Polarization conversion metasurface in terahertz region*

Polarization conversion is a very important electromagnetic wave manipulation method. In this paper, we investigate a high-efficiency linear-to-circular polarization and cross-polarization converter by utilizing coding metasurface. The coding particle consists of top layer metal pattern and bottom metal plate sandwiched with square F4B dielectric, which can manipulate the linear-to-circular polarization and cross-polarization converter of the reflected wave simultaneously. In the terahertz frequency range of 1.0 THz–2.0 THz, the reflection magnitudes reach approximately 90% and the axial ratio is less than 3 dB. The proposed polarization converter may lead to advances in a variety of applications such as security, microscopy, information processing, stealth technology, and data storage.