Simple, passive design for large optical trap arrays for single atoms
Preston Huft, Yunheung Song, Trent Graham, K. Jooya, Sadanand V. Deshpande, Changfeng Fang, Mikhail A. Kats, M. Saffman
Abstract
We present an approach for trapping cold atoms in a two-dimensional (2D) optical trap array generated with a $4f$ filtering scheme and custom transmission mask without any active device. The approach can be used to generate arrays of bright or dark traps, or both simultaneously with a single wavelength for forming two-species traps. We demonstrate the design by creating a 2D array of 1225 dark trap sites, where single Cs atoms are loaded into regions of near-zero intensity in an approximately Gaussian profile trap. Moreover, we demonstrate a simple solution to the problem of out-of-focus trapped atoms, which occurs due to the Talbot effect in periodic optical lattices. Using a high power yet low cost spectrally and spatially broadband laser, out-of-focus interference is mitigated, leading to near perfect removal of Talbot plane traps.