Research Progress of Liquid Crystal Polymer Composites in Augmented and Virtual Reality

The three-dimensional (3D) display technology has always been a hot spot in the display field. The core of augmented reality (AR), virtual reality (VR), and naked-eye 3D display are to visually regulate the light entering the human eye to form a binocular parallax, that is, a visual deviation in the image of the two eyes, which produces a stereoscopic sense in the human brain. In the AR and VR display field, we always pursue a perfect immersive visual experience, which poses great challenges to the wide field of view (FOV) and high resolution of the system. As a new type of polymer material, liquid crystal polymers are widely used in AR and VR because of their unique optoelectronic properties, such as scattering or transparency with the change of an applied electric field. In this paper, we review some key challenges in the field of AR and VR display, such as the well-known vergence-accommodation conflict (VAC), and propose solutions that have been proven effective. We introduce the important functions and optoelectronic properties of liquid crystal (LC) materials by describing in detail the working principle of polymer dispersed liquid crystal (PDLC), doublet geometric phase (GP) lens, and polymer-stabilized liquid crystal (PSLC). Finally, we summarize and discuss the main uses and challenges of liquid crystal materials in the field of AR and VR displays.