Number-resolved imaging of excited-state atoms using a scanning autoionization microscope

TL;DR

This paper introduces a scanning autoionization microscopy method for atom-number-resolved imaging of excited-state atoms, enabling detailed spatial density and electric field gradient measurements with high resolution and efficiency.

Contribution

The work presents a novel scanning autoionization microscope that achieves atom-number-resolved imaging of excited atoms with high spatial resolution and sensitivity.

Findings

Achieved 50 μm spatial resolution in imaging.

Detected electric field gradients with sensitivity of 0.04 V/cm².

Overall detection efficiency of 21%.

Abstract

We report on a scanning microscopy technique for atom-number-resolved imaging of excited-state atoms. A tightly focused laser beam leads to local autoionization, and the resulting ions are counted electronically. Scanning the beam across the cloud builds up an image of the density distribution of excited atoms, with access to the full counting statistics at each spatial sampling point and an overall detection efficiency of 21 %. We apply this technique to the measurement of a spatially inhomogeneous electric field with a spatial resolution of 50 ?m and a sensitivity to electric field gradients of 0.04 V cm$^{-2}$.