Study On Application Of SOA Monolithically Integrated In Tunable Semiconductor Lasers

Tunable lasers have been urgently demanded in numerous critical technologies in the future optical fiber communication, which has been the subject of considerable interest ever since the start of the wavelength division multiplexing (WDM) revolution. Besides being applied as optical sources with large wavelength tuning range in static applications, tunable laser is one of the key components for future dynamic all-optical network. Though multi-sectioned tunable semiconductor lasers under the controlling by multi-electrodes are capable of tuning wavelengths in nanosecond scale,"transition mode"during the switching, due to the inherent properties of the devices, would degrade system performance.With the advantages such as broad bandwidth, high response speed and high compatibility with other semiconductor devices, semiconductor optical amplifiers (SOA) can be employed to eliminate the influence induced by the"transition mode". Attributing to the high switching characteristic of SOA, the"transition mode"in the instable process when the wavelength is tuned fast could be blanked efficiently. In addition, the SOA integrated monolithically with tunable semiconductor laser can amplify and equilibrate the output power of different wavelengths easily and efficiently.Based on the carrier density rate equation and power propagation equation, the Multi-section Mode of SOA has been presented in this thesis. The gain characteristic, under different injected currents and under different input optical powers, has been studied in the static simulation in the first part, followed with some discussion about how to equilibrate the output power; In the next part, the SOA's switching response to the controlling current pulse with different parameters are emphatically studied in the dynamic numerical mode, The simulated results provide some instructive directions for optimize the switching characteristic of SOA.