每条条纹的弧线开口方向相同。例如，图3中条纹的弧线开口方向如箭头所指，其弧线开口方向向右。弯曲方向相同里的“相同”是定性而不是定量的描述。
上述条纹1020例如为衍射光栅，衍射光栅可以在近波长尺度下呈现周期性结构变化或折射率变化，可以对入射光的振幅或相位进行周期性空间调制。衍射型衍射光栅可以将入射光以特定的一个或几个角度反射出去。不同的反射角度对应着特定的衍射级数。
其中，光栅的零阶衍射光的角度是与入射光角度关于光栅表面法线对称的，与光栅周期无关。
高阶衍射光(1阶或以上)的角度不与入射光角度对称，属于异常角度反射，此类反射的角度与光栅周期相关。
衍射光栅的工作原理简单，体积紧凑，已在光谱测量、光通信等领域得到广泛的 应用。
其中，对于共面入射的情况，光栅结构的周期和出射光、入射光之间的关系可以通过光栅衍射方程描述：
sinθ i–sinθ m＝mλ/d
其中，θ i为入射角，θ m为衍射级数为m的衍射角，λ为入射光的波长，d为光栅相邻条纹之间的距离。
需要说明的是，光栅相邻条纹之间的距离指的是相邻条纹的中心之间的距离。
参见图5，衍射光栅的零阶衍射光的衍射角(此时，衍射级数m＝0，衍射角为θ 0)与入射光的入射角(θ i)关于光栅表面法线对称，即零阶衍射光的衍射角等于入射角度，属于对称反射，且与光栅周期无关。
而高阶(±1阶及±1阶以上)衍射光的衍射角与入射光的入射角不对称，例如，衍射光栅的1阶衍射光的衍射角(此时，衍射级数m＝1，衍射角为θ 1)与入射光的入射角(θ i)关于光栅表面法线不对称，衍射光栅的2阶衍射光的衍射角(此时，衍射级数m＝2，衍射角为θ 2)与入射光的入射角(θ i)关于光栅表面法线不对称，属于异常角度反射，异常角度反射与光栅周期有关。
其中，光栅的结构参数(例如光栅周期)取决于工作光波长与光学系统对光的偏转方向的要求，具体的，该条纹1020可以是根据近眼成像系统的光线入射角度、出射角度，以及成像需求而设计的非均匀光栅结构，可以在不同区域呈现不同的光栅结构，如条纹1020之间的间距不同、条纹1020的曲率半径变化等。
条纹之间的间距、以及条纹1020的曲率半径可以根据光学系统在该处对光线的入射、出射角度的需求而定，使得入射光线经过光栅衍射后可以形成高阶衍射光线，衍射光线沿着光学系统所需要的角度发射出来
由此，条纹放置于人的眼前，可以将各角度入射的特定波段的投射光通过衍射后以特定角度进入人眼，使得光线进入人眼后成像。
其中，由于光栅的厚度只有微纳尺度，其体积较小，实现了设备的小型化。
AR显示系统具有眼盒(eyebox)的概念，在眼盒范围内，人眼能观察到清晰的图像。在本发明的一些实施例中，眼盒区域在光学显示元件平面的投影位于光学显示元件内部。
同时，由于光栅的设计与制备具有灵活性，光栅经过设计后可集成像差矫正功能。需要说明的是，AR近眼显示系统中通常会存在像差，如果像差没有得到矫正，会降低视觉体验。尤其在离轴AR近眼显示系统中，像散现象比较严重，导致出现图像模糊的问题。本申请实施例可以通过设计光栅周期与方向的排布，使得光学显示元件在两个相互正交的方向上(如x与y方向)具有不同的光焦度，缓解光系统的像散问题。使得AR近眼显示系统可以避免在前端光路使用像差矫正透镜组，减小系统体积和重量。
本申请实施例对条纹1020的具体曲率半径不做限制。其中，至少1道条纹1020的曲率半径和其他条纹1020的曲率半径不同。
由此，可以根据光线入射角度、出射角度，以及成像需求而设计的非均匀光栅结构，可以在不同区域呈现不同的光栅结构，使得入射光线经过光栅衍射后可以形成一 阶衍射光线，衍射光线沿着光学系统所需要的角度发射出来。
在一些实施例中，如图3所示，所述条纹1020的曲率半径沿一个方向变化。在一些实施例中，条纹1020的曲率半径沿一个方向均匀变化，例如，图3中的条纹1020的曲率半径沿左右方向均匀变化。由此，可在不同区域呈现不同的衍射响应。
在另一些实施例中，不同区域的条纹1020的曲率半径的变化方向不同，可在不同区域呈现不同的衍射响应，导致光进入不同区域可以实现不同方向的衍射光出来，有利于成像。
本申请实施例对相邻两道条纹1020之间的距离不做限制。其中，至少两道相邻条纹1020之间的距离与其他相邻条纹1020的之间的距离不同。
