High aspect ratio, Large area silicon-based gratings for X-ray phase contrast imaging

This paper reports on the latest developments in the manufacturing of high aspect ratio silicon-based gratings used for X-ray phase contrast imaging (XPCI). Grating-based XPCI provides, in one measurement, unique information about the absorption coefficient, the index of refraction and the microscopic structure of a sample at hard X-ray frequencies. For this reason, XPCI can potentially overcome the limitations of classical absorption-based radiography, notably for weakly absorbing materials. New micro-fabrication processes were developed to manufacture full set of large area and high aspect ratio X-ray gratings with few defects. The complementarity of XPCI with conventional absorption-based radiography was experimentally demonstrated.