Fast compression of a cold atomic cloud using a blue-detuned crossed dipole trap

Bienaimé, Tom; Barontini, Giovanni; Lépinay, Laure Mercier de; Bellando, Louis; Chabé, Julien; Kaiser, Robin

doi:10.1103/physreva.86.053412

Cited by 8 publications

(3 citation statements)

References 35 publications

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“…While an additional CPM degree of freedom from a second orthogonal AOM can allow more control over atom cloud compression [27] or final BEC shape [28,29], it is unlikely that it will provide significant improvements to the speed and efficiency of evaporative cooling that we have demonstrated here. In our current implementation, we choose the vertical waist and large initial CPM amplitude to load about 50% of the compressed MOT.…”

Section: Discussionmentioning

confidence: 98%

Rapid cooling to quantum degeneracy in dynamically shaped atom traps

et al. 2016

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We report on a general method for the rapid production of quantum degenerate gases. Using 174 Yb, we achieve an experimental cycle time as low as (1.6 − 1.8) s for the production of BoseEinstein condensates (BECs) of (0.5−1)×10 5 atoms. While laser cooling to 30 µK proceeds in a standard way, evaporative cooling is highly optimized by performing it in an optical trap that is dynamically shaped by utilizing the time-averaged potential of a single laser beam moving rapidly in one dimension. We also produce large (> 10 6 ) atom number BECs and successfully model the evaporation dynamics over more than three orders of magnitude in phase space density. Our method provides a simple and general approach to solving the problem of long production times of quantum degenerate gases.

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Section: Discussionmentioning

confidence: 98%

Rapid cooling to quantum degeneracy in dynamically shaped atom traps

et al. 2016

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“…Indeed, backgroundinduced light shifts at the Hz level (10 −15 fraction of the clock frequency) or much higher are easily possible. There have been various attempts to mitigate ASE effects through amplifier optimization [23,24], spatial filtering with optical fibers [25,26], or spectral filtering using volume Bragg gratings [15,21], Fabry-Perot etalons [27], or absorption cells [28]. For an additional review of the origins and consequences of ASE, as well as an in-depth investigation of several strategies for ASE characterization, see [23].…”

Section: Introductionmentioning

confidence: 99%

Characterization and suppression of background light shifts in an optical lattice clock

Fasano

Chen

McGrew

et al. 2021

Preprint

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Experiments involving optical traps often require careful control of the ac Stark shifts induced by strong confining light fields. By carefully balancing light shifts between two atomic states of interest, optical traps at the magic wavelength have been especially effective at suppressing deleterious effects stemming from such shifts. Highlighting the power of this technique, optical clocks today exploit Lamb-Dicke confinement in magic-wavelength optical traps, in some cases realizing shift cancellation at the ten parts per billion level. Theory and empirical measurements can be used at varying levels of precision to determine the magic wavelength where shift cancellation occurs. However, lasers exhibit background spectra from amplified spontaneous emission or other lasing modes which can easily contaminate measurement of the magic wavelength and its reproducibility in other experiments or conditions. Indeed, residual light shifts from laser background have plagued optical lattice clock measurements for years. In this work, we develop a simple theoretical model allowing prediction of light shifts from measured background spectra. We demonstrate good agreement between this model and measurements of the background light shift from an amplified diode laser in an Yb optical lattice clock. Additionally, we model and experimentally characterize the filtering effect of a volume Bragg grating bandpass filter, demonstrating that application of the filter can reduce background light shifts from amplified spontaneous emission well below the 10 −18 fractional clock frequency level. This demonstration is corroborated by direct clock comparisons between a filtered amplified diode laser and a filtered titanium:sapphire laser.

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“…The ability to deliberately shape trapping or confining light allowed a variety of new geometries, including bottle beam traps [13], holographic mesoscopic traps [14] and blue detuned crossed dipole traps with a compressible dark core [15]. While these traps achieve very high densities this is usually at the expense of high technical complexity, low atom numbers or heating due to compression.…”

mentioning

confidence: 99%

Ultra high densities of cold atoms in a holographically controlled dark SPOT trap

Radwell¹,

Walker²,

Franke‐Arnold³

2013

Preprint

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We demonstrate an atom trap geometry for 87 Rb which is capable of producing ultra high atom densities. Reradiation forces, which usually limit high densities, can be avoided in dark spontaneousforce optical traps (dark SPOTs) by sheltering atoms from intense trapping light. Here we demonstrate a dynamic implementation of a dark SPOT, resulting in an increase in atom density by almost two orders of magnitude up to 1.3 × 10 12 cm −3 . Holographic control of the trapping beams and dynamic switching between MOT and dark SPOT configuration allows us to optimise the trapping geometry. We have identified the ideal size of the dark core to be six times larger than the MOT. Our method also avoids unwanted heating so that we reach a record phase-space density for a MOT.

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Fast compression of a cold atomic cloud using a blue-detuned crossed dipole trap

Cited by 8 publications

References 35 publications

Rapid cooling to quantum degeneracy in dynamically shaped atom traps

Rapid cooling to quantum degeneracy in dynamically shaped atom traps

Characterization and suppression of background light shifts in an optical lattice clock

Ultra high densities of cold atoms in a holographically controlled dark SPOT trap

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