Excitation of linear and nonlinear cavity modes upon interaction of femtosecond pulses with arrays of metallic nanowires

We investigate linear and nonlinear effects induced by the scattering of femtosecond optical pulses by cavity-shaped two-dimensional distributions of metallic cylinders. In particular, by employing a numerical method based on the multiple scattering matrix algorithm, we demonstrate that, at both the fundamental frequency and the second harmonic, such arrays of metallic nanowires support localized (cavity) surface plasmon–polariton modes with characteristic lifetime ranging from a few tens of femtoseconds to more than a hundred of femtoseconds.