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

Journal of the Optical Society of America B

Storage time of cold Rb atoms in an optical dipole trap formed by a multimode fiber laser

Wei-Lun Hung, Panpan Huang, Feng-Chuan Wu, Martins Bruvelis, Hau-Yl Xiao, Aigars Ekers, Ite A. Yu

Published Apr 8, 2015• 9 citations
Publisher

Abstract

We systematically studied the storage time of Rb87 atoms in an optical dipole trap (ODT) formed by a multimode fiber laser. Storage time is an important parameter in cold atom experiments. If atoms are prepared in the hyperfine state |F=2〉, hyperfine-state-changing collisions can transfer these atoms from |F=2〉 to |F=1〉, whereby the released kinetic energy leads to considerable trap loss. In most ODT experiments, atoms are prepared in the hyperfine state |F=1〉. However, two-photon Raman transitions induced by high-power multimode fiber lasers can optically pump these atoms from |F=1〉 to |F=2〉, and the following hyperfine-state-changing collision results in the trap loss. In this work, our experimental data indicate that both the two-photon Raman transition and the hyperfine-state-changing collision can be inhibited if the atoms are prepared in the single Zeeman sublevel of |F=2,m=2〉 (or |F=2,m=−2〉) and an auxiliary magnetic field is applied.

DOI
10.1364/josab.32.000b32

Related papers

Magic-wavelength optical dipole trap of cesium and rubidium atoms

Junmin Wang, Yongjie Cheng, Shanlong Guo +2 more

Optical dipole traps (ODT) with far-off-resonance laser are important tools in more and more present cold-atom experiments, which allow confinement of laser-cooled atoms with a long storage time. Particularly, the magic wavelength ODT can cancel the position-dependent spatially inhomogeneous light shift of desired atomic transition, which is introduced by the ODT laser beam. Now it plays an important role in the state-insensitive quantum engineering and the atomic optical clock. To verify the magic wavelength or the magic wavelength combination for D2 line transition of cesium (Cs) and rubidium (Rb) atoms, we calculated and analyzed the light shift of the 133Cs 6S1/2 - 6P3/2 transition for a monochromatic ODT, and also the 87Rb 5S1/2 - 5P3/2 transition for a dichromatic ODT with a laser frequency ratio of 2:1. Also a dichromatic magic-wavelength ODT laser system for 87Rb atoms is proposed and experimentally realized by employing the quasi-phase-matched frequency doubling technique with telecom laser and fiber amplifier.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Apr 11, 2012•2 citations

Single Atoms in an Optical Dipole Trap: Towards a Deterministic Source of Cold Atoms

Daniel Frese, B. Ueberholz, Stefan Kuhr +4 more

We describe a simple experimental technique which allows us to store a small and deterministic number of neutral atoms in an optical dipole trap. The desired atom number is prepared in a magneto-optical trap overlapped with a single focused Nd:YAG laser beam. Dipole trap loading efficiency of 100% and storage times of about one minute have been achieved. We have also prepared atoms in a certain hyperfine state and demonstrated the feasibility of a state-selective detection via resonance fluorescence at the level of a few neutral atoms. A spin relaxation time of the polarized sample of 4.2+/-0.7 s has been measured. Possible applications are briefly discussed.

arXiv:quant-ph/0003052•Physical Review Letters•Oct 30, 2000•140 citations

Nonlinear magneto-optical effects and quantum coherences in cold rubidium atoms in an optical dipole trap

Adam M. Wojciechowski, Krystian Sycz, Artur Stabrawa +3 more

We report on our experiments on nonlinear magneto-optical effects in laser-cooled, near-degenerate rubidium samples. Atoms are laser-cooled and subsequently transferred to the crossed-beam optical dipole trap (ODT), formed by a tight focusing of 1560-nm laser beams. The trap not only provides long relaxation time but also allows us to investigate the quantum degeneracy regime. Moreover, the tight confinement of atoms enables magnetic field probing with a high spatial resolution of a few tens of micrometers.

Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC)•May 1, 2013•0 citations

Formation of ultracold molecules induced by a high-power single-frequency fiber laser

Henry Fernandes Passagem, Ricardo Colín‐Rodríguez, Paulo Cesar Ventura +3 more

Abstract The influence of a high-power single-frequency fiber laser on the formation of ultracold 85 Rb 2 molecules is investigated as a function of its frequency (in the 1062–1070 nm range) in a magneto-optical trap. We find evidence for the formation of ground-state 85 Rb 2 molecules in low vibrational levels ( v ≤ 20 ) with a maximal rate of 10 4 s −1 , induced by short-range photoassociation by the fiber laser followed by spontaneous emission. When this laser is used to set up a dipole trap, we measure an atomic loss rate at a wavelength far from the PA resonances, only four times smaller than that observed at a PA resonance wavelength. This work may have important consequences for atom trapping using lasers around the conventional 1064 nm wavelength.

Journal of Physics B Atomic Molecular and Optical Physics•Jan 19, 2017•7 citations

Light scattering from laser-trapped atoms

Robert A. Cline, Joseph D. Miller, M. R. Matthews +1 more

We study a novel property of light scattering by Rb atoms confined in a far off-resonance optical dipole force trap. The trapping laser wavelength varies from 780 nm to 860 nm and its intensity is about 1 MW/cm{sup 2}. Spontaneous Raman scattering of photons from the trapping laser can change the ground-state hyperfine quantum number F of the atoms. We observe the relaxation time by measuring the population of the F=3 level after optically pumping the atoms into the F=2 level. Spontaneous photon scatter rates as low as 10{sup 3} s{sup -1} have been observed, corresponding to recoil heating rates below 1 mK/s. For detuning from resonance {Delta} greater than the excited-state fine-structure splitting the total scatter rate, including Rayleigh scattering, decreases as {Delta}{sup 2} while the spontaneous Raman scatter rate decreases as {Delta}{sup 4}. This is due to interference between the Raman scattering amplitudes from the two excited-state fine-structure levels in the Kramers-Heisenberg formula. Because Rayleigh scattering dominates, the atoms` F and M{sub F} quantum numbers are preserved even after many scattering events. This makes far off-resonance optical traps ideal for studies of state-selective collisions and collective phenomena.

Bulletin of the American Physical Society•May 1, 1993•0 citations

Optimized Bose-Einstein-condensate production in a dipole trap based on a 1070-nm multifrequency laser: Influence of enhanced two-body loss on the evaporation process

Thomas Lauber, J. Küber, O. Wille +1 more

We present an optimized strategy for the production of tightly confined Bose-Einstein condensates (BEC) of ${}^{87}$Rb in a crossed dipole trap with direct loading from a magneto-optical trap. The dipole trap is created with light of a multifrequency fiber laser with a center wavelength of 1070 nm. Evaporative cooling is performed by ramping down the laser power only. A comparison of the resulting atom number in an almost pure BEC to the initial atom number and the value for the gain in phase space density per atom lost confirm that this straightforward strategy is very efficient. We observe that the temporal characteristics of evaporation sequence are strongly influenced by power-dependent two-body losses resulting from enhanced optical pumping to the higher-energy hyperfine state. We characterize these losses and compare them to results obtained with a single-frequency laser at 1030 nm.

