A wavelength-preserving photonic integrated regenerator for NRZ and RZ signals

This paper presents a novel Indium Phosphide based photonic integrated circuit (PIC) for all-optical regeneration of both nonreturn-to-zero (NRZ) and return-to-zero (RZ) on-off-keying (OOK) signals. The PIC exploits cross gain compression in two semiconductor optical amplifiers to simultaneously obtain a wavelength-preserved and reshaped copy, and a wavelength-converted yet inverted copy of the input signal. Regeneration of 10 Gb/s signals on multiple wavelengths is demonstrated, showing a Q-factor improvement from 1.5 to 4 for NRZ-OOK signals and from 2.3 to 3.6 for RZ-OOK signals, and a BER improvement up to 1.5 decades.