COMPLEMENTARY X-RAY TOPOGRAPHY AND NEAR-SURFACE DIFFRACTION FOR INVESTIGATIONS INTO THE STRUCTURE OF ION-IMPLANTED OPTICAL WAVE-GUIDES

Ion implantation is now a well established technique for the production of optical waveguides for integrated optics applications. However, in some materials, such as lithium niobate, it leads to anomalous optical properties in the waveguiding region. We have investigated the structure of the waveguide and the damaged region in ion-implanted lithium niobate by carrying out complementary X-ray topography and near surface X-ray diffraction on etched crystals. The results indicate radiation enhanced annealing in the waveguide itself and the upper region of the substrate, as well as a high degree of amorphisation in the damaged layer.