由此，可以根据光线入射角度、出射角度，以及成像需求而设计的非均匀光栅结构，可以在不同区域呈现不同的光栅结构，使得入射光线经过光栅衍射后可以形成一阶衍射光线，衍射光线沿着光学系统所需要的角度发射出来。
在一些实施例中，如图3所示，相邻条纹1020之间的距离沿一个方向变化。在一些实施例中，相邻条纹1020之间的距离沿一个方向均匀变化。例如，图3中的相邻条纹1020之间的距离沿左右方向均匀变化。由此，可在不同区域呈现不同的衍射响应。
在另一些实施例中，不同区域的相邻条纹1020之间的距离的变化方向不同，可在不同区域呈现不同的衍射响应，导致光进入不同区域可以实现不同方向的衍射光出来，有利于成像。
本申请实施例对条纹1020的结构不做限制。该条纹1020例如包括：邻接设置的凸条纹1022和凹条纹1023。其中，该凸条纹1022可以是形成在基底1024表面的凸棱，该凹条纹1023可以是形成在基底表面的凹槽。
在一些实施例中，如图4a、图4b、图4c所示，该光学显示元件102包括基底1024，该基底1024的一个表面形成有多个凸条纹1022，且所述多个凸条纹1022间隔设置，相邻的两个凸条纹1022之间形成凹条纹1023，所述多个凸条纹1022之间形成多个凹条纹1023。
在另一些实施例中，如图4d、图4e所示，该光学显示元件102包括基底1024，该基底1024的一个表面形成有多个凹条纹1023，且所述多个凹条纹1023间隔设置，相邻的两个凹条纹1023之间形成凸条纹1022，所述多个凹条纹1023之间形成多个凸条纹1022。
本申请实施例对该条纹的具体结构不做限制。在一些实施例中，如图4a所示，所述条纹1020包括：多个谐振元件10221，谐振元件10221按照条纹1020的轮廓排列。该谐振元件10221用于限制所述工作光的光场，且所述谐振元件10221的谐振波长位于所述光学显示元件102的工作光波段内。
本申请实施例对谐振元件10221的结构不做限制，在一些实施例中，谐振元件10221具有谐振腔，谐振腔能够使得特定波长的光在其中产生谐振效应。其中，谐振腔可以通过谐振效应，选择特定波长的输入光，增强其与光学显示元件的相互作用，从而增强光学显示元件对特定波长的输入光的反射效率，而其他波长的输入光的反射效率则保持在较低的水平。
本申请实施例对该谐振元件的具体材料不做限制。谐振元件10221采用介质材料组成。其中，谐振元件10221的材料包括但不限于氮化硅、氧化钛、硅、氧化硅、聚合物、金属等介质材料，该谐振元件10221可以采用和基底1024相同的材料，也可以采用和基底1024不同的材料。
由此，该光学显示元件包括对特定波段具有光学谐振作用的谐振元件10221，可增强对工作光的反射效率，而对其他波段的光的反射保持在较低的水平。可同时实现对工作光的高反射率，以及实现对其他波段的光的高透射率，同时，由于光栅本身是色散的，不同波长会被衍射到不同的角度，本申请实施例的光栅具有谐振效应，可对较窄的一段波长进行衍射，而其他的波长衍射效应较弱，因此色散现象较弱，从而可以减弱由于光栅本身的色散特性导致的图像模糊问题。
在一些实施例中，如图4a所示，该谐振元件10221设置在基底1024表面，多个谐振元件10221排列成弧线形状，组成条纹1020中的凸条纹1022。由此，凸条纹直接由谐振元件组成，无需专门在基底上成型凸条纹，制备工艺更简单。
在另一些实施例中，如图4b、图4d所示，基底1024上设有凹条纹1023和凸条纹1022，该谐振元件10221可以设置在凸条纹1022上。
由此，将谐振元件与条纹搭配在一起，可以增强特定阶数的衍射效率。其中，谐振元件10221与凸条纹1022可以增强工作光的高阶衍射效率，使得工作光的高阶衍射效率比零阶衍射效率更高。
在另一些实施例中，如图4c、图4e所示，基底1024上设有凹条纹1023和凸条纹1022，该谐振元件10221可以设置在凹条纹1023中。
由此，可以在光栅结构上设置谐振元件，通过谐振元件与光栅凸条纹搭配，可在不增加工艺复杂度的条件下实现更高的衍射效率。
在另一些实施例中，基底1024上设有凹条纹1023和凸条纹1022，凸条纹1022上和凹条纹1023中例如均设有该谐振元件10221。
