Figure 6
A fringe analysis of the defocussed ptychograms can be used to determine stage positioning errors. Fourier filtered ptychograms, highlighting the fringes caused by interference of grating orders, for a grating defocus of (a) 30 μm and (b) 80 μm (c) Filtered ptychogram after correction of the stage errors (c). (d) Plot of the residual stage errors, with a standard deviation of 65 nm.
