title: Signature of a Fano resonance in a plasmonic metamolecule's local density of optical states.
abstract: We present measurements on plasmonic metamolecules under local excitation using cathodoluminescence which show a spatial redistribution of the local density of optical states at the same frequency where a sharp spectral Fano feature in extinction has been observed. Our analytical model shows that both near- and far-field effects arise due to interference of the same two eigenmodes of the system. We present quantitative insights both in a bare state, and in a dressed state picture that describe Fano interference either as near-field amplitude transfer between coupled bare states, or as interference of uncoupled eigenmodes in the far field. We identify the same eigenmode causing a dip in extinction to strongly enhance the radiative local density of optical states, making it a promising candidate for spontaneous emission control.
authors.affiliation: Center for Nanophotonics, FOM Institute for Atomic and Molecular Physics, Amsterdam, The Netherlands. frimmer@amolf.nl
authors.forename: Martin
authors.initials: M
authors.lastname: Frimmer
authors.forename: Toon
authors.initials: T
authors.lastname: Coenen
authors.forename: A Femius
authors.initials: AF
authors.lastname: Koenderink