We investigate a repumping scheme for magneto-optically trapped calcium atoms. It is based on excitation of the 4s3d1D2-4s5p1P1 transition at 672 nm with an extended cavity diode laser. The effect of the repumping is approximately a factor of three increase in trap lifetime and a doubling of the trapping efficiency from a Zeeman slowed thermal beam. Added to this, the 672-nm laser repumps atoms from an otherwise dark state to yield an overall increase in detected fluorescence signal from the magneto-optic trap (MOT) of more than an order of magnitude. Furthermore, we report isotope shift measurements of the 672-nm transition, for the first time, for four naturally occurring even isotopes. Using available charge radii data, the observed shifts, extending up to 4.3 GHz, display the expected linear dependence in a King plot analysis. The measured shifts are used to determine the isotope shifts of the remaining 41,43,46Ca isotopes. These might be of interest where less abundant isotopes are used enabling isotope selective repumping, resulting in enhanced trapping and detection efficiencies.
- calcium atoms
Dammalapati, U., Norris, I., Burrows, C., Arnold, A. S., & Riis, E. (2010). Spectroscopy and isotope shifts of the 4s3d 1D2–4s5p 1P1 repumping transition in magneto-optically trapped calcium atoms. Physical Review A, 81(2), . https://doi.org/10.1103/PhysRevA.81.023424