# Calibrating High Intensity Absorption Imaging of Ultracold Atoms

## TL;DR

This paper introduces a robust method for calibrating high intensity absorption imaging of ultracold atoms, improving measurement accuracy by precisely determining imaging intensity, polarization purity, and detuning.

## Contribution

A novel technique is developed to accurately calibrate imaging intensity in ultracold atom experiments, reducing systematic errors in absorption imaging.

## Key findings

- Achieved calibration of imaging intensity within 5% accuracy.
- Quantified polarization purity of imaging light.
- Determined optimal imaging detuning.

## Abstract

Absorption imaging of ultracold atoms is the foundation for quantitative extraction of information from experiments with ultracold atoms. Due to the limited exposure time available in these systems, the signal-to-noise ratio is largest for high intensity absorption imaging where the intensity of the imaging light is on the order of the saturation intensity. In this case, the absolute value of the intensity of the imaging light enters as an additional parameter making it more sensitive to systematic errors. Here, we present a novel and robust technique to determine the imaging intensity in units of the effective saturation intensity to better than 5%. We do this by measuring the momentum transferred to the atoms by the imaging light while varying its intensity. We further utilize the method to quantify the purity of the polarization of the imaging light and to determine the correct imaging detuning.