Iterative Phase Retrieval and the Important Role Played by Initial Conditions

Abstract

Recovering the complex amplitude of a coherent wave field has many important applications in modern optics from practical metrology problems to basic diffraction research. Although several techniques exist, in this manuscript, we will examine the iterative Phase Retrieval (PR) [1-6] exclusively. To recover the phase information with this approach several intensity distributions, diffracted from the object of interest, are recorded at different optical planes. A significant advantage of the PR is the relative simplicity of the optical setup, compared with an interferometric approach. With this approach, noise sources such as an imperfect reference wave can be avoided. PR techniques are an ill-posed inverse problem and hence initial conditions play an important and relatively poorly understood role.