Full-color, wide field-of-view single-layer waveguide for augmented reality displays

In the quest for more compact and efficient augmented reality (AR) displays, the standard approach often necessitates the use of multiple layers to facilitate a large full-color field of view (FoV). Here, we delve into the constraints of FoV in single-layer, full-color waveguide-based AR displays, uncovering the critical roles played by the waveguide's refractive index, the exit pupil expansion (EPE) scheme, and the combiner's angular response in dictating these limitations. Through detailed analysis, we introduce an innovative approach, featuring an optimized butterfly EPE scheme coupled with gradient-pitch polarization volume gratings (PVGs). This novel configuration successfully achieves a theoretical diagonal FoV of 54.06° while maintaining a 16:10 aspect ratio.