Amplitude-phase type fractal screens and their application in phase-retrieval method

摘要

In this paper the analysis and comparison of diffraction spectra of amplitude-phase type fractal screens are presented. Amplitude-phase type fractal screens based on well-known fractals, possess exact or statistical self-similarity, but have managed amplitude transmittance and phase shift. Modeling results show that diffraction spectrum of amplitude-phase type fractal screens possess prevailing power of high frequencies in comparison with spectra of fractal structures with binary transmittance and phase shift. Averaging scattering indicatrices for fractal screens with different parameters are presented. The problem of phase retrieval arises in various fields of science and engineering, including electron microscopy, biology, crystallography, astronomy, and optical imaging. At presence there is a great number of phase retrieval methods without reference wave based on iterative algorithms and additional intensity distribution registration. In this paper we propose the new phase retrieval method with using amplitude-phase type fractal screens.