We present an experimental study of a four-beam optical lattice using
the light scattered by the atoms in the lattice. We use both intensity
correlations and observations of the transient behaviour of the scatt
ering when the lattice is suddenly switched on. We compare results for
three different configurations of the optical lattice. We create situ
ations in which the Lamb-Dicke effect is negligible and show that, in
contrast with what has been stated in some of the literature, the damp
ing rate of the 'coherent' atomic oscillations can be much longer than
the inelastic photon scattering rate.