Finite element modeling of plasmon based single-photon sources

A finite element method (FEM) approach of calculating a single emitter coupled to plasmonic waveguides has been developed. The method consists of a 2D model and a 3D model: (I) In the 2D model, we have calculated the spontaneous emission decay rate of a single emitter into guided plasmonic modes by using the translation symmetry of the waveguides; (II) In the 3D model, we have implemented the FEM calculation to include the radiation modes and the nonradiative contributions by solving the wave equation with a harmonic source terms. The FEM approach is rather flexible, and can handle the plasmonic waveguides with different geometries, as long as only one guided plasmonic mode is predominantly excited.