High-Resolution Imaging of Cold Atoms through a Multimode Fiber

TL;DR

This paper presents a compact high-resolution imaging system for cold atoms using a multimode fiber and adaptive optics, enabling versatile imaging modes within restricted optical access environments.

Contribution

The authors introduce a novel ultra-compact imaging system utilizing a multimode fiber and adaptive optics for high-resolution cold atom imaging.

Findings

Achieved ~1 μm resolution over 100x100 μm² field of view.

System allows switching between absorption and fluorescence imaging.

Compatible with hybrid quantum platforms with limited optical access.

Abstract

We developed an ultra-compact high-resolution imaging system for cold atoms. Its only in-vacuum element is a multimode optical fiber with a diameter of $230\,\mu$m, which simultaneously collects light and guides it out of the vacuum chamber. External adaptive optics allow us to image cold Rb atoms with a $\sim 1\,\mu$m resolution over a $100 \times 100\,\mu$m$^2$ field of view. These optics can be easily rearranged to switch between fast absorption imaging and high-sensitivity fluorescence imaging. This system is particularly suited for hybrid quantum engineering platforms where cold atoms are combined with optical cavities, superconducting circuits or optomechanical devices restricting the optical access.