Fiber nonlinearity mitigation of WDM-PDM QPSK/16-QAM signals using fiber-optic parametric amplifiers based multiple optical phase conjugations.

We demonstrate fiber nonlinearity mitigation by using multiple optical phase conjugations (OPCs) in the WDM transmission systems of both 8 × 32-Gbaud PDM QPSK channels and 8 × 32-Gbaud PDM 16-QAM channels, showing improved performance over a single mid-span OPC and no OPC in terms of nonlinear threshold and a best achievable Q factor after transmission. In addition, after an even number of OPCs, the signal wavelength can be preserved after transmission. The performance of multiple OPCs for fiber nonlinearity mitigation was evaluated independently for WDM PDM QPSK signals and WDM PDM 16-QAM signals.

Distributed Raman amplification in a 8 x 10-Gb/s, 40-km, 1:128 TWDM PON.

We demonstrate distributed Raman amplification compatible with the wavelength plans and rates defined in ITU's specification for TWDM PON. We report downstream and upstream gains of 9.8 dB and 8.

Colorless coherent receiver using 3x3 coupler hybrids and single-ended detection.

We demonstrate a single-ended colorless coherent receiver using symmetric 3x3 couplers for optical hybrids. We show that the receiver can achieve colorless reception of fifty-five 112-Gb/s polarization-division-multiplexed quadrature-phase-shift-keyed (PDM-QPSK) channels with less than 1-dB penalty in the back-to-back operation. The receiver also works well in a long-haul wavelength-division-multiplexed (WDM) transmission system over 2560-km TrueWave® REACH fiber.

6×56-Gb/s mode-division multiplexed transmission over 33-km few-mode fiber enabled by 6×6 MIMO equalization.

Mode-division multiplexing over 33-km few-mode fiber is investigated. It is shown that 6×6 MIMO processing can be used to almost completely compensate for crosstalk and intersymbol interference due to mode coupling in a system that transmits uncorrelated 28-GBaud QPSK signals on the six spatial and polarization modes supported by a novel few-mode fiber.

Suppression of intrachannel four-wave-mixing induced ghost pulses in high-speed transmissions by phase inversion between adjacent marker blocks.

We propose a method for suppressing the intensity of the worst ghost pulse (a single ghost pulse between two long marker blocks) resulting from intrachannel four-wave mixing (FWM) in strongly dispersion-managed on-off keying optical transmissions by inverting the optical phases of the marker blocks surrounding the ghost pulse. We show both analytically and numerically that the method provides substantial suppression of the maximum ghost pulse energy. The suppression is experimentally verified in 40-Gbit/s transmission experiment over a 100-km non-zero-dispersion-shifted fiber.