STUDY OF ELECTROMAGNETIC COUPLING BETWEEN GRAPHENE AND LOCALIZED SURFACE PLASMON RESONANCE

Abstract

Localized surface plasmon resonance (LSPs) excited in metal nanoparticles has been utilized in various graphene based optoelectronic applications. However, the electromagnetic coupling between LSPs and graphene has not been studied systematically. In this thesis, the coupling by varying the spacer layer thickness between nanoparticles and graphene has been investigated. Results show that the resonance wavelength of LSPs can be tuned by adjusting the electromagnetic coupling strength between graphene and nanoparticles. Theoretical analysis based on a dipole approximation has been carried out. The coupling strength is also examined using the plasmon ruler equation. In addition, the electromagnetic enhancement characteristics for surface enhanced Raman spectroscopy of graphene have been studied. Both theoretical and experimental results show that enhancement factor is modulated because of electromagnetic coupling between graphene and nanoparticles. The optical characteristics of patterned graphene nanomesh and metal nanoparticles are studied as well in order to study the electromagnetic coupling between them.