Study On Erbium-doped Fiber Amplifiers In Optical Networks

The emergence of EDFA and WDM is the landmark in the history of optical fiber communication. And the development of optical networks moved forward from the previously p2p transport system to the intelligent all-optical networks with various optical processing technology being used. Moreover, the structure of EDFA used in intelligent optical networks will become more and more complex which means a new difficult question for optimizing EDFA in optical networks.In this Paper, study was focus on the optimization of EDFA in optical networks.The main work of this thesis can be list as follows:1. This paper summary the basic principles, key technologies and research status of the EDFA in optical networks. Various kinds of mathematical models of EDFA were shown in this section, simulation experiment of EDFA based on Giles modle was carried out.2. Primarily using PSO algorithm to optimize the effectiveness of Optical fiber amplifier and solutions to optimized parameters of S, C, L-band EDFA in optical networks.(For C-band, L-band EDFA, Average gain>25dB, NF<5dB, for S-band EDFA Average gain>10dB, NF<5dB). Moreover, compared with GA method, PSO algorithm is much faster than GA algorithm for converges on the optimal solution.3. By using PSO algoritum, the parameters of amplifier's structure were optimized both S-band and S+ band EDFA. The optimization results indicate that, for S-band (1486nm-1520nm) EDFA, average gain was greatly improved when ASE filter was inserted. Moreover, the distribution scheme of ASE filter was discussed in detail.4. Two main type of gain flattening methods (gain flattening filter and optimization design) are expounded, according to the results of comparation of different methods, the trends of gain flattening method are presented.