A single-laser alternating-frequency magneto-optical trap

TL;DR

This paper introduces an innovative magneto-optical trapping technique using a single laser that alternates frequencies rapidly, simplifying the setup for cooling and trapping neutral atoms like rubidium isotopes.

Contribution

The paper demonstrates a novel AF-MOT system employing a micro-integrated ECDL with rapid frequency switching, enabling efficient atom trapping with a simplified laser configuration.

Findings

Successful trapping of 87Rb and 85Rb atoms.

Achieved microsecond tuning times and high repetition rates.

Characterized atom numbers and cloud temperatures under various conditions.

Abstract

In this paper, we present a technique for magneto-optical cooling and trapping of neutral atoms using a single laser. The alternating-frequency magneto-optical trap (AF-MOT) uses an agile light source that sequentially switches between cooling and repumping transition frequencies by tuning the injection current of the laser diode. We report on the experimental demonstration of such a system for 87Rb and 85Rb based on a micro-integrated extended cavity diode laser (ECDL) performing laser frequency jumps of up to 6.6 GHz with a tuning time in the microsecond regime and a repetition rate of up to 7.6 kHz. For that, a combination of a feed-forward for coarse frequency control and a feedback for precise locking was used. We discuss the results of the AF-MOT characterization in terms of atom numbers and cloud temperature for different operation parameters.