Glancing angle Talbot-Lau grating interferometers for phase contrast imaging at high x-ray energy

A Talbot-Lau interferometer is demonstrated using micro-periodic gratings inclined at a glancing angle along the light propagation direction. Due to the increase in the effective thickness of the absorption gratings, the device enables differential phase contrast imaging at high x-ray energy, with improved fringe visibility (contrast). For instance, at 28 degrees glancing angle, we obtain up to similar to 35% overall interferometer contrast with a spectrum having similar to 43 keV mean energy, suitable for medical applications. In addition, glancing angle interferometers could provide high contrast at energies above 100 keV, enabling industrial and security applications of phase contrast imaging. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4748882]