Kerr nonlinearity mitigation in 5 × 28-GBd PDM 16-QAM signal transmission over a dispersion-uncompensated link with backward-pumped distributed Raman amplification.

We present experimental and numerical investigations of Kerr nonlinearity compensation in a 400-km standard single-mode fiber link with distributed Raman amplification with backward pumping. A dual-pump polarization-independent fiber-based optical parametric amplifier is used for mid-link spectral inversion of 5 × 28-GBd polarization-multiplexed 16-QAM signals. Signal quality factor (Q-factor) improvements of 1.1 dB and 0.8 dB were obtained in the cases of a single-channel and a five-channel wavelength-division multiplexing (WDM) system, respectively. The experimental results are compared to numerical simulations with good agreement. It is also shown with simulations that a maximum transmission reach of 2400 km enabled by the optical phase conjugator is possible for the WDM signal.

Highly efficient CW parametric conversion at 1550 nm in SOI waveguides by reverse biased p-i-n junction.

In this paper we present four-wave mixing (FWM) based parametric conversion experiments in p-i-n diode assisted silicon-on-insulator (SOI) nano-rib waveguides using continuous-wave (CW) light around 1550 nm wavelength. Using a reverse biased p-i-n waveguide diode we observe an increase of the wavelength conversion efficiency of more than 4.5 dB compared to low loss nano-rib waveguides without p-i-n junction, achieving a peak efficiency of -1 dB. Conversion efficiency improves also by more than 7 dB compared to previously reported experiments deploying 1.5 µm SOI waveguides with p-i-n structure. To the best of our knowledge, the observed peak conversion efficiency of -1dB is the highest CW efficiency in SOI reported so far.

Fiber optical parametric amplifiers in optical communication systems.

The prospects for using fiber optical parametric amplifiers (OPAs) in optical communication systems are reviewed. Phase-insensitive amplifiers (PIAs) and phase-sensitive amplifiers (PSAs) are considered. Low-penalty amplification at/or near 1 Tb/s has been achieved, for both wavelength- and time-division multiplexed formats. High-quality mid-span spectral inversion has been demonstrated at 0.64 Tb/s, avoiding electronic dispersion compensation. All-optical amplitude regeneration of amplitude-modulated signals has been performed, while PSAs have been used to demonstrate phase regeneration of phase-modulated signals. A PSA with 1.1-dB noise figure has been demonstrated, and preliminary wavelength-division multiplexing experiments have been performed with PSAs. 512 Gb/s have been transmitted over 6,000 km by periodic phase conjugation. Simulations indicate that PIAs could reach data rate x reach products in excess of 14,000 Tb/s × km in realistic wavelength-division multiplexed long-haul networks. Technical challenges remaining to be addressed in order for fiber OPAs to become useful for long-haul communication networks are discussed. [Formula: see text].