704 research outputs found
Magnetic dipole radiation tailored by substrates: numerical investigation
Nanoparticles of high refractive index materials can possess strong magnetic
polarizabilities and give rise to artificial magnetism in the optical spectral
range. While the response of individual dielectric or metal spherical particles
can be described analytically via multipole decomposition in the Mie series,
the influence of substrates, in many cases present in experimental
observations, requires different approaches. Here, the comprehensive numerical
studies of the influence of a substrate on the spectral response of high- index
dielectric nanoparticles were performed. In particular, glass, perfect electric
conductor, gold, and hyperbolic metamaterial substrates were investigated.
Optical properties of nanoparticles were characterized via scattering
cross-section spectra, electric field profiles, and induced electric and
magnetic moments. The presence of substrates was shown to introduce significant
impact on particle's magnetic resonances and resonant scattering
cross-sections. Variation of substrate material provides an additional degree
of freedom in tailoring properties of emission of magnetic multipoles,
important in many applications.Comment: 10 page, 28 figure
Subwavelength modulational instability and plasmon oscillons in nanoparticle arrays
We study modulational instability in nonlinear arrays of subwavelength
metallic nanoparticles, and analyze numerically nonlinear scenarios of the
instability development. We demonstrate that modulational instability can lead
to the formation of regular periodic or quasi-periodic modulations of the
polarization. We reveal that such nonlinear nanoparticle arrays can support
long-lived standing and moving oscillating nonlinear localized modes - plasmon
oscillons.Comment: 5 pages, 5 figures, published in Physical Review Letter
Subwavelength plasmonic kinks in arrays of metallic nanoparticles
We analyze nonlinear effects in optically driven arrays of nonlinear metallic
nanoparticles. We demonstrate that such plasmonic systems are characterized by
a bistable response, and they can support the propagation of dissipative
switching waves (or plasmonic kinks) connecting the states with different
polarization. We study numerically the properties of such plasmonic kinks which
are characterized by a subwavelength extent and a tunable velocity.Comment: 6 pages, 5 figures, published in Opt. Expres
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