High-resolution multislice x-ray ptychography of extended thick objects.

We report the first demonstration of hard x-ray ptychography using a multislice approach, which can solve the problem of the limited spatial resolution under the projection approximation. We measured ptychographic diffraction patterns of a two-layered object with a 105  μm gap using 7 keV focused coherent x rays. We successfully reconstructed the phase map of each layer at ∼50  nm resolution using a multislice approach, while the resolution was worse than ∼192  nm under the projection approximation. The present method has the potential to enable the three-dimensional high-resolution observation of extended thick specimens in materials science and biology.