Benhsaien, Abdessamad2013-11-072013-11-0720062006Source: Masters Abstracts International, Volume: 45-02, page: 0982.http://hdl.handle.net/10393/27225http://dx.doi.org/10.20381/ruor-11976A microscopic analysis of a vertical stack of self-assembled InAs/GaAs lens-shaped quantum dot nanostructures is presented. The analysis revolves around a rigorous Hamiltonian formulation of an eight-band k.p. perturbation to account for the lattice-mismatch strain endured by the islands. The numerical implementation yields the effective bandgap energy and electronic structure of an InAs/GaAs quantum dot. Within the framework of a resonant two-level energy system, material gain and absorption spectra are calculated up to a third-order susceptibility to include nonlinearity. The material gain polarization dependence is expressed in the dipole transition strength. Polarization-dependent anisotropy factors corresponding to different interband transitions are derived and shown to satisfy a momentum conservation rule. Modal analysis of a rectangular core waveguide realized by imbedding the active quantum dot layer(s) into a cladding medium with lower refractive index is presented. Polarization-independent modal gain is achieved by optimizing the width of the rectangular core waveguide. In illustration of a quantum dot device, a realistic semiconductor optical amplifier model accounting for both stimulated and spontaneous emission is considered. The calculated carrier density longitudinal profile yields other parameters characterizing the amplifier performance.102 p.enEngineering, Electronics and Electrical.Thesis