A full-color near-eye augmented reality display using a tilted waveguide and diffraction gratings

Full-color imaging is necessary for the wide applications of waveguide displays. To address this challenge, we propose a tilted-waveguide system with diffraction gratings. The waveguide is horizontally inclined at 30°to enlarge the field of view (FOV). Two surface-relief diffraction gratings are designed to be the in-coupler and the out-coupler, respectively. Stray light of this system is analyzed and is not shown to affect the projected images. A freeform surface prism is designed as the projection optics. The diameter of the circular exit pupil is 10 mm at an eye relief of 20 mm, and the diagonal FOV of the system reaches 35°.