A scheme to trap atoms in a blue-detuned optical dipole trap, formed with a single laser beam and a holographic phase plate, is demonstrated. ${10}^{5}$ rubidium atoms are trapped for (1/e lifetime) \ensuremath{\sim}300 msec, at temperatures of \ensuremath{\sim}24 \ensuremath{\mu}K and a density of $\ensuremath{\sim}7\ifmmode\times\else\texttimes\fi{}{10}^{11}{\mathrm{a}\mathrm{t}\mathrm{o}\mathrm{m}\mathrm{s}/\mathrm{c}\mathrm{m}}^{3},$ for a trapping beam detuning of 0.1--30 nm. The time for a trapped atom to scatter one photon off the trapping beam is measured and found to be linear in the trapping laser detuning. At a detuning of 0.5 nm from resonance this time was measured to be \ensuremath{\sim}100 msec, indicating that the atoms are exposed on average only to \ensuremath{\sim}1/700 of the maximal light intensity in the trap. The use of a single laser beam allows for simple dynamical changes of the potential and large adiabatic compressions, while keeping the atoms mainly in the dark.A scheme to trap atoms in a blue-detuned optical dipole trap, formed with a single laser beam and a holographic phase plate, is demonstrated. ${10}^{5}$ rubidium atoms are trapped for (1/e lifetime) \ensuremath{\sim}300 msec, at temperatures of \ensuremath{\sim}24 \ensuremath{\mu}K and a density of $\ensuremath{\sim}7\ifmmode\times\else\texttimes\fi{}{10}^{11}{\mathrm{a}\mathrm{t}\mathrm{o}\mathrm{m}\mathrm{s}/\mathrm{c}\mathrm{m}}^{3},$ for a trapping beam detuning of 0.1--30 nm. The time for a trapped atom to scatter one photon off the trapping beam is measured and found to be linear in the trapping laser detuning. At a detuning of 0.5 nm from resonance this time was measured to be \ensuremath{\sim}100 msec, indicating that the atoms are exposed on average only to \ensuremath{\sim}1/700 of the maximal light intensity in the trap. The use of a single laser beam allows for simple dynamical changes of the potential and large adiabatic compressions, while keeping the atoms mainly in the dark.

Physical Review AMar 1, 1999128 citations

Cold-atom densities of more than 10 12 cm − 3 in a holographically shaped dark spontaneous-force optical trap

Neal Radwell, G. Walker, Sonja Franke‐Arnold

We demonstrate an atom trap geometry for ${}^{87}$ Rb which is capable of producing ultrahigh atom densities. Reradiation forces, which usually limit high densities, can be avoided in dark spontaneous-force 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 $1.3\ifmmode\times\else\texttimes\fi{}{10}^{12}$ cm${}^{\ensuremath{-}3}$. Holographic control of the trapping beams and dynamic switching between magneto-optical trap (MOT) and dark SPOT configuration allows us to optimize 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.We demonstrate an atom trap geometry for ${}^{87}$Rb which is capable of producing ultrahigh atom densities. Reradiation forces, which usually limit high densities, can be avoided in dark spontaneous-force 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 $1.3\ifmmode\times\else\texttimes\fi{}{10}^{12}$ cm${}^{\ensuremath{-}3}$. Holographic control of the trapping beams and dynamic switching between magneto-optical trap (MOT) and dark SPOT configuration allows us to optimize 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.

Physical Review AOct 8, 201332 citations

Cold and dense clouds of atoms in a holographic atom trap

Raymond Newell

Jan 1, 20032 citations

A scheme to trap atoms in a blue-detuned optical dipole trap, formed with a single laser beam and a holographic phase plate, is demonstrated.

{10}^{5}

rubidium atoms are trapped for (1/e lifetime) \ensuremath{\sim}300 msec, at temperatures of \ensuremath{\sim}24 \ensuremath{\mu}K and a density of $\ensuremath{\sim}7\ifmmode\times\else\texttimes\fi{}{10}^{11}{\mathrm{a}\mathrm{t}\mathrm{o}\mathrm{m}\mathrm{s}/\mathrm{c}\mathrm{m}}^{3},$ for a trapping beam detuning of 0.1--30 nm. The time for a trapped atom to scatter one photon off the trapping beam is measured and found to be linear in the trapping laser detuning. At a detuning of 0.5 nm from resonance this time was measured to be \ensuremath{\sim}100 msec, indicating that the atoms are exposed on average only to \ensuremath{\sim}1/700 of the maximal light intensity in the trap. The use of a single laser beam allows for simple dynamical changes of the potential and large adiabatic compressions, while keeping the atoms mainly in the dark.

We demonstrate an atom trap geometry for

{}^{87}

Rb which is capable of producing ultrahigh atom densities. Reradiation forces, which usually limit high densities, can be avoided in dark spontaneous-force 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 $1.3\ifmmode\times\else\texttimes\fi{}{10}^{12}$ cm${}^{\ensuremath{-}3}$. Holographic control of the trapping beams and dynamic switching between magneto-optical trap (MOT) and dark SPOT configuration allows us to optimize 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.