Characterisation of a triple-species ${}^\text{87}$Rb/ ${}^\text{85}$Rb/ ${}^\text{133}$Cs magneto-optical trap

TL;DR

This paper demonstrates the simultaneous trapping and cooling of three different atomic species in a magneto-optical trap using a compact laser system, characterizing interspecies interactions and losses.

Contribution

First implementation of a triple-species MOT with detailed interspecies loss characterization using a robust fibre-based laser system.

Findings

Interspecies trap-loss coefficients are less than 7% for Rb-Rb and Rb-Cs pairs.

No losses observed between ${}^{85}$Rb and ${}^{87}$Rb under experimental conditions.

Able to trap 10^8 atoms of each species simultaneously.

Abstract

We present the simultaneous trapping and cooling of ${}^{85}$Rb, ${}^{87}$Rb and ${}^{133}$Cs in a triple-species magneto-optical trap (MOT). This demonstration is obtained using an all-fibre compact and robust laser system based on telecom 1.5 $\mu$m and 2 $\mu$m technologies. We characterise the two-body interspecies losses in the double and triple-species MOT. We calculate the two-body interspecies trap-loss coefficient for the ${}^{85}$Rb/${}^{133}$Cs and the ${}^{87}$Rb/${}^{133}$Cs pairs, representing a variation of less than 7% in atom number. No losses are observed between ${}^{85}$Rb and ${}^{87}$Rb in our experimental conditions. We find that interspecies interactions inside the triple-species MOT do not prevent trapping and cooling 10$^{8}$ atoms for each species, making our system suitable for future applications such as multi-species atom interferometry.