Geometrical waveguide in see-through head-mounted display: a review

Geometrical waveguide has obvious advantage over other see-through technologies to achieve high resolution, ultra-thin thickness, light weight and full-color display. The general principle of waveguide display is introduced and the key challenges involved with geometrical waveguide display and the way to conquer them is discussed. Ultra-thin geometrical waveguide for see-through HMDs with different properties is reviewed in this paper, including waveguide with partially-reflective mirrors array (PRMA), trapezoidal microstructures and triangular microstructures. Finally, a type of ultra-thin waveguide display which can be fabricated with the technology of injection molding is presented, and the thickness can be reduced to less than 2mm with an EPD of 12mm and a FOV of 36°.