Electrically Tunable Graphene Metasurface for Multiband Superabsorption and Terahertz Sensing

We propose a plasmon induced graphene metasurface for terahertz absorption and sensing. The modelling and numerical analysis are carried out using CST microwave studio whereas a genetic algorithm (GA) is used to optimize the parameters. The metasurface is tunable by means of changing the graphene applied gate voltage. By tuning and exploiting its properties we demonstrate pa multiband absorption within the frequency of 0.1-2.25 THz with a graphene chemical potential (mu(c)) of 0.2 eV. Further results show that, the superabsorber can be used as a sensor having maximum perfect absorption of 99.7%. The metasurface is polarization insensitive and can perform well for wide incident angles for both transverse electric and transverse magnetic field.