Cascadability of an All-Optical 3R Regenerator Utilizing Nonlinear Phase Modulation and Offset Filtering at 10 and 40 Gb/s

The cascadability of a polarization-insensitive wavelength-preserving all-optical 3R regenerator is experimentally investigated for bit rates of 10 and 40 Gb/s. The regenerator consists of a self-pulsating laser for clock recovery, cross-phase-modulation-based retiming, and self-phase-modulation-based reshaping. A recirculating loop is used to demonstrate the cascadability of the regeneration scheme by transmitting return-to-zero on-off-keyed signals over 18 000 km at 10 Gb/s and over 8000 km at 40 Gb/s.