Intelligent terahertz device with dual-function switching capability enabled by VO ₂

Terahertz technology has witnessed significant progress in recent years, with emerging materials, including graphene and vanadium dioxide, being increasingly integrated into advanced terahertz systems. However, most current research still faces the problem of single-device functionality. In order to achieve switchable characteristics of device functions, utilizing vanadium dioxide, we developed an intelligent terahertz system with dynamically reconfigurable functionalities. The architecture comprises three vertically stacked components: a geometrically optimized VO 2 metasurface occupies the uppermost stratum, followed by a silicon dioxide dielectric spacer, with a continuous vanadium dioxide thin film forming the foundational substrate. The simulation results show that when [Formula: see text] [Formula: see text]K, the absorption efficiency of the device is approximately 10% across the entire terahertz frequency range, and the transmittance exceeds 70% within the bandwidth of 3.26–8.31 THz. As the temperature increases, the absorption efficiency improves, while the transmittance gradually decreases. When [Formula: see text] [Formula: see text]K, the absorption efficiency of the device exceeds 95% within the range of 4.21–8.16 THz, and the transmittance is 0 across the entire frequency band. Furthermore, the device demonstrates remarkable insensitivity to both polarization and incident angles. Our research has focused on examining the absorption and transmittance properties of the device under different temperature scenarios. This paper employs impedance matching theory to explain the high absorption capability of the device, and illustrates the reasons for the performance transformation of the device by plotting the surface electric field diagram of the device. We also studied the influence of the device’s structural parameter variations on the absorption rate. This study provides a practical approach for terahertz stealth and related applications.