Characterization of an atom interferometer in the quasi-Bragg regime

TL;DR

This paper thoroughly investigates ultra-cold atom diffraction in the quasi-Bragg regime, analyzing experimental results and numerical models to optimize interferometer performance amid different pulse regimes.

Contribution

It provides a detailed characterization of atom interferometry in the quasi-Bragg regime, including experimental validation and analysis of pulse regimes and parasitic effects.

Findings

Good agreement between experiments and numerical simulations

Identification of limitations in long and short pulse regimes

Optimal balance between regimes for interferometer stability

Abstract

We provide a comprehensive study of ultra-cold atom diffraction by an optical lattice. We focus on an intermediate regime between the Raman-Nath and the Bragg regimes, the so-called quasi-Bragg regime. The experimental results are in a good agreement with a full numerical integration of the Schr\"odinger equation. We investigate the long pulse regime limited by a strong velocity selection and the short pulse regime limited by non-adiabatic losses. For each of these regimes, we estimate the multi-port features of the Bragg interferometers. Finally, we discuss the best compromise between these two regimes, considering the diffraction phase shift and the existence of parasitic interferometers.