Multifunctional metamaterial for realizing absorption and polarization conversion on the basis of vanadium dioxide

Abstract

In this paper, the phase change material vanadium dioxide (VO2) is introduced to propose a tunable multifunctional metamaterial device, which treats the phase change property of VO2 to realize the switching of absorption, linear to linear (LTL) polarization conversion, and linear to circular (LTC) polarization conversion functions. When VO2 is in metal state, the structure can be applied as an absorber to achieve the wide-band and narrow-band absorption. In the broad frequency area of 2.007–2.803 THz, the absorption is above 90%. And the narrow-band absorption near the center frequency 1.0126 THz reaches 95.04%. When VO2 is in the insulator state, the studied device can be treated as a polarization conversion device to achieve LTL and LTC polarization conversion. In the low frequency range, the device achieves LTL with polarization conversion efficiency (PCR) above 90% when the frequency is between 0.439 and 0.907 THz. In the high frequency range, the structure can be treated as the LTC polarization converter to achieve right-hand circular polarization, left-hand circular polarization (LHCP), and LHCP in the ranges of 2.317–2.329 THz, 2.356–2.531 THz and 2.582–2.633 THz, respectively. In addition, the ellipticity is above 0.9. Finally, the effects of geometric parameters, angle of incidence and polarization angle on the absorption and PCR are also discussed. The proposed structure has great potential for advanced technologies such as imaging, sensing, communication, and stealth.