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Résumé |
The presentation will start with an introduction to the general recipe for achieving optimum coupling
of light to resonant optical material systems, such as Fabry Perot resonators, or antenna structures. The
extreme case for the latter is a single atom, which will be treated in detail. This coupling between light
and a single atom is probably the most fundamental process in quantum optics. The best strategy for
efficiently coupling light to a single atom in free space depends on the goal. If the goal is to maximally
attenuate a laser beam, narrow-band on-resonance laser radiation is required as well as a wave front
approaching the atom from a 2 solid angle. If, on the other hand, the goal is to fully absorb the light
bringing the atom to the excited state with unit success probability one will have to provide a single
photon designed to represent the time reversed wave packet which the atom would emit in a spontaneous
emission process. Among other conditions this requires the single photon wave packet impinging from
the full 4 solid angle and having the correct temporal shape. The state of the art is reviewed and the
experimental progress is discussed. If the interaction is strong enough it will allow for building a few
photon quantum gate without a cavity, with possible applications in quantum information processing. |
