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

Advanced materials research

Simulation of Two-Dimensional Transverse Laser Cooling of Cesium Beam from Pyramidal Magneto-Optical Trap Atom Funnel

Bao Wu Zhang, N. Porfido, Francesco Tantussi, F. Fuso, Yan Ma, Wentao Zhang, Tong Bao Li

Published Feb 1, 2011• 0 citations
Publisher

Abstract

Simulation of two-dimensional (2D) transverse laser cooling of Cs atomic beam from pyramidal magneto-optical trap atom funnel (PMOTAF) conceived for atom lithography is presented. The results show that both the minimum full width at half maximum (FWHM) and the maximum peak value of the spatial profile of the atomic beam occur at the frequency detuning of optical molasses equals to -0.5 Г. Moreover, for each frequency detuning, an increase in the intensity of the optical molasses leads to smaller FWHM and higher peak value. The not negligible role of gravity on the atomic beam of sub-thermal longitudinal velocity along the horizontal direction is that every atomic trajectory possesses a parabolic motion either before or after laser cooling which leads to a noticeable displacement of the peak value at the observation plane with respect to the starting point.

DOI
10.4028/www.scientific.net/amr.189-193.3736

Related papers

The L.H.A. 2D magneto-optical trap: on the way to a continuous beam of cold atoms

Eve Aucouturier

A continuous beam of cold atoms is considered as an alternative to improve the performance of caesium frequency standards. A two-dimensional magneto-optical trap (2D MOT) is outlined. The assembling of three counter-propagating circularly polarised laser beams and of two magnetic field gradients along the horizontal axes leads to a transverse cooling and trapping, whereas in the vertical z-direction the atoms are only cooled and not trapped because of the zero magnetic field in this direction. In order to predict the characteristics of the beam of cold atoms, a simulation of the atomic trajectories was carried out by using a two-dimensional model of Doppler cooling and magneto-optical trapping. The velocity distribution of the atoms, which, due to the trapping and cooling process, enter the zone, where they are launched, is calculated.

European Frequency and Time Forum•Jan 1, 1996•0 citations

Realization of an intense cold Rb atomic beam based on a two-dimensional magneto-optical trap: Experiments and comparison with simulations

Saptarishi Chaudhuri, Sanjukta Roy, C. S. Unnikrishnan

We discuss the implementation and characterization of the source of a slow, intense, and collimated beam of rubidium atoms. The cold atomic beam is produced by two-dimensional magneto-optical trapping in directions transverse to the atomic beam axis and unbalanced Doppler cooling in the axial direction. The vacuum design allows use of relatively low laser power and a considerably simplified assembly. The atomic beam has a high flux of about $2\ifmmode\times\else\texttimes\fi{}{10}^{10}\phantom{\rule{0.3em}{0ex}}\mathrm{atoms}∕\mathrm{s}$ at a total cooling laser power of $55\phantom{\rule{0.3em}{0ex}}\mathrm{mW}$. It has a narrow longitudinal velocity distribution with mean velocity $15\phantom{\rule{0.3em}{0ex}}\mathrm{m}∕\mathrm{s}$ with full width at half maximum $3.5\phantom{\rule{0.3em}{0ex}}\mathrm{m}∕\mathrm{s}$ and has a low divergence of $26\phantom{\rule{0.3em}{0ex}}\mathrm{mrad}$. The high flux enables ultrafast loading of about ${10}^{10}$ atoms into a three-dimensional (3D) magneto-optical trap within 500 ms. The variation of the atomic beam flux was studied as a function of the rubidium vapor pressure, cooling laser power, transverse cooling laser beam length, detuning of the cooling laser, and relative intensities of the cooling beams along the atomic beam axis. We also discuss a detailed comparison of our measurements of the cold atomic beam with a 3D numerical simulation.

Physical Review A•Aug 18, 2006•63 citations

Transverse magneto-optical compression of a frequency-chirping slowed cesium atomic beam

P. Pillet, Jia Yu, J. Djemaa +1 more

We have transversally compressed a monokinetic cesium atomic beam in a 2D magneto‐optical trap (MOT), also called a funnel, on the F=4→F’=5 transition of the cesium D2 line. The longitudinal cooling is obtained by frequency‐chirping. Preliminary results show a final diameter of about 50–100 μm with a density of a few 108 atoms/cm3 for slowed atoms. The density is enhanced by a preliminary orientation of the atoms inside the trap.

