Abstract:As a high-quality optoelectronic material, vanadium dioxide(VO2) has drawn much attention over the past years, and it shows great potential for various applications such as information storage device, optical modulator, energy-saving, infrared detector, etc. In this work, nanocrystalline VO2 thin films are prepared by reactive direct current magnetron sputtering and in-situ oxidation annealing, and the microstructures and optical properties of films are investigated. In order to study the switching characteristic of VO2 thin film to 2.52 THz radiation under varied temperature conditions, the corresponding testing system is established. The results show that the VO2 thin film is polycrystalline, exhibiting obvious modulation effect on the terahertz wave at 2.52 THz, which makes VO2 thin film a promising functional material for the terahertz switching/modulation devices.