Liquid crystal planar optics (LCPO) with versatile functionalities is emerging as a promising candidate for overcoming various challenges in near-eye displays, like augmented reality (AR) and virtual reality (VR), while maintaining a small form factor. This type of novel optical element exhibits unique properties, such as high efficiency, large angular/spectral bandwidths, polarization selectivity, and dynamic modulation. The basic molecular configuration of these novel reflective LCPO is analyzed, based on the simulation of molecular dynamics. In contrast to previously assumed planar-twist structure, our analysis predicts a slanted helix structure, which agrees with the measured results. The optical simulation model is established by rigorous coupled-wave analysis (RCWA). With a higher precision and faster computation speed, the model comprehensively investigates the diffraction properties of various types of LCPOs. This fundamental study on LCPO paves the way for its further applications in AR/VR displays. Several approaches adopting LCPO to solve major challenges in AR/VR like insufficient resolution, limited field-of-view (FoV) and small exit pupil are presented. A foveated display system with doublet liquid crystal lenses is built to concentrate the resolution in the central FoV, corresponding to human eye's highest visual acuity. The proposed foveated display can improve the effective resolution with a fixed total resolution and is expected to alleviate the screen-door effect in VR caused by inadequate resolution. In addition, a new display system named scanning waveguide display is proposed to break the FoV limit (80°) of current AR waveguide displays. The system adopts an ultra-low f-number liquid crystal lens array and reaches a FoV of 100°. Finally, a pupil steering approach is proposed to effectively enlarge the exit pupil of retinal-scanning displays. One in a set of liquid crystal lenses is selectively turned on at each time to match the viewer's pupil location. In comparison with previous approaches, our pupil steering exhibits advantages like aberration-free, fast response time, and compact size.
| Identifer | oai:union.ndltd.org:ucf.edu/oai:stars.library.ucf.edu:etd2020-2116 |
| Date | 01 January 2022 |
| Creators | Xiong, Jianghao |
| Publisher | STARS |
| Source Sets | University of Central Florida |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | Electronic Theses and Dissertations, 2020- |
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