Forward Pumping Based Fiber Optical Raman Amplifiers in Different Optical Fiber Transmission Medium Systems

This paper has presented the transmission systems with employing Raman amplifier technology in forward pumping directions in order to have put up with much higher level of design complexities, when compared to conventional transmission lines with doped fiber optical amplifier. Even for the construction of a fundamental, basic building block a unit of a fiber Raman amplifier (FRA), the designer have to struggle with the problems associated with the interactions between pump / signal waves mediated by Raman process, have to wander within the vast degrees of freedom given the choice of pumping directions/ratios, and have to contemplate with the wavelength dependent fiber loss/noise figure profiles. Optimizing optical signal to noise ratio (OSNR) and designing ultralong haul links with best signal quality factor performances and minimum bit error rates, while adjusting variables in the fiber length, Rayleigh penalty, pump noise, nonlinear penalty, dispersion and gain distribution is a problem which can be easily stated, but in reality is not a process which can be easily achieved.