Polarization Mode Dispersion Compensation In High Speed Optical Communication Systems

The research work in this paper are supported by the Natural Science Foundation of Hebei province under Grant F2004000072 and scientific research Project item of Hebei province education office under Grant 2005354.When attenuation and chromatic dispersion are compensated for, PMD is regarded as one of the dominant obstacles in optical fiber communication systems having bit rates of 40Gbit/s and beyond. Research found that PMD can damage the performance of system and limit the transmission distance. However, PMD is very difficult to compensate because of its stochastic feature. The key technologies of PMD compensation are the topics in this thesis.First, a summary of the relating concepts of PMD and its statistics nature was given in chapter 2, which are the fundamentals for farther discussion. In chapter 3, system performance is discussed from the statistical characteristic of first-order PMD, the relation of average DGD and transmission distance, the deterioration of receiver's sensitivity caused by PMD, PMD restrict the system etc, which are based on pulse broadening theory.The focus topic of this thesis is the PMD compensation technology in present high speed optical communication systems. In chapter 4, the principle of PMD compensation technologies are first introduced, including PSP transmission compensation technology, post compensation technology and adaptive PSP compensation technology. System performance of uncompensated and these three kind compensated systems are compared based on PMD-induced pulse broadening theory. Then the compensation schemes in 40Gbit/s optical communication systems are investigated and designed. At last, second-order PMD theory is analyzed. According to the relation of Q-factor and average DGD, it is point out that one fixed and one alterable DGD compensator is the best.