Patent attributes
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.