Beam quality of a non-ideal atom laser

J.-F. Riou (1) , W. Guerin (1) , Y. Le Coq (1) , M. Fauquembergue (1) , Philippe Bouyer (2) , Vincent Josse (1) , Alain Aspect (2)

1 LCFIO - Laboratoire Charles Fabry de l'Institut d'Optique
2 laboratoire Charles Fabry de l'Institut d'Optique / Optique atomique

We have measured the effect of interactions on atom-laser beam quality. We observe a transverse structure containing caustics that vary with the density within the residing Bose-Einstein Condensate. Using WKB approximation, Fresnel-Kirchhoff integral formalism and atom-optical ABCD matrices, we are able to predict analytically these profiles. This allows us to characterize the quality of the non-ideal atom-laser beam by a generalized M$^2$ factor defined in analogy to photon lasers.

Mots clés: atom laser; M2 factor; ABCD matrices; Fresnel-Kirshhoff; interactions

Domaines: Autre [cond-mat.other]; Physique Atomique [physics.atom-ph]

J.-F. Riou, W. Guerin, Y. Le Coq, M. Fauquembergue, Philippe Bouyer, et al.. Beam quality of a non-ideal atom laser. 2005. ⟨hal-00008591v1⟩