Experimental Characterization of SOA-Based Wavelength Converters for DPSK Signals

Abstract

We report a detailed experimental characterization of the wavelength conversion of 10 Gb/s non-return-to-zero differential phase shift keying (NRZ-DPSK) optical signals based on four wave mixing (FWM) in a semiconductor optical amplifier (SOA). The performance of this coherent wavelength converter is compared with theoretical results and found to perform better, in terms of extended range of signal-to-pump ratio (SPR) with lower power penalty, than conventional on-off keying (OOK) and return-to-zero DPSK (RZ-DPSK) signals due to its constant envelope and inherent immunity to data pattern fluctuations.