由此，可以在光栅结构上设置谐振元件，应用范围更广。
本申请实施例对该谐振元件的形状不做限制。在一些实施例中，如图4a所示，该谐振元件10221为圆柱体，其横截面例如为如图6中的(a)所示的圆形。需要说明的是，该谐振元件10221的横截面形状为谐振元件10221在xy平面的投影。
在另一些实施例中，谐振元件10221的横截面形状可以是如图6中(b)所示的矩形、如图6中的(c)所示的十字形、如图6中(d)所示的T字形、或如图6中(e)所示的梯形。由此，谐振元件形状灵活。
需要说明的是，上述谐振元件10221的横截面形状仅为本申请实施例的一些示例，本领域技术人员可根据需要选择合适的谐振元件10221形状，这些均属于本申请的保护范围。
本申请实施例对该谐振元件的尺寸不做限制。其中，谐振元件10221沿z方向的高度例如小于1μm。由此，可以确保光学显示元件具有更高的透明度，且工艺简单。
谐振元件10221所产生的光学谐振的谐振方式可以是Mie米氏共振、导模共振(GMR，guided-mode resonance)、连续体束缚态(BIC，bound states in the  continuum)共振、回音壁模式(WGM，whispering gallery mode)等。
在一些实施例中，组成同一道条纹的谐振元件10221间隔设置，同一道条纹中的相邻谐振元件10221之间的距离应小于或等于该工作光波长的2倍。此时，单个元件可对工作光波长产生谐振，所述谐振元件的谐振方式为米氏共振、导模共振GMR、连续体束缚态BIC共振或回音壁模式WGM中的任意一种或几种。
由此，可以提高谐振元件的谐振强度，有助于产生更高的衍射效率。
在另一些实施例中，组成同一道条纹的谐振元件10221可以连续排布。此时，多个相同的谐振元件10221内限制的光场相互作用，可对工作光波长产生谐振，所述谐振元件的谐振方式为导模共振GMR、连续体束缚态BIC共振中的任意一种或几种。由此，可增加结构对光场的限制作用，形成更高品质因子的谐振效果。
每个谐振元件10221沿着所在条纹的曲率半径方向的尺寸小于该区域相邻条纹之间的距离。
在一些实施例中，在同一道条纹中，沿着所在光栅的曲率半径方向可以不止有一个谐振元件10221。
下面结合示例一对本申请实施例提供的光学显示元件进行具体说明。
示例一：
图7为示例一提供的AR近眼显示系统的工作状态图。如图7所示，AR近眼显示系统包括：光学投影系统101和光学显示元件102。其中，光学显示元件102位于用户的眼前。
本申请对光学投影系统101的结构不做限制，其中，光学投影系统101至少包括：发光元件，在一些实施例中，该发光元件可以是有机发光二极管(Organic Light-Emitting Diode，OLED)显示屏，在另一些实施例中，该光发光元件还可以是微米发光二极管(micro LED)显示屏。
在一些实施例中，光学投影系统101例如还包括：像差矫正光学元件、色散矫正光学元件。
其中，光学显示元件102包括：基底1024，以及设置在基底1024上的条纹1020。
条纹1020放置于人的眼前，既可以透射外部的环境光，还可以将光学投影系统101发出的投射光通过衍射后以特定角度进入人眼103，使得光线进入人眼后成像。
其中，条纹之间的间距、以及条纹1020的曲率半径可以根据光学系统在该处对光线的入射、出射角度的需求而定，使得入射光线经过光栅衍射后可以形成一阶衍射光线，衍射光线沿着光学系统所需要的角度发射出来。
如图7所示，所述光学投影系统101在所述光学显示元件102平面上的投影例如位于所述条纹1020的弯曲方向上。也即，条纹1020的曲率中心与投影系统101在光学显示元件102平面的投影位置位于条纹1020的同一侧，例如均位于条纹1020的右侧，且所述条纹1020的曲率半径指向投影系统101在光学显示元件102平面的投影位置。
图7中示出了条纹1020的整体轮廓。如图7所示，该条纹1020的整体轮廓呈现弯曲渐变状，即条纹之间的间距与条纹1020的曲率半径随着其所在空间位置的不同 而逐渐变化。
具体的，条纹1020整体轮廓是弯曲的，多条条纹1020近似呈现同心圆环状，条纹1020的曲率半径平行于基底1024表面，条纹1020的曲率半径和条纹之间的间距沿一个方向渐变。
