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

Isaac Sackey,Markus Nölle,Colja Schubert,Francesco Da Ros,Christophe Peucheret,Christian Meuer,Klaus Petermann,Lutz Molle,Mahmoud Jazayerifar,Thomas Richter

doi:10.1364/oe.22.027381

Abstract

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.

Highlights

The quest for increasing transmission reach in long haul optical links demands a sufficiently high optical signal-to-noise ratio (OSNR) to be guaranteed at the receiver, and one way to achieve such OSNR is by injecting high signal launch powers into the spans of the optical link
In a similar work applied to the nonlinear compensation of a polarization-division multiplexed (PDM) quadrature phase shift keying (QPSK) signal, the signal and its inverted spectrum were generated at the transmitter and both waves were transmitted through the link to the receiver
After combining all five wavelength-division multiplexing (WDM) channels with an optical coupler, the 28-GBd PDM 16-quadrature amplitude modulation (QAM) signals were amplified with an erbium-doped fiber amplifiers (EDFAs) and the out-of-band amplified spontaneous emission (ASE) noise was suppressed with a 3-nm optical band pass filter (OBPF)

Summary

Introduction

The quest for increasing transmission reach in long haul optical links demands a sufficiently high optical signal-to-noise ratio (OSNR) to be guaranteed at the receiver, and one way to achieve such OSNR is by injecting high signal launch powers into the spans of the optical link. In order to mitigate the signal transmission impairments due to Kerr nonlinearity, various techniques involving electronic domain compensation [6,7,8,9] as well as optical domain compensation [10,11,12,13,14,15,16,17,18,19,20] have been investigated It has been shown in [10,13] that systems with bi-directional distributed Raman amplification (DRA) have power-dispersion maps which make them much more suitable for fiber nonlinearity mitigation through optical phase conjugation (OPC) than pure EDFA amplified links. All-optical coherent superposition of the signal and idler after the link in a low noise phase sensitive amplifier (PSA) has been shown to exhibit a trend to cancel out the effect of fiber nonlinearities [14] This investigation was carried out for a single-channel 10-GBd single-polarization 16-QAM signal

Methods

Results

Conclusion