A Switchable Terahertz Wave Modulator Based on VO2

In this paper, we propose a dynamic THz modulator combining metamaterial with vanadium dioxide (VO2). The phase transformation characteristics of VO2 enable the device to realize the reconstruction of transmission and reflection spatial morphology in two frequency bands, and both have a high polarization conversion efficiency of orthogonal polarization. At the same time, both the phase gradient distribution of transmission and reflection state include 360 degrees by changing the structural parameters of the top structure. Based on this unit structure, we design a switchable THz beam modulator based on VO2, which can achieve 54 degrees deflection of the reflective beam at 140GHz when VO2 is in a metallic state and 32 degrees refraction of the transmitted beam at 220GHz when VO2 is in the dielectric state.