Compact and High-Efficiency Liquid-Crystal-on-Silicon for Augmented Reality Displays

Compact and high efficiency microdisplays are essential for lightweight augmented reality (AR) glasses to ensure longtime wearing comfort. Liquid-crystal-on-silicon (LCoS) is a promising candidate because of its high-resolution density, high brightness, and low cost. However, its bulky illumination system with a polarizing beam splitter (PBS) cube remains an urgent issue to be overcome. To reduce the volume of the LCoS illumination system, here, we propose a compact structure with four thin PBS cuboids. Through simulations, the optical efficiency of 36.7% for an unpolarized input light can be achieved while maintaining reasonably good spatial uniformity. Such a novel design is expected to have a significant impact on future compact and lightweight AR glasses.