Gerchberg–Saxton algorithm: Difference between revisions

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[[File:Gerchberg-Saxton algorithm.jpg|thumb|400px|Gerchberg-Saxton algorithm for iterative phase retrieval, FT is Fourier transform.]]

The '''Gerchberg–Saxton (GS) algorithm''' is an iterative [[algorithm]] phase retrieval algorithm for retrieving the phase of a complex-valued wavefront from two intensity measurements acquired in two different planes.<ref>{{Cite journal|last=Gerchberg|first=R. W.|last2=Saxton|first2=W. O.|date=1972|title=A practical algorithm for the determination of the phase from image and diffraction plane pictures|url=http://www.u.arizona.edu/~ppoon/GerchbergandSaxton1972.pdf|journal=Optik|language=EN|volume=35|pages=237–246}}</ref> Typically, the two planes are: the image plane and the far field (diffraction) plane, and the wavfrontwavefront propagation between these two planes is given by the [[Fourier transform]]. The original paper by Gerchberg and Saxton considered image and diffraction pattern of sample acquired in an electron microscope.

It is often necessary to know only the phase distribution from one of the planes, since the phase distribution on the other plane can be obtained by performing a Fourier transform on the plane whose phase is known. Although often used for two-dimensional signals, the GS algorithm is also valid for one-dimensional signals.