Femtosecond switching with semiconductor-optical-amplifier-based Symmetric Mach-Zehnder-type all-optical switch

We investigate the effect of intraband carrier dynamics on a nonlinear phase shift induced in a semiconductor optical amplifier (SOA) in terms of its applicability to the Symmetric Mach-Zehnder (SMZ) all-optical switch. Nonlinear phase shifts in an SOA and a passive semiconductor waveguide are compared under control-pulse durations ranging from 3.2 to 0.4 ps. The results show that femtosecond switching with higher efficiency is still possible by using the SOA. We experimentally achieve femtosecond (670 fs), femtojoule (140 fJ) switching with the SOA-based SMZ all-optical switch. (C) 2001 American Institute of Physics.