Tunable Optical Parametric Regenerator Assessment in a 43 Gb/s RZ-DPSK Signal Transmission Link

Abstract

We study a wavelength-tunable optical parametric regenerator (OPR) demonstrated experimentally by assessing numerically its performance as an inline component of a 43-Gb/s return-to-zero differential phase-shift keying transmission system. The device features wide input wavelength range operation and regenerative wavelength conversion. The improvement in the transmission reach that it provides is predicted by simulations benchmarked against the experimental data. An up to fourfold improvement at a bit error ratio of ∼ 10 −4 is estimated for a 360-km long regeneration span. We show that the improvement is achieved by a combination of the amplitude regeneration capabilities with the phase noise blocking character of the OPR, despite of the small amount of phase fluctuations induced by the regenerator itself.Index Terms-Optical parametric regeneration, optical signal processing.

Phase noise mitigation of QPSK signal utilizing phase-locked multiplexing of signal harmonics and amplitude saturation

“…However, there might be advantages to mitigate the phase noise in the optical domain, such as avoiding the impact of optical-to-electronic conversion and supporting in-line signal processing for high-baud-rate signal [6]. Different approaches have been demonstrated for optical regeneration of QPSK signals using different variations of phase-sensitive amplification to achieve a level of "phase squeezing" [7][8][9]. However, these methods tend to require coherency between a signal and a pump, typically requiring phase-based feedback loops and injection locking lasers [7][8][9][10].…”