Table 2 Comparisons of different waveguide combiners
From: Waveguide-based augmented reality displays: perspectives and challenges
Waveguide combiners | Efficiency | FoV (diagonal) | Form factor | Major challenges |
|---|---|---|---|---|
Diffractive waveguide | Low (400–1000 nits/lm for FoV \(30^\circ\), up to ~ 2.1%) | Medium for SRGs (\(70^\circ\) at \({n}_{g}=2\)), small for VHGs | Small (single waveguide), medium (multi-waveguide) | Color uniformity, efficiency, eye glow, rainbow effect |
Geometric waveguide | High (650–1000 nits/lm for \(\text{F}\text{o}\text{V} 50^\circ\), ~ 5% for 2D EPE, ~ 15% for 1D EPE) | Potentially large \((50^\circ \; \text{at}\;{ n}_{g}=1.6\)) | Small | Stray light, fabrication |