With the rapid advancement of high-speed communication and computational technologies, AR and VR are regarded as next-generation platforms for immersive human-digital interaction. Polarization Volume Gratings (PVGs) is a game-changing breakthrough in the fast-growing field of augmented reality and virtual reality (AR/VR), considerably advancing holographic waveguide applications. However, replicating the sophisticated performance of human vision while keeping tiny and lightweight near-eye display modules is a huge problem for optical engineers. Recent advances in holographic optical elements (HOEs) and lithography-enabled devices are highlighted as novel approaches to overcoming classic optical restrictions in AR and VR systems. High-resolution-density and high-brightness Liquid Crystal (LC) technology is a promising picture source for see-through AR displays, particularly in bright environments. This comprehensive study investigates the emerging significance of planar and ultrathin diffractive LC polarization optical elements in AR and VR. Ultrathin planar diffractive LC optical elements, like reflective phase LC gratings, geometric phase LC grating and lens, have proven useful in AR and VR for a variety of purposes, including Exit Pupil Expansion (EPE), enlightening field of view (FOV), reducing chromatic aberrations, and achieving gaze-matched Maxwellian displays through dynamic pupil steering. This analysis concludes with a discussion of future research directions, paving the way for the next generation of advances in photonic devices for AR and VR displays.

With the rapid advancement of high-speed communication and computational technologies, AR and VR are regarded as next-generation platforms for immersive human-digital interaction. Polarization Volume Gratings (PVGs) is a game-changing breakthrough in the fast-growing field of augmented reality and virtual reality (AR/VR), considerably advancing holographic waveguide applications. However, replicating the sophisticated performance of human vision while keeping tiny and lightweight near-eye display modules is a huge problem for optical engineers. Recent advances in holographic optical elements (HOEs) and lithography-enabled devices are highlighted as novel approaches to overcoming classic optical restrictions in AR and VR systems. High-resolution-density and high-brightness Liquid Crystal (LC) technology is a promising picture source for see-through AR displays, particularly in bright environments. This comprehensive study investigates the emerging significance of planar and ultrathin diffractive LC polarization optical elements in AR and VR. Ultrathin planar diffractive LC optical elements, like reflective phase LC gratings, geometric phase LC grating and lens, have proven useful in AR and VR for a variety of purposes, including Exit Pupil Expansion (EPE), enlightening field of view (FOV), reducing chromatic aberrations, and achieving gaze-matched Maxwellian displays through dynamic pupil steering. This analysis concludes with a discussion of future research directions, paving the way for the next generation of advances in photonic devices for AR and VR displays.