RESUMEN
This paper presents a discontinuous Galerkin (DG) integral equation (IE) method for the electromagnetic analysis of arbitrarily-shaped plasmonic assemblies. The use of nonconformal meshes provides improved flexibility for CAD prototyping and tessellation of the input geometry. The formulation can readily address nonconformal multi-material junctions (where three or more material regions meet), allowing to set very different mesh sizes depending on the material properties of the different subsystems. It also enables the use of h-refinement techniques to improve accuracy without burdening the computational cost. The continuity of the equivalent electric and magnetic surface currents across the junction contours is enforced by a combination of boundary conditions and local, weakly imposed, interior penalties within the junction regions. A comprehensive study is made to compare the performance of different IE-DG alternatives applied to plasmonics. The numerical experiments conducted validate the accuracy and versatility of this formulation for the resolution of complex nanoparticle assemblies.
RESUMEN
Optical nanocouplers matching a fiber microwaveguide to a plasmonic nanowaveguide are essential components for practical applications of nanophotonic systems. In this Letter we design an efficient nanocoupler using a directive nanoantenna in the visible range λ0=0.65 µm. The antenna has been optimized both in the configuration and in the matching element in order to achieve the maximum coupling efficiency (CE). In spite of the reduced size of the nanoantenna in comparison with the impinging fiber spot size (due to the localized plasmonic resonance at such high frequency), we have shown that a good efficiency can be achieved, improving the CE by a factor of 10 with respect to the nondirective antenna nanocouplers.
RESUMEN
The performance of most widespread surface integral equation (SIE) formulations with the method of moments (MoM) are studied in the context of plasmonic materials. Although not yet widespread in optics, SIE-MoM approaches bring important advantages for the rigorous analysis of penetrable plasmonic bodies. Criteria such as accuracy in near and far field calculations, iterative convergence and reliability are addressed to assess the suitability of these formulations in the field of plasmonics.
RESUMEN
A surface integral equation together with the multilevel fast multipole algorithm is successfully applied to fast and accurate resolution of plasmonic problems involving a large number of unknowns. The absorption, scattering, and extinction efficiencies of several plasmonic gold spheres of increasing size are efficiently obtained solving the electric and magnetic current combined-field integral equation. The numerical predictions are compared with reference analytic results to demonstrate the accuracy, suitability, and capabilities of this approach when dealing with large-scale plasmonic problems.