Self-Synchronization Clock Extraction And Optical Signal Processing

Internet stongly impact the daily life of human beings. Optical communications facilitates the data transmission of Internet, while left a network-bottleneck at signal processing, which remains opto-electronic (OEO) conversion in the switching node currently. All-optical signal processing offers significant advantages to all-optical networks, including protocol and format independence and substantial cost savings from reduced numbers of OEO interfaces.It is necessary to process kinds of signals from optical packets at the nodes of OPS network. All optical signal processing is unavoidable especially in communication system whose speed exceeds 40Gbit/s. All optical self-synchronization is just one of the all optical signal processing at the switching nodes. The optical pulse denoting the beginning of each optical packet named marker pulse is extracted to be the local address clock.The first chapter briefly introduces the OPS network, describing the key technologies and the current researches. The emphasis is at the all optical self-synchronization technology.The second chapter introduces the characteristic of SOA in the self-synchronization schemes, impressing on its dynamic gain and numerical model. It also gives the design and analysis of its drive circuit.A novel self-synchronization scheme utilizing a semiconductor optical amplifier (SOA) monolithically integrated with a delay interferometer (DI) is proposed and numerically demonstrated in Chapter 3. The proposed scheme is based on the fast gain saturation and relatively slow gain recovery of the SOA. With the properly chosen DI delay time, input pulse width and SOA carrier lifetime, input pulse energies as low as 100 fJ can be utilized to achieve a larger than 10 dB contrast ratio of the first to the other pulses of a transmitted packet.In the last chapter an ultra-fast all-optical OR gate using two types semiconductor optical amplifier-based Mach-Zender interferometers (SOA-MZIs) is designed. And its performance is analyzed in terms of contrast ratio (CR). Key parameters are optimized through numerical simulations. With properly designed parameters, 40Gb/s all-optical OR gate using SOA-MZI can be realized with fairly high performance.