Observation of the cooling of free sodium atoms in a resonance laser field with a scanning frequency

V. I. Balykin, Vladilen S Letokhov, V.I. Mishin

V. I. Balykin, Vladilen S Letokhov, V.I. Mishin

Zheng-Zhong Pan

Recently, there have been significant experimental advances in the laser cooling of a sodium atomic beam.1 Only three methods have been successful: (1) fixed frequency nonresonance cooling; (2) chirped frequency resonance cooling; and (3) spatial-varied magnetic-field Zeeman- tuned resonance cooling.

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.

Stephanos Papademetriou, Stephen H. Chakmakjian, Carlos R. Stroud

The interaction of a strong bichromatic field with a two-level atom has been the subject of numerous experimental and theoretical investigations. We performed an experimental study of the Interaction of an intense 100% amplitude-modulated (AM) field with an ensemble of homogeneously broadened two-level atoms. An optically pumped sodium atomic beam is used as the atomic medium. The field is created by interfering two intense frequency-stabilized laser fields. The frequency of one field is held fixed while another field of equal amplitude is scanned in frequency. The beat frequency produced by interfering the two laser fields is equal to twice the modulation frequency of a 100% AM field. We monitor the time-averaged fluorescent intensity of the atoms as the frequency separation between the two fields is varied. A similar experiment was done in the past in the rf regime.1 For the first time, we report the observation of multiple, well-resolved resonances in the absorption spectrum of the field in the optical regime. We present data and theory for several values of detuning between the fixed field and atomic resonance. The experimental results are in good agreement with theory.

Rainer Gaggl, Laurentius Windholz, Christian Neureiter