X-ray coherence evolution in the imaging process plays a key role for x-ray phase-sensitive imaging. In this work we present a phase-space formulation for the phase-sensitive imaging. The theory is reformulated in terms of the cross-spectral density and associated Wigner distribution. The phase-space formulation enables an explicit and quantitative account of partial coherence effects on phase-sensitive imaging. The presented formulas for x-ray spectral density at the detector can be used for performing accurate phase retrieval and optimizing the phase-contrast visibility. The concept of phase-space shearing length derived from this phase-space formulation clarifies the spatial coherence requirement for phase-sensitive imaging with incoherent sources. The theory has been applied to x-ray Talbot interferometric imaging as well. The peak coherence condition derived reveals new insights into three-grating-based Talbot-interferometric imaging and gratings-based x-ray dark-field imaging.
© 2008 Optical Society of AmericaFull Article | PDF Article
Harold T. Yura, Lars Thrane, and Peter E. Andersen
J. Opt. Soc. Am. A 17(12) 2464-2474 (2000)
Xizeng Wu, Hong Liu, and Aimin Yan
Opt. Lett. 30(4) 379-381 (2005)
Xizeng Wu and Hong Liu
Opt. Express 13(16) 6000-6014 (2005)