All-Optical Picosecond Signal Processing in a M-Z Interferometer Based on a Multi-Section Semiconductor Optical Amplifier

New features of the Cross-Gain Modulation and the Cross-Phase Modulation in a nonlinear active device, made by a cascade of differently biased Semiconductor Optical Amplifiers, have been numerically investigated and discussed. In the frame of an inter-ferometric application, the performances of a 4×25 Gb/s all-optical demultiplexer based on such a multi-section amplifier have been derived. This new nonlinear amplifier has been revealing able to manipulate 1ps FWHM optical Gaussian pulses both in terms of their amplitude and phase, without introducing any unwanted distortion in the extracted channel. The demultiplexed signal has shown a significant amplification, an excellent extinction ratio, and no degradation due to the optical gain pattern dependence in the nonlinear multi-section amplifier.