Application of the boundary-element method to the interaction of light with single and coupled metallic nanoparticles

Abstract

The boundary-element method is applied to the interaction of light with resonant metallic nanoparticles. At a certain wavelength, excitation of a surface plasmon takes place, which leads to a resonantly enhanced near-field amplitude and a large scattering cross section. The resonance wavelength for different scatterer geometries is determined. Alteration of the scattering properties in the presence of other metallic nanoparticles is discussed. To treat this problem, a novel formulation of the boundary-element method is presented that solves the interaction problem for all the coupled particles.

Magnetic noise around metallic microstructures

“…We reformulate the wave equation in terms of boundary integral equations. This has been described elsewhere 12,13,14,15 , and we quote only the basic formulas here. Our unknowns are the nonzero component A of the vector potential and its normal derivative F = ∂A/∂n ≡ n · ∇A on the object surface S, where n is the outward unit normal to S. Both quantities are continuous (actually, F is equal to the tangential magnetic field) and can be found from the system of integral equations…”

Analyzing the scattering properties of coupled metallic nanoparticles

“…Among others, the discrete-dipole approximation, 6 the Green's dyadic function, 7 and the generalized multiplemultipole method 8 have been successfully applied. We will use the boundary element method 9 for the numerical treatment of resonant metallic nanoparticles, and we will concentrate on the influence of the plasmon response where the system consists of two or more scatterers with small separation distances. This method is chosen because it formulates the question as a surface problem, which reduces the computational effort in comparison with other methods.…”

Rigorous diffraction theory applied to the analysis of the optical force on elliptical nano- and micro-cylinders

“…Excellent agreement was found for both polarizations for the force acting on a 10 nm glass cylinder. In addition we compared results for a dielectric cylinder with different radii calculated with Lorenz-Mie theory [33], with the MMP and also with the boundary element method (BEM) [24,25]. In all cases the results agree very well.…”