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.

Recent Applications of Optical Elements in Augmented and Virtual Reality Displays: A Review

“…In this section, we focus on the various applications of the LCHOEs to AR/VR devices without describing the LC media and the fabrication process, thoroughly. Readers interested in the material and the fabrication can refer to the previous publications. ,− In this paper, we denote the HOE that responds only to a single circularly polarized light and transmits the reversely polarized one as “PHOE”, and the HOE that has different optical functions depending on the circularly polarization direction as “GPHOE”. Since the wavelength and angle of the input light as well as its polarization can affect the diffraction of the light, the PHOE and GPHOE are often used to improve the performance of the AR/VR devices.…”

Full-color, wide FoV single waveguide AR displays leveraging polarization multiplexing reflective polarization holograms

“…Additionally, the simple fabrication process of PVGs suggests potential for high yield and cost effectiveness. PVGs also provide the advantage of electrically controlled diffraction efficiency with rapid sub-millisecond response times 6 . The possibility of achieving a full-color AR display with a single PVG waveguide has been explored by Ding et al 7 .…”

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

“…Additionally, the simple fabrication process of PVGs suggests potential for high yield and cost effectiveness. PVGs also provide the advantage of electrically controlled diffraction efficiency with rapid sub‐millisecond response time 15 . The possibility of achieving a full‐color AR display with a single PVG waveguide has been explored by Ding et al 6 However, their discussion is primarily focused on the 1D EPE scheme.…”