Hard x-ray phase imaging using simple propagation of a coherent synchrotron radiation beam

Abstract

Particularly high coherence of the x-ray beam is associated, on the ID19 beamline at ESRF, with the small angular size of the source as seen from a point of the sample (0.1-1 µrad). This feature makes the imaging of phase objects extremely simple, by using a `propagation' technique. The physical principle involved is Fresnel diffraction. Phase imaging is being simultaneously developed as a technique and used as a tool to investigate light natural or artificial materials introducing phase variations across the transmitted x-ray beam. They include polymers, wood, crystals, alloys, composites or ceramics, exhibiting inclusions, holes, cracks, ... . `Tomographic' three-dimensional reconstruction can be performed with a filtered back-projection algorithm either on the images processed as in attenuation tomography, or on the phase maps retrieved from the images with a reconstruction procedure similar to that used for electron microscopy. The combination of diffraction (`topography') and Fresnel (`phase') imaging leads to new results.

Hard x-ray phase contrast imaging of black lipid membranes

“…[8][9][10][11][12][13] We show that for the studied membranes a simplified but extendable model can be used to quantitatively monitor the thickness and its changes during the thinning process of BLMs.…”

Experience with Imaging by Using of Microfocus X-Ray Source

“…Recent developments of the x-ray imaging techniques at synchrotrons such as phase contrast imaging [1,2] present a strong driving force for the development of laboratory x-ray imaging techniques [3]. The brilliance of new micro-focus sources combined with suitable source-side optics gives the possibility to transfer some demanding experiments from synchrotrons to laboratories.…”

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

“…Important examples are the holographic reconstruction algorithms designed by P. Cloetens et al at the end of the 20th century. These algorithms are based on numerical backpropagation of full-field holograms and on the inversion of the contrast transfer function [10,11]. High resolution can be obtained by illuminating the sample with a divergent cone beam (i.e.…”