HOLOGRAPHIC CRYSTALLOGRAPHY FOR SURFACE STUDIES: A REVIEW OF THE BASIC PRINCIPLES

Abstract

In this paper, we review the basic principles of the technique of holographic crystallography (HXT) for surface studies. We discuss the appropriateness of the use of the term "holography" in this field in the light of its relation to other branches of that subject. We compare the effects of multiple scattering and the anisotropies of the reference and object waves on the computer reconstruction of images in HXT. We note that the twin-image problem of conventional holography is a direct consequence of the fact that the hologram is recorded on a two-dimensional surface. Like optical volume holography, which overcomes this problem by recording a diffraction pattern on a thick photographic emulsion, multienergy HXT does so by recording the pattern in a volume of reciprocal space. We consider the relative merits of different reconstruction algorithms, particularly proposals for reducing the deleterious effects of the anisotropies of the reference and object waves. We urge the use of techniques of modern computer graphics to render to full effect the striking 3D images reconstructed.