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.
Original Publications
High aspect ratio tilted gratings through local electric field modulation in plasma etching, Z. Shi, K. Jefimovs, A. La Magna, M. Stampanoni, L. Romano, Applied Surface Science, 152938 (2022)
Laboratory X-ray interferometry imaging with a fan-shaped source grating, Z. Shi, K. Jefimovs, L. Romano, J. Vila-Comamala, M. Stampanoni, Optics Letters 46, 3693-3696 (2021)