title: Optical cloaking of cylindrical objects by using covers made of core-shell nanoparticles.
abstract: In this Letter, we propose an engineered design of optical cloaks based on the scattering cancellation technique and intended to reduce the observability of cylindrical objects. The cover, consisting of a periodic arrangement of core-shell nanospheres, is designed in such a way to exhibit near-zero values of the real part of the homogenized effective permittivity at optical frequencies. Full-wave numerical simulations, considering the measured data of the dielectric function of the plasmonic material composing the shell, show that the cloak is able to reduce by about 6 dB the scattering cross section of a finite-length cylinder at around 740 THz with a -3 dB fractional bandwidth of about 7%. We show also that this result is not significantly affected by the perturbation of the periodic alignment of the core-shell nanospheres, due to possible fabrication issues or to an amorphous arrangement.
authors.affiliation: Roma Tre University, Department of Applied Electronics, Via della Vasca Navale 84, 00146 Rome, Italy.
authors.forename: Alessio
authors.initials: A
authors.lastname: Monti
authors.forename: Filiberto
authors.initials: F
authors.lastname: Bilotti
authors.forename: Alessandro
authors.initials: A
authors.lastname: Toscano