Ferrofluid-Assisted Dynamic Metasurface 3D Holography Endowed With Rapid, Linear, and High-Contrast Color Modulation

Metasurface holography offers a highly promising approach for naked-eye, full-color, 3D displays. However, the natural static structure and material of the metasurface limit its ability to dynamically regulate the light field, posing a challenge for achieving photorealistic 3D holography. Here, a ferrofluid-assisted dynamic metasurface is first demonstrated, conducting a 3D holography endowed with rapid, linear, and high-contrast color modulation. The ferrofluid has nano-structural control properties (flow behavior of nanoparticles and emulsion) that enable dynamic manipulation of the extinction (absorption and scattering) intensity in micron region across a broadband spectrum range (400–850 nm). By integrating the ferrofluid with a broadband metasurface, a novel dynamic meta-hologram is created, which can not only regulate both amplitude and phase of the light field under a single wavelength laser but also in situ linearly changing the color of holographic images under multi-wavelength lasers. This method provides a new perspective for implementing dynamic metasurface 3D holography capable of continuous color response.