Optical tunable terahertz metasurface based on the carbon nanotubes film

In this paper, an optical tunable terahertz metasurface based on the carbon nanotube (CNT) film has been designed and fabricated, combining the resonant characteristics of the CNT-based metasurface with the optically tunable properties of the silicon substrate. The transmission properties and optical modulation mechanism of the metasurface were investigated in detail by experiment and simulation. The results show that an obvious transmission peak is located at 0.33 THz when there is no pump beam, but as the pump power increases from 0 to 900 mW, the transmission amplitude decreases, and the modulation depth increases, the modulation depth can achieve 66.0%. The optical tunable response of the CNT metasurface has potential applications in dynamic THz functional devices. The materials and device designed strategies also provide important insights for emerging CNT-based THz devices.