Laboratory X-Ray Interferometry Imaging With A Fan-Shaped Source Grating

The orientation mismatch between the cone beam of an X-ray tube and the grating lines in a flat substrate remains a big challenge for laboratory grating-based X-ray interferometry, since it severely limits the imaging field of view. Here, we fabricated fan-shaped Go source gratings by modulating the electric field during the deep reactive ion etching of silicon. The gold electroplated fan-shaped G(0) grating (3.0 mu m pitch) in a 20 keV interferometer improves the uniformity of the field of view with an increase of average visibility from 16.2% to 18.5% and a better angular sensitivity (by a factor 5.8) at the edges. (C) 2021 Optical Society of America