9803066 Menoni This project addresses basic materials science issues limiting the performance of near-IR solid state lasers used in high speed fiber optics communications systems. Key areas of study include the epitaxial temperature dependence of misfit dislocation formation and propagation, the influence of strain and strain compensation effected through materials combinations and MBE parameters on critical thicknesses for pseudomorphic growth, band offsets, and carrier confinement. The approach incorporates iterative feedback between materials growth/characterization and detailed carrier transport measurements in InAsyP1-y/InGaAsP multiple quantum well structures. Mechanisms of carrier transport in strained InAsP lasers structures will be studied and related to high temperature laser operation. Measurements will include quantum well carrier capture and emission rates, and carrier diffusion through a separate confinement heterostructure to assess how these phenomena vary with injection conditions, temperature, and geometry of the structures. %%% The project addresses basic research issues in a topical area of materials science having high potential technological relevance. The research will contribute basic materials science knowledge at a fundamental level to new aspects of electronic/photonic materials and devices. The basic knowledge and understanding gained from the research is expected to contribute to improving the performance and stability of advanced devices by providing a fundamental understanding and a basis for designing and producing improved materials, and materials combinations. An important feature of the program is the integration of research and education through the training of students in a fundamentally and technologically significant area. ***