Tunable and three-dimensional dual-band metamaterial absorber based on electromagnetically induced transparency with vanadium dioxide.

A tunable and three-dimensional dual-band metamaterial absorber based on electromagnetically induced transparency (EIT) is proposed. The unit cell of the metamaterial absorber consisted of a cut wire (CW), two split ring resonators (SRRs), a metal plate and a patterned vanadium dioxide (VO2) film. The two absorption peaks could be dynamically controlled by tuning the conductivity of VO2 with the maximum absorptions of 97.5% at 1.05 THz and 96.5% at 1.16 THz. The physical mechanism of the metamaterial absorber was explained by the electric field, magnetic field, power loss density and surface current distributions. In addition, the metamaterial absorber exhibited a wide polarization angle for y-polarization wave and x-polarization wave and showed good robustness against oblique incidence. Moreover, the metamaterial absorber exhibited a high fault tolerance with a variation in the geometric parameters. Our work provides a novel method for the fabrication of multi-band metamaterial absorbers and has promising applications in terahertz sensors, modulators and filters.