This contribution is focused on the numerical studies of resonant processes in individual
plasmonic nanostructures, with the attention particularly given to rectangular nanoparticles
and concominant localized surface plasmon resonance processes. Relevant models for
the description and anylysis of localized surface plasmon resonance are introduced, in particular: quasistatic approximation, Mie theory and in particular, a generalized (quasi)analytical approach
for treating rectangularly shaped nanostructures. The parameters influencing resonant behavior
of nanoparticles are analyzed with special interest in morphology and sensor applications.
Results acquired with Lumerical FDTD Solutions software, using finite-difference time-domain simulation method, are shown and discussed. Simulations were mostly performed for selected nanostructures composed of
finite rectangular nanowires with square cross-sections. Systematic analysis is made for single
nanowires with varying length, parallel couple of nanowires with varying gap (cut -wires) and selected
dolmen structures with varying gap between one nanowire transversely located with respect to parallel
couple of nanowires (in both in-plane and -out-of-plane arrangements). The dependence of resonant peaks of cross-section spectral behavior (absorption, scattering, extinction) and their tunability via suitable structuring and morphology changes are primarily researched. These studies are then followed with an analysis of the effect of periodic arrangements. The results can be usable with respect to possible sensor applications.
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