Semiconductor optical amplifier (SOA) is very fit for all opticalmodulationformat conversion due to its high nonlinear characteristics, lower switch power and small size.
A format conversion from a non-return-to-zero (NRZ) signal to return-to-zero (RZ) signal is presented based on four-wave mixing (FWM) and cross-phase modulation (XPM) in a silicon optical waveguide.