Open AccessNumerical and experimental study of partial coherence for near-field and far-field ptychography
Author(s) -
Weihe Xu,
Shoucong Ning,
Fucai Zhang
Publication year - 2021
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.445978
Subject(s) - ptychography , coherence (philosophical gambling strategy) , quantum decoherence , optics , near and far field , degree of coherence , coherence theory , coherence time , spatial coherence , diffraction , physics , coherence length , quantum , superconductivity , quantum mechanics
High degree of coherence is essential in coherent diffraction imaging (CDI). The coherence requirement on the light source varies with the experimental configuration. As a scanning variant of CDI, ptychography has shown great potential for extensive applications. To determine the influence of partially temporal and spatial coherence on near- and far-field ptychography, we have performed a series of numerical simulations and visible light optical experiments. We demonstrated that the near-field is more robust to spatial and temporal decoherence than the far-field. In addition, the far-field is found to be more sensitive to spatial decoherence than to temporal decoherence. Our experiments also show that a known probe estimate with good spatial coherence enables the retrieval qualities to be enhanced dramatically and helps prevent falling into the local minimums in the reconstruction process. Our work would provide a valuable reference for implementing ptychography with sources of limited coherence.