Multifunctional terahertz wavefront manipulation based on a metasurface

Composite notched square-loop tunable terahertz metasurfaces are formed by integrating a top-layer split square-loop metallic pattern with a second-layer split square-loop vanadium dioxide pattern. By combining two square-loop structures with asymmetric splitting configurations, dynamic geometric phase manipulation is achieved. The designed metasurface enables functionalities including vortex beams with variable topological charges, directionally steerable beams, focused beams, multi-channel beam splitting, and multi-channel vortex generation. This breakthrough overcomes the limitation of single functionality in traditional static metasurfaces, demonstrating significant application potential in tunable metasurfaces and dynamic holographic imaging.