  We consider scattering of surface plasmon polaritons (SPPs) and light by
individual high-refractive-index dielectric nanoparticles (NPs) located on a
metal (gold) substrate and supporting electric and magnetic dipole resonances
in the visible spectral range. Numerical calculations are carried out by making
use of the discrete dipole approximation including the multipole decomposition
procedure. Extinction and scattering cross section spectra of spheroid silicon
NPs in visible and near-infrared are presented and discussed. The roles of the
in-plane and out-of-plane components of electric and magnetic dipoles in the
scattering processes are clarified and demonstrated. It is revealed that, owing
to the NP interaction with electromagnetic fields reflected from the substrate
(that leads to bianisotropy), the in-plane electric and magnetic dipoles can
resonantly be excited at the same wavelength. Due to this effect, the resonant
unidirectional (forward) and elastic (in-plane) scattering of SPPs by oblate
spheroid NPs can be realized within a narrow spectral range. In the case of
normal light incidence, the bianisotropy effect can provide significant
suppression of the SPP excitation because of the destructive interference
between the SPP waves generated by induced electric and magnetic dipole
moments. The results obtained open new possibilities for the Development of
SPP-based photonic components and metasurfaces, whose operation involves
resonant excitations of dielectric NPs.
