Broadband High Transmittance 220 GHz Polarization Rotator with Chiral Metamaterial

In this paper a novel chiral metamaterial structure is presented for polarization rotating with polarization azimuth insensitive characteristic at terahertz range. This structure is composed of two dielectric substrates and three metallic layers with C
₄
symmetry. High transmittance and high polarization conversion rate are achieved simultaneously within 208-248GHz. Polarization rotation angle can be tuned when the loading length of coupling layer is changed. To verify the inherent mechanism, the current distribution of the unit cell is studied.