Abstract: When binary gratings are used in X-ray dual-phase grating interferometers, the fringe visibility is relatively low, resulting in a serious reduction of the signal-to-noise ratio of dark-field images. Therefore, it is necessary to explore potential ways to improve the fringe visibility. In this paper, a study based on dual-sinusoidal phase grating interferometer is presented, and fringe visibility as a function of grating spacing between the dual-sinusoidal and dual-binary phase grating interferometers is compared under different experimental parameters. The results show that the dual-sinusoidal phase grating interferometer has certain advantages in large grating period, large light source focus size and large detector pixel size, and the grating spacing corresponding to the fringe visibility peak is smaller, which makes the system more compact. The results of this paper can provide theoretical guidance for parameter design and performance optimization of X-ray dual-phase grating interferometers.
Keywords: X-ray imaging; dual-phase grating interferometer; sinusoidal phase grating; fringe visibility