Incidence angle and polarization-insensitive multi-band absorption and an all-reflective dual-function switchable...

In this paper, we present a reconfigurable metasurface with a wide range of incidence angles and insensitivity to polarization, which may be used to switch between multi-frequency tunable perfectly absorbing and totally reflecting dual functionality. It is based on a graphene resonant ring group and vanadium dioxide (VO₂) and is intended to realize the modulation of terahertz wave amplitude. When the VO₂ layer is in its insulating condition, it produces a near-perfect wave-absorbing action in two of the four unique frequency bands and reaches over 90% absorption as a wave-absorbing surface. By altering the graphene's Fermi energy level, the four working frequency bands can be adjusted. The metasurface changes from an absorbing to a reflecting surface when the VO₂ becomes metallic at high temperatures, allowing complete terahertz wave reflection. The proposed multifunctional absorber has bifunctionality, is insensitive to incident angle polarization, is easy to integrate and prepare, and is of research value for future 6G terahertz communications.