We report on the dynamics of ultracold collisions induced by near-resonant frequency-chirped light. A series of identical chirped pulses, separated by a variable delay, is applied to an ultracold sample of $^{85}\mathrm{Rb}$ , and the rate of inelastic trap-loss collisions is measured. For small detunings of the chirped light below the atomic resonance, we observe that the rate of collisions induced by a given pulse can be increased by the presence of an earlier pulse. We attribute this to the enhancement of short-range collisional flux by the long-range excitation of atom pairs to an attractive molecular potential. For larger detunings and short delays, we find that a leading pulse can suppress the rate of collisions caused by a following pulse. This is due to a depletion of short-range atom pairs by the earlier pulse. Comparison of our data to classical Monte Carlo simulations of the collisions yields reasonable agreement.We report on the dynamics of ultracold collisions induced by near-resonant frequency-chirped light. A series of identical chirped pulses, separated by a variable delay, is applied to an ultracold sample of $^{85}\mathrm{Rb}$, and the rate of inelastic trap-loss collisions is measured. For small detunings of the chirped light below the atomic resonance, we observe that the rate of collisions induced by a given pulse can be increased by the presence of an earlier pulse. We attribute this to the enhancement of short-range collisional flux by the long-range excitation of atom pairs to an attractive molecular potential. For larger detunings and short delays, we find that a leading pulse can suppress the rate of collisions caused by a following pulse. This is due to a depletion of short-range atom pairs by the earlier pulse. Comparison of our data to classical Monte Carlo simulations of the collisions yields reasonable agreement.

arXiv:physics/0611003Physical Review ADec 4, 200614 citations

On excitation of light by collisions

Miloslav A. Valouch

Časopis pro pěstování matematiky a fysikyJan 1, 19250 citations

Optical excitation of colliding atoms to a state of quasibound motion

T. A. Vartanyan, Sergey G. Przhibel'skii

Journal of Experimental and Theoretical PhysicsMay 1, 19780 citations

Transition strengths and lifetimes measured by optical nutation

Arlee V. Smith, T. D. Raymond

A transform-limited light pulse from a tunable laser can be used to measure atomic lifetimes much shorter or much longer than the light puke duration by measuring linewidths in the case of short lifetimes or decay rates in the case of long lifetimes. However, when the atomic lifetime is comparable to the duration of the exciting pulse, these methods are difficult to apply. We demonstrate that, for the latter case, an optical nutation measurement yields both lifetimes and transition strengths with high accuracy. We prepare oxygen atoms in a single angular momentum state (J, mj) in a collision-free and Doppler-free environment.A transform-limited light pulse from a tunable laser can be used to measure atomic lifetimes much shorter or much longer than the light puke duration by measuring linewidths in the case of short lifetimes or decay rates in the case of long lifetimes. However, when the atomic lifetime is comparable to the duration of the exciting pulse, these methods are difficult to apply. We demonstrate that, for the latter case, an optical nutation measurement yields both lifetimes and transition strengths with high accuracy. We prepare oxygen atoms in a single angular momentum state (J, mj) in a collision-free and Doppler-free environment.

Quantum Electronics and Laser Science ConferenceMay 12, 19910 citations

Collisions of Light with Atoms

Peter Franken

Oct 31, 19692 citations

Ultrafast Phase Relaxation of Excitons via Exciton-Exciton and Exciton-Electron Collisions

Lothar Schultheis, J. Kühl, A. Honold +1 more

The ultrafast relaxation of excitons in GaAs, coherently excited by a short optical pulse and subjected to collisions with free carriers and noncoherent excitons which are independently created by a second synchronized light pulse, is studied directly in the time domain by a probing of the excitonic phase coherence. The relaxation rates reveal strong exciton-exciton scattering with a collision efficiency of 1.6 \ifmmode\times\else\texttimes\fi{} ${10}^{\ensuremath{-}4}$ ${\mathrm{cm}}^{3}$ ${\mathrm{s}}^{\ensuremath{-}1}$ and even 10 times more efficient exciton-free-carrier scattering.The ultrafast relaxation of excitons in GaAs, coherently excited by a short optical pulse and subjected to collisions with free carriers and noncoherent excitons which are independently created by a second synchronized light pulse, is studied directly in the time domain by a probing of the excitonic phase coherence. The relaxation rates reveal strong exciton-exciton scattering with a collision efficiency of 1.6 \ifmmode\times\else\texttimes\fi{} ${10}^{\ensuremath{-}4}$ ${\mathrm{cm}}^{3}$ ${\mathrm{s}}^{\ensuremath{-}1}$ and even 10 times more efficient exciton-free-carrier scattering.

Physical Review LettersSep 29, 1986303 citations

^{85}\mathrm{Rb}

, and the rate of inelastic trap-loss collisions is measured. For small detunings of the chirped light below the atomic resonance, we observe that the rate of collisions induced by a given pulse can be increased by the presence of an earlier pulse. We attribute this to the enhancement of short-range collisional flux by the long-range excitation of atom pairs to an attractive molecular potential. For larger detunings and short delays, we find that a leading pulse can suppress the rate of collisions caused by a following pulse. This is due to a depletion of short-range atom pairs by the earlier pulse. Comparison of our data to classical Monte Carlo simulations of the collisions yields reasonable agreement.

{\mathrm{cm}}^{3}

${\mathrm{s}}^{\ensuremath{-}1}$ and even 10 times more efficient exciton-free-carrier scattering.