Multiple electromagnetically induced transparency-like effects of a metal nanostructure induced by a graphene grating deposited on a gallium oxide substrate.

Abstract

The electromagnetically induced transparency (EIT)-like effect can be generated in the metamaterial system, but most metamaterial systems are composed of complex and elaborated components (nanostructures) that cannot be removed or replaced easily. In this paper, a graphene grating is used to interact with random metal nanostructures (i.e., individual and connecting nanostructures) to induce the EIT-like effect through two destructive interference excitation pathways. Except for the new induced EIT-like mode, the overall original optical patterns (the shape and intensity of the transmission spectrum) remain unchanged as compared with the single metal nanostructure. Furthermore, due to the optical properties of graphene, the induced EIT-like effect was blueshifted as the Fermi energy of graphene increased. By depositing the graphene grating and the metal nanostructures on a gallium oxide substrate, the EIT-like effect was redshifted as the temperature of the environment increased. Through this study, the EIT-like effect induced by the graphene grating with a random metal nanostructure system was demonstrated by using a simple geometric system; further, the mechanism is easy and can be introduced to many different metamaterial systems to generate the EIT-like effect without changing other optical properties of the original metamaterial system. As such, this opens the door to broader applications for optical communication networks.