Signal to noise ratio in nonlinear optical amplification process

In this communication, one looks at the influence of the saturation process over the statistical fluctuations (signal to noise ratio) of the optical power at the output of a travelling wave semiconductor optical amplifier (TWOA) . The statistical behaviour of this device is described starting from the photon density matrix equation. The obtained theoretical results, both for the noise figure and for the signal to noise ratio, allow to take out some conclusions about noise behaviour in the non-linear light amplification process.Peer Reviewe