Tunable terahertz metasurface resonator based on phase transition of VO2 crosses

Based on the insulator to metal transition (IMT) characteristics of vanadium dioxide (VO2), a highly active tunable terahertz (THz) metasurface resonator patterned VO2 cross structures is proposed. The simulation results show that the transmission of the proposed structure at low temperature is higher than 0.7 because of the VO2 in its insulation phase. With the increasing temperature, a strong transmission dip appears at 0.76 THz due to the metal phase of VO2, which indicates the onset of a new resonant mode. The maximum tunable range of transmission for THz wave is 0.06-0.86. Simultaneously, we also demonstrate that the resonant responses of the heating and cooling processes are quite different and the heating process is more sensitive. The transition temperature is close to room temperature and the device can achieve good modulation effect on both TE and TM waves. The TE and TM mode resonances are selective by altering the cross arms, which is almost impossible for other THz devices. So, the resonator can greatly promote practical applications of THz functional devices such as filters, sensors, modulators, and switches.