Abstract: An optical waveguide includes an input diffractive optical element arranged for being aligned with an optical projector for diffracting the light beam therefrom, a waveguide substrate arranged for reflecting the light beam diffracted by the input diffractive optical element by means of total internal reflection, and an output diffractive optical element coupled at said waveguide substrate for partially diffracting the light beam as a diffracted light and partially transmitting the light beam as a transmitted light during the total internal reflection of the light beam within the waveguide substrate. The diffracted light is diffracted by the output diffractive optical element and is projected out of the waveguide substrate toward the user eye. The transmitted light is continuously transmitted and reflected within the waveguide substrate by the total internal reflection until the transmitted light is totally diffracted out of the waveguide substrate, so as to complete an exit pupil expansion.

Abstract: An optical waveguide includes an input diffractive optical element arranged for being aligned with an optical projector for diffracting the light beam therefrom, a waveguide substrate arranged for reflecting the light beam diffracted by the input diffractive optical element by means of total internal reflection, and an output diffractive optical element coupled at said waveguide substrate for partially diffracting the light beam as a diffracted light and partially transmitting the light beam as a transmitted light during the total internal reflection of the light beam within the waveguide substrate. The diffracted light is diffracted by the output diffractive optical element and is projected out of the waveguide substrate toward the user eye. The transmitted light is continuously transmitted and reflected within the waveguide substrate by the total internal reflection until the transmitted light is totally diffracted out of the waveguide substrate, so as to complete an exit pupil expansion.

Abstract: An optical waveguide includes an input diffractive optical element arranged for being aligned with an optical projector for diffracting light beams therefrom, a waveguide substrate n, and an output diffractive optical element. Light beams diffracted by the output diffractive optical element are coupled out of the waveguide substrate towards users' eyes. The output diffractive optical element has an effective area arranged to maintain a constant output flux per unit area therein for providing an uniform image in brightness when the image is being projected out of the waveguide substrate.

Abstract: An optical waveguide includes an input diffractive optical element arranged for being aligned with an optical projector for diffracting light beams therefrom, a waveguide substrate, and an output diffractive optical element. Light diffracted by the output diffractive optical element is projected out of the waveguide substrate towards users' eyes. The output diffractive optical element has an effective area arranged to maintain a constant output flux per unit area therein for providing an uniform brightness of the light when the light is being projected out of the waveguide substrate.

Abstract: A planar optical waveguide based on two-dimensional grating includes an optical waveguide substrate which is a transparent plane-parallel plate, and a functional grating element which includes a two-dimensional grating having two grating directions with an angle of 60° in between. The two-dimensional grating is either protruded or recessed into the top surface of the optical waveguide substrate. The output image from a micro-projector can enter the optical waveguide and then gets projected to cover the entire area of the functional grating element, enabling a human eye to view the output image across a large eye-box.