Spatial coherence measurement of divergent x-ray beam without prerequisite source information

Abstract Understanding the spatial coherence of synchrotron x-ray sources is crucial for both source characterization and coherent experimental techniques. Here, we present a method to probe the two-dimensional spatial complex coherence factor (CCF) of divergent x-ray beams without prerequisite source information. Phases of the divergent beams are obtained by the transport-of-intensity equation, which is indispensable for the retrieval of the CCF from the diffraction intensity of a Poisson-disk binary phase mask. Our method has been validated through simulations and is expected to be widely used in measuring coherence for fourth-generation synchrotron x-ray sources.