Performance of Fiber Raman Amplifier due to Change in Refractive Index of Second Core of Dual Core Fiber Raman Amplifier

Abstract

We vary the refractive index of second core of dual concentric cores of a single mode Fiber Raman Amplifier (FRA), having a step profile. Based on well known scalar analysis, we study crucially the effects of this variation on the performance characteristics of FRA for the first time. For practically important frequency shift band of 20 cm -1 to 700 cm -1 , our interesting observation is that values of refractive indices in a certain higher range show better flattening of effective raman gain in comparison to those in lower range with single pump; side by side, larger negative coefficient of dispersion is achieved in the operating range of wavelength with increase of refractive indices keeping the outer core radius, core gap radius and refractive index of the first core fixed. These promising criteria should attract the attention of system designers engaged in fabrication of FRA.