▎ 摘 要
Graphene-based polygonal optical antenna is designed and analyzed for enhanced bio-molecular detection. Absorption cross section and electric field enhancement factors of three polygonal structures are compared. The hexagonal structure has exhibited 50% better absorption cross section as compared to that of other structures. Variation of electric field enhancement with frequency is studied and observed on the basis of mode theory. The hexagonal structure has shown an increment in electric field enhancement by 16.60 and 24.11% in contrast to the circular and rhombic structures respectively. Approximation of the hexagonal antenna structure using lumped equivalent circuit is done for better intuition. The vitality of the hexagonal optical antenna for bio-molecular detection is discussed with the aid of chemical potential tuning.