Atomic scatterin G by a resonant standing light wave

E. V. Baklanov, Vladimir G. Minogin

Roland Abfalterer, Stefan Bernet, Claudia Keller +3 more

Atoms interacting with standing light waves are a model system for the propagation of waves in static and time varying periodic media. We present here experiments studying the coherent motion of atomic deBroglie waves in periodic potentials made from on and off resonant light. We observe anomalous transmission of atoms through resonant standing light waves and experimentally confirm that atoms fulfilling the Bragg condition form a standing matter wave pattern. We furthermore demonstrate how Bragg diffraction of atomic matter waves at a time-modulated thick standing light wave can be used to coherently shift the deBroglie frequency of the diffracted atoms. Our frequency shifter for atomic matter waves is similar to an acousto-optic frequency shifter for photons.

V. A. Grinchuk, A. P. Kazantsev, E. F. Kuzin +4 more

S. Altshuler, Lee M. Frantz, Rubin Braunstein

David E. Pritchard, P. L. Gould

We discuss two possible processes that may lead to unidirectional momentum transfer to atoms from a near-resonant standing-wave light field. The first is Bragg scattering of the matter waves from the tilted light grating—this process leaves the atoms unexcited. The second is a multiphoton (Doppleron) process in which the atom, by sequential absorption/emission of photons from/into the two traveling-wave components of the standing wave (which appear at different frequencies owingto the motion of the atom in the field), can complete the energy resonance condition for excitation to its excited state. Detailed consideration of the inteferring process of spontaneous emission and experimental factors such as the interplay among interaction length, angular collimation of the standing wave, and transit-time frequency broadening of the light frequency show that the two processes are both potentially observable but under considerably different experimental conditions.

V. A. Grinchuk, I. A. Grishina, E. F. Kuzin +3 more

In this paper we present some new results concerning the observed anomalous frequency properties of the process of the neutral atom scattering in the standing light wave field near the reflecting mirror. The investigations were carried out using the method of scattering of the sodium atomic strip beam, intersecting at right angle the region of the standing light wave field. The standing light wave field was formed by two counterpropagating waves of resonant laser radiation -- incident and reflected from the mirror, mounted at a distance of about 1 cm from the atomic beam. The coherence length of the laser radiation was about 10 cm, that's why the interaction of atoms with the field of two counterpropagating light waves was coherent. The width of the strip atomic beam (a equals 0.02 cm) was much less than the distance to the mirror. The specific feature of the given setup is the use of pulsed laser radiation with the duration (tau) less than 1/(gamma) ((gamma) -1- the time of resonant level spontaneous decay), so the atoms are scattered only due to the induced light pressure force. In this paper the detailed investigation of the distance R influence on the scattering process was carried out. With this purpose the mirror was mounted at different distances from the atomic beam. (truncated)