Display waveguide assembly with color cross-coupling
AssigneeMeta Platforms Technologies, LLC
InventorsHee Yoon Lee, Ningfeng Huang, Wai Sze Tiffany Lam, Pasi Saarikko
Life of this patent
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Abstract
A waveguide display includes a display projector for emitting polychromatic image light, and a waveguide assembly for transmitting image light to an exit pupil. The waveguide assembly includes two or more waveguides disposed in a stack, each having an in-coupler aligned with the other in-couplers and an offset out-coupler aligned with the other out-couplers. The assembly is configured so that at least one color channel of the image light propagates to the exit pupil along at least two waveguides. A method for selecting the waveguides of the stack to suppress color channel splitting at the exit pupil is provided.
Claims20
A method for fabricating a waveguide stack for conveying polychromatic image light to an exit pupil, the method comprising:
- for each waveguide from a plurality of first waveguides and a plurality of second waveguides, each waveguide comprising an in-coupler and an out-coupler:
- directing a light beam of a first reference wavelength to impinge upon the in-coupler at a first angle of incidence, and determining an exit angle of the light beam of the first reference wavelength from the out-coupler of the waveguide;
- selecting, for the waveguide stack, a first waveguide from the plurality of first waveguides and a second waveguide from the plurality of second waveguides, so that the exit angles of the light beam from the out-couplers of the selected first and second waveguides match with a pre-defined accuracy;
- and
- combining the selected first and second waveguides to form the waveguide stack.
A method for fabricating a waveguide stack for conveying polychromatic image light to an exit pupil, the method comprising:
- providing a plurality of first waveguides, each of the first waveguides comprising an in-coupler and an out-coupler and being pre-fabricated according to a same first specification;
- providing a plurality of second waveguides, each of the second waveguides comprising an in-coupler and an out-coupler and being pre-fabricated according to a same second specification;
- for each waveguide from the plurality of first waveguides and the plurality of second waveguides, determining an exit angle of a light beam of a first reference wavelength from the out-coupler of the waveguide, the light beam being coupled into the waveguide by the in-coupler thereof,
- selecting, for the waveguide stack, a first waveguide from the plurality of first waveguides and a second waveguide from the plurality of second waveguides, so that the exit angles of the light beam from the out-couplers of the selected first and second waveguides match with a pre-defined accuracy;
- and
- combining the selected first and second waveguides to form the waveguide stack;
- wherein the determining comprises directing, prior to the combining, the light beam of the first reference wavelength to impinge upon the input coupler of each waveguide from the plurality of first waveguides and the plurality of second waveguides.
Dependencies are inferred from the claim text.