Interleaved dual-species arrays of single atoms using a passive optical element and one trapping laser
- Chengyu Fang
- Jared Miles
- Jonathan Goldwin
- Martin Lichtman
- Matthew Gillette
- Michael Bergdolt
- Sanket Deshpande
- Sam A. Norrell
- Preston Huft
- Mikhail A. Kats
- Mark Saffman
2025-07-16
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 4 f system with spatial filtering. Our approach exploits the opposite-sign dynamic polarizabilities of Rb and Cs, ensuring that 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.