Super-resolution microscopy of single atoms in optical lattices

TL;DR

This paper introduces advanced image processing techniques enabling super-resolution localization of single atoms in optical lattices, surpassing diffraction limits and improving accuracy in atom position determination.

Contribution

It develops a deconvolution method utilizing prior knowledge of the optical transfer function and noise, enhancing localization reliability in optical lattice imaging.

Findings

Achieved super-resolution of atom positions in dense ensembles

Demonstrated precise reconstruction of the point spread function

Provided a quantitative noise model for CCD cameras

Abstract

We report on image processing techniques and experimental procedures to determine the lattice-site positions of single atoms in an optical lattice with high reliability, even for limited acquisition time or optical resolution. Determining the positions of atoms beyond the diffraction limit relies on parametric deconvolution in close analogy to methods employed in super-resolution microscopy. We develop a deconvolution method that makes effective use of the prior knowledge of the optical transfer function, noise properties, and discreteness of the optical lattice. We show that accurate knowledge of the image formation process enables a dramatic improvement on the localization reliability. This allows us to demonstrate super-resolution of the atoms' position in closely packed ensembles where the separation between particles cannot be directly optically resolved. Furthermore, we demonstrate experimental methods to precisely reconstruct the point spread function with sub-pixel resolution from fluorescence images of single atoms, and we give a mathematical foundation thereof. We also discuss discretized image sampling in pixel detectors and provide a quantitative model of noise sources in electron multiplying CCD cameras. The techniques developed here are not only beneficial to neutral atom experiments, but could also be employed to improve the localization precision of trapped ions for ultra precise force sensing.