The modeling of surface plasmon polaritons excitation in a rectangular gold-based nanoresonator

This paper considers the modeling of surface plasmon polaritons excitation in a limited nanostructure on the basis of a two-dimensional area discrete model, the area interacts with the oscillator. The nanostructure is a rectangle defined on the metal surface at the interface of the gold–silicon oxide, the surface plasmon–polaritons are excited by an electromagnetic radiation point source located above the metal surface. The dynamics of radiation point source is described by a discrete version of the Van der Pol equation with a small nonlinearity of the source parameters. The parameters of the gold-silicon oxide structure (the wave phase speed, the radiation source frequency, the characteristic time in the system, etc.) will be received from the dispersion relation for surface plasmon–polaritons at a single metal–dielectric interface. The distributions of the wave field in the structure will be analyzed at different positions of the point oscillator and different coupling coefficients of the wave field with the oscillators. The resonant wave field mode composition at different positions of the point oscillator and different coupling coefficients will be found using the two-dimensional Fourier transform of the wave field, the time evolution of excited modes of the wave field amplitudes will be also analyzed. In conclusion, the paper gives applicability limits of the considered model for studying the surface plasmon polaritons excitation in a limited nanostructure.