Upconversion fluorescence Radiation Engineering on Nanopatterned Plasmonic Metasurface
Huijun, Wu1*, Ming Lun, Tseng1, Wei Yi, Tsai1, Ting Yu, Chen1, Din Ping, Tsai1
1Department of Physics, National Taiwan University, Taipei, Taiwan
* presenting author:Huijun Wu, email:wuhuijun@ntu.edu.tw
Upconversion fluorescence has attracted a lot of interest because of its greatly potential application in various fields, such as photonic crystal lasers, material science, biological therapy, and so on. Meanwhile, plasmonic materials have been widely used to control the radiation efficiency and relaxation process of the upcovnersion nanocrystals. In a multi-layered plamsonic metasurface with anti-symmetric split ring resonator structure, both the electric and magnetic modes could be generated simultaneously, which provides two different channels for the engineering of upconversion fluorescence. Here we demonstrated that the upconversion fluorescence intensity and lifetime could be engineered by tuning the overlap between the electric and magnetic resonance frequency of the metasurface and the absorption/emission band of the upcovnersion nanocrystals. We found that over ten times enhancement of the fluorescence intensity could be achieved when the electric resonance frequency of the metasurface matches with the absorption band of the upconversion nanocrystals, while the magnetic mode overlaps with its emission band. The detailed results and mechanism will be discussed.

Keywords: Upconversion Fluorescence, Plasmonic Metamaterials