VO2-based Active Terahertz Chiral Metamaterials

In this paper, we demonstrate a vanadium dioxide (VO2) integrated chiral metamaterial exhibiting tunable chiroptical responses at terahertz frequencies. Simulated results show that a circular dichroism of similar to 40 degrees and a maximum polarization rotation of similar to 200 degrees/lambda can be achieved around 0.7 THz with VO2 in its metallic phase. More importantly, the chiroptical response from the hybrid metamaterial varies dramatically with the phase transition determined by the THz conductivity of VO2. Our results reveal that the unification of structured metals and phase-change materials provides the foundation to establish a new paradigm for THz chiroptical metadevices.