FDTD Simulation of Femtosecond Pulse Propagation in Semiconductor Lasers

This work aims to improve the understanding of optical pulse propagation in semiconductor lasers through advanced numerical simulation. A new technique is developed for simulating the injection of short-duration optical pulses into semiconductor lasers. The model incorporates an accurate complex susceptibility, material and gain dispersion and full phase information, and may be integrated on a desktop computer to simulate time evolution over a period of nanoseconds in a matter of hours. The model is applied to the experimentally observed phenomena of dark pulse formation following the injection of optical pulses into semiconductor lasers and furnishes an explanation for their formation, subsequent evolution and stability. These investigations led to a hypothesis, and subsequent demonstration by numerical simulation, for generating stable streams of customisable pulse trains by coherent control of the phase of the injected pulse.