A tunable reflective polarization converter based on hybrid metamaterial

Abstract

A hybrid metamaterial converter based on a hybrid layer, a gold (Au) film and a dielectric substrate is proposed to realize linear and circular polarization conversions in the terahertz (THz) band. The hybrid layer is composed of a vanadium dioxide (VO2) plane and I-shaped resonators. The polarization conversion ratio (PCR) above 90% is achieved in a broad band range from 2.10 to 5.03 THz under both linearly and circularly polarized waves. And, the PCR is up to near unity around the resonant frequency. Meanwhile, the metamaterial convertor is sensitive to the incident angles. Moreover, a controlled modulation characteristic can be realized by the proposed polarization converter. In addition, the physical mechanism of the polarization conversion is analyzed by the distributions of surface currents. These features pave a novel way for the broad band polarization converter and hold application in the area of sensing, THz communication and tunable polarizers.