Verification and modulation of multi-mode chiral hybrid metamaterial based on VO2 layer

Abstract

In this paper, a high absorption performance metamaterial based on phase change material vanadium dioxide (VO2) is verified in experiments. Two absorption peaks (P1, P2) with 60% and 72% amplitudes are achieved based on bright-bright modes coupling or the Ohmic loss mode in 2–40.0 THz at room temperature. P1 and P2 are enhanced and shifted to lower frequency with the diameter D of metal disks increasing or the linear distance L reducing between two metal disks in experiments. When L = 0, a new metal array is achieved since two metal disks contacting with each other, which results in two new absorption peaks (P3, P4) based on new plasmon-resonance hybridization or Ohmic loss mode, respectively. In further experiments, a new absorption peak (P5) is found in heating process or cooling process based on the insulator-metal phase transition of the VO2 layer, while P1 and P2 are insensitive to temperature. The metamaterial exhibits the stability of the original absorption properties and the tunability of the temperature.