Single-Cell-Driven Tri-Channel Encryption Meta-Displays.

Multi-functional metasurfaces have attracted great attention due to the significant possibilities to realize highly integrated and ultra-compact meta-devices. Merging nano-printing and holographic information multiplexing is one of the effective ways to achieve multi-functionality, and such a merger can increase the information encoding capacity. However, the current approaches rely on stacking layers and interleaving, where multiple resonators effectively combine different functionalities on the cost of efficiency, design complexity, and challenging fabrication. To address such challenges, a single meta-nanoresonator-based tri-functional metasurface is proposed by combining the geometric phase-based spin-decoupling and Malus's law intensity modulation. The proposed strategy effectively improves information capacity owing to the orientation degeneracy of spin-decoupling rather than layer stacking or super-cell designs. To validate the proposed strategy, a metasurface demonstrating two helicity-dependent holographic outputs is presented in far-field, whereas a continuous nano-printing image is in near-field. It is also employed on CMOS-compatible and cost-effective hydrogen amorphous silicon providing transparent responses for the whole visible band. As a result, the proposed metasurface has high transmission efficiency in the visible regime and verifies the design strategy without adding extra complexities to conventional nano-pillar geometry. Therefore, the proposed metasurface opens new avenues in multi-functional meta-devices design and has promising applications in anti-counterfeiting, optical storage and displays.​.