Analysis and applications of the optical amplifiers

It is very important to transmit optical signal over the optical communication systems with very low losses and noise. The optical amplifiers can transmit optical signals along long distances while amplifying them with high gain and low noise.In this thesis, erbium doped fiber amplifiers, ytterbium doped fiber amplifiers, semiconductor optical amplifiers and Raman fiber amplifiers are investigated and the design of these amplifiers are simulated in Optisystem 7.0 simulation program by considering the results of litterateur researches. The optimum operating conditions of the amplifiers are determined and amplifier performances are obtained in the optimum operating conditions by changing system design parameters at specific intervals; the performance of the amplifiers are compared based on their the simulation results. A two stage hybrid optical amplifier is designed to transmit optical signal along the very long distances by considering simulation results.After the optical amplifiers and their usage in optical networks are introduced in the First Section of this study, the material structure and operating method of erbium doped fiber amplifiers (EDFA) are explained. The material structure and operating method of ytterbium doped fiber amplifiers (YDFA) are explained in the Third section, modeling of semiconductor optical amplifiers (SOA) are achieved and working process of SOAs are explained in the Fourth Section and in the Fifth Section, the material structure and operating method of Raman fiber amplifiers are explained. In the Sixth Section, the amplifiers are designed by using OptiSystem 7.0 simulation program and the optimum operating conditions of amplifiers are achieved after the effects of design parameters on amplifier performance are examined. In the Seventh Section, a two stage hybrid optical amplifier, which is built by cascading a Raman fiber amplifier and an EDFA, is designed to transmit the optical signal over long distances based on the results that are achieved in the previous section and gain and power measurements in the output of the hybrid optical amplifier are examined. As a conclusion, all the simulation data and results are evaluated in the Eighth Section.