Calculations and Measurements of Raman Gain Coefficients of Different Fiber Types
MetadataShow full item record
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 the Raman gain spectrum from the doping level and refractive index profiles of different fiber designs. This thesis develops a method to predict the Raman gain coefficients and spectra for a pure silica core fiber and two different types of GeO2-doped silica fibers given their index profiles. An essential feature of the model is the inclusion of the variation in Raman gain coefficient over the mode field due to the variation in the Ge concentration across the fiber core. The calculated Raman gain coefficients were compared with measurements of the peak Raman gain on a step-index GeO2-doped fiber and with published measurements from various sources. Agreement between the calculated and measured peak gain for the step-index fiber was excellent. There was qualitative agreement with published measurements but there were significant differences between the calculated and published gain coefficients, which are not understood. Part of the work sought a way of predicting Raman gain coefficients from a standard gain curve given only the fiber type and the effective area. This approach appears promising for moderately-doped fibers with the proper choice of effective area.
- Masters Theses 
Showing items related by title, author, creator and subject.
Phenotypic and Metabolic Profiling of Biological Samples in Near Real-Time Using Raman Spectroscopy Zu, Theresah Nom Korbieh (Virginia Tech, 2014-10-22)Raman spectroscopy, together with multivariate statistical analyses, has proven to be a near real-time analytical technique capable of phenotyping cells, tissues and organs. This dissertation will show exclusively the ...
Lahr, Rebecca Halvorson (Virginia Tech, 2014-01-09)Due to an ever-increasing global population and limited resource availability, there is a constant need for detection of both natural and anthropogenic hazards in water, air, food, and material goods. Traditionally a ...
Photogeneration and recombination processes of neutral and charged excitations in films of a ladder-type poly(para-phenylene) Wohlgenannt, M.; Graupner, W.; Leising, G.; Vardeny, Z. V. (American Physical Society, 1999-08-15)We introduce a version of the cw photomodulation technique, measured far from the steady state, for obtaining the quantum efficiency, eta, of long-lived photoexcitations in pi-conjugated polymers. We apply this technique ...