Cold cesium molecules: From formation to cooling

A. Fioretti, D. Sofikitis, R. Horchani, X. Li, M. Pichler, S. Weber, M. Allegrini, B. Chatel, D. Comparat, P. Pillet*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

12 Citations (Scopus)


Recent experiments on formation of translationally cold ground state molecules, their subsequent broadband vibrational cooling and study of rotations are presented together with the related modeling. We produce cold molecules by photoassociating pairs of cold cesium atoms that can decay into ground state molecules in different vibrational levels. Then we laser cool the vibrational degree of freedom by selecting a single target vibrational level. Our method is based on repeated optical pumping by laser light with a spectrum broad enough to excite all populated vibrational levels but limited in its frequency bandwidth with a spatial light modulator. In such a way we are able to eliminate transitions from the selected level, in which molecules accumulate. Results for vibrational cooling into the v = 0, v = 1, v = 2 and v = 7 level of the singlet X1g σg ground electronic state are presented. Depletion spectroscopy is performed to study the rotational distribution of the created molecules. In the theoretical modeling of the process we are able to reproduce our results and investigate the prospects for a 'complete' cooling of molecules, including also their rotational degree of freedom.

Original languageEnglish
Pages (from-to)2089-2099
Number of pages11
JournalJournal of Modern Optics
Issue number18-19
Publication statusPublished - Oct 2009
Externally publishedYes


  • Cold molecules
  • Laser cooling
  • Optical pumping
  • Vibrational cooling

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics

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