Fiber-comb-stabilized light source at 556 nm for magneto-optical trapping of ytterbium

TL;DR

This paper reports a stable 556 nm light source for ytterbium atom trapping, achieved via frequency-doubling a fiber-stabilized 1112 nm laser phase-locked to an optical frequency comb, enabling effective magneto-optical trapping and cooling.

Contribution

It introduces a fiber-comb-stabilized 556 nm light source for Yb trapping, demonstrating long-term frequency stability and effective cooling for optical lattice loading.

Findings

Achieved five-day continuous frequency stabilization.

Successfully completed second-stage MOT of Yb atoms.

Atoms cooled to 40 μK suitable for optical lattice loading.

Abstract

A frequency-stabilized light source emitting at 556 nm is realized by frequency-doubling a 1112-nm laser, which is phase-locked to a fiber-based optical frequency comb. The 1112-nm laser is either an ytterbium (Yb)-doped distributed feedback fiber laser or a master-slave laser system that uses an external cavity diode laser as a master laser. We have achieved the continuous frequency stabilization of the light source over a five-day period. With the light source, we have completed the second-stage magneto-optical trapping (MOT) of Yb atoms using the 1S0 - 3P1 intercombination transition. The temperature of the ultracold atoms in the MOT was 40 uK when measured using the time-of-flight method, and this is sufficient for loading the atoms into an optical lattice. The fiber-based frequency comb is shown to be a useful tool for controlling the laser frequency in cold-atom experiments.