Reflective triple-band line-to-circular polarization conversion based on diamond-shaped graphene metasurface

In this paper, we present a triple-band line-to-circular (LTC) polarization converter based on graphene-integrated metasurface, which is composed of graphene diamond patches. Finite element method results show that there are two LTC polarizations bands with 0.36 and 0.44 THz 1 dB bandwidth, which can achieve line-to-right-circular (LTRC) conversion; there is one LTC polarization band with 2.23 THz 1 dB bandwidth, which can achieve line-to-left-circular (LTLC) conversion. We found two graphene surface plasmons (GSPs) modes were excited, which were responsible for the three LTC bands. The influences of axis lengths on the performances of LTC bands are investigated. Besides, the triple-band polarization converter can be realized when the incidence angle ranges from 0 degrees to 30 degrees and polarization angle ranges from 0 degrees to 9 degrees. Also, the frequency shifts of three LTC bands are also achieved by changing Fermi level of graphene. It is believed that our proposed polarizer can be widely used for multiband and tunable polarization conversion.

Automated summary

This paper presents a triple-band line-to-circular (LTC) polarization converter based on a graphene-integrated metasurface, with two LTC polarization bands at 0.36 and 0.44 THz and one at 2.23 THz. Two graphene surface plasmons (GSPs) modes were excited, responsible for the three LTC bands. The triple-band polarization converter can be realized within incidence angles ranging from 0 to 30 degrees and polarization angles ranging from 0 to 9 degrees.