Design of an efficient single photon source from a metallic nanorod dimer: a quasi-normal mode finite-difference time-domain approach.

We describe how the finite-difference time-domain (FDTD) technique can be used to compute the quasi-normal mode (QNM) for metallic nano-resonators, which is important for describing and understanding light-matter interactions in nanoplasmonics. We use the QNM to model the enhanced spontaneous emission rate for dipole emitters near a gold nanorod dimer structure using a newly developed QNM expansion technique. Enhanced single photon emission factors of around 1500 and output β-factors of around 60% are found near the localized plasmon resonance.