© 2026 Aqora Quantum S.A.S.

Terms Privacy Legal Notice

Conference on Lasers and Electro-Optics Pacific Rim (CLEO-PR)

Magneto-optical trap loaded from a low-velocity intense source

Chang Yong Park, Myung Sim Jun, D. Cho

Published Jan 20, 2003• 0 citations

Abstract

With a vapor-cell magneto-optical trap (VCMOT) atoms are trapped directly from the equilibrium vapor at room temperature without the complication of a precooling stage. The background vapor, however, can also be a source of energetic atoms hitting and ejecting those atoms already trapped. The background collision limits trap confinement time /spl tau/ and consequently the total number N of atoms trapped in a VCMOT. In order to have large /spl tau/ and N without losing the convenience and simplicity of a VCMOT, double MOT systems were built. In such a system there is a VCMOT with a usual background vapor pressure, and connected to it is another MOT without the vapor. The VCMOT captures atoms and transfers them to the second MOT through a long tube. The tube provides the constriction to maintain the pressure difference between the two MOT chambers. For the second MOT there is a steady supply of slow atoms without the complication of the background vapor, and it can hold a large number of atoms for a long time. Such systems were successfully used for a Bose Einstein condensation experiment and to study cold collisions.

DOI: 10.1109/cleopr.1999.811399

Related papers

A double magneto-optical trap system using a slow atomic beam for atom transfer

Shuyu Zhou, Zhen Xu, Zhou Shan-Yu +2 more

A rubidium double magneto-optical trap(MOT) system for Bose-Einstein condensation experiments has been set up. A slow atomic beam has been obtained with a low-velocity intense source (LVIS) and used to transfer atoms into an ultra-high-vacuum (UHV) MOT. By maintaining a pressure difference of 3 orders between LVIS-MOT and UHV-MOT, a lowest pressure of 1×10-9Pa can be achieved in UHV-MOT. The flux of the slow atomic beam is 1×109/s. About 4×108 87Rb atoms can be loaded into UHV-MOT. In this paper, maximum number of atoms captured in MOTs under two typical conditions have also been discussed.

Acta Physica Sinica•Jan 1, 2007•4 citations

Multiply loaded magneto-optical trap

Christopher J. Myatt, Nathan R. Newbury, R. W. Ghrist +2 more

We report a two-chambered, differentially pumped system that permits rapid collection of trapped atoms with a vapor cell magneto-optical trap (MOT) and efficient transfer of these atoms to a second MOT in a lowerpressure chamber. During the transfer the atoms are guided down a long, thin tube by a magnetic potential, with 90(15%) transfer efficiency. By multiply loading, we accumulate and hold as many as 30 times the number collected by the vapor cell MOT. By thus separating the collection and holding functions of a MOT, we can collect as many as 1.5(0.6) x 10(10) rubidium atoms and hold them for longer than 100 s, using inexpensive low-power diode lasers.

Optics Letters•Feb 15, 1996•111 citations

Analysis of a vapor cell magneto optical trap for sodium atoms based on a two level. Doppler theory

D. M. B. P. Milori, M. T. de Araújo, I. Guedes +2 more

We present an experimental study to characterize a sodium vapor-cell magneto-optical trap (VCMOT) in terms of the number and density of trapped atoms, loading rate and load-ing time. We have investigated how these quantities change with the vapor temperature, magnetic- eld gradient and laser intensity. The results obtained are explained with a sim-ple model that employs the Doppler theory. Good agreement is obtained for most of the experimental data. Investigations on the size of the cloud as a function of the trap external parameters are also carried out. The information MOT in order to obtain the maximum presented here is useful in optimizing the number and density of trapped atoms, normally required for experiments of atomic collisions and Bose-Einstein condensation. I.

Brazilian Journal of Physics•Jun 1, 1997•9 citations

Loading and Compression of a Large Number of Rubidium Atoms Using a Semi-Dark Type Magneto-Optical Trap

Lan‐Sheng Yang, Bai-Tzeng Han, De-Sheng Hong +2 more

We have built an apparatus for setting up a double magneto-optical trap (double MOT) which allows more than 10 Rb atoms to be loaded in 15 seconds. This compact system consists mainly of a stainless steel chamber and a homemade glass cell. The two chambers are spatially separated by a small diameter transfer tube for differential pumping. The stainless steel chamber is maintained at a pressure of 10 Torr, enabling fast capturing of background Rb atoms. The optically cooled atomic clouds are pushed by a laser beam towards the glass cell which is in a much higher vacuum. Under this condition, the glass cell provides a rather long life time for holding the atoms. After the atoms are loaded in the temporarily bright MOT, a semi-dark type MOT compression is employed to reach a spatial density of 1×10 atoms/cm. The compressed atom clouds are further cooled by polarization gradient cooling to a temperature of 30 μK. The high phase space density cloud is suitable for experiments related to ultracold atoms.

Chinese Journal of Physics•Dec 1, 2007•3 citations

Magneto-optical trap loaded from a low-velocity intense source

Chang Yong Park, Myung Sim Jun, D. Cho

We produced a slow atomic beam of rubidium with a low-velocity intense source (LVIS) and loaded a magneto-optical trap (MOT) in a connected chamber with the beam. The hole for the atomic beam allowed us to keep the MOT chamber at a much lower pressure than that of the LVIS. The LVIS produced an atomic beam with a continuous flux of (4.3±0.4)×109/s and an average velocity of only 11±3 m/s. The MOT captured the atoms with 67±15% efficiency, which was limited by the atomic-beam divergence. The MOT held 6×109 atoms with a typical trap-confinement time of 8 s.

