Switchable metasurface for high-efficiency absorption and broadband polarization conversion based on vanadium dioxide in the terahertz frequency

Abstract

High-performance devices with superior execution will facilitate the practical application of terahertz (THz) technology and foster THz innovation. In this paper, taking advantage of the phase transition characteristics of vanadium dioxide (VO2), a reconfigurable metasurface with absorption and polarization conversion capacities is proposed. The metallic condition of VO2 results in the formation of a wideband absorber. It provides more than 90% absorption over a broad spectral range from 3.32 to 5.30 THz. Due to the regularity of the meta-atom, the absorber is not polarization-delicate and keeps a high retention rate in the scope of incoming angles from 0° to 45°. When VO2 is in the insulating condition, the calculated outcomes demonstrate that the cross-polarization conversion rate can reach more than 90% in the range of 2.29–7.85 THz when x-polarized or y-polarized waves are incident vertically. The proposed metasurface is likely to be used in the fields of emitters, sensors, imaging systems, and wireless communication.