  The mechanisms of coupling between the lattice modes of a two-dimensional
(2D) array consisting of Al nanoparticles and the localized modes of individual
Al nanoparticles have been studied in detail. The results have been obtained
employing the finite-difference time-domain method (FDTD) and the generalized
Mie theory. It was shown that interactions of single particles with 2D lattice
modes significantly change the extinction spectra depending on the particle
radius and the lattice period. The Rayleigh anomalies of higher orders
contribute to formation of hybrid modes resulting in increase of the extinction
efficiency in short wavelength range of the spectrum. It is shown that high
intensity magnetic modes are excited in aluminum nanoparticles arrays. The
patterns of spatial electromagnetic field distribution at the frequencies of
hybrid modes have been studied. We note that comprehensive understanding the
mode coupling mechanisms in arrays paves the way for engineering different
types of modern photonic devices with controllable optical properties.
