Physical Review A

Laser cooling of cesium atoms in gray optical molasses down to 1.1 μK

Denis Boiron, A. Michaud, P. Lemonde, Yvan Castin, Ch Salomon, S. Weyers, K. Szymaniec, Laurent Cognet, Andr Clairon

Published Jun 1, 1996• 91 citations

Abstract

We have studied the behavior of cesium atoms cooled in six-beam "gray" optical molasses. Cooling occurs for a laser detuned to the blue side of the $6{S}_{\frac{1}{2}}$, $F=3\ensuremath{\rightarrow}6{P}_{\frac{3}{2}}$, ${F}^{\ensuremath{'}}=2$ transition, and a Sisyphus-type effect accumulates the atoms in states not coupled to the light. We measure a minimum temperature of 1.1\ifmmode\pm\else\textpm\fi{}0.1 \ensuremath{\mu}K at low atomic density. The typical cooling time is on the order of 1 ms. A linear dependence of the temperature versus atomic density is found with a slope of \ensuremath{\sim}0.6 \ensuremath{\mu}K/(${10}^{10}$ atoms/${\mathrm{cm}}^{3}$).

DOI: 10.1103/physreva.53.r3734

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Physical Review A

Laser cooling of cesium atoms in gray optical molasses down to 1.1 μK

Denis Boiron, A. Michaud, P. Lemonde, Yvan Castin, Ch Salomon, S. Weyers, K. Szymaniec, Laurent Cognet, Andr Clairon

Published Jun 1, 1996• 91 citations

Publisher

Abstract

We have studied the behavior of cesium atoms cooled in six-beam "gray" optical molasses. Cooling occurs for a laser detuned to the blue side of the

6{S}_{\frac{1}{2}}

F=3\ensuremath{\rightarrow}6{P}_{\frac{3}{2}}

{F}^{\ensuremath{'}}=2

transition, and a Sisyphus-type effect accumulates the atoms in states not coupled to the light. We measure a minimum temperature of 1.1\ifmmode\pm\else\textpm\fi{}0.1 \ensuremath{\mu}K at low atomic density. The typical cooling time is on the order of 1 ms. A linear dependence of the temperature versus atomic density is found with a slope of \ensuremath{\sim}0.6 \ensuremath{\mu}K/(

{10}^{10}

atoms/

{\mathrm{cm}}^{3}

DOI: 10.1103/physreva.53.r3734

Related papers

Three-dimensional cooling of cesium atoms in four-beam gray optical molasses

Denis Boiron, C. Triché, D. R. Meacher +2 more

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AIP conference proceedingsJan 1, 20010 citations

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arXiv:1512.07053Physical Review AFeb 18, 201645 citations

We have studied the behavior of cesium atoms cooled in six-beam "gray" optical molasses. Cooling occurs for a laser detuned to the blue side of the

6{S}_{\frac{1}{2}}

F=3\ensuremath{\rightarrow}6{P}_{\frac{3}{2}}

{F}^{\ensuremath{'}}=2

{10}^{10}

atoms/

{\mathrm{cm}}^{3}

We report the observation of three-dimensional cooling of cesium atoms using a four-beam optical molasses tuned to the blue side of the

{\mathit{F}}_{\mathit{g}}

=3\ensuremath{\rightarrow}

{\mathit{F}}_{\mathit{e}}

=2 hyperfine component of the 6

{\mathit{S}}_{1/2}

\ensuremath{\rightarrow}6

{\mathit{P}}_{3/2}

transition. The cooling mechanism is a Sisyphus effect involving atomic states that are nearly uncoupled from the light field. Starting from a magneto-optical trap at 70 \ensuremath{\mu}K, the cooling time was on the order of 1 ms with almost 100% capture efficiency and temperature smaller than 5 \ensuremath{\mu}K measured. We also present a probe transmission spectrum showing that almost all the atoms are found in the nearly dark states.

We report on the realization of sub-Doppler laser cooling of sodium atoms in gray molasses using the

{D}_{1}

optical transition $(3s\phantom{\rule{0.16em}{0ex}}^{2}S_{1/2}\ensuremath{\rightarrow}3p\phantom{\rule{0.16em}{0ex}}^{2}P_{1/2})$ at 589.8 nm. The technique is applied to samples containing $3\ifmmode\times\else\texttimes\fi{}{10}^{9}$ atoms, previously cooled to $350\phantom{\rule{0.28em}{0ex}}\ensuremath{\mu}\mathrm{K}$ in a magneto-optical trap, and it leads to temperatures as low as $9\phantom{\rule{0.28em}{0ex}}\ensuremath{\mu}\mathrm{K}$ and phase-space densities in the range of ${10}^{\ensuremath{-}4}$. The capture efficiency of the gray molasses is larger than 2/3, and we observe no density-dependent heating for densities up to ${10}^{11}\phantom{\rule{0.28em}{0ex}}{\mathrm{cm}}^{\ensuremath{-}3}$.