THE METHOD OF PHASE RETRIEVAL OF COMPLEX WAVE-FIELD FROM 2 INTENSITY MEASUREMENTS APPLICABLE TO HARD X-RAYS

A novel algorithm for a reconstruction of the phase shift profile prod uced by a transparent object in a coherent wave, from a set of two rec orded intensity distributions is presented. Contrary to well known alg orithms of in-line holography, the method works under the near-held co ndition where the size of the first Fresnel zone is much less than the characteristic size of the object's details. Such a condition is typi cal for an in-line holography experimental setup with the use of coher ent high energy X-rays (E > 20 keV) produced by synchrotron radiation sources of the third generation like ESRF. The novel algorithm is fast and insensitive to a partial loss of coherence or weak detector resol ution. The method can be applied to X-ray refraction tomography.