CN-121995564-A - Optical waveguide and near-to-eye display module

Abstract

The embodiment of the application discloses an optical waveguide and a near-to-eye display module, wherein the optical waveguide comprises a waveguide substrate, at least a coupling-in area and a coupling-out area are arranged on the waveguide substrate, a substrate material of the coupling-in area and the coupling-out area is made of uniaxial crystal materials, and an optical axis of crystals in the uniaxial crystal materials is configured such that an optical axis angle of uniaxial crystal materials in the optical waveguide is related to a propagation angle and an azimuth angle of each view field ray in different areas.

Inventors

• Request for anonymity

Assignees

• 成都理想境界科技有限公司

Dates

Publication Date

20260508

Application Date

20241105

Claims (7)

1. 1. The optical waveguide is characterized by comprising a waveguide substrate, wherein the waveguide substrate is at least provided with a coupling-in region and a coupling-out region, and the substrate materials of the coupling-in region and the coupling-out region adopt uniaxial crystal materials; the optical axis of the crystals in the uniaxial crystal material is configured such that the optical axis angle of the uniaxial crystal material in the optical waveguide is related to the propagation angle and azimuth angle of each field of view ray in different regions.
2. 2. The optical waveguide of claim 1 wherein the waveguide substrate further has a relay region disposed thereon.
3. 3. The optical waveguide according to any one of claims 1-2, wherein the optical axis angle in the uniaxial crystalline material of the optical waveguide is configured such that the optical path difference due to birefringence of light coupled into each field of view of the optical waveguide is greater than the coherence length.
4. 4. The optical waveguide according to any one of claims 1 to 2, wherein the angle between the optical axis and the direction perpendicular to the plane of the waveguide substrate is not less than 20 °.
5. 5. The optical waveguide of claim 4 wherein the optical axis forms an angle with the propagation axis of the expanded beam and the propagation beam in the corresponding region with zero degree field of view rays that is greater than 20 ° plus the maximum angular difference of the incident field of view.
6. 6. The optical waveguide of claim 5 wherein the projection angle of the optical axis onto the waveguide substrate plane is such that: Wherein, the Azimuth angle of extended light formed in the relay area for zero-degree view field light An azimuth angle of a propagating light ray formed in the relay region for a zero-degree field-of-view light ray; is the angle of the optical axis with respect to the second direction on the plane of the waveguide substrate.
7. 7. A near-eye display module, comprising an image source and the optical waveguide of any one of claims 1-6; The image source is used for providing image light and outputting the image light to the optical waveguide, and the image light is subjected to imaging display under the action of the optical waveguide.

Description

Optical waveguide and near-to-eye display module Technical Field The application relates to the technical field of display, in particular to an optical waveguide and a near-to-eye display module. Background Consumer electronics with light weight, compactness and energy conservation have a wide range of applications, and consumer Augmented Reality (AR) glasses are also evolving in a light, thin, compact direction as one of consumer electronics. Among them, the fabrication of optical elements with enhanced optical performance and reduced size and weight has become one of the important technological developments of consumer grade AR glasses. As an important optical element applied in AR glasses, an optical waveguide (generally used as a lens of AR glasses) can be prepared using a material having a high refractive index, which is advantageous for reducing the size and weight and enhancing the optical characteristics. In some embodiments uniaxial crystalline materials are used as the base material for optical waveguides. However, since the propagation direction of the light entering the optical waveguide does not entirely propagate along the optical axis of the uniaxial crystal, a birefringence phenomenon occurs, which is liable to further cause the generation of interference fringes, thereby severely affecting the display effect. Disclosure of Invention Based on the above, the present application provides an optical waveguide and a near-to-eye display module for solving the display problem caused by the birefringence phenomenon generated in the existing optical waveguide. According to one aspect of the application, the embodiment of the application provides an optical waveguide, which comprises a waveguide substrate, wherein the waveguide substrate is at least provided with a coupling-in region and a coupling-out region, and the substrate materials of the coupling-in region and the coupling-out region adopt uniaxial crystal materials; the optical axis of the crystals in the uniaxial crystal material is configured such that the optical axis angle of the uniaxial crystal material in the optical waveguide is related to the propagation angle and azimuth angle of each field of view ray in different regions. Optionally, a relay region is also arranged on the waveguide substrate Optionally, the optical axis angle in the uniaxial crystalline material of the optical waveguide is configured such that light rays coupled into the fields of view of the optical waveguide have an optical path difference due to birefringence that is greater than the coherence length. Optionally, the angle of the optical axis to a direction perpendicular to the plane of the waveguide substrate is not less than 20 °. Optionally, the angle between the optical axis and the propagation axis of the expanded beam and the propagation beam formed by the zero-degree view field light in the corresponding region is greater than 20 ° and the sum of the maximum angle difference of the incident view field. Optionally, the projection angle of the optical axis on the waveguide substrate plane satisfies: Wherein, the Azimuth angle of extended light formed in the relay area for zero-degree view field light An azimuth angle of a propagating light ray formed in the relay region for a zero-degree field-of-view light ray; is the angle of the optical axis with respect to the second direction on the plane of the waveguide substrate. Based on one aspect of the present application, an embodiment of the present application provides a near-eye display module, including an image source and the optical waveguide described above; The image source is used for providing image light and outputting the image light to the optical waveguide, and the image light is subjected to imaging display under the action of the optical waveguide. Additional features and advantages of the application will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the application. The objectives and other advantages of the application may be realized and attained by the structure and/or process particularly pointed out in the written description and claims hereof as well as the appended drawings. Drawings Other features, objects and advantages of the present application will become more apparent upon reading of the detailed description of non-limiting embodiments, made with reference to the accompanying drawings in which: FIG. 1a is a schematic diagram of an optical waveguide 1 according to an embodiment of the present application FIG. 1b is a schematic diagram of an optical waveguide 10 according to an embodiment of the present application; FIG. 1c is a schematic diagram of the coupling of image light 3 into an optical waveguide 10 according to an embodiment of the present application; fig. 2a is a schematic diagram of the embodiment of the present application when the image light 3 is coupled into the coupling-in region 1