需要说明的是，上述多条条纹1020近似呈现同心圆环状，指的是条纹可以不严格按照同心圆环排布，允许存在误差。
在一个空间维度(图中为左右方向的维度)，条纹1020的曲率半径和相邻条纹之间的间距发生变化，其中，如图7所示，条纹1020的曲率半径和相邻条纹之间的间距沿左右方向均匀变化。
如图7所示，相邻条纹1020之间的距离沿着工作光入射的方向在光学显示元件102上的投影逐渐变小，也即相邻条纹1020之间的间距从左到右逐渐变大，即条纹1020的空间排布变疏。同时条纹1020的曲率半径沿着工作光入射的方向在光学显示元件102上的投影逐渐变大，也即条纹1020弯曲的曲率半径从左到右逐渐变小，即光栅的曲率变大。
其中，需要说明的是，条纹1020之间的间距的变化范围与工作时使用的光波长直接相关。例如，相邻条纹1020之间的间距的大于或等于光波长的1/4，且小于或等于工作光波长的10倍。由此，保证了条纹对工作光的衍射性能。
光栅弯曲的最小曲率半径不小于100μm，每道该条纹的弧度小于π。
由此，使得条纹的衍射效率均匀性更好。
同时，在另一空间维度(图中为上下方向的维度)，条纹1020的曲率半径方向也逐渐变化。
例如，如图7所示，沿着图中从上到下的方向，条纹1020的曲率半径指向曲率中心的方向呈现右下-右-右上方向的变化。
其中，本示例中弯曲渐变光栅所包含的每段弧线对应的角度小于180度。
其中，在条纹中心处，工作光的入射角不小于40度，即工作光的入射方向与条纹1020所在表面法向方向的夹角应不小于40度。由此，该光学显示元件可对大角度倾斜入射的光进行衍射，使得光系统结构更加紧凑。
此时，所述工作光形成的像与光学元件之间的距离大于或等于5cm。由此，可以在合适的位置成像。
如图7所示，所述工作光经光学显示元件反射后呈收敛状。使得每个区域的条纹1020结构均可使得以大角度倾斜入射的投射光线经过光栅衍射后形成一阶衍射光，所述一阶衍射光按照成像所需要的角度反射出来，进入到人眼或其他光学成像系统中成像。
其中，所述工作光经光学显示元件反射后，成像的眼盒区域在光学显示元件所在平面的投影位于光学显示元件内部。
由此，可以使得以大角度倾斜入射的投射光线经过光栅衍射后按照成像所需要的角度反射出来，并在光学显示元件内部成像。
其中，该光学显示元件的厚度仅为微纳尺度，其结构紧凑，占用空间小，用于AR近眼系统中，可以实现系统小型化，便于使用和携带。
此外，该条纹的设计与制备更加灵活，本申请实施例可以通过设计光栅周期与方向的排布，使得光学显示元件在两个相互正交的方向上(如x与y方向)具有不同的光焦度，可集成像差矫正(如可矫正像素)等功能，缓解光系统的像散问题，使得AR近眼显示系统可以避免在前端光路使用像差矫正透镜组，减小系统体积和重量。
该条纹的具体结构可参考图4a。如图4a所示，条纹1020包括：多条邻接设置的凹条纹1023和凸条纹1022。其中，凸条纹1022由多个谐振元件10221排列组成，所述多个凸条纹1022且间隔设置，相邻的两个凸条纹1022之间形成凹条纹1023，所述多个凸条纹1022之间形成多个凹条纹1023。
如图4a所示，该谐振元件10221为圆柱体形状。谐振元件10221沿z方向的高度例如小于1μm。
如图4a所示，组成同一道条纹的谐振元件10221间隔设置，同一道条纹中的相邻谐振元件10221之间的距离应小于或等于该工作光波长的2倍。此时，所述谐振元件例如采用米氏共振。
图8为示例一中的光学显示元件进行波长选择的示意图。如图8所示，横坐标为波长，纵坐标为反射率，如图8所示，该光学显示元件对波长位于工作光L1波段范围的光反射率较高，对工作频率位于工作光L1波段范围之外的环境光L2的反射率低。
由此，该光学显示元件利用谐振现象增强对特定波段的入射光的反射，实现波长选择性，以增强对工作光的反射效率，而同时对其他波段的环境光的反射保持在较低的水平。
图9为示例一提供的光学显示元件的成像结果示意图。实验中使用的投影工作光波长为525nm，条纹1020的材料采用氮化硅，基底1024的材料采用石英。
在可见光波段的器件结构是透明的，在实现衍射成像的同时可观察到条纹背后的环境。在条纹中心处，入射光的入射角约为45度。
