@@Several key techniques in high-speed optical time division multiplexing (OTDM) systems, including the generation and compression of gain-switched picosecond optical pulses, the all optical demultiplexer based on a nonlinear optical loop mirror (NOLM), terahertz optical asymmetric demultiplexer (TOAD) and the electroabsorption modulator in OTDM systems, are studied in this dissertation. The gain-switching characteristics and the nonlinear dynamics of a semiconductor laser are investigated by solving its single-mode rate equations numerically, highlighting the dependence of the pulse width and the peak power of a gain-switched pulse on the parameters such as the differential gain and the photon lifetime, and the effects of the DC bias current and the modulation current of the laser on the pulse width and the spectral width of the gain-switched pulse. The two-dimensional bifurcation diagram is computed in a large modulation current and modulation frequency range, and it is found that the low-frequency period doubling (multipling) and chaos region are not closed fully and outspread to the high modulation current direction with a narrow modulation frequency region. In addition, a new clock recovery scheme employing the period multipling is proposed. Besides compressing the gain-switched laser diode pulse can be compressed to 6.9ps by using this DILM compressor, and such a short pulse completely satisfies the requirement for a 40 Gbit/s optical time division multiplexing (OTDM) system.
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