Single-layer multifunctional wideband polarization conversion metasurface based on vanadium dioxide

In this paper, a reflective multifunctional polarization conversion metasurface utilizing vanadium dioxide for operating in the terahertz band is proposed. Employing a single-layer dielectric substrate enables a lightweight and cost-effective design. Exploiting the temperature-induced phase transition of VO₂ enables switchable multifunctional polarization conversion. In VO₂'s insulated state, the device operates as a wideband cross-polarization conversion within 1.25-1.82 THz (37.13%). In its metallic state, the device operates as dual-wideband linear-to-circular polarization conversion within the ranges of 0.92-1.12 (19.61%) and 1.39-1.91 THz (31.52%). Furthermore, the metasurface achieves good angular stability. These features highlight their significant potential for applications in the terahertz communication, bio-detection, imaging, and sensing.