Broadband Tunable Terahertz Polarization Converter based on Graphene-shaped Metasurfaces

TL;DR

This paper presents a broadband, tunable terahertz polarization converter using graphene metasurfaces, achieving high conversion efficiency over a wide frequency range and insensitivity to incident angles.

Contribution

It introduces a novel graphene-shaped metasurface design for tunable polarization conversion in the terahertz band with high efficiency and angular insensitivity.

Findings

Polarization conversion ratio exceeds 0.85 from 4.86 to 8.42 THz

Fractional bandwidth of 54% in the THz range

Insensitive to incident angles up to 40 degrees

Abstract

In this paper, a broadband tunable polarization converter based on graphene metasurfaces is proposed. This polarization converter works in the terahertz (THz) frequency region, using the advantage of graphene characteristics to have a tunable frequency response. The designed graphene-shaped periodic structure on top of the substrate is utilized to convert the incident wave polarization to the desired target in a flexible operational band in the THz frequencies. The polarization conversion ratio is more than 0.85 in a wide range of frequencies in the THz band from 4.86 to 8.42 THz (the fractional bandwidth is 54%). The proposed polarization converter is insensitive to the angle of the incident wave up to 40{\deg}. Using graphene provides a tunable frequency response without changing the geometry of the designed structure.