Modulational instability of stochastic optical waves in nonlinear media with anomalous dispersion

is researched the influence of the phase fluctuations on the coherence properties of the laser's radiation at propagation of short pulses in the optical fibers at the anomalous dispersion region. Two different methods for studying of modulational instability are applied and compared -method based on the solving of the Nonlinear Schrodinger Equation (NLSE) with stochastic initial conditions and method for researching of the Four-Wave Mixing in the fibers. The results received by these two methods are compared to determine the applicability of each of them.