A Muti-band Polarizataion Convertor With Dual Functionalities Based on a Asymmetric Cruciform Shaped Metasurface at Terahertz Frequency

Abstract

Abstract In this paper, a terahertz wave polarization converter is proposed as the metasurface. Resonators in a cross form make up the unit cell. The suggested metasurface performs as a linear to cross polarization converter with a polarization conversion ratio more than 95% and ellipticity zero for the reflected wave at the frequency bands 0.8726 ~ 0.8924 THz, 1.1075 ~ 1.1147 THz, and 1.2614 ~ 1.2731 THz. It also demonstrates the traits of a linear to circular polarization converter over frequency ranges of 0.516 ~ 0.862 THz, 0.947 ~ 0.986 THz, and 1.986 ~ 1.203 THz. For these three frequency ranges, the reflected wave's ellipticity is between − 1 and + 1. Up to 500 degrees of oblique incidence, the suggested metasurface is angularly stable. Surface current distribution and multiple interference theory are used to investigate the fundamental mechanism of polarization conversion. The converter has potential uses in terahertz detection, assessing the absorption spectrum of complex biological samples, and satellite communication due to its straightforward structure, angular stability, and dual functionality.