DISLOCATION DISTRIBUTIONS IN ION-IMPLANTED OPTICAL WAVE-GUIDES

The origin of anomalous refractive index values in ion implanted optic al waveguides in some crystalline materials has been an outstanding pr oblem for several years. By use of complementary X-ray edge-topography and Raman microprobe imaging we have found evidence that changes in t he dislocation density after implantation correlate with changes in th e dynamic response of the lattice to light. This implies that the effe cts of reduced dislocation density may be related to the origin of the refractive index anomalies, possibly as a result of strain relief. Fu rther support for this hypothesis comes from the fact that the origina l bulk dislocation density is recovered throughout the crystal by anne aling to the temperature at which the refractive index anomalies are l ost.