Terahertz coding metasurface enabled by the phase transition of vanadium dioxide

Terahertz (THz) technology shows great potential in various fields, but the development of efficient THz components is still challenging. Here, we propose a terahertz coding metasurface using the phase transition of vanadium dioxide (V0₂). At 1.34 THz, the phase difference between V0₂'s insulating and metallic states is 180°. By coding the reflection phase of V0₂ (0 for insulating, 1 for metallic), we achieve dynamic beam manipulation. Different coding arrangements enable diverse beam splitting and shaping, such as generating two beams, four beams, spiral beams, and super multi-beams. This digital coding method allows arbitrary beam modulation, offering a versatile solution for advanced THz applications.