Broadening the field of view with a fan-shaped source grating
The grating fabrication team recently presented a new solution for the beam alignment of high aspect ratio gratings in imaging systems with an X-ray tube. The field of view of an X-ray Talbot-Lau interferometry setup has been increased by 1.5 times thanks to a source grating with a fan-shaped microstructure. We invented a novel tilted etching method by modulating the electric field during the plasma etching process (see figure below). A model is built with finite elements method and experiments validate the simulation results, showing that a desired tilt profile can be achieved with a proper parameters tuning. The tilted plasma etching method can be applied for many other optics that need a continuous slant gradient.