https://doi.org/10.1140/epjd/e2006-00234-8
Nonlinear lensing mechanisms in a cloud of cold atoms
1
Institut Non Linéaire de Nice, UMR 6618 CNRS, 1361 route des Lucioles, 06560 Valbonne, France
2
Dipartimento di Fisica dell'Università di Ferrara and INFN-Sezione di Ferrara, 44100 Ferrara, Italy
3
Georgia Institute of Technology, Atlanta, Georgia, 30332, USA
4
SUPA, Department of Physics, University of Strathclyde, Glasgow G4, ONG, UK
Corresponding author: a Robin.Kaiser@inln.cnrs.fr
Received:
18
July
2006
Revised:
5
September
2006
Published online:
20
October
2006
We present an experimental study of nonlinear lensing of near-resonant light by a cloud of laser-cooled rubidium atoms, specifically aimed at understanding the role of the interaction time between the light and the atomic vapor. We identify four different nonlinear mechanisms, each associated with a different time constant: electronic nonlinearity, Zeeman optical pumping, hyperfine optical pumping and radiation pressure. Our observations can be quite accurately reproduced using a simple rate equation model which allows for a straightforward discussion of the various effects. The results are important for planning more refined experiments on transverse nonlinear optics and self-organization in samples of cold atoms.
PACS: 42.65.Jx – Beam trapping, self-focusing and defocusing; self-phase modulation / 32.80.Pj – Optical cooling of atoms; trapping / 42.65.Sf – Dynamics of nonlinear optical systems; optical instabilities, optical chaos and complexity, and optical spatio-temporal dynamics
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2006
