Photoinduced active terahertz metamaterials with nanostructured vanadium dioxide film deposited by sol-gel method

Applying the photoexcitation characteristics of vanadium dioxide (VO2), a dynamic resonant terahertz (THz) functional device with the combination of VO2 film and dual-resonance metamaterial was suggested to realize the ultrafast external spatial THz wave active manipulation. The designed metamaterial realizes a pass band at 0.28–0.36 THz between the dual-resonant frequencies, and the VO2 film is applied to control the transmittance of the spatial THz wave. More than an 80% modulation depth has been observed in the statics experiment, and the dynamic experimental results illustrate that this active metamaterial realizes up to a 1 MHz amplitude modulation signal loaded on a 0.34 THz carrier wave without any low noise amplified devices. The electromagnetic properties and photoinduced dynamic characteristics of this structure may have many potential applications in THz functional components, including modulators, intelligent switches, and sensors.