The thesis focus is on numerical simulations of GaAs-AlGaAs core-shell nanowire lasers on silicon waveguides, which are promising in the context of chip-level optical interconnects.
We employ several numerical simulation tools to investigate different properties of the chosen structures. We start by studying the propagating modes defined by the nanowire waveguide. The nanowire end facet reflectivity, an important parameter for low-threshold lasing, can be enhanced from 40% to 90% with a metal mirror. By asymmetrically placing a nanowire which supports a circularly polarized propagating wave on top of a Si waveguide, unidirectional coupling of light can be achieved via the spin-orbit coupling. The ratio between the amount of light coupled in opposite directions of the waveguide can reach values of nearly 10^4 but is extremely sensitive to the position of the nanowire. The coupling is influenced by many parameters, such as nanowire and waveguide dimensions and the thickness of the oxide, resulting in a huge parameter space which makes the task of finding an optimal structure more challenging.
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