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

Subject Areas : Journal of Optoelectronical Nanostructures

Aida Firoozi ¹ , Ahmad Mohammadi ²

1 - Department of Physics, Bushehr Branch, Persian Golf University, Bushehr, Iran
2 - Department of Physics, Bushehr Branch, Persian Golf University, Bushehr, Iran

Received: 2016-11-29 Accepted : 2017-06-10 Published : 2016-12-15

Keywords: Spontaneous emission rate enhancement, Plasmonic nanoparticles, boundary integral method,

Abstract :

Utilizing boundary integral method (BIM), we investigate molecular
spontaneous emission rate enhancement in the vicinity of plasmonic nanoparticles of
elliptical cross section. These types of nanoparticles can considerably enhance the
molecule decay rate. The spontaneous emission rate can be modified by altering the
aspect ratio of the elliptical nanoparticle, the background refractive index and
nanoparticles material. It is shown that the decay rate can be enhanced by two or three
orders of magnitude for dipole distances below 10 nanometers. The position of
enhancement peaks can be 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 it with analytical
result. Then the effect of various parameters, including aspect ratio and material of
nanoparticle and the background refractive index, on the decay rate is investigated.

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