Matched Backprojection Operator for Combined Scanning Transmission Electron Microscopy Tilt- and Focal Series

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

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 Microscopy and Microanalysis. Downloads to appear.