Optical Nanoantenna: Directional Light from Coupled Nanorods

A single nanoemitter radiates light in almost every direction, which is a problem the moment you want to collect it efficiently. Give it a row of passive metal nanorods, tuned and spaced like a rooftop Yagi-Uda antenna shrunk a million-fold, and the emission collapses into one bright forward lobe. This simulator solves the actual coupled-dipole equations for a driven feed rod plus reflector and director rods — no shortcuts, the near-field coupling between every pair of rods is computed each frame — and renders both the 3D rod array and the resulting far-field radiation pattern live, with front-to-back ratio and directivity read out as you adjust spacing and detuning.