如图9所示，工作光经过该条纹衍射可以产生清晰的图像。
此外，本示例提供的光学显示元件，可基于成熟的半导体微纳制备工艺而实现，制备难度更低，更易实现量产。
并且，该光学显示元件可由性质稳定的材料组成，在不同环境条件下的表现保持一致性，不存在体积收缩的问题。
本示例提供的光学显示元件，采用整体轮廓呈现弯曲渐变状的非均匀结构条纹对光学系统的入射光线进行衍射，形成高阶衍射光线，使得每个区域的衍射光线可沿着光学系统所需要的光线角度发射出来。
其中，条纹的厚度只在微纳尺度，其体积可以忽略不计。且得益于设计与制备的高度灵活性，本发明条纹可集成像差矫正功能，使得AR近眼显示系统可以避免在前端光路使用像差矫正透镜组，减小系统体积和重量。
此外，本申请实施例对条纹1020在基底1024上的分布位置不做限制。在上述实施例中，所述光学显示元件包括一个区域(基底1024的一个表面)，条纹1020分布在该区域内。
在另一些实施例中，所述光学显示元件包括多个子区域，条纹1020分布在子区 域内。
例如，如图10所示，所述多个子区域位于同一平面，且相邻子区域之间不存在光栅结构。
或者，如图11、图12所示，所述多个子区域沿垂直于条纹所在平面的方向层叠设置。
其中，每个子区域的光学显示元件对应一个工作光波长，多个子区域的光学显示元件至少具有两个工作光波长。由此，不同子区域的条纹具有不同的波长选择性，使得该多个子区域的条纹可以实现对多个波长进行衍射。
一种可选的实现方式中，所包括的多个子区域的工作光波长包括红、绿、蓝三种颜色。由此，实现彩色的衍射成像。
下面分别结合图10、图11和图12光学显示元件102包括多个子区域的情况进行具体说明。
图10为本申请实施例提供的另一种光学显示元件的结构示意图。如图10所示，该示例与图7中条纹1020的区别在于本实施例的条纹只分布在基底1024结构的部分区域，并不完全分布在整个基底1024结构的表面。
如图10所示，所述光学显示元件102包括多个子区域S0，所述多个子区域S0位于同一平面(图10所示的XY平面)，且相邻子区域S0之间为空白区域10201。
参考图10，子区域S0例如为矩形，基底1024结构表面被一系列相互垂直的平行线划分成多个子区域S0，这些子区域S0在两个空间维度上(从左到右和从上到下)均周期性重复排列，呈现为矩形网格结构。
条纹1020分布在这些被隔开的子区域S0中，条纹1020可以实现衍射功能。相邻子区域S0之间的部分是空白的，没有光栅结构分布。
本实施例的光栅结构只分布在基底1024结构的部分区域，增加了光学显示元件透明度，可以增加条纹的环境光透过率。
在本示例的一些实施例中，可以在不同子区域设计对应不同工作波长的光栅结构(例如不同子区域分别对应红、绿、蓝三种颜色的不同波长的工作光)，使得整个条纹能够对多个波长进行衍射，实现彩色的衍射成像。
例如，如图10所述，光学显示元件包括位于同一层的第一子区域S1、第二子区域S2，以及第三子区域S3。其中，第一子区域S1的工作波长为红色，第二子区域S2的工作波长为绿色，第三子区域S3的工作波长为蓝色。
图11为本申请实施例提供的另一种光学显示元件的主视图。图12为本申请实施例提供的另一种光学显示元件的俯视图。如图11、图12所示，所述光学显示元件包括多个子区域(第一子区域S1、第二子区域S2，以及第三子区域S3)，所述多个子区域沿垂直于条纹所在平面的方向(z方向)层叠设置，每个子区域包括：基底，以及设置在基底上的条纹。
在本示例的一些实施例中，可以在不同子区域设计对应不同工作波长的条纹(例如不同子区域分别对应红、绿、蓝三种颜色的不同波长的工作光)，使得整个条纹能够对多个波长进行衍射，实现彩色的衍射成像。例如，不同层的条纹具有不同的波长选择性，使得该多层条纹可以实现对多个波长进行衍射。
例如，如图11、图12所示，光学显示元件包括：位于不同层的第一子区域S1、第二子区域S2，以及第三子区域S3。其中，第一子区域S1的工作波长为红色，第二子区域S2的工作波长为绿色，第三子区域S3的工作波长为蓝色。。
由此，节省了光学显示元件水平方向的空间。
在上述实施例中，该光学显示元件可以用于AR近眼系统中，在另一些实施例中，该光学显示元件还可以用于抬头显示(HUD)系统。
