Lensless imaging from diffraction intensity measurements by use of a noniterative phase-retrieval method

A method of reconstructing the complex amplitude of an object that is illuminated by a coherent wave from its Fresnel diffraction patterns is proposed for high-frequency wave phenomena such as x-rays and electron waves. A noniterative phase-retrieval method that uses a Gaussian filter is employed here, and it is shown that the object's illumination with amplitude distribution in the Fraunhofer diffraction pattern of a circular aperture can be used as a substitute for the Gaussian filter. This method has an advantage over other noniterative phase-retrieval methods in that it can retrieve phase vortices.