All-optical Switching In Otdm System

The appearance of high-speed communication Services and the increasing of access subscribers bring more and more pressures to the transmission rate of communication networks and bandwidth. The optical time division multiplexing (OTDM) technology is a effective scheme of increasing capacitance that can availably overcome the bandwidth choke point of electron and circuit and utilize fully low loss bandwidth resources. OTDM can significantly improve the problem of networks bandwidth. The optical switch is one of the key technologies for OTDM systems and optical networks. All-optical switches and their applications in OTDM communication systems, especially demultiplexing technology and add-drop multiplexingtechnology——the key technologies for OTDM, are researched in this dissertation.Firstly, the nonlinear Schr(o|¨)dinger equation(NLSE) and coupled Nonlinear Schr(o|¨)dinger Equations considering Cross-phase modulation which describe the transmission of optical pulses in the optical fiber, their numerical analysis using split-step Fourier Algorithm and primary factors influencing transmission of optical pulses in the optical fiber are described in this dissertation. They are the foundation of numerical analysis.Secondly, we introduce the all-optical switches of OTDM. Several optical switches used for optical demultiplexing are described and analyzed, and their performance is compared.Thirdly, demultiplexing technology of OTDM systems is dissertated. We review the configurations and characteristics of all-optical demultiplexer using phase-shifting optical switch and frequency-shifting optical switch. NOLM demultiplexer is particularly studied. The basic theory of NOLM is described first. Then switching characteristics of NOLM are discussed ignoring group-velocity dispersion. We also analyze the impacts of several factors on NOLM demultiplexer in detailed.Lastly, add-drop multiplexing technology of OTDM systems is studied. We especially study the performance of OTDM add-drop multiplexer based on XPM-induced frequency shifting in highly nonlinear fiber. Then, we analyze the impacts of factors on frequency chirp.