Theoretical Investigation of a Vanadium Dioxide Based Terahertz Metasurface with Maximum Overlap Band- width for Polarization Conversion and Absorption

Abstract

In this paper, a wideband dual-functional terahertz (THz) metasurface based on VO 2 is proposed. By varying the temperature of VO 2 , the device can switch between wideband reective cross-polarization converter and wideband perfect absorber applications. The functionality of the polarization converter is obtained by using a double-headed arrow resonator, and the perfect absorption characteristics are achieved by using a quad-square split-ring resonator. The structure results in a high polarization conversion ratio of > 95% over the operating frequency from 1.09 -5.59 THz. This wideband response is achieved by superposition of four distinctly spaced resonant frequencies: 1.68 THz, 2.69 THz, 4.18 THz, and 4.97 THz. On the other hand, the perfect absorber provides high absorption of > 90% over a wideband frequency range from 2.15 -6.64 THz with two resonant frequencies at 2.62 THz and 5.91 THz. The structure provides a maximum overlap bandwidth of 61.98 % with high angular stability of 60 • for both functionalities. The proposed TeraHertz functional device has potential applications in sensing and communications.