Dissertation Title:
“Liquid crystal flat optics for near-eye displays ”
Abstract:
Augmented reality (AR) and virtual reality (VR) displays, considered as the next-generation information platform, have shown great potential to revolutionize the way how we interact with each other and the digital world. Both AR and VR are disruptive technologies that can enable numerous applications in education, healthcare, design, training, entertainment, and engineering. Among all the building blocks of these emerging devices, near-eye displays (NEDs) play a critical role in the entire system, through which we can perceive the virtual world as the real one. However, the visual experience offered by existing NED technologies is still far from satisfying the human vision system regarding the display resolution, image clarity, and light efficiency.
This dissertation provides original solutions to overcome the abovementioned roadblocks using a novel type of liquid crystal (LC) planar optics based on the Pancharatnam-Berry phase (PBP). Firstly, we demonstrate a polarization-multiplexed method that can double the perceived angular resolution of most NEDs, utilizing the polarization-selectivity of a customized PBP deflector. Secondly, a broadband LC PBP lens is developed and integrated with conventional VR optics, such that both chromatic and monochromatic aberrations are reduced by more than two times, offering significantly sharper imagery to the viewer. Moreover, a diffractive deflection film based on PBP is designed with a directional display panel to reduce the wasted light in present VR devices, which can boost the system optical efficiency by more than two times. Also, novel fabrication methods of the PBP optical elements are invented for the readiness of mass-production.
The proposed methods and designs are examined in both optical simulation and prototype hardware with public demonstrations. The verified performance enhancement proves that the proposed LC-based PBP optical elements offer considerable value and potential for practical applications in next-generation NEDs.
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