Plasmonic Fano switches in Au-SiO2-Au multilayer nanoshells with broken core

We demonstrate that concentric Au-SiO2-Au multilayer nanoshells with a core broken by removing half of the Au sphere core are sensitively dependent on the polarization orientations of the incident wave and can support highly tunable Fano resonances, realizing multi-wavelength plasmonic Fano switches at the orthogonal incident polarization orientations. The plasmon hybridization theory and coupled oscillator model are used to interpret the interaction between the inner broken core and the outer shell. The Fano resonances in the Au-SiO2-Au multilayer nanoshells with a broken core can be adjusted easily by means of varying the geometrical parameters, showing good tunability. Au-SiO2-Au multilayer nanoshells with a broken core in a compact sub-150 nm size range supports plasmonic Fano switches at the visible and near-infrared spectral regions, providing various applications in switching devices and photonic integrated technologies.