Wavefront reconstruction for in-line holograms formed by pure amplitude objects

A recursive algorithm is described which gives a numerical solution to the twin image problem of in-line holography for pure amplitude objects. This algorithm combines the benefits of the Fraunhofer method and the Gerchberg–Saxton type algorithm, so that the applicability is extended to include features whose Fresnel numbers are significantly larger than one. A solution to the wavefront reconstruction problem from a single hologram formed by a general object is found to be impossible, due to non-uniqueness of the solution. q1999 Published by Elsevier Science B.V. All rights reserved.