High-Efficiency and Tunable Terahertz Linear-to-Circular Polarization Converters Based on All-Dielectric Metasurfaces
Yanzhao Hou, Chao Zhang, Chengrui Wang
Abstract
Terahertz polarization converter has drawn great attention for its properties of wavefront control in recent years. However, the low transmission efficiency of these converters remains a major obstruction to be resolved. A promising solution is the all-dielectric metasurface, based on which, this study proposes a high-efficiency transmissive terahertz linear-to-circular polarization converter. The simulations show the transmission efficiency of the converter is beyond 88% with an ellipticity < −0.8 from 0.555 to 0.737 THz, and the maximum efficiency even reaches 100% at 0.660 THz. Furthermore, the converter can also be actively manipulated by combining with dynamic material. The frequency sensitivity is 98 GHz/100K, and the modulation depth of ellipticity at 0.725 THz exceeds 76%. The excellent performances of these converters offer more potentials for terahertz devices.