Optical pumping of a Cal metastable triplet

We propose a process to convert ultracold metastable ${\mathrm{Cs}}_{2}$ molecules in their lowest triplet state into (singlet) ground-state molecules in their lowest vibrational levels. Molecules are first pumped into an excited triplet state, and the triplet-singlet conversion is facilitated by a two-step spontaneous decay through the coupled $A {}^{1}{\ensuremath{\Sigma}}_{u}^{+}\ensuremath{-}b {}^{3}{\ensuremath{\Pi}}_{u}$ states. Using spectroscopic data and accurate quantum chemistry calculations for ${\mathrm{Cs}}_{2}$ potential curves and transition dipole moments, we show that this process competes favorably with the single-photon decay back to the lowest triplet state. In addition, we demonstrate that this conversion process represents a loss channel for vibrational cooling of metastable triplet molecules, preventing an efficient optical pumping cycle down to low vibrational levels.We propose a process to convert ultracold metastable ${\mathrm{Cs}}_{2}$ molecules in their lowest triplet state into (singlet) ground-state molecules in their lowest vibrational levels. Molecules are first pumped into an excited triplet state, and the triplet-singlet conversion is facilitated by a two-step spontaneous decay through the coupled $A {}^{1}{\ensuremath{\Sigma}}_{u}^{+}\ensuremath{-}b {}^{3}{\ensuremath{\Pi}}_{u}$ states. Using spectroscopic data and accurate quantum chemistry calculations for ${\mathrm{Cs}}_{2}$ potential curves and transition dipole moments, we show that this process competes favorably with the single-photon decay back to the lowest triplet state. In addition, we demonstrate that this conversion process represents a loss channel for vibrational cooling of metastable triplet molecules, preventing an efficient optical pumping cycle down to low vibrational levels.

arXiv:1011.2563Physical Review AFeb 8, 20118 citations

Optical self-pumping of atoms

Evgenii B. Aleksandrov, N. N. Yakobson

Uspekhi Fizicheskih NaukJan 1, 19801 citation

We propose a process to convert ultracold metastable

{\mathrm{Cs}}_{2}

molecules in their lowest triplet state into (singlet) ground-state molecules in their lowest vibrational levels. Molecules are first pumped into an excited triplet state, and the triplet-singlet conversion is facilitated by a two-step spontaneous decay through the coupled $A {}^{1}{\ensuremath{\Sigma}}_{u}^{+}\ensuremath{-}b {}^{3}{\ensuremath{\Pi}}_{u}$ states. Using spectroscopic data and accurate quantum chemistry calculations for

{\mathrm{Cs}}_{2}

potential curves and transition dipole moments, we show that this process competes favorably with the single-photon decay back to the lowest triplet state. In addition, we demonstrate that this conversion process represents a loss channel for vibrational cooling of metastable triplet molecules, preventing an efficient optical pumping cycle down to low vibrational levels.