Waveguide combiner with stacked plates

Abstract

Disclosed are a mixed-reality optical waveguide-based combiner apparatus that includes stacked plates of reflective optical elements (ROEs) and associated methods of fabrication. ROEs in the plates of the waveguide combiner share a commonly shaped and sized footprint and are aligned in the stack. A top plate in the stack of plates includes an input-coupler, such as a prism, for in-coupling light for virtual images from a display engine into the waveguide combiner. The top plate also includes a top ROE comprising a cascaded array of mirror elements in a waveguide that horizontally expands an exit pupil of the virtual images and couples the light to a corresponding bottom ROE, disposed in a bottom plate in the stack, comprising a cascaded array of mirror elements in a waveguide. The bottom ROE couples the virtual image light to an output coupler in the bottom plate which out-couples light from the waveguide combiner.