Fig. 3. Metasurface hologram with differently sequenced dynamics.

(A) Mg/Pd (P₁) and Mg/Pd/Cr (P₃) nanorods work as dynamic pixels with different reaction kinetics. Overview SEM image of the hybrid plasmonic metasurface as well as the enlarged SEM image of the unit cell (600 nm × 600 nm). The Mg/Pd/Cr (P₃) nanorods are represented in blue color. (B) Time evolutions of P₁ (solid line) and P₃ (dash-dotted line) during hydrogenation and dehydrogenation. The scattered intensities at resonance peak positions of P₁ and P₃ are used to track the dynamic processes, respectively. (C) Representative snapshots of the holographic images during hydrogenation and dehydrogenation. H₂(1) or H₂(2) refers to a hydrogenation process until the first or second feature completes transition. Both the portrait of Marie Curie and the chemical elements Po and Ra can be switched on and off independently.