Far-field control of radiation from an individual optical nanocavity: analogue to an optical dipole.

We demonstrate long-range control of the radiative lifetime of a silicon optical nanocavity using a metallic atomic force microscope probe. We extract changes in the radiative lifetime from changes in the cavity's transmittivity resulting from probe-cavity interaction over distances of several optical wavelengths. Analogous to atomic systems, the cavity acts as an individual radiating dipole with a radiative rate that is modified by a metallic interface.