We propose a new spectroscopic method for measuring weak transitions in cold and trapped atoms, which exploits the long spin relaxation times and tight spatial confinement offered by dark optical traps to achieve extremely high sensitivity. We demonstrate our scheme by measuring a 5 S 1/2 → 5 D 5/2 two-photon transition in cold Rb atoms trapped in a new single-beam dark optical trap, using an extremely weak probe laser power of 25 μW. We were able to measure transitions with as small excitation rate as < 0.1 s −1 , using 10 7 fold quantum amplification of the transition rate due to spin shelving and normalized detection with a strong cycling transition.We propose a new spectroscopic method for measuring weak transitions in cold and trapped atoms, which exploits the long spin relaxation times and tight spatial confinement offered by dark optical traps to achieve extremely high sensitivity. We demonstrate our scheme by measuring a 5 S 1/2 → 5 D 5/2 two-photon transition in cold Rb atoms trapped in a new single-beam dark optical trap, using an extremely weak probe laser power of 25 μW. We were able to measure transitions with as small excitation rate as < 0.1 s −1 , using 10 7 fold quantum amplification of the transition rate due to spin shelving and normalized detection with a strong cycling transition.

Europhysics Letters (EPL)May 15, 200021 citations

Cold-atom confinement in an all-optical dark ring trap

Spencer E. Olson, Matthew L. Terraciano, Mark Bashkansky +1 more

We demonstrate confinement of $^{85}\mathrm{Rb}$ 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 $\ensuremath{\approx}1.5\phantom{\rule{0.3em}{0ex}}\mathrm{s}$ for a trap detuning of $4.0\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$ . 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.We demonstrate confinement of $^{85}\mathrm{Rb}$ 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 $\ensuremath{\approx}1.5\phantom{\rule{0.3em}{0ex}}\mathrm{s}$ for a trap detuning of $4.0\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$. 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.

arXiv:0802.1213Physical Review ADec 28, 200791 citations

Spinor Condensates in Optical Dipole Traps

WORLD SCIENTIFIC eBooksDec 1, 20060 citations

Long spin relaxation times in a single-beam blue-detuned optical trap

Roee Ozeri, Lev Khaykovich, Nir Davidson

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

We demonstrate confinement of

^{85}\mathrm{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 $\ensuremath{\approx}1.5\phantom{\rule{0.3em}{0ex}}\mathrm{s}$ for a trap detuning of

4.0\phantom{\rule{0.3em}{0ex}}\mathrm{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.

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.