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A universal Moiré effect and application in x-Ray phase-contrast imaging



Houxun Miao, Alireza Panna, Andrew A. Gomella, Eric E. Bennett, sami Znati, Lei Chen, Han Wen


A moiré pattern is created by superimposing two black-and-white or gray-scale patterns of regular geometry, such as two sets of evenly spaced lines. We observed an analogous effect between two transparent phase masks in a light beam which occurs at a distance. This phase moiré effect and the classic moiré effect are shown to be the two ends of a continuous spectrum. The phase moiré effect allows the detection of sub-resolution intensity or phase patterns with a transparent screen. When applied to x-ray imaging, it enables a polychromatic far-field interferometer (PFI) without absorption gratings. X-ray interferometry can non-invasively detect refractive index variations inside an object. Current bench-top interferometers operate in the near field with limitations in sensitivity and x-ray dose efficiency. The universal moiré effect helps overcome these limitations and obviates the need to make hard x-ray absorption gratings of sub-micron periods.
Nature Physics


x-ray, phase, imaging


Miao, H. , Panna, A. , Gomella, A. , Bennett, E. , Znati, S. , Chen, L. and Wen, H. (2016), A universal Moiré effect and application in x-Ray phase-contrast imaging, Nature Physics, [online],, (Accessed July 20, 2024)


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Created April 24, 2016, Updated October 12, 2021