Coherent diffractive imaging with X-rays and visible light - Dmitry Karpov (ESRF)

Electromagnetic waves interacting with matter contain rich information on structural and compositional heterogeneity and disorder. The information is encoded in the wavefront of the outgoing wave in terms of amplitude and phase. One of the greatest challenges in imaging is to obtain the wavefront information with highest possible resolution, that is typically capped by the diffraction limit. Visible light microscopes benefit from long development in manufacturing of diffraction-limited optical components and super-resolution techniques. The same level of sophistication is currently not available to the X-ray community as that requires optics fabricated with Angstrom precision.

To circumvent the fabrication problem the image forming lens can be removed completely and replaced instead with a phase retrieval algorithm. This solution is collectively termed as Coherent Diffractive Imaging (CDI) and has been successfully applied to visualization of chemical composition and oxidation states in functional catalysts, transistors fabrication defects, magnetic and ferroelectric topologies, deformations in batteries among many other applications.

In this talk I will demonstrate recent advancements in CDI techniques strongly driven by availability of next generation synchrotron sources such as recently upgraded ESRF-EBS. I will also show how CDI can be applied in the domain of visible light imaging where it can provide a quantitative information of dielectric constant and allows to visualize magnetic topologies through birefringent contrast modality.

Contact: Aurélien Gourrier