Abstract-Broadband tunable terahertz polarization converter based on a sinusoidally-slotted graphene metamaterial

Jianfeng Zhu, Shufang Li, Li Deng, Chen Zhang, Yang Yang, and Hongbo Zhu

https://www.osapublishing.org/ome/abstract.cfm?uri=ome-8-5-1164

A new wideband sinusoidally-slotted graphene-based cross-polarization converter (CPC) is proposed in this paper. The proposed polarization converter can realize a broadband terahertz polarization conversion from 1.28 to 2.13-THz with a polarization conversion ratio (PCR) of more than 0.85. Taking advantage of the gradient width modulation of the graphene-based unit structure, the continuous plasmon resonances are excited at the edges of the sinusoidal slot. Therefore, the proposed converter can achieve a broadband polarization conversion in a simplified structure. Furthermore, the polarization conversion characteristics of the CPC are insensitive to the incident angle. The PCR remains more than 0.85 with little bandwidth degradation even as the incident angle increases to as high as 50°. More importantly, the operating bandwidth and the magnitude of the PCR can be tuned easily by adjusting the chemical potential and the electron scattering times of the graphene. In a way, we believe this kind of graphene-based polarization converter can enrich the polarization conversion community for realizing broadband and tunable polarization conversion.

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