The exploit of on-chip metasurfaces with full optical controllability and multiplexing capability holds great promise for photonic integration circuits (PIC). Despite previous endeavors in metasurfaces controlling guided waves, it still faces critical challenges to realize practical display applications, for instance, augmented reality (AR). Here, a new type of AR based on multiplexed on-chip meta-holography is proposed and experimentally demonstrated by integrating judiciously engineered meta-atoms above waveguide. Through hybridizing detour and Pancharatnam-Berry phases, on-chip metasurfaces can independently manipulate both guided waves and free-space light to enable a triple-channel holography-multiplexing with independent-encoding freedom. Eventually, an RGB-coloring AR hologram free from zero-order diffraction that can project virtual images into a real-world environment is realized, showcasing its significant potential for wearable devices (glasses or contact lens) integration. This study finds a feasible route toward multifunctional PIC devices and applications in wearable AR displays, imaging multiplexing, information storage, etc.

Although metasurface‐based devices exhibit great potential in optical display and storage technology, the challenges in practical nanoantenna fabrication limit their wide application. In parallel, flat optics, including planar thin‐film nanocavities, have also been extensively studied to realize various spectral engineering and imaging functionalities with large areas and simpler architecture. However, a longstanding practical challenge is to achieve multiplexing imaging functionalities with dynamic switchable ability in real‐time, which to date remains unexplored. In this study, by utilizing the typical inflation sensitivity of hydrogels to humidity change, a multiplexing imaging tunable strategy based on stepwise metal–hydrogel–metal (MHM) nanocavities is originally explored and demonstrated to exhibit dynamic switchable red–green–blue multichannel nanoprinting in real‐time. By decoupling the amplitude/phase correlation, MHM nanocavities successfully enable the hybrid encryption of simultaneous meta‐holography with independent‐encoding freedom in addition to multiplexing nanoprinting. Such an imaging approach, which employs a dynamic tuning scheme, paves a promising avenue toward various applications including state‐of‐the‐art tunable imaging display/storage/encryption, humidity optical sensors, and next‐generation dynamic augmented reality technology.

Heading towards to intelligent photonic technology, meta‐optics is in the revolutionary process of changing from passive to active controllable devices. Despite various emerging tuning mechanisms exploration and demonstration, they mainly focus on spectral amplitude alternation or near‐field imaging switch. Most tuning schemes inevitably demand quite complicated nanofabrication to incorporate nanotextured active materials, thus limiting its applicable scenarios outside the laboratory. Hence, a practically accessible solution in real life to simultaneously realize multi‐field (both near‐ and far‐field) dynamic displays remains a critical challenge. Here, a practical electric‐driven liquid‐crystal‐integrated metasurface (ELIM) is proposed and demonstrated toward advanced intelligent dynamic display. Through elaborately screening building block (α‐Si nanopillar) geometry to build up a systematic architectural dictionary, conventional spatial‐multiplexing is successfully achieved and the degeneracy for amplitude/phase selections is created and thus any arbitrary multi‐field encryptions are allowed. By leveraging ELIM anisotropic characteristics for orthogonal polarizations, an electric‐driven dynamic tuning is practically realized for the first time to enable quad‐fold dynamic exhibitions, including switchable dual‐nanoprinting (near‐field) and simultaneous dual‐holography (far‐field) images with independent‐encryption freedom. Overall, it is envisioned that meta‐optics integrated with the liquid‐crystal platform can easily find practical applications in real life for intelligent dynamic display, imaging multiplexing, information encryption/security, etc.

On-chip integrated meta-optics could enable high-performance, lightweight, and compact integrated photonic devices for augmented reality (AR). Despite previous endeavors in controlling guided waves for holographic phase control, such devices lack versatile performance with the full optical controllability in both amplitude and phase needed to generate multi-functional displays. Here, we propose and experimentally demonstrate an on-chip metasurface integrated on a waveguide to enable a multiplexing semi-transparent screen display in sync with an AR holographic display for human eyes. Through judicious engineering of on-chip meta-diatom displacement and interference at the nanoscale, we can locally modulate the on-chip optical scattering intensities to create a semi-transparent screen display. More intriguingly, we can project a simultaneous dual-channel AR holographic display by incorporating independent encoding freedom of its detour phase. Beyond the all-dielectric properties and high transparency, the projected AR images are free of zeroth-order diffraction interference due to the on-chip optical propagation scheme. We envision that the proposed on-chip meta-optic display could be readily applied to next-generation wearable AR displays, multiplexing optical displays, colored signage, information storage/encryption, and cosmetic visual applications.

As metasurfaces have shown great potential for light manipulation, the majority of optical source parameters have been extensively explored and progressively realized for new degrees of freedom in optical control and multiplexing, including wavelength, polarization, and forward/backward illumination, etc. However, the incident wave vector (k) direction, namely the illumination angle, as one of the critical parameters, has not been fully explored for optical multiplexing due to the lack of angular‐encoding freedom. Here, a general strategy is proposed to realize angular‐multiplexing metasurface based on building up an independent‐encoded amplitude/phase dictionary, in which one can retrieve any arbitrary combination of optical response with different angular illuminations. A series of angular‐multiplexing designs are theoretically and experimentally demonstrated, including angular‐multiplexed meta‐holographs, nanoprintings as well as a hybridized nanoprinting with holography. These studies’ numerical calculations and experiments confirm the new degree of freedom for arbitrary encoded amplitude and phase at different illumination angles. The findings establish a new platform for achieving a complexity of functions for angular resolved illumination, and expanding the manipulative capabilities for optical multiplexing.