Simultaneous nonlinearity mitigation in 92 × 180-Gbit/s PDM-16QAM transmission over 3840 km using PPLN-based guard-band-less optical phase conjugation

Abstract

We experimentally demonstrated the simultaneous nonlinearity mitigation of PDM-16QAM WDM signals using complementary-spectrally-inverted optical phase conjugation (CSI-OPC). We achieved reserved-band-less, guard-band-less, and polarization independent OPC based on periodically poled LiNbO₃ waveguides. By employing the CSI-OPC, 2.325-THz-band (93 × 25 GHz) complementary spectral inversion was achieved while retaining the original WDM bandwidth. A Q²-factor improvement of over 0.4 dB and a 5120 km transmission with a Q²-factor above the FEC limit were confirmed using a 10-channel WDM transmission at the signal band center and signal band edge. We then demonstrated the mitigation of the nonlinear impairments in a 3840 km long-haul WDM signal transmission for all 92-channel 180-Gbit/s PDM-16QAM quasi-Nyquist-WDM signals.

Optical Phase Conjugation in a Silicon Waveguide With Lateral p-i-n Diode for Nonlinearity Compensation

“…Additionally, the access to a broad bandwidth allows for compensation of the intrachannel nonlinear interaction, which would be challenging to address at the receiver side when only one channel is processed. Using optical phase conjugation (OPC), nonlinear compensation over a record bandwidth up to 2.3 THz has been reported [16], which is well beyond the capabilities of practical coherent receivers. The majority of OPC demonstrations so far have relied on implementing the conjugation through four-wave mixing (FWM) in a highly nonlinear fiber (HNLF) [6], [9]- [15] or cascaded second-order effects in periodically-poled lithium niobate (PPLN) [16].…”

Volterra-Assisted Optical Phase Conjugation: A Hybrid Optical-Digital Scheme for Fiber Nonlinearity Compensation

“…Mid-link OPC can jointly compensate for chromatic dispersion and nonlinear effects within the transmission link [16], [19], with the big advantage, compared to digital NLC schemes, of compensating for inter-channel effects without requiring joint detection/processing of multiple channels. As such a compensation takes place in the optical domain, NLC can be performed jointly over very large optical bandwidths, e.g., in [21] NLC was achieved over 92 channels using OPC for long-haul transmission systems . Performing digital NLC over such bandwidths would be infeasible due to the high computational complexity.…”

Link-Placement Characterization of Optical Phase Conjugation for Nonlinearity Compensation

“…Amongst them, in-line optical phase conjugation (OPC) has been proven effective for nonlinearity compensation. Several impressive demonstrations show significant improvement achieving bandwidths up to 2.3 THz [2].…”