A Centimeter-Scale Dielectric Metasurface for the Generation of Cold Atoms
Mingke Jin, Xu Zhang, Xuan Liu, Changwen Liang, Jixun Liu, Zixian Hu, Kingfai Li, Guochao Wang, Jun Yang, Lingxiao Zhu, Guixin Li
Abstract
The single-beam magneto-optical trap (MOT) based on the diffractive optical element offers a new route to develop compact cold atom sources. However, the optical efficiency in the previous single-beam MOT systems is usually low and unbalanced, which will affect the quality of the trapped atoms. To solve this issue, we developed a centimeter-scale dielectric metasurface optical chip with dynamic phase distributions, which was used to split a single incident laser beam into five separate ones with well-defined polarization states and uniform energy distributions. The measured diffraction efficiency of the metasurface is up to 47%. A single-beam MOT integrated with the metasurface optical chip was then used to trap the 87 Rb atoms with numbers ∼1.4 × 10 8 and temperatures ∼7.0 μK. The proposed concept in this work may provide a promising solution for developing ultracompact cold atom sources.