Practical implementation of a direct method for coherent diffractive imaging.
We experimentally implement a direct, non-iterative method for recovering the complex wave in the exit-surface plane of a coherently illuminated object. The form of illumination is subject to certain conditions. By satisfying these conditions, the complex exit-surface wave is directly recovered from a single far-field intensity pattern, by solving a set of linear equations. These linear equations, whose coefficients depend on the incident illumination, are obtained by analyzing the autocorrelation function of the exit-surface wave. This autocorrelation is constructed by taking the inverse Fourier transform of the diffraction pattern. We introduce a preconditioning step, for the system of linear equations, which improves the robustness of the method to noise. While the present experimental proof of concept has been performed using a visible-light laser, the method is applicable to diffractive imaging using coherent X-ray and electron sources.
School of Physics, University of Melbourne, Victoria 3010, Australia.
A V
AV
Martin
A I
AI
Bishop
D M
DM
Paganin
L J
LJ
Allen
D003952:Diagnostic Imaging / Q000379:methods*; D004583:Electrons; D005583:Fourier Analysis; D008027:Light; D014961:X-Ray Diffraction / Q000295:instrumentation / Q000379:methods*