Integrated Optics

During this reporting period emphasis was placed mainly on improving growth techniques for epitaxial layers by the slide bar and the infinite melt methods. New slide bar assemblies made from pyrolytic graphite have eliminated many of the imperfections previously observed. More than a dozen layers were grown in the new system. Waveguiding of 1.15-micrometers light has been observed in these layers, made possible by the graded aluminum concentration profile which results from the limited melt and the segregation effect. As part of the continuing effort to evaluate device elements for which GaAs and GaAlAs are particularly suitable, the authors have performed an analysis of an integral waveguidedetector in which proton bombardment was used to produce sensitivity to wavelengths greater than 0.9 micrometers. The authors have also evaluated the projected performance of leaky waveguides for which the guide index is less than that of the substrate.