下面结合示例二对光学显示元件应用于抬头显示(HUD)系统中的情况进行说明。
示例二：
图13为示例二提供的一种抬头显示系统的工作状态示意图。如图13所示，抬头显示系统包括：光学投影系统101和光学显示元件102。其中，光学显示元件102位于用户的眼前。光学显示元件102包括：基底1024以及设置在基底1024上的条纹1020。条纹1020放置于人的眼前，既可以透射外部的环境光，还可以将光学投影系统101发出的投射光衍射后以特定角度进入人眼103，使得光线进入人眼后成像。
本实施例与AR近眼显示系统最主要的区别在于条纹1020的尺寸，HUD系统的光学显示元件102的宽度通常在10cm以上。
其中，抬头显示(HUD)系统的应用场景在车载应用上，例如可以安装在车的前挡风玻璃，而不是直接佩戴在人的眼前。
此外，该光学显示元件还可以作为光束聚焦元件或光束准直元件。下面分别结合示例三和示例四对光学显示元件作为光束聚焦元件或光束准直元件的情况进行说明。
示例三：
图14为示例三提供的一种光束准直元件的工作状态示意图。如图14所示，在光束元件应用中，可通过设置条纹参数，使得在器件外部同一个点发射并入射到条纹上不同区域的光经过局部光栅衍射后，均朝着一个相同的方向出射，形成平行光，从而实现光束准直。
示例四：
图15为示例四提供的一种光束聚焦元件的工作状态示意图。如图15所示，在光束聚焦应用中，可通过设置条纹参数，使得以同一方向入射到条纹上不同区域的光经过局部光栅衍射后，均朝着器件外部的一个空间位置点反射，形成聚焦光，从而实现光束聚焦。
该光学显示元件的光束聚焦功能和光束准直功能均可通过调整条纹的参数而实现，条纹的整体轮廓均为弯曲渐变状，在实施例1的描述范围内。相邻条纹之间的距离，和条纹的曲率半径可以根据光系统所使用的光波长与其对光线的输入输出角度需求确定。
上述示例一至示例四仅为本申请的一些实施例，在上述示例中，本申请的光学显示元件均产生投影，为人眼所见。需要说明的是，本申请的光学显示元件不仅可以应用于光学波段，如可见光波段、红外波段、紫外波段等，还可以应用于太赫兹、微波、无线电等领域，这些均属于本申请的保护范围。
以上所述，仅为本申请的具体实施方式，但本申请的保护范围并不局限于此，任 何在本申请揭露的技术范围内的变化或替换，都应涵盖在本申请的保护范围之内。因此，本申请的保护范围应以所述权利要求的保护范围为准。

Claims (36)

  1. 一种光学显示元件，其特征在于，包括：多道条纹，所述条纹呈弧线形状，且所述条纹的弯曲方向相同，所述条纹用于对所述光学显示元件的工作光进行反射，使得所述工作光成像；
    其中，所述条纹包括：多个谐振元件，其中，所述工作光在一个或多个所述谐振元件中产生谐振效应。
  2. 根据权利要求1所述的光学显示元件，其特征在于，所述条纹的弯曲方向与所述光学显示元件的表面平行。
  3. 根据权利要求1或2所述的光学显示元件，其特征在于，至少1道条纹的曲率半径和其他条纹的曲率半径不同。
  4. 根据权利要求3所述的光学显示元件，其特征在于，所述条纹的曲率半径沿一个方向变化。
  5. 根据权利要求3或4所述的光学显示元件，其特征在于，所述条纹的曲率半径沿着工作光入射的方向在光学显示元件上的投影逐渐变大。
  6. 根据权利要求3-5任一项所述的光学显示元件，其特征在于，所述条纹的最小曲率半径不小于100μm。
  7. 根据权利要求1-6任一项所述的光学显示元件，其特征在于，至少一对相邻条纹之间的距离与其他相邻条纹的之间的距离不同。
  8. 根据权利要求7所述的光学显示元件，其特征在于，相邻条纹之间的距离沿一个方向变化。
  9. 根据权利要求7或8所述的光学显示元件，其特征在于，相邻条纹之间的距离沿着工作光入射的方向在光学显示元件上的投影逐渐变小。
  10. 根据权利要求7-9任一项所述的光学显示元件，其特征在于，相邻两道条纹之间的距离大于或等于工作光波长的1/4，且小于工作光波长的10倍。
  11. 根据权利要求1-10任一项所述的光学显示元件，其特征在于，所述工作光的入射方向与所述条纹所在平面的法线方向的夹角大于或等于40度。
