Terahertz phase modulator based on a metal-VO₂ reconfigurable metasurface

Abstract

Actively controlling the phase of a terahertz (THz) wave is of great significance for beaming, tunable focusing, and holography. We present a THz phase modulator based on an electrically triggered vanadium dioxide ( V O 2 ) reconfigurable metasurface. The unit cell of the device consists of two split-ring resonators embedded with a V O 2 ribbon. By electrically triggering the insulator-to-metal transition of V O 2 , the resonance mode and resonance intensity of the unit cell can be dynamically controlled. The simulation results show that the structure can achieve a phase shift of about 360° in the range of 1.03–1.13 THz, and the reflection amplitude can reach 80%. The device has potential applications in THz imaging, radar, broadband wireless communications, and array phase control.

An Interesting Functional Phase Change Material VO2: Response to Multivariate Control and Extensive Applications in Optics and Electronics

“…[ 109a,149 ] For example, Li et al. [ 148b ] found that the vdW bond between the mica substrate and the VO 2 film was used to avoid the clamping effect, reduce the lattice effect of the film and the substrate, and reduce the heat conduction of the film to the substrate because of the weak lattice coupling, and finally reduce the trigger threshold and keep ideal Md.…”

“…In addition, high modulation depth can be achieved by setting the metasurface structure to change the optical transmission of the device. [ 16d,148 ] In general, high modulation depth means that a large number of signals can be controlled, increasing the diversity of modulation. As shown in the Table 6, some current studies have achieved modulation depth of more than 99% at specific frequencies and 90% average modulation depth in a certain band.…”