Double Fano resonances in a composite metamaterial possessing tripod plasmonic resonances

By embedding four-rod resonators inside a double-split ring resonator superlattice, a planar composite metamaterial possessing tripod plasmonic resonances is fabricated. Double Fano resonances are observed where a common subradiant driven oscillator is coupled with two superradiant oscillators. As a classical analogue of a four-level tripod atomic system, the extinction spectrum of the composite metamaterial exhibits a coherent effect based on double Fano resonances. Transfer of the absorbed power between two orthogonal superradiant oscillators is shown to be mediated by the common subradiant oscillator.