Iterative design of mesh-defined phase masks for wavefront coding

Abstract

A new phase mask typology for wavefront-coding is proposed, the meshed phase mask (MPM). It is intended to be a flexible form in order to be easily adaptable. The use of an evaluating criterion to measure the performance of the MPM is used to optimize its shape. The MPM is uniquely defined by the fixed phase in a number of control points equally spaced in the pupil area. These control points define a regular mesh, and the continuous MPM phase surface is obtained from cubic spline interpolation. A global search algorithm is used to optimize the values at the control points, thus optimizing the MPM. The preliminary results show an improvement over the conventional cubic phase mask, especially in reducing the undesired artefacts in the final restored images.