Physical Review A

Contribution of energy continuum states to probe the absorption signal of atoms in one-dimensional optical molasses

Jun Guo

Published May 1, 1994• 23 citations

Abstract

We present a calculation of the probe absorption spectrum of atoms in a one-dimensional optical molasses formed by a pair of counterpropagating, cross-polarized fields. When the finite angle \ensuremath{\theta} between the propagation direction of a probe field and that of one of the cooling fields is taken into account, we find that, apart from the contributions to the probe absorption signal that are related to the Raman and Rayleigh resonances between the discretized atomic motional states in the molasses direction, there is also a signal arising from the recoil-induced resonances between atomic states with different center-of-mass momenta in the directions transverse to the molasses beams. The magnitudes of these different contributions are compared.

DOI: 10.1103/physreva.49.3934

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Physical Review A

Contribution of energy continuum states to probe the absorption signal of atoms in one-dimensional optical molasses

Jun Guo

Published May 1, 1994• 23 citations

Publisher

Abstract

DOI: 10.1103/physreva.49.3934

Related papers

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Probe transmission in one-dimensional optical molasses: Theory for linearly cross-polarized cooling beams

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Bulletin of the American Physical SocietyMay 1, 19930 citations

{\mathit{J}}_{\mathit{g}}

=1\ensuremath{\rightarrow}

{\mathit{J}}_{\mathit{e}}

=2 atomic transition and the external degrees of freedom are described by means of a Fokker-Planck equation in the regime where the stationary momentum distribution lies within the range of linearity of the cooling force. We analyze the stimulated Raman transitions occurring between differently populated and light-shifted ground-state Zeeman sublevels. In the case where the probe beam has the same polarization as the copropagating cooling beam, an additional narrow Rayleigh resonance appears for a probe frequency close to the pump frequency. Its width is equal to 2\ensuremath{\alpha}/M, where \ensuremath{\alpha} is the friction coefficient of the cooling force and M is the atomic mass. In the case where the probe beam has the same polarization as the counterpropagating cooling beam, a central recoil-induced resonance is expected. Its width is related to the Doppler width of the optical molasses.

{\mathit{J}}_{\mathit{g}}

=1/2\ensuremath{\rightarrow}

{\mathit{J}}_{\mathit{e}}

=3/2 atomic transition in the limit where the Hamiltonian part of the atom-field coupling is predominant over the relaxation part. We analyze the stimulated Raman transitions occurring between different vibrational levels of the atoms in the periodic potential created by the light shifts, and we show a dramatic lengthening of the damping time of coherences between such levels due to the Lamb-Dicke effect. Very narrow Rayleigh resonances with a shape sensitive to the probe polarization appear for a probe frequency close to the pump frequency. We interpret these resonances in terms of scattering of the pump waves on density and magnetization gratings, and show that they provide important information about the dynamics and localization of atoms at the bottom of the potential wells. Such information should also be accessed by phase-conjugation experiments. Finally, indications on the treatment of other atomic transitions are given.

We study theoretically the spectrum of resonance fluorescence and laser-cooling dynamics corresponding to quantized atomic motion in one-dimensional optical molasses. We consider an atom with a

{\mathit{J}}_{\mathit{g}}

=1\ensuremath{\rightarrow}

{\mathit{J}}_{\mathit{e}}

=2 transition interacting with two counterpropagating laser beams. The laser light is assumed to be linearly polarized with an angle \ensuremath{\theta} between the polarization vectors. We discuss the spectrum of resonance fluorescence, the spectroscopy of band structure in the optical potentials, and the population of the vibrational quantum levels as a function of the angle between the polarization vectors.