Theory and verification of moiré fringes for x-ray three-phase grating interferometer

• Published in: Chinese physics B Vol. 33; no. 5; pp. 56101 - 541
• Main Authors: Shan, Yu-Zheng, Ge, Yong-Shuai, Yang, Jun, Guo, Da-Yu, Cai, Xue-Bao, Liu, Xiao-Ke, Hou, Xiao-Wen, Guo, Jin-Chuan
• Format: Journal Article
• Language: English
• Published: Chinese Physical Society and IOP Publishing Ltd 01.04.2024
• Subjects: moiré fringe; phase grating; x-ray phase contrast; moiré fringe; x-ray phase contrast; phase grating
• ISSN: 1674-1056; 2058-3834
• DOI: 10.1088/1674-1056/ad2bf5

Dual-phase and three-phase grating x-ray interference is a promising new technique for grating-based x-ray differential phase contrast imaging. Dual-phase grating interferometers have been relatively completely studied and discussed. In this paper, the corresponding imaging fringe formula of the three-phase grating interferometer is provided. At the same time, the similarities and differences between the three-phase grating interferometer and the dual-phase grating interferometer are investigated and verified, and that the three-phase grating interferometer can produce large-period moiré fringes without using the analyzing grating is demonstrated experimentally. Finally, a simple method of designing three-phase grating and multi-grating imaging systems from geometric optics based on the thin-lens theory of gratings is presented. These theoretical formulas and experimental results provide optimization tools for designing three-phase grating interferometer systems.