Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Physical Review Letters

Observation of Focusing of Neutral Atoms by the Dipole Forces of Resonance-Radiation Pressure

John E. Bjorkholm, Richard R. Freeman, Arthur Ashkin, D. B. Pearson

Published Nov 13, 1978• 266 citations
Publisher

Abstract

For sodium atoms in an atomic beam, we demonstrate focusing, defocusing, and steering caused by the transverse dipole forces exerted by the radial intensity gradient of a superimposed and co-propagating resonant cw light beam. Dipole radiation-pressure forces differ from the forces due to spontaneous emission and are needed to achieve optical traps for neutral atoms.

DOI
10.1103/physrevlett.41.1361

Related papers

Focusing and defocusing of neutral atomic beams using resonance-radiation pressure

D. B. Pearson, Richard R. Freeman, John E. Bjorkholm +1 more

We demonstrate strong focusing and defocusing of a sodium atomic beam using the transverse resonance-radiation pressure of a superimposed cw dye laser beam tuned near the atomic resonance. Focal spot diameters of about 60 μm and a 30-fold increase of the on-axis atomic beam intensity have been obtained. For defocusing, the on-axis intensity can be reduced to less than 10−2 of its original value.

Applied Physics Letters•Jan 1, 1980•28 citations

Experimental observation of the influence of the quantum fluctuations of resonance-radiation pressure

John E. Bjorkholm, Richard R. Freeman, Arthur Ashkin +1 more

We experimentally demonstrate that quantum fluctuations of the photon–atom interaction have a limiting influence on the focusing of neutral atomic beams by the dipole resonance-radiation pressure of a superimposed and co-propagating cw laser beam.

Optics Letters•Mar 1, 1980•54 citations

Efficient transverse deflection of neutral atomic beams using spontaneous resonance-radiation pressure

John E. Bjorkholm, Richard R. Freeman, D. B. Pearson

We report the efficient transverse deflection of all atoms in a well-collimated sodium atomic beam by the spontaneous radiation pressure of a beam of resonance light which illuminates the atomic beam at right angles. Our results are obtained using two cw single-mode dye lasers to excite the two ground-state levels of sodium; this enables all atoms to interact with the light and it also eliminates optical pumping of the ground state. We obtained deflection angles greater than 5\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}3}$ rad which was ten times the divergence angle of the undeflected atomic beam; these deflections are due to the spontaneous scattering of more than 200 photons by each atom. The distribution of deflection angles is well described by a simple calculation. Fitting theory to experiment indicates that a fractional atomic excitation of 24 percent was obtained at an intensity of approximately 1 W/${\mathrm{cm}}^{2}$. When single-frequency light was used, only a fraction of the atoms were deflected, and the deflection angles were much smaller due to optical pumping.

Physical Review A•Feb 1, 1981•21 citations

Dipole laser trap for neutral atoms

P. L. Gould, Alan L. Migdall, H. Metcalf +1 more

We describe a relatively large volume dipole laser trap for the confinement of sodium atoms. Two counterpropagating beams, tuned below resonance, with foci separated by approximately one con focal parameter, provide radial confinement via the dipole force and axial confinement by balancing the radiation pressures of the two beams.1 Identical circular polarization for both beams prevents optical pumping and serves to maintain a two-state system. Alternation of the two beams2 is necessary to avoid the effects of standing-wave heating. Additionally, the trapping cycle is alternated with a Doppler cooling cycle2 to achieve low temperatures and long confinement times. Trapping beams of 100 mW focused to 50-μm spot radii and detuned ~2 GHz below the F = 2 to F′= 3 transition of the D2 line provide a well depth of 50 mK and a confinement volume of 10-4 cm3. Analysis of atomic motion and escape mechanisms as well as progress toward the experimental realization of this trap is presented.

