Iterative approach to solve the inverse diffraction problem under sharp focusing conditions

Abstract

In this paper, we consider an iterative approach to solve the inverse diffraction problem under sharp focusing conditions. It is shown that using this approach we can obtain a complex distribution in the entrance of the focusing system that creates desired intensity distribution in the focal area. As a result of the iteration process we obtained a complex distribution of transverse components of the initial field which reminds of Laguerre–Gauss mode with radial polarization and is focused in a light spot twice smaller than the diffraction limit.