Metagrating solutions for full color single-plate waveguide combiner

Abstract

In this work we propose several full-color metagrating solutions for single waveguide-based Augmented and Virtual Reality near-eye display systems. The presented solutions are based on a combination of reflective and/or transmissive diffraction gratings inside or outside a waveguide. The proposed in-coupler designs have high diffraction efficiency across a wide angular range. Applying our new grating combination solution, we can provide good gathering of diffracted rays for the different colors. We demonstrate that by using a dual-mode symmetrical in-coupling system and angular pupil tiling, we can extend the overall horizontal FoV for three RGB colors. The new characteristics of the full single waveguide system including Eye Pupil Expander and out-coupling components compatible with the proposed in-coupling solutions are discussed. We show that a new nonsymmetrical design of metagratings can be used to change its diffraction properties improving the diffraction efficiency and diffraction uniformity of the optical components.