4π Photon Atom Coupling (4piPAC)

It is the aim of this project to excite a single atom in free space by
absorption of a single photon. Atom and photon are to be coupled
in such a way that the absorption probability is as close as possible
to one. One condition for the realization of such high probabilities is
the illumination of the atom from almost the full solid angle - a solid
angle close to 4π.