X-ray multimodal imaging using a random-phase object

We demonstrate an extension of the x-ray grating interferometer three modal imaging method to a generalized stepping scheme using a phase object with small, random features. The method allows the recovery of the absorption, scattering, and two-dimensional phase image of the sample from a raster scan of the phase object. An additional extension of the method to recover the effective wave-front curvature is also described. The technique provides fine sensitivity and high spatial resolution and has only low requirements on spatial and longitudinal coherence of the x-ray beam. Imaging modes and processing methods are explained, and an experimental demonstration of the technique is provided by imaging a feather and the quantitative characterization of a compound refractive lens.