High-uniformity dielectric U-shaped surface relief grating coupler for AR headsets

Abstract

In this work we propose a new type of symmetrical surface relief diffractive grating for waveguide -based Augmented Reality near-eye display system with a wide Field of View (FoV). We demonstrate that by using a dual-mode symmetrical in-coupling system and angular pupil tiling, we can extend the overall horizontal FoV. Our grating coupler is optimized for the second diffraction orders. The proposed concept is validated numerically via full-wave electromagnetic analysis of a 1D diffraction grating. Measurements of the diffraction efficiency of the micro-fabricated prototype are compared with the results of the numerical simulation.