Ultrafast and narrow linewidth lasers are combined to study multiphoton photoassociative ionization (PAI) in a Rb magneto-optical trap. Through the use of time of flight spectroscopy and by varying the parameters of the ultrafast laser, the excitation pathway for PAI was determined. It was found that ${{\mathrm{Rb}}_{2}}^{+}$ is formed, not by direct photoionization, but by sequential excitation of ${\mathrm{Rb}}_{2}$ to an autoionizing state. Determining the excitation and ionization pathway was a necessary first step for future efforts in trying to establish coherent control techniques, first for the efficient production of translationally cold ${\mathrm{Rb}}_{2}$ , and then for transferring population to a desired vibrationally cold molecular state.Ultrafast and narrow linewidth lasers are combined to study multiphoton photoassociative ionization (PAI) in a Rb magneto-optical trap. Through the use of time of flight spectroscopy and by varying the parameters of the ultrafast laser, the excitation pathway for PAI was determined. It was found that ${{\mathrm{Rb}}_{2}}^{+}$ is formed, not by direct photoionization, but by sequential excitation of ${\mathrm{Rb}}_{2}$ to an autoionizing state. Determining the excitation and ionization pathway was a necessary first step for future efforts in trying to establish coherent control techniques, first for the efficient production of translationally cold ${\mathrm{Rb}}_{2}$, and then for transferring population to a desired vibrationally cold molecular state.

Physical Review ANov 19, 20079 citations

Demonstrating coherent control in R85b2 using ultrafast laser pulses: A theoretical outline of two experiments

Hugo E. L. Martay, David J. McCabe, Duncan G. England +3 more

Calculations relating to two experiments that demonstrate coherent control of preformed rubidium-85 molecules in a magneto-optical trap using ultrafast laser pulses are presented. The two experiments are a step toward the stabilization of ultracold rubidium dimers using ultrafast lasers. In the first experiment, it is shown that preassociated molecules in an incoherent mixture of states can be made to oscillate coherently using a single ultrafast pulse. A mechanism that can transfer molecular population to more deeply bound vibrational levels is used in the second. Optimal parameters of the control pulse are presented for the application of the mechanism to molecules in a magneto-optical trap. The calculations make use of an experimental determination of the initial state of molecules photoassociated by the trapping lasers in the magneto-optical trap and use shaped pulses consistent with a standard ultrafast laser system. The experiment's purpose is to demonstrate and evaluate the use of ultrafast shaped pulses to manipulate ultracold rubidium dimers with a view to the eventual stabilization of the molecules.Calculations relating to two experiments that demonstrate coherent control of preformed rubidium-85 molecules in a magneto-optical trap using ultrafast laser pulses are presented. The two experiments are a step toward the stabilization of ultracold rubidium dimers using ultrafast lasers. In the first experiment, it is shown that preassociated molecules in an incoherent mixture of states can be made to oscillate coherently using a single ultrafast pulse. A mechanism that can transfer molecular population to more deeply bound vibrational levels is used in the second. Optimal parameters of the control pulse are presented for the application of the mechanism to molecules in a magneto-optical trap. The calculations make use of an experimental determination of the initial state of molecules photoassociated by the trapping lasers in the magneto-optical trap and use shaped pulses consistent with a standard ultrafast laser system. The experiment's purpose is to demonstrate and evaluate the use of ultrafast shaped pulses to manipulate ultracold rubidium dimers with a view to the eventual stabilization of the molecules.

arXiv:0904.0225Physical Review ASep 3, 200910 citations

Optimal laser control of molecular photoassociation along with vibrational stabilization

Emanuel F. de Lima, Tak‐San Ho, HERSCHEL A. RABITZ

Chemical Physics LettersDec 10, 201039 citations

Femtosecond Photoassociation: Coherence and Control of Bimolecular Reactions

Marcos M. Dantus, Peter Groß, Una Marvet

APSApr 1, 19970 citations

{{\mathrm{Rb}}_{2}}^{+}

is formed, not by direct photoionization, but by sequential excitation of

{\mathrm{Rb}}_{2}

to an autoionizing state. Determining the excitation and ionization pathway was a necessary first step for future efforts in trying to establish coherent control techniques, first for the efficient production of translationally cold

{\mathrm{Rb}}_{2}

, and then for transferring population to a desired vibrationally cold molecular state.