Resonator-Aided Single-Atom Detection on a Microfabricated Chip

TL;DR

This paper demonstrates a resonator-based method for detecting single atoms on an atom chip using optical cavities, achieving high efficiency and resolution through fluorescence and absorption techniques.

Contribution

The authors introduce a novel cavity-based detection scheme combining fluorescence and absorption for single-atom detection on a chip.

Findings

75% detection efficiency in 250 microseconds

Able to resolve about 1 atom with high precision

Measured 3.3% transmission attenuation per atom

Abstract

We use an optical cavity to detect single atoms magnetically trapped on an atom chip. We implement the detection using both fluorescence into the cavity and reduction in cavity transmission due to the presence of atoms. In fluorescence, we register 2.0(2) photon counts per atom, which allows us to detect single atoms with 75% efficiency in 250 microseconds. In absorption, we measure transmission attenuation of 3.3(3)% per atom, which allows us to count small numbers of atoms with a resolution of about 1 atom.