Research On Dispersion Compensation Technology Using Fiber Bragg Grating

In optical communication systems, enlargement of capacity, improvement of rate and extension of distance are all closely related with fiber loss, nonlinear effect and chromatic dispersion effect. As the large range of dispersion compensation in the bandwidth of fiber Bragg grating(FBG), technique of FBG becomes one of the most attractive dispersion compensation techniques in actual transmission systems. The technique of dispersion management is used to optimize the dispersion, which not only reduces dispersion of optical fiber transmission system, but also suppresses nonlinear effects effectively.This paper studies the optical dispersion compensation communication systems based on FBG. Some schemes based on FBG are proposed, and some key system parameters of dispersion management are discussed, which are analyzed through simulation of the optimal one for the best system performance. The main contents of this paper are as follow:1. The nonlinear Schrodinger (NLS) equation is solved using split-step Fourier method. The transmission process of the optical pulse in the optical fiber is discussed, and the loss, the dispersion, the nonlinear effects are analysed. The results demonstrate that the input power plays an important role on the performance of system. We get the optimal input power through simulation, which is proved to be the same as the supposition by the result of the NLS equation soluted by numerical method.2. Four schemes based on FBG are realized through simulation, the post-compensation shows the best performance among these. And comparing with the post-compensation based on DCF, FBG shows a better performance.3. According to the optimization scheme, the performance of the 2500km-10Gbps optical communication systems were simulated with the key system parameters, such as the modulation format, the duty cycle, the input power, the amplifier span length and the range of FBG bandwidth. The simulation results show that the optimal system improves the transmission performance and extends the transmission distance effectively.4. FBGs are cascaded as the form of comb filter module, which are used as the dispersion compensation devices in WDM optical fiber transmission systems. And we design the appropriate model to achieve the multi-channel dispersion compensation through the optical communication simulation software named optisystem.5. The nonlinear effect of WDM systems are analyzed, and the transmission performances of WDM system based on optical fiber Bragg grating and dispersion compensation fiber are discussed, and the performances of two systems are compared through the simulation experiment.