Achieving broadband multifunctional modulation of wavefront via terahertz anisotropic metasurface

Abstract

Vanadium dioxide (VO2) has become a reliable phase change material (PCM) and is increasingly utilized in multifunctional metasurface design. This study introduces designs of bilayer anisotropic VO2 meta-atoms in simulation for multifunctional wavefront modulation in the terahertz band. By leveraging the phase change property of VO2 and incident wave polarization, a reconfigurable metasurface composing anisotropic meta-atoms is proposed with four distinct functions. When VO2 is in its insulating state, the metasurface serves as a hologram generator for the x-polarized wave and a focusing reflector for the y-polarized wave. Upon the transition of VO2 into the metallic state, the metasurface functions as a generator of vortex beam for the x-polarized wave, while as an anomalous reflector for the y-polarized wave. The proposed metasurface showcases an outstanding broadband performance, delivering impressive four-channel wavefront modulation within a frequency range of 2.2–3.0 THz. Depending on the compact structure and integrated multi-functionalities, our design may have immense potential across a wide range of terahertz applications, including communication exchange and multiplexing utilization.

Keywords

• Metasurface
• Multifunctional
• Terahertz
• Vanadium dioxide