Table 2 Comparison of different AR combiners
From: Augmented reality and virtual reality displays: emerging technologies and future perspectives
| Â | Combiner efficiency | FoV (diagonal) | Eyebox | Form factor | Major challenge |
|---|---|---|---|---|---|
Geometric optics | ~4000 nit/lm | 50°–120°158 | ~8 mm158 | Large | Shrinking size, etendue conservation |
Maxwellian-type | ~50000 nit/lm (pupil st.) ~3000 nit/lm (pupil dup.) | ~100°143 | 2–4 mm (single view) ~8 mm (pupil st./dup.) | Small | Implementation of pupil steering or duplication. |
Diffractive waveguide | 50–200 nit/lm6 | ~50°6 | ~15 mm | Medium (multilayer) | Combiner efficiency, FoV |
Achromatic waveguide | 650–1000 nit/lm (2D EPE)197 1500–3000 nit/lm (1D EPE)199 | ~60°199 | ~15 mm | Small | Fabrication, FoV |
