Mode-balancing far field control of light localization in nanoantennas

Abstract

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 3 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 cavity while nullifying the light intensity in the other cavity. 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. Consequently, optical transparency can be achieved in an ultra-compact symmetric metallic structure.