Ultra-Broadband Reflective Polarization Converter Using Ring-Chain Metamaterial

In this work, a novel bi-layered metamaterial structure composed of a ring-chain structure and metal sheet-backed is proposed, which can realize ultra-broadband reflected polarization conversion in the near-infrared spectral region. Numerical results reveal that the structure possesses the ability to convert x-polarized and y-polarized waves to their orthogonal direction in frequency range from 109.5 to 338.8 THz, and the polarization conversion ratio can reach 99%. Based oncurrent density, the physical mechanism of polarization conversion is investigated at the resonant frequency. What is more, the resonant frequencies can be tunable with the change of the structure parameters. In addition, the polarization conversion of this structure is sensitive to the incident angle.