Studies On Some Key Technologies In Optical Packet Switched Networks

It is now in the 21st century, an information century. Optical communication plays a very important role. The telecommunication is experiencing a profound revolution induced by the transmission predominance of optical communication technology since last century. At present, the internet service, multi-media telecommunication service, mobile and wireless service are explosively growing. All these technologies accelerate the civilization course of our human society. Although optical communication can provide an immense transmission bandwidth, the consumption of networks resource by these emerged telecommunication services. Optical communication currently faces the challenge, which is how to integrate the immense bandwidth of optical transmission technology with the new data services borne efficiently and agilely by the Internet Protocol (IP) switching technology. The optical packet switched networks (OPSN) is thus proposed to solve the problems. In the OPSN, data services are carried in the optical packets. The transmission and switching of the payload are accomplished in the optical domain, and the processing and control of the header are accomplished in the optical or electric domain. The OPSN supports the multi-granularities services and improves the bandwidth utilization, because the smallest switching granularity is optical packet and the bandwidth is allocated agilely according to the consumers'demands in the OPSN. My thesis theme includes some key technologies in OPSN. The works are listed in the following, Part I, a study on the optical buffer technology in OPSN For the first time, the queue model in the optical buffer system is built when the interval of the optical packets'arrival is Weibull distributing. The relation between the performance of the optical buffer system and the parameters of the optical delay lines is got according to the numerical simulation. It gives us some good analysis of the optimization of the optical buffer system. Part II, a study on all optical logic XOR gate based on cross polarization modulation (XPolM) in a semiconductor optical amplifier (SOA) For the first time, we simulate the nonlinear polarization rotation (NPR) theory and the dynamic gain and phase phase of two polarization directions. The NPR theory is applied to analyze all optical logic XOR gate based on XPolM in a SOA for the first time. The relation between the logic gate performance parameters and the related parameters of the SOA and the input singal is simulated and discussed. The performance may be optimized with properly chosen parameters. Part III, a study on all optical wavelength conversion based on NPR effect in a SOA The NPR theory is applied to analyze all optical wavelength conversion based on NPR effect in a SOA for the first time in my thesis. The non-inverted and inverted wavelength conversion is achieved through numerical simulation. We emphasize the non-inverted wavelength conversion for the typical research. The study includes the relation of the wavelength converter performance parameters with the parameters of the SOA and the input signals. We can optimize the performance of such a wavelength converter by properly designing these parameters according to the relation. Part IV, a study on self-synchronization scheme based on the self-polarization rotation (SPR) in a SOA For the first time, we simplify the optical seed-pulse generation scheme based on the SPR effect in a SOA and analyze it according to the NPR theory. According to the simulation of the scheme, the performance parameters of the scheme are dependent on the parameters of the SOA and the input signals. The optimal performance of the scheme is obtained if we consider the special values of these parameters.