Reconstruction Strategies for Combined Tilt- and Focal Series Scanning Transmission Electron Microscopy

Tim Dahmen, Holger Kohr, Niels de Jonge, Philipp Slusallek

Winner of an 2015 M&M Presidential Scholar Award

Combined tilt- and focal series scanning transmission electron microscopy (STEM)
is a recently developed method to obtain nanoscale three-dimensional (3D) information of thin
specimens. In this study, we formulate the forward projection in this acquisition scheme as
a linear operator and prove that it is a generalization of the Ray transform for parallel il-
lumination. We analytically derive the corresponding backprojection operator as the adjoint
of the forward projection. We further demonstrate that the matched backprojection operator
drastically improves the convergence rate of iterative 3D reconstruction compared to the case
where a backprojection based on heuristic weighting is used. In addition, we show that the 3D
reconstruction is of better quality.

Accepted to Proceddings of Microscopy & Microanalysis 2015, Portland, Oregan, 2. - 6. August 2015.

Downloads to appear.