R. Barbé

Doppler-free reflection spectroscopy of rubidium D1 line in optically dense vapour

Abstract Frequency-modulated selective reflection on Rb vapour has been used to measure the long range van der Waals atom-glass attraction potential and the RbRb collisional self-broadening for each hyperfine component of the 85 Rb D 1 line.

Pulsed magnetic lenses for producing intense and bright cold atom beams

Abstract We report on the experimental study of cold atom bunch imaging by means of magnetic forces. A cesium atom cloud is released at low temperature from a standard cold atom source with a repetition period of 1 s. This cloud has been imaged in one-, two- and three-dimensions at a distance of about 1 m by means of pulsed magnetic lenses made of simple coils. Strong space and velocity compressions have been achieved providing bright and intense cold polarized atom beams. Transverse temperatures down to 350 nK have been achieved by means of 3D-collimation. The 3D-imaging procedure yields a pulsed beam of 4-ms duration with a flux density up to 4.5×10 15 atoms / s m 2 ; this figure represents a 20-fold increase in comparison with the free expanding cloud case. The duty cycle being 0.4% the mean temporal flux density is then 1.8×10 13 atoms / s m 2 . 3D-collimation allows for the production of a pulsed beam of 4-ms duration and with a brightness up to 5×10 15 atoms/s sr. This represents a 12-fold increase in comparison with the free expansion case while the mean temporal brightness is 2.0×10 13 atoms/s sr.

Magnetic compression of a falling cold atom cloud

Abstract Strong compression effects are experimentally demonstrated by acting magnetic forces upon a cold cesium atom cloud. Atoms released from an optical molasses at a temperature of 5 μK experience during their fall a pulsed longitudinal force. Magnetic state selection occurs and time-of-flight spectrum compressions are obtained for definite experimental parameters. Corresponding spatial or velocity compressions are reported.