Study On C-And L-Band Erbium-Doped Fiber Amplifiers

High speed and capacity are goals of modern optical fiber communicationsystems. The invention of erbium-doped fiber amplifier (EDFA) has brought asignificant evolution to the modern optical fiber communication systems.In this dissertation C-and L-band EDFAs of high quality are analyzed anddesigned. The first, theoretical models of EDFAs are studied completely, then on thiscondition, experimental study on C-and L-band EDFAs have been carried outrespectively and the results are compared to the theoretical simulation. The maincontents of this dissertation are classified as follows:Theory:1. Various optical amplifiers, which are applied to the areas of the opticalcommunications, have been introduced comprehensively. A presentation on thehistory and recent development of EDFAs are discussed.2. The principle and characteristic of EDFAs are introduced, and various theoreticalmodels for optical amplifiers are summarized. Among the models, those based onclassical rate propagation equations are emphasized and their characteristics andapplication environment are analyzed.3. Numerical integration method on Giles model: shooting method is discussed,andthe conventional shooting method has been improved by adding an initial valueestimation.4. The spontaneous emission characteristics of EDFAs are investigated by Gilesmodel. Spectrum as a function of the fiber length has been obtained.Experiment:1. Experiments on C-band EDFA are carried out by measuring input and outputspectrum concentration. The gain and the noise figure have been abtained so thatthe deficiency and improvement are discussed.2. L-band EDFA is studied experimentally with EDF-L1500 of high concentration.Based on the former amplifier structure we have tested the property of theoptimized amplifier structure and compared the effect of different structures onthe pump efficiency.