Doppler-free polarization spectroscopy of the B 1Πu state of Cs2

The electrostatic interaction between an excited atom and a diatomic ground state molecule in an arbitrary rovibrational level at large mutual separations is investigated with a general second-order perturbation theory, in the perspective of modeling the photoassociation between cold atoms and molecules. We find that the combination of quadrupole-quadrupole and van der Waals interactions compete with the rotational energy of the dimer, limiting the range of validity of the perturbative approach to distances larger than 100 a.u.. Numerical results are given for the long-range interaction between Cs and Cs 2 , showing that the photoassociation is probably efficient whatever the Cs 2 rotational energy.

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“…[18], and the one of the B 1 Π u (6s + 6p) state from Ref. [19]. The A 1 Σ + u (6s + 6p) and b 3 Π u (6s + 6p)…”

Section: Long-range Potential Curves For the Cs-cs 2 Complexmentioning

confidence: 99%

Photoassociation of a cold-atom-molecule pair. II. Second-order perturbation approach

et al. 2011

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“…Taking into account the efficiency of the detection, the detected ion signal corresponds to about one thousand molecules in the v X = 0 level in the MOT area, and thus to a formation rate of v X = 0 molecules of more than 10 5 per second, which represent roughly 1% of the atomic loading flux in the MOT. We have modeled the optical pumping process using the experimentally known X 1 Σ + g and B 1 Π u potential curves (22,23). In our perturbative regime, the excitation probabilities are proportional to the laser spectral density at the transition frequencies.…”

mentioning

confidence: 99%

Optical Pumping and Vibrational Cooling of Molecules

Viteau

Chotia

Allegrini

et al. 2008

Science

276

285

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The methods producing cold molecules from cold atoms tend to leave molecular ensembles with substantial residual internal energy. For instance, Cs 2 molecules initially formed via photoassociation of cold Cs atoms are in several vibrational levels, v, of the electronic ground state. Here we apply a broadband femtosecond laser that redistributes the vibrational population in the ground state via a few electronic excitation -spontaneous emission cycles. The laser pulses are shaped to remove the excitation frequency band of the v = 0 level, preventing re-excitation from that state. We observe a fast and efficient accumulation, ∼ 70% of the initially detected molecules, in the lowest vibrational level, v = 0, of the singlet electronic state. The validity of this incoherent depopulation pumping method is very general and opens exciting prospects for laser cooling and manipulation of molecules.

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“…Stimulated emission is also neglected because of the small femtosecond laser intensity. Using the known potential curves of the chosen molecular system and their rotational constants [30,39], we calculate the ro-vibrational energy levels and the Franck-Condon (FC) factors for the transitions. The average laser intensity is very low, which corresponds to a perturbative regime, and thus, we assume that the excitation probability is simply proportional to the laser spectral den- sity at the transition frequencies, the FC factor, and the Hönl-London factor.…”

Section: Theoretical Modelingmentioning

confidence: 99%

Laser cooling of internal degrees of freedom of molecules

Horchani

2016

Front. Phys.

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Optical pumping techniques using laser fields combined with photo-association of ultracold atoms leads to control of the vibrational and/or rotational population of molecules. In this study, we review the basic concepts and main steps that should be followed, including the excitation schemes and detection techniques used to achieve ro-vibrational cooling of Cs 2 molecules. We also discuss the extension of this technique to other molecules. In addition, we present a theoretical model used to support the experiment. These simulations can be widely used for the preparation of various experiments because they allow the optimization of several important experimental parameters.

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Doppler-free polarization spectroscopy of the B 1Πu state of Cs2

Cited by 43 publications

References 17 publications

Photoassociation of a cold-atom-molecule pair. II. Second-order perturbation approach

Photoassociation of a cold-atom-molecule pair. II. Second-order perturbation approach

Optical Pumping and Vibrational Cooling of Molecules

Laser cooling of internal degrees of freedom of molecules

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