Patent ID: 11874503

Abstract:
The present application provides a diffractive optical waveguide for optical pupil expansion and a display device, comprising a waveguide substrate having a coupling-in region in which a coupling-in grating is located and a coupling-out region. A first and a second diffractive light obtained by the input light diffracted by the coupling-in grating are respectively totally reflected in the waveguide substrate and directed to a first and a second coupling-out regions. A first coupling-out grating disposed in the first coupling-out region and a second coupling-out grating disposed in the second coupling-out region both are configured to couple at least a portion of light propagating therein out of the waveguide substrate by diffraction. The first and the second coupling-out regions are respectively located at both sides of the coupling-in region. A center of the coupling-in region deviates from the center line connecting the centers of the first and the second coupling-out regions.