Semianalytical approach to the gain ripple minimization in multiple pump fiber Raman amplifiers

A simplified approach to the search of Raman pump powers and wavelengths minimizing the gain ripple in a Raman multiple-pump amplifier is presented. The first step is to evaluate the pump path average powers and the wavelengths through a minimization algorithm. Then, an approximated analytical derivation of the initial pump powers, that yields an approximated path average power, is given. The results of the algorithm are in excellent agreement with the full numerical calculations.