All-optical switching at multi-100-Gb/s data rates with Mach-Zehnder interferometer switches

We present experimental and theoretical results on ultrafast nonlinear dynamics in InGaAsP semiconductor optical amplifiers (SOAs). Carrier heating, spectral hole burning, and two-photon absorption are analyzed by heterodyne pump-probe experiments which deliver basic model parameters like gain-phase coupling parameters of the material. The impact on the device performance induced by these physical effects is verified by cross-gain/cross-phase experiments on InGaAsP-based SOAs and Mach-Zehnder interferometer switches. In the co-propagation arrangement, the switching window with maximum transmission is shown to be 1.5 ps which translates into demultiplexing capabilities beyond 600 Gb/s. Calculations based on a distributed rate equation model show that, for high-speed applications, the switching window can be limited by pulse saturation and by subpicosecond nonlinear effects.