International Laser Science Conference•Jan 1, 1986•0 citations

Laser Control of the Motion of Neutral Atoms and Optical Atomic Traps

V. I. Balykin, Vladilen S Letokhov, Vladimir G. Minogin

We consider various methods (longitudinal and transverse cooling, focusing and reflection) of controlling the motion of atoms in a beam in a resonant laser field by means of the dissipative force of laser light pressure and the potential gradient force which are required to realize various types of optical traps for slow neutral atoms. We anticipate the extension of these methods for molecules in the future.

Physica Scripta•Jan 1, 1988•13 citations

Trapping of Neutral Sodium Atoms with Radiation Pressure

Eric L. Raab, Mara Goff Prentiss, Alex Cable +2 more

We report the confinement and cooling of an optically dense cloud of neutral sodium atoms by radiation pressure. The trapping and damping forces were provided by three retroreflected laser beams propagating along orthogonal axes, with a weak magnetic field used to distinguish between the beams. We have trapped as many as ${10}^{7}$ atoms for 2 min at densities exceeding ${10}^{11}$ atoms ${\mathrm{cm}}^{\ensuremath{-}3}$. The trap was \ensuremath{\simeq}0.4 K deep and the atoms, once trapped, were cooled to less than a millikelvin and compacted into a region less than 0.5 mm in diameter.

Physical Review Letters•Dec 7, 1987•1,524 citations
For sodium atoms in an atomic beam, we demonstrate focusing, defocusing, and steering caused by the transverse dipole forces exerted by the radial intensity gradient of a superimposed and co-propagating resonant cw light beam. Dipole radiation-pressure forces differ from the forces due to spontaneous emission and are needed to achieve optical traps for neutral atoms.
We report the efficient transverse deflection of all atoms in a well-collimated sodium atomic beam by the spontaneous radiation pressure of a beam of resonance light which illuminates the atomic beam at right angles. Our results are obtained using two cw single-mode dye lasers to excite the two ground-state levels of sodium; this enables all atoms to interact with the light and it also eliminates optical pumping of the ground state. We obtained deflection angles greater than 5\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}3}$ rad which was ten times the divergence angle of the undeflected atomic beam; these deflections are due to the spontaneous scattering of more than 200 photons by each atom. The distribution of deflection angles is well described by a simple calculation. Fitting theory to experiment indicates that a fractional atomic excitation of 24 percent was obtained at an intensity of approximately 1 W/cm2{\mathrm{cm}}^{2}cm2. When single-frequency light was used, only a fraction of the atoms were deflected, and the deflection angles were much smaller due to optical pumping.
We describe a relatively large volume dipole laser trap for the confinement of sodium atoms. Two counterpropagating beams, tuned below resonance, with foci separated by approximately one con focal parameter, provide radial confinement via the dipole force and axial confinement by balancing the radiation pressures of the two beams.1 Identical circular polarization for both beams prevents optical pumping and serves to maintain a two-state system. Alternation of the two beams2 is necessary to avoid the effects of standing-wave heating. Additionally, the trapping cycle is alternated with a Doppler cooling cycle2 to achieve low temperatures and long confinement times. Trapping beams of 100 mW focused to 50-μm spot radii and detuned ~2 GHz below the F = 2 to F′= 3 transition of the D2 line provide a well depth of 50 mK and a confinement volume of 10-4 cm3. Analysis of atomic motion and escape mechanisms as well as progress toward the experimental realization of this trap is presented.
We report the confinement and cooling of an optically dense cloud of neutral sodium atoms by radiation pressure. The trapping and damping forces were provided by three retroreflected laser beams propagating along orthogonal axes, with a weak magnetic field used to distinguish between the beams. We have trapped as many as 107{10}^{7}107 atoms for 2 min at densities exceeding 1011{10}^{11}1011 atoms ${\mathrm{cm}}^{\ensuremath{-}3}$. The trap was \ensuremath{\simeq}0.4 K deep and the atoms, once trapped, were cooled to less than a millikelvin and compacted into a region less than 0.5 mm in diameter.