Demonstration of 40 Gbit/s all-optical return-to-zero to nonreturn-to-zero format conversion with wavelength conversion and dual-channel multicasting based on multiple cross-phase modulation in a highly nonlinear fiber

We propose and experimentally demonstrate all-optical returnto- zero (RZ) to nonreturn-to-zero (NRZ) format conversion by using multiple cross-phase modulation (MXPM) in a highly nonlinear fiber. The proposed all-optical format converter can perform simultaneously wavelength conversion and dual-channel signal multicasting. This is achieved by properly filtering two broadened probe spectra induced by MXPM between the RZ signal and continuous-wave double probe lights. We also study experimentally wavelength tunability for the proposed format converter at 40 Gbit/s, which is feasibly achieved by varying the central wavelengths of the double probe lights. Our results show that a wide operation wavelength range of 24 nm is obtained. By monitoring eye diagrams, the converted 40 Gbit/s NRZ signals can have an extinction ratio of 10.9 dB and the Q-factor of 6.1, respectively. Moreover, the proposed scheme is simple and robust, which is promising for high-speed optical fiber communication applications. (C) 2013 Society of Photo-Optical Instrumentation Engineers (SPIE)