Extinction ratio improvement and wavelength conversion based on four-wave mixing in a semiconductor optical amplifier

We have demonstrated an extinction ratio improvement of more than 3 dB at 2.5 Gb/s with a method based on four-wave mixing in a semiconductor optical amplifier. A wavelength conversion and a data format conversion from nonreturn-to-zero (NRZ) to return-to-zero (RZ) have been simultaneously achieved.