Switchable polarization volume gratings for augmented reality waveguide displays

Abstract

A new electrically driven polymer-stabilized polarization volume grating (PVG) is developed. The diffraction efficiency can be modulated by a vertical electric field. A small amount of liquid crystal monomer is doped into the host cholesteric liquid crystal to form a stabilized polymer network to make the unwinding process reversible. The fabricated device exhibits submillisecond response time, a large range of diffraction efficiency modulation, and clear see-through capability. Some potential applications are demonstrated, including a significantly suppressed rainbow effect, enhanced light efficiency, and expanded field of view for a waveguide-based augmented reality display. The unique properties and benefits of switchable PVGs could open a new space in near-eye display research, especially novel optical systems for augmented reality waveguide displays.