Raman Optical Amplifier

Fiber Raman amplification using the transmission line is a promising technology to increase the repeater distance as well as the capacity of the communication systems. Because of the growing importance of fiber Raman amplification, it is desired to predict the magnitude and shape of Raman gain spectrum for different materials. This thesis develops a study for Raman gain, Raman gain coefficient and Raman cross section for four different materials: SiO2, GeO2, B2O3 and P2O5 over the wavelength rang from 1.5 to 1.6 m. We investigated Raman gain at different fiber lengths: 10, 20, 30 and 40 km for the four different materials and also at different pump powers 350, 400, 450 and 500 mW. It is shown that the SiO2 and GeO2 amplifiers offer higher Raman gain. So, it is suitable to use both as power amplifiers. While P2O5 and B2O3 achieve larger bandwidths and hence, both are recommended in wavelength division multiplexing (WDM) telecommunication systems. A part of the work sought a way of predicting Raman gain coefficients from the standard gain curve given only the fiber type and the effective area. This approach appears promising for moderately-doped fibers with the proper ch