Investigating Molecular Spontaneous Emission Rate Enhancement Close to Elliptical Nanoparticles by Boundary Integral Method

Utilizing boundary integral method (BIM), we investigate molecularspontaneous emission rate enhancement in the vicinity of plasmonic nanoparticles ofelliptical cross section. These types of nanoparticles can considerably enhance themolecule decay rate. The spontaneous emission rate can be modified by altering theaspect ratio of the elliptical nanoparticle, the background refractive index andnanoparticles material. It is shown that the decay rate can be enhanced by two or threeorders of magnitude for dipole distances below ۱۰ nanometers. The position ofenhancement peaks can be adjusted in the investigated spectral range (۴۰۰-۱۰۰۰ nm) bychanging the aspect ratio of the nanoparticle or the refractive index of backgroundmedium and nanoparticles material. To validate our result, we use BIM method tocalculate light scattering by a circular gold nanowire and compare it with analyticalresult. Then the effect of various parameters, including aspect ratio and material ofnanoparticle and the background refractive index, on the decay rate is investigated.

Keywords:

Spontaneous emission rate enhancement , Plasmonic nanoparticles , boundary integral method