Ptychographic nanotomography at the Swiss Light Source

Abstract

Ptychography combines elements of scanning probe microscopy with coherent diffractive imaging and provides a robust high-resolution imaging technique. The extension of X-ray ptychography to 3D provides nanoscale maps with quantitative contrast of the sample complex-valued refractive index. We present here progress in reconstruction and post-processing algorithms for ptychographic nanotomography, as well as outline advances in the implementation and development of dedicated instrumentation for fast and precise 3D scanning at the Swiss Light Source. Compared to the first demonstration in 2010, such developments have allowed a dramatic improvement in resolution and measurement speed, with direct impact in the application of the technique for biology and materials science. We showcase the technique by detailing the measurement and reconstruction of a fossilized dispersed spore.

Ptychographic X-ray computed tomography at a high-brilliance X-ray source

“…At first limited to returning two-dimensional (2D) projections of the imaged areas, X-ray ptychography was soon demonstrated to be compatible with computed tomography (CT) and hence able to provide three-dimensional (3D) quantitative characterisation of scattering specimens. The first implementation of ptychographic X-ray computed tomography (PXCT) occurred at the cSAXS beamline at the Swiss Light Source [16], which kept leading the development of such kind of ptychography experiments [17][18][19][20][21]. However, PXCT remains more technically challenging than other 2D ptychography experiments on account of both experimental constraints and the relatively higher complexity of the data analysis pipeline.…”