Optical waveguide with two metasurface gratings and head-mounted device

Abstract

The invention provides an optical waveguide with two metasurface gratings and a head-mounted device. The optical waveguide comprises an optical waveguide sheet, a first metasurface grating and a second metasurface grating, the first metasurface grating comprises three strip-shaped units with the same height and width; the three strip-shaped units are arranged in parallel at a first distance to form basic units, and the basic units are periodically arranged on the surface of the optical waveguide sheet at a second distance; when the height of each strip-shaped unit is larger than or equal to one third of the minimum wavelength of a light beam emitted by an optical machine, the light beam enters the first metasurface grating to be deflected for the first time, generates a phase difference in direct proportion to the height of the strip-shaped unit, enters the optical waveguide sheet to be deflected for the second time towards the two sides and is totally reflected; the light beams are emitted to the human eyes from the two second metasurface gratings to be imaged, and the second metasurface gratings only conduct one-way deflection on the light beams. Bidirectional pupil expansion can be realized towards two sides through the first metasurface grating, and the utilization rate of the optical waveguide is improved.

Description

technical field [0001] The invention relates to the technical field of metasurfaces, in particular to an optical waveguide and a head-mounted device with two kinds of metasurface gratings. Background technique [0002] Augmented Reality (AR) superimposes virtual images onto human eyes and real space to form a display effect that is both real and illusory. With its human-computer interaction, realistic immersion and rich imagination space, augmented reality provides users with an unprecedented experience, and has a very broad application prospect in the fields of industry and consumer electronics. The implementation scheme of an augmented reality display device is usually a scheme based on a traditional geometrical optics lens or a scheme based on an optical waveguide. [0003] Optical waveguide is a technology that uses gratings to realize near-eye display of images. As optical elements change from millimeter level to micronano level, from "stereo" to "planar", the applicat...

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Problems solved by technology

[0005] The invention provides an optical waveguide and a head-mounted device with two kinds of metasurface gratings, which are used to solve the problems in the prior art that the optical waveguide is prone to chromatic dispersion, ghosting, etc., and multi-level diffraction causes image leakage and binocular parallax The problem of dizziness caused by the problem can be realized by a single optical waveguide to achieve color display, improve the diffraction efficiency, effectively suppress multi-level diffraction, and obtain better imaging effects, which can meet the needs of AR equipment

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