We report the realization of a blue-detuned magneto-optical trap (BDM) of BaF molecules. The (1+1) type BDM and (1+2) type conveyor-belt MOT (CB-MOT) are explored. While the (1+1) BDM provides only a weak trapping force, the CB-MOT significantly compresses the molecular cloud, achieving a Gaussian rms width of 316 μm, a temperature of 240 μK, and a peak number density of 2.4×10^{7} cm^{-3}. This performance marks two orders of magnitude improvement over red-detuned MOTs. More importantly, we demonstrate the efficient direct loading of the CB-MOT from a slowed molecular beam, surpassing the loading efficiency of the standard dual-frequency MOT. This surprising result is attributed to the dipole-force-dominated trapping mechanism, wherein the capture velocity increases continuously with laser power, unimpeded by the saturation limit of photon scattering. This method is particularly advantageous for laser cooling and trapping challenging molecular species with large mass, small photon recoil, and narrow linewidths.We report the realization of a blue-detuned magneto-optical trap (BDM) of BaF molecules. The (1+1) type BDM and (1+2) type conveyor-belt MOT (CB-MOT) are explored. While the (1+1) BDM provides only a weak trapping force, the CB-MOT significantly compresses the molecular cloud, achieving a Gaussian rms width of 316 μm, a temperature of 240 μK, and a peak number density of 2.4×10^{7} cm^{-3}. This performance marks two orders of magnitude improvement over red-detuned MOTs. More importantly, we demonstrate the efficient direct loading of the CB-MOT from a slowed molecular beam, surpassing the loading efficiency of the standard dual-frequency MOT. This surprising result is attributed to the dipole-force-dominated trapping mechanism, wherein the capture velocity increases continuously with laser power, unimpeded by the saturation limit of photon scattering. This method is particularly advantageous for laser cooling and trapping challenging molecular species with large mass, small photon recoil, and narrow linewidths.

Physical Review LettersJan 20, 20262 citations

Loading an optical dipole trap

S. J. M. Kuppens, Kristan L. Corwin, Kurt W. Miller +2 more

WORLD SCIENTIFIC eBooksJan 1, 20080 citations

Beating the density limit by continuously loading a dipole trap from millikelvin-hot magnesium atoms

Matthias Riedmann, Hrishikesh Kelkar, Temmo Wübbena +8 more

We load ${10}^{5}$ magnesium atoms in a dipole trap from a millikelvin-hot magneto-optical trap (MOT) using a continuous-loading scheme. Light-assisted two-body processes limit the maximum achievable density in a MOT, resulting in a reduced transfer efficiency into a dipole trap when using the conventional sequential scheme. It is overcome in a continuous-loading scheme where a loss channel is opened in the MOT. This allows the accumulation of atoms in the dipole trap over the trap lifetime, determined by collisions with the background gas. This results in a significantly higher number of trapped atoms even at a lower steady-state peak density in the MOT.We load ${10}^{5}$ magnesium atoms in a dipole trap from a millikelvin-hot magneto-optical trap (MOT) using a continuous-loading scheme. Light-assisted two-body processes limit the maximum achievable density in a MOT, resulting in a reduced transfer efficiency into a dipole trap when using the conventional sequential scheme. It is overcome in a continuous-loading scheme where a loss channel is opened in the MOT. This allows the accumulation of atoms in the dipole trap over the trap lifetime, determined by collisions with the background gas. This results in a significantly higher number of trapped atoms even at a lower steady-state peak density in the MOT.

Physical Review AOct 10, 201238 citations

Loading Dynamics and Characteristics of a Far Off-Resonance Optical Dipole Trap

Pascal G. Mickelson, Y. N. Martinez, Sarah Nagel +2 more

Bulletin of the American Physical SocietyJun 8, 20070 citations

Loading an optical dipole trap

S. J. M. Kuppens, Kristan L. Corwin, Kurt W. Miller +2 more

We present a detailed experimental study of the physics involved in transferring atoms from a magneto-optical trap (MOT) to an optical dipole trap. The loading is a dynamical process determined by a loading rate and a density dependent loss rate. The loading rate depends on cooling and the flux of atoms into the trapping volume, and the loss rate is due to excited state collisions induced by the MOT light fields. From this study we found ways to optimize the loading of the optical dipole trap. Key ingredients for maximum loading are found to be a reduction of the hyperfine repump intensity, increased detuning of the MOT light, and a displacement of the optical dipole trap center with respect to the MOT. A factor of 2 increase in the number of loaded atoms is demonstrated by using a hyperfine repump beam with a shadow in it. In this way we load $8\ifmmode\times\else\texttimes\fi{}{10}^{6}{}^{85}\mathrm{Rb}$ atoms into a 1 mK deep optical dipole trap with a waist of $58 \ensuremath{\mu}\mathrm{m},$ which is 40% of the atoms initially trapped in the MOT.We present a detailed experimental study of the physics involved in transferring atoms from a magneto-optical trap (MOT) to an optical dipole trap. The loading is a dynamical process determined by a loading rate and a density dependent loss rate. The loading rate depends on cooling and the flux of atoms into the trapping volume, and the loss rate is due to excited state collisions induced by the MOT light fields. From this study we found ways to optimize the loading of the optical dipole trap. Key ingredients for maximum loading are found to be a reduction of the hyperfine repump intensity, increased detuning of the MOT light, and a displacement of the optical dipole trap center with respect to the MOT. A factor of 2 increase in the number of loaded atoms is demonstrated by using a hyperfine repump beam with a shadow in it. In this way we load $8\ifmmode\times\else\texttimes\fi{}{10}^{6}{}^{85}\mathrm{Rb}$ atoms into a 1 mK deep optical dipole trap with a waist of $58 \ensuremath{\mu}\mathrm{m},$ which is 40% of the atoms initially trapped in the MOT.

Physical Review AJun 13, 2000185 citations

Improved loading of an optical dipole trap by suppression of radiative escape

Stephan Dürr, Kurt W. Miller, Carl Wieman

WORLD SCIENTIFIC eBooksJan 1, 20080 citations

We load

{10}^{5}

magnesium atoms in a dipole trap from a millikelvin-hot magneto-optical trap (MOT) using a continuous-loading scheme. Light-assisted two-body processes limit the maximum achievable density in a MOT, resulting in a reduced transfer efficiency into a dipole trap when using the conventional sequential scheme. It is overcome in a continuous-loading scheme where a loss channel is opened in the MOT. This allows the accumulation of atoms in the dipole trap over the trap lifetime, determined by collisions with the background gas. This results in a significantly higher number of trapped atoms even at a lower steady-state peak density in the MOT.