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

Utilizing Boundary Integral Method (BIM), we investigate the spontaneous emission enhancement rate in the vicinity of plasmonic nanoparticles of elliptical cross section. These types of nanoparticles can considerably enhance molecules decay rate. One can easily adjust the spontaneous emission rate of the elliptical nanoparticle by altering the aspect ratio and the background refractive index. It is shown that the decay rate can be enhanced by two or three orders of magnitude for dipole distances below 10 nanometers. Also, the position of enhancement peaks is adjusted in the investigated spectral range (400-1000 nm) by changing the aspect ratio of the nanoparticle or the refractive index of background medium and nanoparticles material. To validate our result, we use BIM method to calculate light scattering by a circular gold nanowire and compare the results with those obtained from Mie theory. The results show a good agreement. Moreover, the BIM method is considerably faster that domain methods.