Radiative cooling of atoms in a homogeneous light field

G. Labeyrie, Christian Miniatura, Cord Axel Müller +3 more

We study the shape of the coherent-backscattering (CBS) cone obtained when resonant light illuminates a thick cloud of laser-cooled rubidium atoms in the presence of a homogenous magnetic field. We observe new magnetic field-dependent anisotropies in the CBS signal. We show that the observed behavior is due to the modification of the atomic-radiation pattern by the magnetic field (Hanle effect in the excited state).

V. I. Balykin, Vladilen S Letokhov, Vladimir G. Minogin

The present state of research on the cooling of atomic ensembles by means of laser radiation pressure is discussed. First the basic theory of resonance radiation pressure is reviewed. The effect of recoil on the drift and fluctuations of the momentum of an atom interacting with resonance radiation is examined. There is an analysis of the forces acting on an atom in some simple light fields: a traveling plane wave, a Gaussian beam, and counterpropagating Gaussian beams. The review then focuses on the monochromatization of atoms by resonance radiation pressure and related methods for laser cooling of atoms. The roles played by the radiation pressure force and by momentum diffusion in shaping the narrow velocity distributions of the ensemble of atoms are analyzed. The lowest temperature obtainable in the radiation cooling of atoms is estimated. The basic experimental methods for laser cooling of atomic beams are described. Problems of the three-dimensional cooling of atomic ensembles and problems of localizing cold atoms in light fields, steady-state magnetic fields, and electrostatic fields are discussed. The review concludes with a discussion of some applications of cold atoms in high-precision spectroscopy, frequency standards, and atomic physics.

Vladilen S Letokhov, Vladimir G. Minogin

Analysis of the possiblity of cooling, trapping, and storage of atoms in the resonant field of a laser standing wave is presented. Under certain regimes of frequency scanning the laser radiation can cool atoms in low-pressure gas to the temperature T ≃ 10−4−10−3 K. Because of gradient force effects, cooled atoms will be held in the light field for a long time. Joint cooling and storage of atoms in a resonant light field is important for spectroscopic studies with an extremely high sensitivity and resolution.

Н. І. Жукова, A. P. Kazantsev