Demonstrations of all-optical conversions between the RZ and NRZ data formats incorporating noninverting wavelength shifting leading to format transparency

We demonstrate a polarization insensitive semiconductor optical amplifier (SOA)-based system that converts an RZ (return-to-zero) WDM channel into the NRZ (non-return-to-zero) format (RZ/spl rarr/NRZ). Our system allows the input RZ wavelength to be either preserved or wavelength shifted. Additionally, we use a previous NRZ/spl rarr/RZ converter and our new RZ/spl rarr/NRZ converter to realize an all-optical NRZ/spl rarr/RZ/spl rarr/NRZ reconverter; such an operation may be necessary for intermediate optical processing of packets. To demonstrate the robustness of the reconverter, we incorporate 4 EDFAs and 80 km of fiber between the individual converters. These functions may significantly help to realize RZ/NRZ data format transparency within dynamically-reconfigurable and fully-functional WDM networks.