Enhanced plasmonic Fano-like resonances in multilayered nanoellipsoid

Plasmonic Fano-like resonances, which arise from the destructive interference of bright and dark plasmon modes, are theoretically investigated in gold-silica-gold multilayered nanoellipsoid. It is found that the higher-order Fano resonances with sharp modulation depth can be achieved in the symmetric case by simply varying the structural parameters of the nanoparticle. Moreover, for the generation of unique multiple Fano-like resonances, two types of symmetry-breaking conception are also introduced: first by offsetting the inner metal core from its central position and then by relaxing the rotational symmetry of the nanoparticle. The multiple plasmonic Fano-like resonances make the proposed nanostructure highly suitable for plasmon line shaping, electromagnetic-induced transparency, and slow light applications.