Study On The Simulator Of EDFA

Erbium-Doped Fiber Amplifier (EDFA) plays an important role in the optical fiber communication system, so more and more studies on EDFA have been done. At the same time, the simulations on EDFA are more than before, because an effective simulation is helpful to analyze and optimize EDFA.The main work in this thesis is to design an EDFA simulator which can be used to simulate EDFA's major performance when EDFA is under the static condition. It also can be used to simulate the pulse propagation in EDFA. One of the simulator's functions is to analyze EDFA's work performance and optimize EDFA's work parameters. The other is to study the status of pulse propagation in EDFA. Before designing the EDFA simulator, we should build two theory models which are for numerical computation. One is the theory model when EDFA is under the static condition. The other is the model about the pulse propagation in EDFA. Then we transfer the theory models into mathematic models. We use GUI tool of MATLAB 6.5 to design the static graphical user interfaces and dynamic program. In the end, the mathematic models are assembled to the EDFA simulator.The main contents in this thesis include as follows:(1) Based on the widely learning of many references, theories, construction and basic functions of EDFA are addressed. The ideas and steps of using MATLAB GUI tool to design the EDFA's simulator are introduced in brief. (2) Based on the current theoretical model of EDFA, an approximative model is presented. The nonlinear Schroedinger (NLS) equation is introduced, which is used to describe the pulse propagation in the fiber. NLS is extended to describe the pulse propagation in EDFA and the split-step Fourier method is discussed, which is used to solve the extended NLS equation.(3) A design pattern of MATLAB file is defined. Based on the design pattern, we use MATLAB GUI tool to implement the EDFA's simulator.(4) We can use the designed EDFA's simulator to simulate and analyze the impact of the wavelength and the power, the length of EDF, the power of pump on the gain. The relationship between the noise of EDFA and the power of pump and the length of EDF is also analyzed here. The simulator can be also used to simulate the pulse propagation in EDFA and analyze the reasons of the pulses' changes.