AIP conference proceedings•Jan 1, 1993•2 citations

A novel simplified two-dimensional magneto-optical trap as an intense source of slow cesium atoms

N. Castagna, Jocelyne Guéna, Mark D. Plimmer +1 more

We describe the design and performance of a slow atom source based on a 2D magneto-optical trap (MOT) that uses an innovative simple optical configuration. Metal-coated retro-reflecting prisms replace mirrors and quarter-wave plates so the optical power of the cooling laser beam is recycled. This source has been characterised for three different configurations: with and without transverse magnetic field gradient, and with a pusher beam to obtain a 2D+-MOT. The longitudinal velocity is of the order of 25 m·s−1, with a transverse velocity spread ≤1 m·s−1, while the typical atomic flux density obtained is up to 1.3×1014 at ·s−1·m−2 for a cesium vapour pressure of ~4×10−8 mbar in the source. We use this slow atom beam, instead of cesium vapour, to load a 3D moving optical molasses that feeds a continuous cold atom fountain. We obtain a gain of a factor ~20 in the atomic flux launched by the fountain.

The European Physical Journal Applied Physics•Apr 1, 2006•23 citations

A cold cesium beam source based on a two-dimensional magneto-optical trap

Weibin Xie, Qing Wang, Xuan He +4 more

A beam source is proposed for the production of an intense cold cesium atomic beam that can be used in cesium beam atomic clocks. The source is based on a two-dimensional magneto-optical trap (2D-MOT), but introduces hollow cooling and pushing lights in the axial direction to create a 2D+-MOT, which separates the cooling and pushing functions while the low-power pushing light pushes atoms out to form a cold atomic beam. This cold cesium atomic beam source reduces the light shift due to leakage light and retains longitudinal cooling to increase the flux of the cold atomic beam compared with that of the conventional 2D+-MOT scheme. The specifics of the design are investigated, the atomic velocity and beam flux are calculated, and the results are experimentally verified. The results demonstrate that when the power of the pushing light is 180 µW and when its frequency resonates with the 4 → 5′ transition of the Cs D2 line, the most probable longitudinal velocity of the outgoing cold atomic beam, the width of velocity distribution, and the atomic beam flux are 19.38 m/s, 8.1 m/s, and 1.7 × 1010 atoms/s, respectively.

AIP Advances•Jul 1, 2022•4 citations

Bright, slow, and continuous beam of laser-cooled cesium atoms

P. Berthoud, E. Fretel, P. Thomann

By the moving molasses technique we have extracted laser-cooled cesium atoms in a continuous way directly from an optical molasses. The mean launching velocity is precisely tunable from 1 to 12 m/s. The atomic beam has a flux of $1.3\ifmmode\times\else\texttimes\fi{}{10}^{8} \mathrm{a}\mathrm{t}\mathrm{o}\mathrm{m}/\mathrm{s}$ at 7 m/s and a longitudinal temperature of $70 \ensuremath{\mu}\mathrm{K},$ which represents the highest flux and lowest velocity spread obtained so far in a continuous beam of cold atoms. These features makes it well suited for atomic fountains. The atomic flux can be slightly increased in a two-dimensional magneto-optical trap operation $(+40%).$ A simple model accounts for the observed dependence of the flux with the magnetic-field gradient.

