Converting State of Polarization With a Miniaturized Metasurface Device

We have designed and experimentally demonstrated a radial and azimuthal polarization converter, which is a plasmonic metasurface with a radius of not more than $5~\mu \text{m}$ . The metasurface is composed of an array of metal–insulator–metal gap plasmon resonators, each of which reflects the incident local electric field to a predesignated polarization angle. The simulation results show effective polarization conversion within a broad band from 700 to 930 nm.