Broadband perfect polarization conversion metasurfaces

We propose a broadband perfect polarization conversion metasurface composed of copper sheet-backed asymmetric double spilt ring resonator (DSRR). The broadband perfect polarization convertibility results from metallic ground and multiple plasmon resonances of the DSRR. Physics of plasmon resonances are governed by the electric and magnetic resonances. Both the simulation and measured results show that the polarization conversion ratio (PCR) is higher than 99% for both x- and y-polarized normally incident EM waves and the fractional bandwidth is about 34.5%. The metasurface possesses the merits of high PCR and broad bandwidth, and thus has great application values in novel polarization-control devices.