4 × 160-Gbit/s multi-channel regeneration in a single fiber

Area of Science:

• Optical communications
• Nonlinear optics

Background:

• High-speed optical networks require robust signal regeneration to combat noise and nonlinearities.
• Existing regeneration techniques often face limitations in handling complex modulation formats like PDM-WDM signals simultaneously.

Purpose of the Study:

• To demonstrate simultaneous regeneration of four 160 Gbit/s WDM-PDM signals in a single highly nonlinear fiber (HNLF).
• To suppress noise and mitigate inter-channel nonlinearities in high-speed optical transmissions.

Main Methods:

• Utilizing four-wave mixing (FWM) in HNLF, where data signals act as the pump.
• Employing cross-phase modulation (XPM) to suppress stimulated Brillouin scattering (SBS).
• Implementing an inter-channel time delay and bidirectional propagation to manage nonlinear impairments.

Main Results:

• Simultaneous noise suppression on both '0' and '1' levels for all four channels.
• Achieved receiver power improvements at a bit-error rate (BER) of 10(-9) ranging from 1.5 dB to 1.9 dB.
• Effective mitigation of stimulated Brillouin scattering (SBS) and inter-channel nonlinearities.

Conclusions:

• The proposed FWM-based regeneration scheme in HNLF is effective for simultaneous multi-channel WDM-PDM signal recovery.
• The technique offers improved receiver sensitivity and noise suppression, crucial for future high-capacity optical networks.