Synchrotron radiation topographic study of Ti-diffused and proton-exchanged LiNbO₃single crystals

Abstract

Titanium-diffused and proton-exchanged (PE) LiNbO3 single crystals of congruent composition were investigated by topographic methods in reflection mode using synchrotron radiation. The white beam topographs obtained for z-cut Ti:LiNbO3 samples revealed a characteristic distribution of defects with increasing concentration of Ti atoms in the near-surface region. For crystals with doses above 3.0*1020 cm-3 of indiffused atoms the density of introduced defects was fairly high resulting in rather homogeneous images. For white beam topographs of z-cut LiNbO3 samples with PE regions two images arising from the PE layer and from the substrate are distinguished, indicating the different lattice parameter of both parts of the crystal.