Wide-angle chiral polarization converter for reflection and transmission modes

Metamaterials provide high degrees of freedom for the design and manipulation of electromagnetic (EM) waves such as polarization conversion due to their unique controllable capabilities. In this paper, we propose a tunable wide-angle chiral metamaterial incorporating with vanadium dioxide (VO2), which can realize different operating modes and polarization conversions. When working in reflection mode, it can achieve circular polarization conversion at 3.35 THz and 3.07 THz for two different incident directions, the corresponding polarization conversion rate (PCR) can reach 93.5% and 97.1%, respectively. When operating in transmission mode, the incident x (y)-polarized waves can be converted to the orthogonal counterparts in the range of 2.24–2.88 THz, the asymmetric transmission (AT) parameter is over 0.6. Moreover, the good PCR and large AT effect can still be maintained in wide angle range. The proposed structure has potential application prospects in controllable switch, isolation device, communication system and so on.