arXiv:1110.5192•Physical Review A•Oct 28, 2011•31 citations
We systematically studied the storage time of Rb87 atoms in an optical dipole trap (ODT) formed by a multimode fiber laser. Storage time is an important parameter in cold atom experiments. If atoms are prepared in the hyperfine state |F=2〉, hyperfine-state-changing collisions can transfer these atoms from |F=2〉 to |F=1〉, whereby the released kinetic energy leads to considerable trap loss. In most ODT experiments, atoms are prepared in the hyperfine state |F=1〉. However, two-photon Raman transitions induced by high-power multimode fiber lasers can optically pump these atoms from |F=1〉 to |F=2〉, and the following hyperfine-state-changing collision results in the trap loss. In this work, our experimental data indicate that both the two-photon Raman transition and the hyperfine-state-changing collision can be inhibited if the atoms are prepared in the single Zeeman sublevel of |F=2,m=2〉 (or |F=2,m=−2〉) and an auxiliary magnetic field is applied.
Optical dipole traps (ODT) with far-off-resonance laser are important tools in more and more present cold-atom experiments, which allow confinement of laser-cooled atoms with a long storage time. Particularly, the magic wavelength ODT can cancel the position-dependent spatially inhomogeneous light shift of desired atomic transition, which is introduced by the ODT laser beam. Now it plays an important role in the state-insensitive quantum engineering and the atomic optical clock. To verify the magic wavelength or the magic wavelength combination for D2 line transition of cesium (Cs) and rubidium (Rb) atoms, we calculated and analyzed the light shift of the 133Cs 6S1/2 - 6P3/2 transition for a monochromatic ODT, and also the 87Rb 5S1/2 - 5P3/2 transition for a dichromatic ODT with a laser frequency ratio of 2:1. Also a dichromatic magic-wavelength ODT laser system for 87Rb atoms is proposed and experimentally realized by employing the quasi-phase-matched frequency doubling technique with telecom laser and fiber amplifier.
We describe a simple experimental technique which allows us to store a small and deterministic number of neutral atoms in an optical dipole trap. The desired atom number is prepared in a magneto-optical trap overlapped with a single focused Nd:YAG laser beam. Dipole trap loading efficiency of 100% and storage times of about one minute have been achieved. We have also prepared atoms in a certain hyperfine state and demonstrated the feasibility of a state-selective detection via resonance fluorescence at the level of a few neutral atoms. A spin relaxation time of the polarized sample of 4.2+/-0.7 s has been measured. Possible applications are briefly discussed.
We report on our experiments on nonlinear magneto-optical effects in laser-cooled, near-degenerate rubidium samples. Atoms are laser-cooled and subsequently transferred to the crossed-beam optical dipole trap (ODT), formed by a tight focusing of 1560-nm laser beams. The trap not only provides long relaxation time but also allows us to investigate the quantum degeneracy regime. Moreover, the tight confinement of atoms enables magnetic field probing with a high spatial resolution of a few tens of micrometers.
Abstract The influence of a high-power single-frequency fiber laser on the formation of ultracold 85 Rb 2 molecules is investigated as a function of its frequency (in the 1062–1070 nm range) in a magneto-optical trap. We find evidence for the formation of ground-state 85 Rb 2 molecules in low vibrational levels ( v ≤ 20 ) with a maximal rate of 10 4 s −1 , induced by short-range photoassociation by the fiber laser followed by spontaneous emission. When this laser is used to set up a dipole trap, we measure an atomic loss rate at a wavelength far from the PA resonances, only four times smaller than that observed at a PA resonance wavelength. This work may have important consequences for atom trapping using lasers around the conventional 1064 nm wavelength.
We study a novel property of light scattering by Rb atoms confined in a far off-resonance optical dipole force trap. The trapping laser wavelength varies from 780 nm to 860 nm and its intensity is about 1 MW/cm{sup 2}. Spontaneous Raman scattering of photons from the trapping laser can change the ground-state hyperfine quantum number F of the atoms. We observe the relaxation time by measuring the population of the F=3 level after optically pumping the atoms into the F=2 level. Spontaneous photon scatter rates as low as 10{sup 3} s{sup -1} have been observed, corresponding to recoil heating rates below 1 mK/s. For detuning from resonance {Delta} greater than the excited-state fine-structure splitting the total scatter rate, including Rayleigh scattering, decreases as {Delta}{sup 2} while the spontaneous Raman scatter rate decreases as {Delta}{sup 4}. This is due to interference between the Raman scattering amplitudes from the two excited-state fine-structure levels in the Kramers-Heisenberg formula. Because Rayleigh scattering dominates, the atoms` F and M{sub F} quantum numbers are preserved even after many scattering events. This makes far off-resonance optical traps ideal for studies of state-selective collisions and collective phenomena.
We present an optimized strategy for the production of tightly confined Bose-Einstein condensates (BEC) of 87{}^{87}87Rb in a crossed dipole trap with direct loading from a magneto-optical trap. The dipole trap is created with light of a multifrequency fiber laser with a center wavelength of 1070 nm. Evaporative cooling is performed by ramping down the laser power only. A comparison of the resulting atom number in an almost pure BEC to the initial atom number and the value for the gain in phase space density per atom lost confirm that this straightforward strategy is very efficient. We observe that the temporal characteristics of evaporation sequence are strongly influenced by power-dependent two-body losses resulting from enhanced optical pumping to the higher-energy hyperfine state. We characterize these losses and compare them to results obtained with a single-frequency laser at 1030 nm.