An analytical method for determining comprehensive impact of Rayleigh backscattering on performance of systems with distributed Raman amplifiers
An analytical method to determine the impact of amplified spontaneous Raman scattering and double Rayleigh backscattering noise in distributed Raman amplifiers (DRAs) is derived. By this method, two applications of DRAs are discussed. Firstly, DRAs are used as preamplifiers before receivers. Secondly, DRAs are used as preamplifiers of EDFAs in repeated systems. In both cases, calculations show that there is an optimal Raman pump power at which the system has the best performance.