Theoretical Analysis And Experimental Research Of Tunable Chromatic Dispersion Compensation Based On SOA

With the increase of the optical fiber communication data, dispersion has become a major factor in evaluating the signal transmission quality. Thus, the influence of dispersion will become more and more significant. Furthermore, due to the low tolerable dispersion in the high-bit-rate transmission system, a certain amount of residual dispersion still exists in the transmission after the static dispersion compensation, which will influence communication quality. Therefore, tunable dispersion compensation has become a key technology to the performance of40Gbit/s or more high-bit-rate transmission system. In the thesis, a tunable dispersion compensation method for the40Gbit/s transmission system is proposed based on the nonlinear effect of SOA. After analyzing the theory of the tunable dispersion compensation based on the SPM and XPM effect of SOA, influences of each parameter on the compensation effect are simulated by optisystem. Finally, consecutive and small range tunable dispersion compensation is realized in experiments of the tunable dispersion compensation based on the XPM effect of SOA.This work concentrates on:1. Some traditional tunable dispersion compensation technologies are introduced, in terms of optical dispersion compensation (ODC), electronic dispersion compensation (EDC), and the new modulation format of signal. The transmission function while the optical signal propagates in the transmission fiber is deduced based on the fundamental theory of dispersion. According to the transmission function, the group velocity dispersion equation is obtained. Simulation results based on the optical pulse’s change of waveform and spectrum is affected by the accumulate dispersion.2. According to the carriers equation and gain equation of SOA, the transmission function of SOA is got. Based on the transmission function, the situations that single optical pulse and optical pulse sequence propagates through the SOA are simulated. The situation that the chirp changes in terms of different incident optical pulse power and different current situation is also simulated.3. Based on the SPM and XPM effect of SOA, the change of chirp is influenced by different parameters,such as the delay between the signal and the clock signal, injection current, and the optical power of the clock signal. Eye diagrams before and after dispersion compensation were presented inlOGbit/s and40Gbit/s optical communication systems.4. An40Gbit/s optical communication experimental system was carried out based on the SPM and XPM effect of SOA. The eye diagrams and the BER measured by Bit error tester before and after dispersion compensation show that the simulation results match the experimental results.