Patent ID: 11841523

Abstract:
A diffractive optical waveguide and a display device for optical pupil expansion are provided. The diffractive optical waveguide comprises a waveguide substrate; a coupling-in grating; and a coupling-out grating comprising first, second, and third coupling-out gratings that are arranged successively in a first direction. The second coupling-out grating is corresponding to a region that includes a first edge and a second edge spaced in a second direction orthogonal to the first direction. The second direction is orthogonal to the first direction. The first edge is closer to the coupling-in grating than the second edge. A first width of the first edge in the first direction is greater than a second width of the second edge in the first direction. The light output by the coupling-in grating is incident on the second coupling-out grating through the waveguide substrate, and is diffracted by the second coupling-out grating into a plurality of beam splits.