| In recent years,controlling molecular fluorescence via surface plasmon of metal nanostructures has attracted broad attention with potential applications in sensing,integrated photonics and solar energy conversion.In this paper,we present a metal-dielectric core-shell optical antenna and investigate its enhancement of molecular fluorescence.This paper consists of following parts:1.Introducing main concepts and features of surface plasmon,then introducing principles and relevant effects of coupling between plamonic optical antenna and fluorescent molecule.2.We theoretically analyzed enhancement of molecular fluorescence via metal-dielectric core-shell optical antenna by using COMSOL.By comparing with traditional metal nanoparticle antenna,we find that it takes more advantage of the enhanced electromagnetic fields which caused by surface plasmon.Meanwhile,the quantum yield of fluorescent molecule remains high.Hence,it can further enhance the molecular fluorescence.We also find that the enhancement is quite related to structure parameters,it can be optimized to achieve maximum.3.We prepared metal-dielectric core-shell optical antenna samples via a series of fabrication technology and processes.Adjusting structure parameters by varying processes.We use COMSOL to simulate transmission spectrum and to obtain the structure parameters in experiment.4.We measured fluorescence spectrum of samples and calculated enhancement factors.We build the connection between structure parameters and enhancement factors and analyze their relations.We find it was agreed with our theoretic simulation. |
