Partial coherence and the influence of overlap and curvature in ptychography

In this paper, we use optical coherence theory to define the limit for the spatial coherence length with respect to the degree of overlap between adjacent probe positions in ptychography. The influence of the degree of curvature of the probe in relation to partial coherence in the Fresnel geometry for a fixed overlap is also considered. This work has implications for the application of ptychographic coherent imaging using partially coherent sources. We validate these results through a simulation study of coherence versus overlap parameter and curvature.