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Several works in our group share an original imaging approach called ptychography. Ptychography uses a series of diffraction patterns recorded when illuminating a sample at different locations. Then, a quantitative picture of the object (amplitude and phase) can be reconstructed numerically. Initially developed and widely exploited in electron and X-ray microscopy, it has been recently successfully extended by our pioneering work in X-ray Bragg ptychography and in optical vectorial ptychography. More about ptychography can be found on wikipedia.

Figure : Left : series of intensity diffraction patterns. Right : Reconstructed object (phase and amplitude).

X-ray Bragg ptychography

Bragg ptychography allows the 3D high resolution imaging of the crystalline properties of nanostructured materials.

Structural imaging of biominerals

Biocrystallization involves extraordinary complex and regular biochemical processes where living organisms control the crystalline form and texture of their organo-mineral components...

Optical vectorial ptychography

We have developed ptychography in order to reconstruct maps of the full polarization-related properties of an object using the Jones’ matrix formalism, such as biominerals or metasurfaces.

Hierarchical imaging of biomineralized tissue

We address the problem of determining the crystallographic texture and the local nanostructure in biomaterials in 3D by introducing texture tomography, a 3D imaging technique based on X-ray diffraction.

Schematic representation of Texture tomography which allows to extract quantities such as the tissue absorption, nanoscale orientation, crystallographic texture and crystalline properties.