Continuous loading of S-1(0) calcium atoms into an optical dipole trap

Link:
Autor/in:
Erscheinungsjahr:
2007
Medientyp:
Text
Beschreibung:
  • We demonstrate an efficient scheme for continuous trap loading based upon spatially selective optical pumping. We discuss the case of S01 calcium atoms in an optical dipole trap (ODT), however, similar strategies should be applicable to a wide range of atomic species, which do not permit efficient conventional trap loading. Our starting point is a moderately cold (300 μK) and dense (9× 109 cm-3) reservoir of metastable P23 atoms in a magneto-optic trap (triplet MOT). A focused 532 nm laser beam produces a strongly elongated optical potential for S01 atoms with up to 350 μK well depth. A weak focused laser beam at 430 nm, carefully superimposed upon the ODT beam, selectively pumps the P23 atoms inside the capture volume to the singlet state, where they are confined by the ODT. The triplet MOT perpetually refills the capture volume with P23 atoms, thus providing a continuous stream of cold atoms into the ODT at a rate of 107 s-1. Limited by evaporation loss, in 200 ms we typically load 5× 105 atoms with 3.5× 1010 cm-3 peak density and axial and radial temperatures of 300 and 85 μK, respectively. After terminating the loading we observe evaporation during 50 ms, typically leaving us with 105 atoms with nearly equal radial and axial temperatures close to 40 μK and a peak density of 5× 1011 cm-3. A simple model is presented, which identifies the relevant physical mechanisms of the loading and decay dynamics. We point out that a comparable scheme could be employed to load a dipole trap with P03 atoms. © 2007 The American Physical Society.
Lizenz:
  • info:eu-repo/semantics/restrictedAccess
Quellsystem:
Forschungsinformationssystem der UHH
Interne Metadaten
Quelldatensatz
oai:www.edit.fis.uni-hamburg.de:publications/ea5c1ec1-5b3e-47a4-ad5d-0302bfb73d13