Fig. 1. Experimental setup for ptychography

Fig. 2. Functions of the modeled sample, probe and background noise used in the simulation and the produced diffraction patterns. (a)(b) Sample amplitude and phase; (c)(d) probe amplitude and phase; (e) typical diffraction pattern at a scanning position; (f) simulation of background noise intensity distribution; (g) diffraction pattern after adding the modeled background noise; (h) background noise image reconstructed by our signal－to－noise separation algorithm

Fig. 3. Reconstructed sample images by three different algorithms. (a)(e) Sample amplitude and phase reconstructed by the ePIE algorithm; (b)(f) sample amplitude and phase reconstructed by 3－mode Mm－ePIE algorithm; (c)(g) sample amplitude and phase reconstructed by 5－mode Mm－ePIE algorithm; (d)(h) sample amplitude and phase reconstructed by our signal－to－noise separation algorithm

Fig. 4. Reconstructed probe amplitude images by three different algorithms. (a) Probe amplitude reconstructed by the ePIE algorithm; (b) probe amplitude reconstructed by 3－mode Mm－ePIE algorithm; (c) probe amplitude reconstructed by 5－mode Mm－ePIE algorithm; (d) probe amplitude reconstructed by our signal－to－noise separation algorithm

Fig. 5. Reconstruction results from the experimental data. (a) Typical diffraction pattern at a scanning position; (b)(f) sample amplitude and phase reconstructed by ePIE algorithm; (c)(g) sample amplitude and phase reconstructed by 3－mode Mm－ePIE algorithm; (d)(h) sample amplitude and phase reconstructed by our signal－to－noise separation algorithm; (e) background noise image reconstructed by our signal－to－noise separation algorithm