Metasurfaces have shown their unprecedented ability in wavefront shaping and triggered various applications with state-of-the-art performances, e.g., color nanoprinting and metaholograms. Recently, these two functions have been combined into a single metasurface to further expand its capabilities. Despite the progress, the current dual-mode metasurfaces are mostly static and strongly hinder their practical applications. Herein, the realization of dynamic bifunctional metasurfaces is reported. Five metaholograms at two different wavelengths are multiplexed with structural colors by controlling the spectral and phase response of metasurface. Owing to the destructive interference and the resonance on external environment, the light diffraction at particular wavelengths can be switched between "ON" and "OFF" states, or remain unchanged with the change of surrounding refractive index. Consequently, the encoded metaholograms are selectively turned on and off, making the overall holographic image dynamically switchable. This concept paves a solid step toward practical applications of all-dielectric metasurfaces.
Keywords: bifunctional metasurfaces; dynamic metasurfaces; holography; metasurfaces; structural color.
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