We report on the sub-Doppler laser cooling of neutral 171Yb and 173Yb in a magneto-optical trap (MOT) using the 1S 0 - 1P1 transition at 398.9 nm. We use two independent means to estimate the temperature of the atomic cloud for several of the Yb isotopes. The two methods of MOT cloud imaging and release-and-recapture show consistency with one another. Temperatures below 400 and 200 μK are recorded for 171Yb and 173Yb, respectively, while ∼1 mK is measured for both 172Yb and 174Yb. By comparison, the associated one-dimensional Doppler cooling temperature limit is 694 μK. The sub-Doppler cooling of the I = 1/2 171Yb isotope in a σ+ - σ- light-field trap adds further evidence that the Sisyphus cooling mechanism is occurring in such three-dimensional MOTs. © 2014 Optical Society of America.
|Journal||Journal of the Optical Society of America B: Optical Physics|
|Early online date||23 Jun 2014|
|Publication status||Published - Jul 2014|