Light-shift tomography in an optical-dipole trap for neutral atoms

Jean-Philippe Brantut (1) , Jean-François Clément (1) , Martin Robert-De-Saint-Vincent (1) , Gaël Varoquaux (1) , Robert Nyman (1) , Alain Aspect (1) , Thomas Bourdel (1) , Philippe Bouyer (1)

1 laboratoire Charles Fabry de l'Institut d'Optique / Optique atomique

We report on light-shift tomography of a cloud of 87 Rb atoms in a far-detuned optical-dipole trap at 1565 nm. Our method is based on standard absorption imaging, but takes advantage of the strong light-shift of the excited state of the imaging transition, which is due to a quasi-resonance of the trapping laser with a higher excited level. We use this method to (i) map the equipotentials of a crossed optical-dipole trap, and (ii) study the thermalisation of an atomic cloud by following the evolution of the potential-energy of atoms during the free-evaporation process.

Domaines: Physique Atomique [physics.atom-ph]; Optique [physics.optics]

Jean-Philippe Brantut, Jean-François Clément, Martin Robert-De-Saint-Vincent, Gaël Varoquaux, Robert Nyman, et al.. Light-shift tomography in an optical-dipole trap for neutral atoms. Physical Review A : Atomic, molecular, and optical physics [1990-2015], 2008, 78, pp.031401 (R). ⟨10.1103/PhysRevA.78.031401⟩. ⟨hal-00303321⟩