Relative intensity noise characteristics of wavelength converters based on four-wave mixing in semiconductor optical amplifiers

A detailed numerical and experimental study of the additional RIN induced to the input waves by the FWM process, is presented. The nonlinear medium used in the experiments is a bulk Semiconductor Optical Amplifier (SOA). The measurements are carried out for different operating conditions (pumping level of the SOA, input power, input signals with different intensity noise characteristics, etc.). A complete numerical model is employed to simulate the FWM process, taking into account interaction of four waves in the SOA (two input waves and two product waves). The latter is used in order to obtain realistic behavior of the model, when operation at a wide range of input power is considered. The theoretical interpretation of the above results is based on the static transfer function of the FWM process where all waves interacting in the SOA are continuous waves (CW).