Active all-optical spectral tuning of nanorod plasmonic nanoantennas

We suggest a novel all-optical spectral tuning mechanism over subwavelength light focusing with a plasmonic nanorod nanoantenna. The tunability originates from the manipulation of Fano resonances in an auxiliary intermediate resonator that couples the nanoantenna with a far-field light source. Our approach presents a decisive step toward active spectral tuning of plasmonic nanoantennas without relying on nonlinear optical effects or mechanical reconfiguration of the antenna.