Atomic fountain of laser-cooled Yb atoms for precision measurements

TL;DR

This paper reports the development of a laser-cooled ytterbium atomic fountain, enabling precise control and launching of cold Yb atoms for potential applications in high-precision measurements.

Contribution

It introduces a novel method for launching laser-cooled Yb atoms in a cold atomic fountain using a two-stage MOT process on different transitions.

Findings

Trapped over 10^7 Yb atoms in the blue MOT.

Transferred up to 70% of atoms to the green MOT.

Reduced atom temperature by a factor of 40 in the green MOT.

Abstract

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 a magneto-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 MOT on the weakly-allowed ${^1S}_0 \rightarrow {^3P}_1$ transition at 556~nm (green line). Cold atoms from the green MOT are launched against gravity at a velocity of around 2.5~m/s using a pair of green beams. We trap more than $10^7$ atoms in the blue MOT and transfer up to 70\% into the green MOT. The temperature for the odd isotope, $^{171}$Yb, is $\sim$1~mK in the blue MOT, and reduces by a factor of 40 in the green MOT.