Atom Interferometry with Top-Hat Laser Beams

TL;DR

This paper demonstrates the implementation of top-hat laser beams in atom interferometers to improve uniformity, efficiency, and reduce systematic effects caused by inhomogeneous laser intensity profiles.

Contribution

It introduces the use of top-hat laser beams in atom interferometry and characterizes their benefits over traditional Gaussian beams.

Findings

Top-hat beams provide more uniform intensity profiles.

Enhanced atom-optics efficiency with top-hat beams.

Potential improvements in interferometer performance.

Abstract

The uniformity of the intensity and phase of laser beams is crucial to high-performance atom interferometers. Inhomogeneities in the laser intensity profile cause contrast reductions and systematic effects in interferometers operated with atom sources at micro-Kelvin temperatures, and detrimental diffraction phase shifts in interferometers using large momentum transfer beam splitters. We report on the implementation of a so-called top-hat laser beam in a long-interrogation-time cold-atom interferometer to overcome the issue of the inhomogeneous laser intensity encountered when using Gaussian laser beams. We characterize the intensity and relative phase profiles of the top-hat beam and demonstrate its gain in atom-optics efficiency over a Gaussian beam, in agreement with numerical simulations. We discuss the application of top-hat beams to improve the performance of different architectures of atom interferometers.