ABSTRACT
In quantum optical problems involving the interaction of atoms
with laser fields, the atoms are usually considered being stationary
during the interaction. Since every photon has a momentum, the
atomic momentum (motion) can be changed in the process of
absorption and emission of photons. This may force a stationary
atom to move or to change momentum of an already moving atom.
Therefore, the dynamical behaviour of atoms can be varied by
the interaction with a radiation field. For a weak driving field,
the influence of this field on the atomic motion can be neglected.
However, the intensities of laser fields are generally very strong,
and then the motion of the atoms can be considerably changed by
the laser field. Here, we discuss this aspect, especially the effect of
a driving field on the motion of atoms and the atomic momentum
distribution. In particular, we will consider diffraction of atoms by
a standing-wave laser field due to an exchange of momentum with
the photons of the wave, and radiation force on atoms driven by a
running-or standing-wave laser field.
