الفهرس 
cover EnglishOnly 14 pages are availabe for public view
 |  | from | 120 |  |  |
| | | from | 120 | | |
Abstract
Erbium Doped Fiber Amplifier, EDFA, is used in optical communication systems because it has the maximum gain and low pump power and its performance are better in comparison to other similar amplifiers. There are 3 different configurations for characterizing EDFA:1- Co-propagation. 2- Counter-propagation. 3- Bi-directional configuration.They depend on how we connect a signal to an Erbium doped fiber and apply pumping via optical multiplexers and isolators. Performance can be enhanced when we determine the EDFA characteristics. We need to know the maximum gain for a given fiber and also the saturation intensity. This should be tested at different pumping powers for the same fiber in different techniques to find out the optimum design of an EDFA.We simulate a design for an EDFA consists of an erbium doped fiber, signal source, pumping, passive optical components like: multiplexers and isolators, detector and an oscilloscope. This design contains many variables, including the power of the signal source, 1550nm, and the pumping, 980nm, in order to determine the maximum gain and, also, the saturation power. Furthermore, we varied the core and doping radii in the Erbium doped fiber, plus the doping density to achieve the optimum one. In addition to all above, trying different lengths of the Erbium doped fiber provided us with different results according to the pumping configuration. We attempted the three configurations, mentioned above, to decide the best parameters will be chosen as a final design before fabricating this fiber. It is important to choose the best core and doping radii, doping density and the fiber length to match with the signal and pumping powers. The design is performed using Optsim Software, we also put in consideration that our design attains the requirements of amplifying an attenuated signal in long distance communications, which is usual 1550nm. Our design of erbium doped fiber is sent to FiberCore Company to be fabricated. The parameters of the manufactured fiber were tested using Gain master.