A transmission-type terahertz beam reconfigurable metasurface based on a multilayer annular structure.

To achieve flexible control over terahertz beams, vanadium dioxide (VO) with phase transition temperatures of 60 °C and 72 °C is selected. The effects of VO in its two states-insulator (before phase transition) and metallic (after phase transition)-on the amplitude and phase of the unit structure are analyzed. A terahertz beam reconfigurable phase gradient metasurface based on VO with different phase transition temperatures is designed.