Integrated metasurface-freeform system enabled multi-focal planes augmented reality display

The advent of artificial intelligence (AI) has propelled augmented reality (AR) display technology to a pivotal juncture, positioning it as a contender for the next generation of mobile intelligent terminals. However, the pursuit of advanced AR displays, particularly those capable of delivering immersive 3D experiences, is significantly hindered by the performance limitations of current hardware and the complexity of system integration. In this study, we present an innovative multi-focal plane AR display system that integrates a non-orthogonal polarization-multiplexing metasurface, freeform optical elements, and an OLED display screen. All optical elements are integrated into a single solid-state architecture, based on a joint optimization design approach of ray tracing and diffraction theory. The multi-focal plane AR visual effect is realized by the compact and multiplexing metasurface, which performs distinct phase functions across diverse polarization channels. Meanwhile, freeform surfaces offer ample design flexibility for the collaborative optimization of multi-focal plane imaging and the see-through systems. Followed by a mechanical design and prototype assembly, we demonstrate the system's capabilities in real-time and multi-focal plane display. The digital images at all virtual image distances seamlessly integrate with the real environment, fully exhibiting the system's high parallelism and real-time interactivity. With the innovative design concept and joint design method, we believe that our work will spur more innovative and compact intelligent solutions for AR displays and inject new vitality into hybrid optical systems.