A Sideband-Enhanced Cold Atomic Source For Optical Clocks

TL;DR

This paper presents a method to significantly enhance cold atomic beams for optical clocks using a sideband technique in a 2D-MOT, achieving higher flux and brightness, with potential advantages for portable and precise atomic clock systems.

Contribution

The study introduces a sideband-enhanced 2D-MOT method that improves atomic flux and brightness compared to conventional systems, suitable for advanced optical clocks.

Findings

Achieved 2.3 times larger atomic flux and 4 times brightness.

Demonstrated comparable loading rates to Zeeman slower systems.

Showed potential for extension to other alkaline-earth species.

Abstract

We demonstrate the enhancement and optimization of a cold strontium atomic beam from a two-dimensional magneto-optical trap (2D-MOT) transversely loaded from a collimated atomic beam by adding a sideband frequency to the cooling laser. The parameters of the cooling and sideband beams were scanned to achieve the maximum atomic beam flux and compared with Monte Carlo simulations. We obtained a 2.3 times larger, and 4 times brighter, atomic flux than a conventional, single-frequency 2D-MOT, for a given total power of 200 mW. We show that the sideband-enhanced 2D-MOT can reach the loading rate performances of space demanding Zeeman slower-based systems, while it can overcome systematic effects due to thermal beam collisions and hot black-body radiation shift, making it suitable for both transportable and accurate optical lattice clocks. Finally we numerically studied the possible extensions of the sideband-enhanced 2D-MOT to other alkaline-earth species.