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

Signal integrity of femtosecond pulses patterns in a 500Gb/s all-optical demultiplexer for otdm interconnections by using nonlinearities in semiconductor optical amplifiers

“…An interferometric demultiplexing architecture like that considered in [1] is particularly suitable for exploring the main attractive features of a SOA-based pump-probe scheme at extremely high repetition rates (Fig.1). This demultiplexer is based on a Mach-Zehnder (M-Z) scheme, equipped with two identical SOAs, each one placed on one arm of the interferometer.…”

“…In this sense, an intense research activity which has been carrying on since over ten years suggests that the all-optical networks will be a profitable alternative to the hybrid solutions available today when photonic technology becomes mature for managing a large quantity of ultrafast optical patterns in the time domain, according to the particular approach which is a peculiarity of the Optical Time Domain Multiplexing (OTDM) technology [1]- [2]. In the OTDM systems, many RZ-format data channels are time interleaved to form a single higher speed data stream (even at several hundreds of Gbit/s), and the ultrafast optical signals are processed in a pure photonic layer.…”

“…In particular, the nonlinear gain saturation dynamics, which generally produce a modulation of the amplitude of the probe field as well (i.e. the Cross Gain Modulation (XGM) [1]- [4]), can generate a dependence of the optical gain on the particular pump pulses sequence at the SOA input. This phenomenon, known as "optical gain pattern-dependence" [2], produces an unwanted modulation of both the amplitude and the phase of the probe field in a OTDM board, with a severe degradation of the integrity of the signals to be processed.…”

“…[1], [2]) have pointed out new SOAs features which appear particularly attractive in alloptical signal processing applications: the gain patterndependence can be suppressed by properly managing the TwoPhoton Absorption (TPA) and the nonlinear optical gain saturation dynamics. In this way, simple SOA-based pumpprobe architectures resulted suitable for performing the fundamental functions of signal processing with no significant pattern-dependence.…”

“…In OTDM applications, the nonlinear features of these amplifiers are exploited especially in pump-probe interferometric architectures, where the ultrafast phase deviations, induced by a high-power optical pump pulses sequence traveling into the SOA, are transferred on a lowpower optical probe pulses sequence (i.e. the Cross Phase Modulation (XPM) [1], [3], [4]). These phase deviations depend on both the optical gain saturation dynamics (i.e.…”