Transmission performance improvement using random DFB laser based Raman amplification and bidirectional second-order...

Area of Science:

• Optical Communications
• Fiber Laser Technology
• Signal Amplification

Background:

• Conventional Raman amplification schemes face limitations in extending transmission reach.
• Relative intensity noise (RIN) can degrade signal quality in high-speed optical transmissions.
• Bidirectional pumping is crucial for long-haul optical networks.

Purpose of the Study:

• To demonstrate a distributed Raman amplification scheme for enhanced long-haul optical transmission.
• To investigate the impact of random distributed feedback (DFB) fiber laser on bidirectional Raman pumping.
• To assess the compatibility of the proposed scheme with nonlinearity compensation techniques.

Main Methods:

• Implementation of a distributed Raman amplification scheme utilizing a random distributed feedback (DFB) fiber laser.
• Employing bidirectional second-order Raman pumping.
• Testing 10 × 116 Gb/s dual-polarization quadrature phase-shift keying (DP-QPSK) wavelength-division multiplexing (WDM) transmission.

Main Results:

• Achieved an extended transmission reach of up to 7915 km for 10 × 116 Gb/s DP-QPSK WDM signals.
• Demonstrated bidirectional second-order Raman pumping without increasing signal relative intensity noise (RIN).
• Maintained uniform and symmetric signal power distribution, outperforming conventional schemes.

Conclusions:

• The proposed DFB fiber laser-based Raman amplification scheme significantly extends optical transmission reach.
• This method offers superior performance compared to existing Raman amplification techniques.
• The scheme's compatibility with nonlinearity compensation (e.g., OPC, NFT) enhances its applicability for future optical networks.