We demonstrate launching of laser-cooled Yb atoms in a cold atomic fountain.Atoms in a collimated thermal beam are first cooled and captured in amagneto-optic trap (MOT) operating on the strongly-allowed ${^1S}_0 \rightarrow{^1P}_1$ transition at 399~nm (blue line). They are then transferred to a MOTon the weakly-allowed ${^1S}_0 \rightarrow {^3P}_1$ transition at 556~nm (greenline). Cold atoms from the green MOT are launched against gravity at a velocityof around 2.5~m/s using a pair of green beams. We trap more than $10^7$ atomsin the blue MOT and transfer up to 70\% into the green MOT. The temperature forthe odd isotope, $^{171}$Yb, is $\sim$1~mK in the blue MOT, and reduces by afactor of 40 in the green MOT.
展开▼
