Optical Activity in Graphene Metasurface for Futuristic Modulation and Sensing Applications

The 6G communication system is anticipated to expand to THz frequency band in order to support higher data rate embedded with wireless sensors for public health monitoring. This paper explores the graphene metasurface reflector for the control of optical activity via surface plasmon currents for both the forward and inverse problems. The ultrathin graphene chiral metasurfaces supports strong optical activity at THz frequencies. The optical activity originates from chiral metasurface due to asymmetric surface plasmon currents induced by incident waves. By utilizing tunable graphene conductivity, it is demonstrated that linearly polarized incident light can switch to either linear, circular, or elliptical polarization states for reflected fields. Furthermore, since the THz spectrum is well suited for detection bio-molecular binding events. The interaction of surface plasmons with bio-molecules enables the identification of bio-molecules like viruses by observing their distinct polarization states in the reflected fields. The designed graphene metasurface reflector allows next generation telecommunication and sensing technologies on a single platform.