Open AccessNonlinear phase retrieval from single-distance radiograph
Author(s) -
Julian Moosmann,
Ralf Hofmann,
A. V. Bronnikov,
Tilo Baumbach
Publication year - 2010
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.18.025771
Subject(s) - optics , physics , phase retrieval , phase (matter) , detector , intensity (physics) , paraxial approximation , plane (geometry) , contrast (vision) , nonlinear system , plane wave , imaging phantom , phase contrast imaging , mathematics , fourier transform , geometry , phase contrast microscopy , quantum mechanics , beam (structure)
Phase contrast in the object plane of a phase object is retrieved from intensity contrast at a {\sl single} object-detector distance. Expanding intensity contrast and phase shift in the detector plane in powers of object-detector distance, phase retrieval is performed beyond the solution to the linearized transport-of-intensity equation. The expansion coefficients are determined by the entire paraxial wave equation. The Laplacian of the phase shift in the object plane thus is written as a local expression linear in the intensity contrast and nonlinear in the phase shift in the object plane. A perturbative approach to this expression is proposed and tested with simulated phantom data.