Holographic display étendue expansion with a binary π-metasurface.
Holographic displays trade field of view against eyebox size because a spatial light modulator provides a fixed étendue. We pair a commercial 4-bit piston-mode phase light modulator (PLM) with a pixel-registered binary metasurface designed for an achromatic π phase step. Grouping the PLM into s×s superpixels while reta...