Near-field and polarization control at terahertz with a 2D MXene/VO2 phase change metasurface Academic Article uri icon

abstract

  • Near-field direction control of terahertz metasurface provides a new paradigm in photonic devices for terahertz (THz) communications. The control of near-field patterns and polarization states is the major challenge for THz metasurface devices. In this work, the hybrid MXene (Ti3C2Tx)/ vanadium dioxide (VO2) metasurface structure is explored for the tuning of transmission amplitude modulation, polarization control, and near-field pattern switching. The hybrid metasurface device is comprised of Ti3C2Tx/VO2 hexagon resonators arranged in a periodic array having silicon (Si) as a substrate with a thin silicon dioxide (SiO2) layer. The response of Ti3C2Tx/VO2 hybrid structure has been investigated under the influence of gate biasing and different optical pump intensities. The enhanced bandwidth tuning has been realized under the polarization and phase control. The rise of MXene conductivity with increasing gate bias is also investigated for transmission tuning. The transition of VO2 from an insulator to a conductor is specifically induced by an increase in optical pump intensity, with 95% of the transmission achieved at the 1-4 THz range. Furthermore, π/2 rotation of near-field is realized with a change in near-field pattern symmetry at various planes. VO2 phase shifting, switch the near-field dipolar pattern from the z-axis to the x-axis into a twisted Gaussian pattern, when TMyx (p-polarized) incidence source is used. The low-cost MXene material can serve as a promising material for terahertz devices.

publication date

  • 2025

start page

  • 198

volume

  • 4

issue

  • 2