  12. 根据权利要求11所述的光学显示元件，其特征在于，所述工作光经光学显示元件反射后呈收敛状。
  13. 根据权利要求11或12所述的光学显示元件，其特征在于，所述工作光经光学显示元件反射后，成像的眼盒区域在光学显示元件所在平面的投影位于光学显示元件内部。
  14. 根据权利要求1-13任一项所述的光学显示元件，其特征在于，所述光学显示元件集成有像差矫正功能。
  15. 根据权利要求1-14任一项所述的光学显示元件，其特征在于，所述光学显示元件对入射的工作光在沿着光学显示元件表面的两个相互正交的方向上具有不同的光焦度。
  16. 根据权利要求1-15任一项所述的光学显示元件，其特征在于，所述工作光形成的像与光学元件之间的距离大于或等于5cm。
  17. 根据权利要求1-16任一项所述的光学显示元件，其特征在于，所述条纹包 括：邻接设置的凸条纹和凹条纹。
  18. 根据权利要求17所述的光学显示元件，其特征在于，所述凸条纹由多个所述谐振元件组成。
  19. 根据权利要求17所述的光学显示元件，其特征在于，所述凸条纹上设有多个所述谐振元件。
  20. 根据权利要求17-19任一项所述的光学显示元件，其特征在于，所述凹条纹中设有多个所述谐振元件。
  21. 根据权利要求1-20任一项所述的光学显示元件，其特征在于，所述条纹包括：多个间隔排布的谐振元件，每道条纹的相邻谐振元件之间的距离小于或等于工作波长的2倍。
  22. 根据权利要求21所述的光学显示元件，其特征在于，所述谐振元件的谐振方式为米氏共振、导模共振GMR、连续体束缚态BIC共振或回音壁模式WGM中的任意一种或几种。
  23. 根据权利要求1-20任一项所述的光学显示元件，其特征在于，所述条纹包括：多个连续排布的谐振元件。
  24. 根据权利要求23所述的光学显示元件，其特征在于，所述谐振元件的谐振方式为导模共振GMR、连续体束缚态BIC共振中的任意一种或几种。
  25. 根据权利要求1-24任一项所述的光学显示元件，其特征在于，所述谐振元件的高度小于1μm。
  26. 根据权利要求1-25任一项所述的光学显示元件，其特征在于，所述谐振元件的截面形状包括圆形、矩形、十字形、T字形、或梯形。
  27. 根据权利要求1-26任一项所述的光学显示元件，其特征在于，所述光学显示元件包括多个子区域，所述多个子区域位于同一平面。
  28. 根据权利要求1-26任一项所述的光学显示元件，其特征在于，所述光学显示元件包括多个子区域，所述多个子区域沿垂直于条纹所在平面的方向层叠设置。
  29. 根据权利要求27或28所述的光学显示元件，其特征在于，每个子区域的光学显示元件对应一个工作光波长，多个子区域的光学显示元件至少具有两个工作光波长。
  30. 根据权利要求27或28所述的光学显示元件，其特征在于，所包括的多个子区域的工作光波长包括红、绿、蓝三种颜色。
  31. 根据权利要求1-30任一项所述的光学显示元件，其特征在于，每道所述条纹的弧度小于π。
  32. 一种光学设备，其特征在于，所述光学设备包括：光学投影系统，以及如权利要求1-31任一项所述的光学显示元件；
    其中，所述光学投影系统用于产生工作光，并将所述工作光射向所述光学显示元件；
    所述光学显示元件用于将所述工作光反射至人眼。
  33. 根据权利要求32所述的光学设备，其特征在于，所述光学投影系统在所述光学显示元件上的投影位于所述条纹的弯曲方向上，且所述条纹的曲率半径方向指向 所述光学投影系统在所述光学显示元件上的投影。
  34. 一种增强现实近眼成像系统，其特征在于，包括如权利要求32或33所述的光学设备。
  35. 一种抬头显示系统，其特征在于，包括如权利要求32或33所述的光学设备。
  36. 一种车辆，其特征在于，包括如权利要求35所述的抬头显示系统。
PCT/CN2022/104451 2021-07-13 2022-07-07 光学显示元件及光学设备 Ceased WO2023284627A1 (zh)

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN203433193U (zh) * 2013-08-01 2014-02-12 成都理想境界科技有限公司 头戴显示光学系统及头戴显示装置
