Design of high-reflectivity dynamic switchable metasurface holography

In the field of holographic imaging, high-reflectivity metasurfaces have become a crucial technology for achieving high efficiency and high-resolution image reconstruction. This study utilizes the dynamic tunability of magnesium (Mg) to numerically design an optical metasurface capable of displaying multiple holographic images in different states, achieving a reflectivity of up to 82%. In its normal state, the metasurface uses the resonance phase modulation of the metallic Mg structure to display images. Upon the introduction of hydrogen, the Mg transitions to its dielectric state, and a separate gold (Au) structure is used to modulate and display different images. The core contribution of this research lies in the application of a high-reflectivity metal layer, which enhances the imaging effects post-magnesium switching and improves the quality of image display. This work provides a new solution for dynamic optical displays and information storage technologies, thereby expanding the application scope of optical metasurfaces.