Enhancement Factors of Metallic Nano-coreshells on Fluorescence

Excitation stage and emission stage models for the fluorescence are used for analysis. For the excitation stage, the scatterer and the nearby molecule is irradiated by an incident plane wave. Due to the surface plasmon resonance (SPR), the Mie theory is presented for the simulation for the local electric field amplifying to pump the electrons of the molecule. After the molecule is excited, it is modeled as an electric dipole to radiate fluorescence in the emission stage. Using the method of dyadic Green’s functions, an analytic solution in series form is obtained to calculate the radiative and nonradiative decay rates of the dipole in the presence of the scatterer. According to the above results, we can even get the average enhancement facor through the principl of superposition. By this way we can explain the behavior and differences between the theory and experiment.