X-ray interferometer using wavefront division

The properties of an X-ray Laue-case wavefront-dividing interferometer have been analysed using time-dependent dynamical diffraction theory. The visibility and the fringe spacing of the interference pattern depend both on the coherence function of the isochronous wavefields on the entrance surface of the interferometer and the spreads of the wavefields into Borrmann fans in the Laue plates. Interference patterns for partially coherent incident X-rays were observed experimentally. The changes of the visibility and of the fringe spacing with respect to the coherence length of the incident X-rays agreed well with the results of the calculations from the dynamical theory.