Distributed phase plates for super-Gaussian focal-plane irradiance profiles.

The design of phase plates based on a phase-retrieval algorithm has been shown to be successful in achieving high order super-Gaussian distributions in the far field; however, these phase plates exhibit wide-angle scattering losses due to phase discontinuities. We report that, by starting with a distributed phase plate that is a strictly continuous surface and using only a few cycles of a phase-retrieval algorithm, we have obtained good fourth-order super-Gaussian fit and lower scattering loss.