Laser light control of atomic beams

Alain Aspect

J Ruseckas, A Mekys, Gediminas Juzeliūnas

We consider propagation, storing and retrieval of slow light (probe beam) in a resonant atomic medium illuminated by two control laser beams of larger intensity.The probe and two control beams act on atoms in a tripod configuration of light-matter coupling.The first control beam is allowed to have an orbital angular momentum (OAM).Application of the second vortex-free control laser ensures the adiabatic (lossless) propagation of the probe beam at the vortex core where the intensity of the first control laser goes to zero.Storing and release of the probe beam is accomplished by switching off and on the control laser beams leading to the transfer of the optical vortex from the first control beam to the regenerated probe field.A part of the stored probe beam remains frozen in the medium in the form of atomic spin excitations, the number of which increases with increasing intensity of the second control laser.We analyze such losses in the regenerated probe beam and provide conditions for the optical vortex of the control beam to be transferred efficiently to the restored probe beam.

Julius Ruseckas, Algirdas Mekys

We consider propagation, storing and retrieval of slow light (probe beam) in a resonant atomic medium illuminated by two control laser beams of larger intensity. The probe and two control beams act on atoms in a tripod configuration of light–matter coupling. The first control beam is allowed to have an orbital angular momentum (OAM). Application of the second vortex-free control laser ensures the adiabatic (lossless) propagation of the probe beam at the vortex core where the intensity of the first control laser goes to zero. Storing and release of the probe beam is accomplished by switching off and on the control laser beams leading to the transfer of the optical vortex from the first control beam to the regenerated probe field. A part of the stored probe beam remains frozen in the medium in the form of atomic spin excitations, the number of which increases with increasing intensity of the second control laser. We analyze such losses in the regenerated probe beam and provide conditions for the optical vortex of the control beam to be transferred efficiently to the restored probe beam.

Alain Aspect

V. I. Balykin, Vladilen S Letokhov, Vladimir G. Minogin +1 more

This paper presents the results of experimental and theoretical investigations on the control of atomic beam motion by light pressure of laser radiation. Collimation, focusing, and compression of an atomic beam are considered. Collimation of an atomic beam was achieved under the interaction of laser radiation with atoms when the light pressure force depended only on the atoms’ velocity. A similar regime of atomic beam interaction with radiation was performed under transversal irradiation of a beam by the axisymmetric field. The latter was formed by laser radiation reflected from the conical mirror surface of a reflecting axicon. The axis of an atomic beam coincided with that of the axicon. The collimation regime was reached under negative detuning of the laser radiation frequency from that of the atomic transition one by a value equal to a few homogeneous widths. Under positive detuning by the same value beam decollimation was observed.

K. Sengstock, Wolfgang A. Ertmer