Coherent spectroscopy in strongly confined optical fields

A single emitter is usually expected to have a weak effect on a light beam. However, recent experiments have shown that up to 12% of the incident power can be extinguished in the forward direction if it is focused or confined by a small aperture. To explore the theoretical limits of the effect of a single emitter on a stream of photons, we investigate the interaction of a single oscillating dipole with tightly confined optical fields and demonstrate that light can be attenuated even by 100% under appropriate conditions. These findings are not only interesting for applications in spectroscopy and sensing, but also open doors for information processing at the nanometer scale. (c) 2011 Elsevier B.V. All rights reserved.