Optimal strategies for low-noise detection of atoms using resonant frequency modulation spectroscopy in cold atom interferometers

TL;DR

This paper theoretically analyzes resonant frequency modulation spectroscopy for cold atom interferometers, identifying optimal conditions for high sensitivity and comparing its performance to fluorescence imaging under various experimental scenarios.

Contribution

It provides a detailed model of the technique considering realistic effects and compares its effectiveness to fluorescence imaging, highlighting regimes where each method excels.

Findings

Resonant frequency modulation spectroscopy outperforms fluorescence imaging in compact setups with limited photon collection.

Fluorescence imaging remains preferable with squeezed atomic sources due to atom number limitations.

Optimal parameter regimes for high signal-to-noise ratio are identified considering realistic experimental conditions.

Abstract

Resonant frequency modulation spectroscopy has been previously used as a highly-sensitive method for measuring the output of cold atom interferometers. Using a detailed model that accounts for optical saturation, laser intensities and atomic densities that vary spatially, and radiation pressure on the atoms, we theoretically investigate under what parameter regimes the optimum signal-to-noise ratio is found under experimentally realistic conditions. We compare this technique to the standard method of fluorescence imaging and find that it outperforms fluorescence imaging for compact interferometers using condensed atomic sources or where the photon collection efficiency is limited. However, we find that fluorescence imaging is likely to be the preferred method when using squeezed atomic sources due to limited atom number.