Nano-manipulation of confined electromagnetic fields with a near-field probe

While optical near-field microscopy techniques have been devoted to mapping the electromagnetic fields down to the Raleigh limit, an exciting challenge is now to use near-field probes to manipulate in situ the properties of these electromagnetic fields. Here we report the resonance tuning and therefore switching of an ultra-low volume (V approximate to 0.6 (lambda/n)(3)) solid state resonator by evanescent interaction with a nanometric dielectric tip. By modelling the tip-nanocavity interaction, we demonstrate that a lossless interaction regime can be achieved in which the tip behaves as a pure optical path length modulator.