Abstract
In this paper, the method for THz radiation modulation based on the semiconductor–metal phase transition in vanadium dioxide (VO \({}_{2}\) ) was explored. Thermal heating of a VO \({}_{2}\) film on the silicon substrate above the metallic-state temperature resulted in the \({\sim}80\%\) reduction of THz radiation transmission. For two-electrode VO \({}_{2}\) film structures with millimeter-sized interelectrode gap, heating the film by means of electric current leads to the \({\sim}42\%\) transmission reduction only. At the same time, due to the heating of the VO \({}_{2}\) film substrate, a slow (seconds-running) cooling process and the film reverse transition to the semiconductor state occur. To increase the modulation frequency up to hundreds of kHz, it is proposed to create a structured system of separated micron-sized VO \({}_{2}\) -elements instead of a continuous film, which allows for much faster cooling such elements, which was confirmed experimentally.
