All-optical NRZ to RZ format conversion using a walk-off balanced nonlinear fiber loop mirror

We demonstrate a novel method of converting all-optical nonreturn-to-zero (NRZ) format to return-to-zero (RZ) format using a walk-off balanced nonlinear fiber loop mirror (WBNFLM). In this scheme, the pulse width of the converted RZ signal, i.e., duty cycle, can be adjusted easily according to bit rates and timing tolerances, which is required in high speed transmission systems. This scheme is expected to play an important role in future all-optical communications as a means to interface low-speed all-optical networks to high-speed optical transmission systems.