Three-wave X-ray diffraction: an analysis scheme of the sensitivity in determining triplet phase invariants

Abstract

A model for analysing the phase sensitivity of the reflection coefficients of a diffracted wave in the case of three-wave X-ray diffraction is proposed. This model considers three-wave diffraction as the interference of the directly excited and the Umweg-excited diffracted waves and seems to account properly for the phase sensitivity as well as the behaviour of an involved diffracted wave as a function of the triplet phase invariant, the polarization state of the incident wave and the diffraction geometry. The practical issues for phase determination are also considered.