Fig. 10.

Ptychography reconstruction results of the Siemens star sample with deliberately-included errors in actual probe position. (a) Reconstruction with 5 probe modes, and probe position refinement. The area covered by the scan grid is shown in the green dashed boxes; the larger reconstructed image area arises due to the large finite size of the illumination probe. In (b), we show the probe position refinement results within the region bounded by the smaller yellow box of (a); here the assumed positions are represented by open dots on a square grid, with the refined positions shown by blue dots. Also shown is the reconstruction with probe modes included but no position refinement (c), or with position refinement included but no probe modes (d). All reconstructed images are shown over the same dynamic range. Comparing the yellow boxes in (a) and (c), one can see that the bounded segment of the Siemens star spoke in (c) is shifted slightly to the left. Thus, the refined probe positions are mostly to the right of the original positions within that window, which agrees with (b).