Wide Band Polarization Converter Graphene Metasurface for Mid-Infrared Band

Wide band, insensitive incidence angle graphene metasurface for polarization conversion is introduced in this work. A high Polarization Conversion Ratio (PCR) is verified in Mid-Infrared band by using a graphene as an upper conductor for metasurface. The metasurface construction is composed of a single layer of graphene, which has a half ring slots with rectangular slot connecting between them while the whole shape is rotated with 45 degrees. Silicon dioxide substrate is used with a metal backed ground. The simulation results of the proposed metasurface indicate that a linearly polarized incident wave is converted to a circular polarized one over more than one THz along the Mid-Infrared frequency band. PCR has a maximum value of approximately 98% at 1.45 THz. The polarization conversion ratio is studied for different angles of incidence, with stable value for a wide range of incident angles.