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arXiv · 0802.1213

Cold atom confinement in an all-optical dark ring trap

Spencer E. Olson·Matthew L. Terraciano·Mark Bashkansky·Fredrik K. Fatemi
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Abstract

We demonstrate confinement of $^{85}$Rb atoms in a dark, toroidal optical trap. We use a spatial light modulator to convert a single blue-detuned Gaussian laser beam to a superposition of Laguerre-Gaussian modes that forms a ring-shaped intensity null bounded harmonically in all directions. We measure a 1/e spin-relaxation lifetime of ~1.5 seconds for a trap detuning of 4.0 nm. For smaller detunings, a time-dependent relaxation rate is observed. We use these relaxation rate measurements and imaging diagnostics to optimize trap alignment in a programmable manner with the modulator. The results are compared with numerical simulations.

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Spencer E. Olson, Matthew L. Terraciano, Mark Bashkansky, Fredrik K. Fatemi. 2008-02-08. Cold atom confinement in an all-optical dark ring trap. https://doi.org/10.1103/physreva.76.061404

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