We have analysed the influence of non-linear refractive indexes on the four-wave mixing (FWM) conversion efficiency in semiconductor optical amplifiers (SOAs). It is shown that the characteristics of generated FWM signal can be modified due to the variation of nonlinear refractive index of the SOA. To simulate the wave propagation in the SOA, we have used the nonlinear propagation equation taking into account the gain spectrum dynamics, gain saturation which depends on carrier depletion, carrier heating, spectral hole-burning, group velocity dispersion, self-phase modulation and two photon absorption. Simulation results show that the higher FWM conversion efficiency can be achieved for the higher values of non-linear refractive index.
