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

TL;DR

This paper introduces a novel light-shift tomography technique using absorption imaging to map potentials and study thermalization of rubidium atoms in a far-detuned optical dipole trap, enhancing understanding of atomic cloud dynamics.

Contribution

The paper presents a new method leveraging light-shift effects for detailed potential mapping and thermalization analysis in optical dipole traps.

Findings

Mapped the equipotentials of a crossed optical-dipole trap.

Tracked the evolution of atomic potential energy during evaporation.

Demonstrated the effectiveness of light-shift tomography for atomic cloud studies.

Abstract

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.