Spatial calibration of high-density absorption imaging

Abstract

The accurate determination of atom numbers is an ubiquitous problem in the field of ultracold atoms. For modest atom numbers, absolute calibration techniques are available, however, for large numbers and high densities, the available techniques neglect many-body scattering processes. Here, a spatial calibration technique for time-of-flight absorption images of ultracold atomic clouds is presented. The calibration is obtained from radially averaged absorption images and we provide a practical guide to the calibration process. It is shown that the calibration coefficient scales linearly with optical density and depends on the absorbed photon number for the experimental conditions explored here. This allows for the direct inclusion of a spatially dependent calibration in the image analysis. For typical ultracold atom clouds the spatial calibration technique leads to corrections in the detected atom number up to $\approx 12\%$ and temperature up to $\approx 14\%$ in comparison to previous calibration techniques. The technique presented here addresses a major difficulty in absorption imaging of ultracold atomic clouds and prompts further theoretical work to understand the scattering processes in ultracold dense clouds of atoms for accurate atom number calibration.

References in corpus (22)

• Strong saturation absorption imaging of dense clouds of ultracold atoms
• Single-particle-sensitive imaging of freely propagating ultracold atoms
• Making, probing and understanding Bose-Einstein condensates
• Accurate Atom Counting in Mesoscopic Ensembles
• Non-destructive Faraday imaging of dynamically controlled ultracold atoms
• Absorption imaging of a single atom
• Preparation of ultracold atom clouds at the shot noise level
• Partial-Transfer Absorption Imaging: A versatile technique for optimal imaging of ultracold gases
• Non-destructive spatial heterodyne imaging of cold atoms
• Diffraction-contrast imaging of cold atoms
• Calibrating High Intensity Absorption Imaging of Ultracold Atoms
• Microscopic Lensing by a Dense, Cold Atomic Sample
• Single-exposure absorption imaging of ultracold atoms using deep learning
• Non-destructive shadowgraph imaging of ultracold atoms
• Sub-atom shot noise Faraday imaging of ultracold atom clouds
• Optimized fringe removal algorithm for absorption images
• Spatially-selective in situ magnetometry of ultracold atomic clouds
• Effective statistical fringe removal algorithm for high-sensitivity imaging of ultracold atoms
• Micro lensing induced lineshapes in a single mode cold-atom hollow-core fiber interface
• Dispersive detection of atomic ensembles in the presence of strong lensing
• Multiple-camera defocus imaging of ultracold atomic gases
• Effective two-level approximation of a multi-level system driven by coherent and incoherent fields

Cited by in corpus (5)

• Atom Number Fluctuations in Bose Gases -- Statistical analysis of parameter estimation
• On the fluctuations of the number of atoms in the condensate
• Adaptive, symmetry-informed Bayesian metrology for precise quantum technology measurements
• Cloud parameter estimation for interacting BEC after time-of-flight
• Three-body Physics in the Impurity Limit of 39K Bose-Einstein Condensates