Investigation on Fano resonance and energy transfer of Hyper Ring–Loop nanostructure

Abstract

Fano resonance can appear in the coupling of two nanoparticles. Energy transfer through photon exchange acts as the bonding bridge in this coupling. A novel nanostructure called Nano Hyper Ring–Loop (NHR–L) is designed and reported in this paper. Through theoretical calculations, we observed plasmonic Fano resonance appeared in the coupling between Nano Hyper Ring (NHR) and the loop. Results shows that the quadrupolar mode of the NHR and dipolar mode of the loop hybridize to two bright coupling modes and a dark mode stay with different energy levels. Also, NHR and loop have different types of energy transfer relation between each other in two coupling modes. By changing the geometric shape and environmental refractive index we can modify the resonance wavelength and coupling strength simple and convenient. The investigation and obtained results are helpful for deeper understanding on the plasmon resonance coupling and offer more choice on further exploration of refractive sensing, nanosized photonic device and enhanced spectroscopy.