Sub-Doppler laser cooling of40K with Raman gray molasses on the ${D}_{2}$ lineSub-Doppler laser cooling of40K with Raman gray molasses on the ${D}_{2}$ line

G D Bruce, E Haller, Bruno Peaudecerf +6 more

Gray molasses is a powerful tool for sub-Doppler laser cooling of atoms to low temperatures. For alkaline atoms, this technique is commonly implemented with cooling lasers which are blue-detuned from either the D 1 or D 2 line. Here we show that efficient gray molasses can be implemented on the D 2 line of 40 K with red -detuned lasers. We obtained temperatures of , which enables direct loading of atoms from a magneto-optical trap into an optical dipole trap. We support our findings by a one-dimensional model and three-dimensional numerical simulations of the optical Bloch equations which qualitatively reproduce the experimentally observed cooling effects.Gray molasses is a powerful tool for sub-Doppler laser cooling of atoms to low temperatures. For alkaline atoms, this technique is commonly implemented with cooling lasers which are blue-detuned from either the D 1 or D 2 line. Here we show that efficient gray molasses can be implemented on the D 2 line of 40 K with red -detuned lasers. We obtained temperatures of , which enables direct loading of atoms from a magneto-optical trap into an optical dipole trap. We support our findings by a one-dimensional model and three-dimensional numerical simulations of the optical Bloch equations which qualitatively reproduce the experimentally observed cooling effects.

arXiv:1612.04583Journal of Physics B Atomic Molecular and Optical PhysicsApr 12, 201724 citations

Laser cooling of cesium atoms in far-detuned optical lattices

S. Lukman Winoto

Nov 1, 19990 citations

Sub-Doppler Laser Cooling of23Na in Gray Molasses on theD2Line

Zhenlian Shi, Ziliang Li, Pengjun Wang +3 more

We report on the efficient gray molasses cooling of sodium atoms using the D 2 optical transition at 589.1 nm. Thanks to the hyperfine split about 6 Γ between | F ′ = 2 ⟩ and | F ′ = 3 ⟩ in the excited state 3 2 P 3 / 2 , this atomic transition is effective for the gray molasses cooling mechanism. Using this cooling technique, the atomic sample in F = 2 ground manifold is cooled from 700 μ K to 56 μ K in 3.5 ms. We observe that the loading efficiency into magnetic trap is increased due to the lower temperature and high phase space density of atomic cloud after gray molasses. This technique offers a promising route for the fast cooling of the sodium atoms in the F = 2 state .We report on the efficient gray molasses cooling of sodium atoms using the D 2 optical transition at 589.1 nm. Thanks to the hyperfine split about 6 Γ between | F ′ = 2 ⟩ and | F ′ = 3 ⟩ in the excited state 3 2 P 3 / 2 , this atomic transition is effective for the gray molasses cooling mechanism. Using this cooling technique, the atomic sample in F = 2 ground manifold is cooled from 700 μ K to 56 μ K in 3.5 ms. We observe that the loading efficiency into magnetic trap is increased due to the lower temperature and high phase space density of atomic cloud after gray molasses. This technique offers a promising route for the fast cooling of the sodium atoms in the F = 2 state .

arXiv:1803.05108Chinese Physics LettersDec 1, 201815 citations

Sub-Doppler cooling of sodium atoms in gray molasses

Giacomo Colzi, Gianmaria Durastante, Eleonora Fava +3 more

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 ${10}^{11}\phantom{\rule{0.28em}{0ex}}{\mathrm{cm}}^{\ensuremath{-}3}$.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 ${10}^{11}\phantom{\rule{0.28em}{0ex}}{\mathrm{cm}}^{\ensuremath{-}3}$.

arXiv:1512.07053Physical Review AFeb 18, 201645 citations

Sub-Doppler laser cooling of40K with Raman gray molasses on the

{D}_{2}

line

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 ${10}^{11}\phantom{\rule{0.28em}{0ex}}{\mathrm{cm}}^{\ensuremath{-}3}$.