X-ray nanotomography using near-field ptychography

Abstract

Propagation-based imaging or inline holography in combination with computed tomography (holotomography) is a versatile tool to access a sample's three-dimensional (3D) micro or nano structure. However, the phase retrieval step needed prior to tomographic reconstruction can be challenging especially for strongly absorbing and refracting samples. Near-field ptychography is a recently developed phase imaging method that has been proven to overcome this hurdle in projection data. In this work we extend near-field ptychography to three dimensions and we show that, in combination with tomography, it can access the nano structure of a solid oxide fuel cell (SOFC). The quality of the resulting tomographic data and the structural properties of the anode extracted from this volume were compared to previous results obtained with holotomography. This work highlights the potential of 3D near-field ptychography for reliable and detailed investigations of samples at the nanometer scale, with important applications in materials and life sciences among others.

Divide and update: towards single-shot object and probe retrieval for near-field holography

“…1. This is to be compared to established near-field ptychographic schemes, which are based on lateral [43,44] and/or longitudinal translations of the object [22,45]. Hence, the standard approaches require sequential recordings and significantly more input data.…”

X-Ray Near-Field Holography: Beyond Idealized Assumptions of the Probe

“…5.1. This is to be compared to established near-field ptychographic schemes, which are based on lateral [13,154] and/or longi- tudinal translations of the object [14,76]. Hence, the standard approaches require sequential recordings and significantly more input data.…”

Phase retrieval for object and probe in the optical near-field

“…After that, the object's transmission function is calculated similarly as in the PIE method of J. M. Rodenburg and H. M. L. Faulkner [68,69]. In 2013, M. Stockmar et al published near-field ptychography based on the difference map and -as in far-field ptychography -on exclusively lateral diversity [79] and which finally was also extended to tomography [80]. The main differences with the methods which were just described are that firstly, an illumination extending over the entire field of view is used.…”