  Efficient coupling of light to single atomic systems has gained considerable
attention over the past decades. This development is driven by the continuous
growth of quantum technologies. The efficient coupling of light and matter is
an enabling technology for quantum information processing and quantum
communication. And indeed, in recent years much progress has been made in this
direction. But applications aside, the interaction of photons and atoms is a
fundamental physics problem. There are various possibilities for making this
interaction more efficient, among them the apparently 'natural' attempt of
mode-matching the light field to the free-space emission pattern of the atomic
system of interest. Here we will describe the necessary steps of implementing
this mode-matching with the ultimate aim of reaching unit coupling efficiency.
We describe the use of deep parabolic mirrors as the central optical element of
a free-space coupling scheme, covering the preparation of suitable modes of the
field incident onto these mirrors as well as the location of an atom at the
mirror's focus. Furthermore, we establish a robust method for determining the
efficiency of the photon-atom coupling.
