Broadband linear polarizer with high-efficient asymmetric transmission using a chiral metasurface

Asymmetric transmission, as a peculiar electromagnetic phenomenon in electromagnetic wave transmission, has been attracted extensive attention because of its important applications in polarization control and photodiode. This wok proposes a broadband linear polarizer based on a chiral metasurface with high-efficient asymmetric transmission performance. The designed polarizer consists of double arc-shaped structures interconnected via two circular cavities, which has the capacity to achieve broadband asymmetric transmission effect at 4-15 GHz for linear polarization conversion. The polarization conversion ratio exceeds 90% at 6.8-11.9 GHz and has a relative bandwidth of 54.5%. The asymmetric transmission parameter is above 0.59 in the frequency band 7.4-11.6 GHz. The microwave experiment results show a great consistency between simulation and experiment. The physical mechanism of polarization conversion and asymmetric transmission are further studied by introducing the surface current and electric field distributions. The designed polarizer has the superiority of uncomplicated structure and easy control, and can be extended to terahertz and optical regime. We believe that it has a broad application prospect in the field of chiral metamaterial structure design.