Fig. 1. Schematic diagram of the designed multifunctional metamaterial device unit

Fig. 2. Response characteristics of devices to incident waves

Fig. 3. When σVO2=2×10⁵ S/m，the absorption curve of the structure when the structural parameters change

Fig. 4. Top view and side view of the electric field distribution on the surface of the device structure at a frequency of 3.75 THz when δVO2=2×10⁵ S/m

Fig. 5. Influence of terahertz wave incidence angle and polarization angle on structural absorption when δVO2=2×10⁵ S/m

Fig. 6. The cross polarization coefficient R_xy，common polarization reflection coefficient R_yy，R_xy phase φ_xy，R_yy phase φ_yy and its phase difference ∆φ，ellipticity and axial ratioAR

Fig. 7. Effect of parameters of metamaterial structure on ellipticity

Fig. 8. PCR curve of the device structure when σVO2=20 S/m

Fig. 9. When σVO2=20 S/m，Top view and side view of surface electric field distribution of device unit structure at different frequency points