Dark and bright modes manipulation for plasmon-triggered photonic devices

In the last decade, several efforts have been spent in the study of near-field coupled systems, in order to induce hybridization of plasmonic modes. Within this context, particular attention has been recently paid on the possibility to couple conventional bright and dark modes. As a result of such phenomenon, a Fano resonance appears as a characteristic sharp dip in the scattering spectra. Here we show how, gradually coupling a single rod-like nanostructure to an aligned nanoantenna dimer, it is possible to induce the near-field activation of an anti-bonding dark mode. The high polarization sensitivity presented by the far-field response of T-shape trimer, combined with the sharp Fano resonance sustained by this plasmonic device, opens interesting perspectives towards a new era of photonic devices.