All-optical format conversion using a periodically poled lithium niobate waveguide and a reflective semiconductor optical amplifier

In the present letter, the authors report on the realization of all-optical format conversion by using the cascaded sum- and difference-frequency generation in a periodically poled lithium niobate waveguide and the active mode locking in a reflective-semiconductor-optical-amplifier-based fiber ring laser. Tunable format conversions from nonreturn-to-zero pseudorandom binary sequence (PBRS) signal to return-to-zero PRBS idler at 10 and 20 Gbit / s are observed in the experiment.