Fig. 2. Metasurface hologram with dynamic and static patterns.

(A) Two holographic patterns, harmony and peace, reconstructed from two independent phase profiles containing Mg/Pd (P₁) and Au (P₂) nanorods as dynamic and static pixels, respectively. Ti is omitted for conciseness. The two sets of pixels are merged together with a displacement vector of (300 nm, 300 nm). (B) Overview SEM image of the hybrid plasmonic metasurface. The Au (P₂) nanorods are represented in yellow color. Inset: Enlarged SEM image of the unit cell (600 nm × 600 nm). (C) Time evolutions of P₁ (solid line) and P₂ (dashed line) during hydrogenation and dehydrogenation. The scattered intensities at resonance peak positions of P₁ and P₂ are used to track the dynamic processes, respectively. P₁ can be switched off/on through hydrogenation/dehydrogenation, whereas P₂ stays at the on state. (D) Schematic of the optical setup for capturing the holographic images. QWP, quarter-wave plate; LP, linear polarizer. (E) Representative snapshots of the holographic images during hydrogenation and dehydrogenation. Harmony (left) can be switched off/on using H₂/O₂, whereas peace (right) stays still.