3d 2D5/2 lifetime in laser cooled Ca+: Influence of cooling laser power
Institut für Physik, Universität Mainz, 55099 Mainz, Germany
Published online: 15 October 1999
We have measured the lifetime of the metastable 3D5/2 level in Ca+ using the "quantum jump" technique on a single stored and laser cooled ion in a linear Paul trap. We found a linear dependence of the measured decay rate on the power of the laser which repumps the ions from the long lived 3D3/2 level. This can be explained by off-resonant depletion of the 3D5/2 level. The proper lifetime of this level is obtained by a linear extrapolation of the measured lifetime to zero laser power. We obtain 1100(18) ms in agreement with theoretical calculations. The observed systematic change of the decay rate resolves discrepancies between earlier experiments in which this effect had not been considered. Measurements on a linear chain of 10 laser cooled ions showed unexpected frequent coincidences of quantum jumps within our observation time of 20 ms. This indicates a so far unexplained correlation between the ions in the chain at large distances.
PACS: 32.70.Fw – Absolute and relative intensities / 42.50.Vk – Mechanical effects of light on atoms, molecules, electrons, and ions / 42.50.Fx – Cooperative phenomena; superradiance and superfluorescence
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 1999