A terahertz temperature-controlled switch based on dual-pattern structure: achieving transmission and shielding in the same frequency band

Abstract

In this research, a terahertz temperature-controlled switch (TCS) composed of VO 2 and Cu is proposed to achieve reversible state switching. When VO 2 acts as an insulating phase, the TCS is in the "on" state, exhibiting a transmittance greater than 0.8 in the 4.47-7.92 terahertz (THz) frequency range. The operating bandwidth and transmission efficiency are 3.45 THz and 90%, respectively. When VO 2 is converted to its metallic phase, the TCS goes into the "off" state, attaining an absorption exceeding 0.9 within the 3.65-7.56 THz range. It has a bandwidth of 3.91 THz. During this state, the TCS implies nearly infinite absorption in shielding efficiency, with reflection shielding surpassing 20 dB. Furthermore, the TCS has a 79% overlapping operational bandwidth between its two states. High technological tolerance in its fabrication process guarantees reliable performance at any polarization angle and within a 30° incidence angle range. Through dynamic switching within a constrained spectral range, these qualities allow the TCS to execute time-division multiplexing (TDM) of different signals in the same frequency band. As a result, the TCS offers far more opportunities for use in communication systems.