US20200241353A1 (en) * 2019-01-30 2020-07-30 Samsung Electronics Co., Ltd. Grating device, screen including the grating device, method of manufacturing the screen and display apparatus for augmented reality and/or virtual reality including the screen
CN111512189A (zh) * 2017-10-02 2020-08-07 瑞士Csem电子显微技术研发中心 谐振波导光栅及其应用
CN112088141A (zh) * 2018-05-04 2020-12-15 脸谱科技有限责任公司 用于光束重定向的衍射光栅

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5678709B2 (ja) * 2011-02-10 2015-03-04 ソニー株式会社 表示装置
WO2015186488A1 (ja) * 2014-06-03 2015-12-10 矢崎総業株式会社 車両用投影表示装置
JP6779984B2 (ja) * 2015-09-05 2020-11-04 レイア、インコーポレイテッドＬｅｉａ Ｉｎｃ． 集光型バックライトおよびそれを使用するニアアイディスプレイシステム
CN111781724B (zh) * 2017-02-28 2021-10-26 华为技术有限公司 一种信息显示设备及信息显示方法
KR102909206B1 (ko) * 2019-02-15 2026-01-06 삼성전자주식회사 다층 메타 렌즈 및 이를 포함하는 광학 장치
KR102899480B1 (ko) * 2019-08-08 2025-12-11 메사추세츠 인스티튜트 오브 테크놀로지 초광각 시야 평면 광학
US11592646B2 (en) * 2019-08-30 2023-02-28 University Of Rochester Mechanically tunable reflective metamirror optical device
EP4329947A4 (en) * 2021-04-30 2025-03-26 Magic Leap, Inc. Imprint lithography process and methods on curved surfaces

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN203433193U (zh) * 2013-08-01 2014-02-12 成都理想境界科技有限公司 头戴显示光学系统及头戴显示装置
CN111512189A (zh) * 2017-10-02 2020-08-07 瑞士Csem电子显微技术研发中心 谐振波导光栅及其应用
CN112088141A (zh) * 2018-05-04 2020-12-15 脸谱科技有限责任公司 用于光束重定向的衍射光栅
US20200241353A1 (en) * 2019-01-30 2020-07-30 Samsung Electronics Co., Ltd. Grating device, screen including the grating device, method of manufacturing the screen and display apparatus for augmented reality and/or virtual reality including the screen

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP4357837A4

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