Thermally switchable and tunable metasurface with polarization independence based on VO2 phase transition

In this paper, a thermally tunable metasurface (TTMS) based on phase material vanadium dioxide (VO2) is designed and demonstrated, which consists of VO2 patterns, metallic resonators, dielectric substrates, and a gold reflective plate. Exhibiting ultra-broadband absorption from 4.72 THz to 9.88 THz with absorptivity exceeding 90% above the phase change temperature of VO2 and realizing single-band absorption when the VO2 resonators are in the insulator phase, the proposed TTMS possesses excellent low radar cross-section (RCS) performance as well as can be tailored by controlling the temperature of the phase material VO2. Furthermore, the devised TTMS is polarization-insensitive and can work well under a wide range of incident angles. The demonstrated tunable metasurface promises potential applications in the terahertz regime, such as modulating, radar stealth, and thermal detection.