Abstract

We present a new method of spectroscopy for atoms cooled and trapped in an optical lattice. This method which makes use of coherent transients permit to improve the signal to noise ratio by more than one order of magnitude by comparison with the previous optical detection methods such as probe transmission or atomic fluorescence [1]. We apply this method to the spectroscopy of cesium atoms first in a four-beam lattice [2] and second in a quasi-periodic structure obtained by adding supplementary incident beams. These structures are strongly connected with the field of quasi-crystals [3] which is very active in solid-state physics. Because of the topological invariance of the optical potential, the same spectra are obtained whatever the phases of the incident beams. Additional information about distribution of atoms among the potential wells can be deduced from the analysis of the coherent transients.

© 1996 Optical Society of America