Journal of the Optical Society of America B•Jun 1, 1999•12 citations

Revisiting the capture velocity of a cesium magneto-optical trap: model, simulation and experiment

Muhammad Anwar, Daniel Varela Magalhães, Stella Müller +3 more

In this work, we have explored ab initio the capture process in a magneto-optical trap by theory, simulation and experiment. We measured the capture velocity vc of a cesium vapor cell magneto-optical trap (VCMOT) from its capture rate R and developed an exact model for the capture rate of a VCMOT in terms of its capture velocity, background density and trap laser beam diameter. We measured the capture velocity of a cesium VCMOT for various trap laser intensities and magnetic field gradients. We observed that the capture velocity is a damping force as well as a restoring force phenomenon. We supported our findings by performing simulations for single atom trajectories in a 1D cesium MOT. Finally, we concluded that two MOTs can have the same capture velocities but very different capture rates, thereby revealing that these are two fundamentally different characteristics of the MOT.

Laser Physics•Oct 7, 2014•4 citations

With a vapor-cell magneto-optical trap (VCMOT) atoms are trapped directly from the equilibrium vapor at room temperature without the complication of a precooling stage. The background vapor, however, can also be a source of energetic atoms hitting and ejecting those atoms already trapped. The background collision limits trap confinement time /spl tau/ and consequently the total number N of atoms trapped in a VCMOT. In order to have large /spl tau/ and N without losing the convenience and simplicity of a VCMOT, double MOT systems were built. In such a system there is a VCMOT with a usual background vapor pressure, and connected to it is another MOT without the vapor. The VCMOT captures atoms and transfers them to the second MOT through a long tube. The tube provides the constriction to maintain the pressure difference between the two MOT chambers. For the second MOT there is a steady supply of slow atoms without the complication of the background vapor, and it can hold a large number of atoms for a long time. Such systems were successfully used for a Bose Einstein condensation experiment and to study cold collisions.

A rubidium double magneto-optical trap(MOT) system for Bose-Einstein condensation experiments has been set up. A slow atomic beam has been obtained with a low-velocity intense source (LVIS) and used to transfer atoms into an ultra-high-vacuum (UHV) MOT. By maintaining a pressure difference of 3 orders between LVIS-MOT and UHV-MOT, a lowest pressure of 1×10-9Pa can be achieved in UHV-MOT. The flux of the slow atomic beam is 1×109/s. About 4×108 87Rb atoms can be loaded into UHV-MOT. In this paper, maximum number of atoms captured in MOTs under two typical conditions have also been discussed.

We report a two-chambered, differentially pumped system that permits rapid collection of trapped atoms with a vapor cell magneto-optical trap (MOT) and efficient transfer of these atoms to a second MOT in a lowerpressure chamber. During the transfer the atoms are guided down a long, thin tube by a magnetic potential, with 90(15%) transfer efficiency. By multiply loading, we accumulate and hold as many as 30 times the number collected by the vapor cell MOT. By thus separating the collection and holding functions of a MOT, we can collect as many as 1.5(0.6) x 10(10) rubidium atoms and hold them for longer than 100 s, using inexpensive low-power diode lasers.

We present an experimental study to characterize a sodium vapor-cell magneto-optical trap (VCMOT) in terms of the number and density of trapped atoms, loading rate and load-ing time. We have investigated how these quantities change with the vapor temperature, magnetic- eld gradient and laser intensity. The results obtained are explained with a sim-ple model that employs the Doppler theory. Good agreement is obtained for most of the experimental data. Investigations on the size of the cloud as a function of the trap external parameters are also carried out. The information MOT in order to obtain the maximum presented here is useful in optimizing the number and density of trapped atoms, normally required for experiments of atomic collisions and Bose-Einstein condensation. I.

We have built an apparatus for setting up a double magneto-optical trap (double MOT) which allows more than 10 Rb atoms to be loaded in 15 seconds. This compact system consists mainly of a stainless steel chamber and a homemade glass cell. The two chambers are spatially separated by a small diameter transfer tube for differential pumping. The stainless steel chamber is maintained at a pressure of 10 Torr, enabling fast capturing of background Rb atoms. The optically cooled atomic clouds are pushed by a laser beam towards the glass cell which is in a much higher vacuum. Under this condition, the glass cell provides a rather long life time for holding the atoms. After the atoms are loaded in the temporarily bright MOT, a semi-dark type MOT compression is employed to reach a spatial density of 1×10 atoms/cm. The compressed atom clouds are further cooled by polarization gradient cooling to a temperature of 30 μK. The high phase space density cloud is suitable for experiments related to ultracold atoms.

We produced a slow atomic beam of rubidium with a low-velocity intense source (LVIS) and loaded a magneto-optical trap (MOT) in a connected chamber with the beam. The hole for the atomic beam allowed us to keep the MOT chamber at a much lower pressure than that of the LVIS. The LVIS produced an atomic beam with a continuous flux of (4.3±0.4)×109/s and an average velocity of only 11±3 m/s. The MOT captured the atoms with 67±15% efficiency, which was limited by the atomic-beam divergence. The MOT held 6×109 atoms with a typical trap-confinement time of 8 s.

In this work, we have explored ab initio the capture process in a magneto-optical trap by theory, simulation and experiment. We measured the capture velocity vc of a cesium vapor cell magneto-optical trap (VCMOT) from its capture rate R and developed an exact model for the capture rate of a VCMOT in terms of its capture velocity, background density and trap laser beam diameter. We measured the capture velocity of a cesium VCMOT for various trap laser intensities and magnetic field gradients. We observed that the capture velocity is a damping force as well as a restoring force phenomenon. We supported our findings by performing simulations for single atom trajectories in a 1D cesium MOT. Finally, we concluded that two MOTs can have the same capture velocities but very different capture rates, thereby revealing that these are two fundamentally different characteristics of the MOT.