Abstract This study introduces a broadband tunable multifunctional terahertz (THz) metasurface platform based on vanadium dioxide (VO2) phase transition. The proposed meta-atom design achieves bistable electromagnetic responses through a hybrid resonant architecture combining a Cu-VO2 composite hexagonal ring and a VO2 rectangular patch. In the insulating state, the meta-atom’s response is dominated by the Cu-VO2 hexagonal ring, enabling full 2π phase coverage across 2-6 THz through structural rotation. Transitioning to the metallic state shifts the dominant response to the VO2 rectangular patch, which maintains stable reflection coefficient while providing complete 2π phase coverage over 4.8-7.1 THz via rotational tuning, demonstrating remarkable phase modulation performance. Through systematic arrangement of these meta-atoms, we demonstrate three distinct classes of phase-reconfigurable metasurfaces, including an anomalous reflection and beam splitting metasurface that dynamically controls reflection and azimuthal angles, a reconfigurable orbital angular momentum (OAM) generator with switchable topological charges, and a deflected OAM generator that simultaneously manipulates reflection angle, azimuthal orientation, and topological charge. All metasurface configurations exhibit dynamic phase reconfigurability through VO2 state modulation, with comprehensive numerical simulations validating their broadband wavefront manipulation capabilities. This work offers significant potential for advanced applications in THz communications, high-resolution sensing, and information encryption. The proposed architecture overcomes conventional limitations in tunable THz devices by enabling independent control of multiple wavefront parameters through a single reconfigurable platform.
Chen et al. (Mon,) studied this question.