High-efficiency broadband and multiband cross-polarization conversion using chiral metamaterial

Metamaterials with tailored electromagnetic properties present incomparable advantages in manipulation and control of electromagnetic polarization states. Here, we report a unique chiral metamaterial (CMM) composed of three layers of metasurfaces. Taking advantage of the Fabry-Pérot-like interference effect, the suggested CMM is capable of achieving high-efficiency broadband or multiband cross-polarization conversion for different linearly polarized incident waves, while also showing strong asymmetric transmission effect for the opposite propagation directions. With the specially designed geometry, the present CMM can even simultaneously accomplish nearly 90°-polarization rotation for both the x- and y-polarized incident waves, thereby enabling more opportunities for designing high-performance polarimetric devices.