Polarization squeezing with cold atoms

Vincent Josse (1) , Aurelien Dantan (1) , Laurent Vernac (1) , Alberto Bramati (1) , Michel Pinard (1) , Elisabeth Giacobino (1)

1 LKB (Jussieu) - Laboratoire Kastler Brossel

We study the interaction of a nearly resonant linearly polarizedlaser beam with a cloud of cold cesium atoms in a high finesseoptical cavity. We show theoretically and experimentally that thecross-Kerr effect due to the saturation of the optical transitionproduces quadrature squeezing on both the mean field and theorthogonally polarized vacuum mode. An interpretation of thisvacuum squeezing as polarization squeezing is given and a methodfor measuring quantum Stokes parameters for weak beams via a localoscillator is developed.

Mots clés: Polarization squeezing; cold atoms; quantum fluctuations

Domaines: Physique Quantique [quant-ph]

Vincent Josse, Aurelien Dantan, Laurent Vernac, Alberto Bramati, Michel Pinard, et al.. Polarization squeezing with cold atoms. Physical Review Letters, 2003, 91, pp.103601. ⟨hal-00000279v2⟩