X-ray nano-holotomography reconstruction with simultaneous probe retrieval

TL;DR

This paper introduces an iterative reconstruction method for nano-holotomography that simultaneously retrieves the probe function, improving resolution and reducing artifacts in 3D reconstructions of samples using coherent X-ray imaging.

Contribution

The novel algorithm jointly reconstructs the sample and probe, addressing phase artifacts and enhancing resolution in nano-holotomography beyond existing methods.

Findings

Achieves twice thinner layer resolution in 3D reconstructions.

Reduces artifacts caused by probe imperfections.

Implemented efficiently on GPUs for practical use.

Abstract

In conventional tomographic reconstruction, the pre-processing step includes flat-field correction, where each sample projection on the detector is divided by a reference image taken without the sample. When using coherent X-rays as probe, this approach overlooks the phase component of the illumination field (probe), leading to artifacts in phase-retrieved projection images, which are then propagated to the reconstructed 3D sample representation. The problem intensifies in nano-holotomography with focusing optics, that due to various imperfections create high-frequency components in the probe function. Here, we present a new iterative reconstruction scheme for holotomography, simultaneously retrieving the complex-valued probe function. Implemented on GPUs, this algorithm results in 3D reconstruction resolving twice thinner layers in a 3D ALD standard sample measured using nano-holotomography.