Mode-balancing far-field control of light localization in nanoantennas

Light localization is controlled at a scale of lambda/10 in the harmonic regime from the far-field domain in a plasmonic nanoantenna. The nanoantenna under study consists of three aligned spheres 50 nm in diameter separated by a distance of 5 nm. By simply tuning the orientation of an incident plane wave, symmetric and antisymmetric mode balancing induces a strong enhancement of the near-field intensity in one nanogap while nullifying the light intensity in the other nanogap. Furthermore, it is demonstrated that the dipolar moment of a plasmonic particle can be fully extinguished when strongly coupled with a dimer of identical nanoparticles.