A study of atom localization in an optical lattice by analysis of the scattered light

G. Birkl, M. Gatzke, Anders Kastberg +5 more

Christoph Ira Westbrook, Christophe Jurczak, G. Birkl +3 more

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 scattering when the lattice is suddenly switched on. We compare results for three different configurations of the optical lattice. We create situations in which the Lamb–Dicke effect is negligible and show that, in contrast with what has been stated in some of the literature, the damping rate of the ‘coherent’ atomic oscillations can be much longer than the inelastic photon scattering rate.

Todd A. Van Woerkom

Wei Guo, Sudhakar Prasad

A theoretical study of the scattering of light from a randomly occupied optical lattice of resonant atoms is presented to reveal both the characteristics of the lattice and the properties of light scattered from the lattice. In the first-order Born approximation we discuss here, a number of interesting effects are established, including sideband Stokes scattering, a finite angular coherence of the scattered light, and spectral line narrowing. Specifically, the degree of angular coherence of the scattered light is calculated, and it is shown that such coherence is strongly influenced by the regularity and size of the underlying lattice structure. The previously observed phenomenon of the sideband spectral line narrowing is also explained in terms of the localization of atoms in the trapping potential wells. Important information about the lattice can thus be recovered by analyzing the scattered light in the Born approximation.

G. Birkl, M. Gatzke, Ivan Deutsch +2 more

We observe coherently enhanced reflection (Bragg scattering) of a near resonant laser beam from cesium atoms ordered by a periodic array of optical potential wells known as an optical lattice. The reflected light is enhanced by a factor of $\ensuremath{\sim}{10}^{5}$ over scattering from a disordered atomic sample. We measure the magnitude of the reflectivity and its detuning dependence as functions of the density and the degree of localization of the atoms. The change in lattice constant due to the frequency-dependent effective index of refraction seen by the lattice light field is observed.

Jie-Yun Yan, Xiao-Hui Hu, Zhe Zhou +2 more