Clarification on Generalized Lau condition for X-ray interferometers based on dual phase gratings

Autor: Yan, Aimin, Wu, Xizeng, Liu, Hong
Rok vydání: 2019
Předmět:
Druh dokumentu: Working Paper
DOI: 10.1364/OE.27.022727
Popis: To implement dual phase grating x-ray interferometry with x-ray tubes, one needs to incorporate an absorbing source grating. In order to attain good fringe visibility, the period of a source grating should be subject to a stringent condition. In literature some authors claim that the Lau-condition in Talbot-Lau interferometry can be literally transferred to dual phase grating interferometry. In this work we show that this statement in literature is incorrect. Instead, through an intuitive geometrical analysis of fringe formation, we derived a new generalized Lau-condition that provides a useful design tool for implementation of dual phase grating interferometry.
Comment: submitted to Optics Express
Databáze: arXiv