Physical Review A•Dec 1, 1999•41 citations
Simulation of two-dimensional (2D) transverse laser cooling of Cs atomic beam from pyramidal magneto-optical trap atom funnel (PMOTAF) conceived for atom lithography is presented. The results show that both the minimum full width at half maximum (FWHM) and the maximum peak value of the spatial profile of the atomic beam occur at the frequency detuning of optical molasses equals to -0.5 Г. Moreover, for each frequency detuning, an increase in the intensity of the optical molasses leads to smaller FWHM and higher peak value. The not negligible role of gravity on the atomic beam of sub-thermal longitudinal velocity along the horizontal direction is that every atomic trajectory possesses a parabolic motion either before or after laser cooling which leads to a noticeable displacement of the peak value at the observation plane with respect to the starting point.
A continuous beam of cold atoms is considered as an alternative to improve the performance of caesium frequency standards. A two-dimensional magneto-optical trap (2D MOT) is outlined. The assembling of three counter-propagating circularly polarised laser beams and of two magnetic field gradients along the horizontal axes leads to a transverse cooling and trapping, whereas in the vertical z-direction the atoms are only cooled and not trapped because of the zero magnetic field in this direction. In order to predict the characteristics of the beam of cold atoms, a simulation of the atomic trajectories was carried out by using a two-dimensional model of Doppler cooling and magneto-optical trapping. The velocity distribution of the atoms, which, due to the trapping and cooling process, enter the zone, where they are launched, is calculated.
We discuss the implementation and characterization of the source of a slow, intense, and collimated beam of rubidium atoms. The cold atomic beam is produced by two-dimensional magneto-optical trapping in directions transverse to the atomic beam axis and unbalanced Doppler cooling in the axial direction. The vacuum design allows use of relatively low laser power and a considerably simplified assembly. The atomic beam has a high flux of about $2\ifmmode\times\else\texttimes\fi{}{10}^{10}\phantom{\rule{0.3em}{0ex}}\mathrm{atoms}∕\mathrm{s}$ at a total cooling laser power of 55mW55\phantom{\rule{0.3em}{0ex}}\mathrm{mW}55mW. It has a narrow longitudinal velocity distribution with mean velocity 15m∕s15\phantom{\rule{0.3em}{0ex}}\mathrm{m}∕\mathrm{s}15m∕s with full width at half maximum 3.5m∕s3.5\phantom{\rule{0.3em}{0ex}}\mathrm{m}∕\mathrm{s}3.5m∕s and has a low divergence of 26mrad26\phantom{\rule{0.3em}{0ex}}\mathrm{mrad}26mrad. The high flux enables ultrafast loading of about 1010{10}^{10}1010 atoms into a three-dimensional (3D) magneto-optical trap within 500 ms. The variation of the atomic beam flux was studied as a function of the rubidium vapor pressure, cooling laser power, transverse cooling laser beam length, detuning of the cooling laser, and relative intensities of the cooling beams along the atomic beam axis. We also discuss a detailed comparison of our measurements of the cold atomic beam with a 3D numerical simulation.
We describe the design and performance of a slow atom source based on a 2D magneto-optical trap (MOT) that uses an innovative simple optical configuration. Metal-coated retro-reflecting prisms replace mirrors and quarter-wave plates so the optical power of the cooling laser beam is recycled. This source has been characterised for three different configurations: with and without transverse magnetic field gradient, and with a pusher beam to obtain a 2D+-MOT. The longitudinal velocity is of the order of 25 m·s−1, with a transverse velocity spread ≤1 m·s−1, while the typical atomic flux density obtained is up to 1.3×1014 at ·s−1·m−2 for a cesium vapour pressure of ~4×10−8 mbar in the source. We use this slow atom beam, instead of cesium vapour, to load a 3D moving optical molasses that feeds a continuous cold atom fountain. We obtain a gain of a factor ~20 in the atomic flux launched by the fountain.
A beam source is proposed for the production of an intense cold cesium atomic beam that can be used in cesium beam atomic clocks. The source is based on a two-dimensional magneto-optical trap (2D-MOT), but introduces hollow cooling and pushing lights in the axial direction to create a 2D+-MOT, which separates the cooling and pushing functions while the low-power pushing light pushes atoms out to form a cold atomic beam. This cold cesium atomic beam source reduces the light shift due to leakage light and retains longitudinal cooling to increase the flux of the cold atomic beam compared with that of the conventional 2D+-MOT scheme. The specifics of the design are investigated, the atomic velocity and beam flux are calculated, and the results are experimentally verified. The results demonstrate that when the power of the pushing light is 180 µW and when its frequency resonates with the 4 → 5′ transition of the Cs D2 line, the most probable longitudinal velocity of the outgoing cold atomic beam, the width of velocity distribution, and the atomic beam flux are 19.38 m/s, 8.1 m/s, and 1.7 × 1010 atoms/s, respectively.
By the moving molasses technique we have extracted laser-cooled cesium atoms in a continuous way directly from an optical molasses. The mean launching velocity is precisely tunable from 1 to 12 m/s. The atomic beam has a flux of $1.3\ifmmode\times\else\texttimes\fi{}{10}^{8} \mathrm{a}\mathrm{t}\mathrm{o}\mathrm{m}/\mathrm{s}$ at 7 m/s and a longitudinal temperature of $70 \ensuremath{\mu}\mathrm{K},$ which represents the highest flux and lowest velocity spread obtained so far in a continuous beam of cold atoms. These features makes it well suited for atomic fountains. The atomic flux can be slightly increased in a two-dimensional magneto-optical trap operation (+40(+40%).(+40 A simple model accounts for the observed dependence of the flux with the magnetic-field gradient.