Interleaved dual-species arrays of single atoms using a passive optical element and one trapping laser

TL;DR

This paper presents a passive optical system that traps individual rubidium and cesium atoms in an interleaved array using a single laser, simplifying the setup and achieving high loading rates.

Contribution

The authors introduce a passive optical element with a single trapping laser to create interleaved dual-species atom arrays, reducing system complexity and maintaining high efficiency.

Findings

Achieved near 50% atom loading rates for both species.

Successfully used a passive optical mask with three transmittance levels.

Demonstrated trapping of two different atomic species with a single laser beam.

Abstract

We demonstrate trapping of individual rubidium (Rb) and cesium (Cs) atoms in an interleaved array of bright tweezers and dark bottle-beam traps, using a microfabricated optical element illuminated by a single laser beam and a 4F system with spatial filtering. Our approach exploits the opposite-sign dynamic polarizabilities of Rb and Cs, ensuring each species is exclusively trapped in either bright or dark sites. The passive optical mask creates optimal trap depths for both species using three transmittance levels while minimizing the optical phase difference, implemented using a variable-thickness absorbing layer of amorphous germanium. This trapping architecture achieves atom loading rates close to 50% while reducing system complexity compared to conventional methods using active optoelectronic components and/or multiple laser wavelengths.