All-optical multi-level amplitude regenerator in a polarization-effect optimized nonlinear-optical loop mirror...

Area of Science:

• Nonlinear optics
• Optical communications
• Photonics

Background:

• All-optical signal regeneration is crucial for high-speed communication networks.
• Conventional nonlinear-optical loop mirrors (NOLMs) have limitations in their regeneration region (RR).
• Multi-level amplitude modulation, like 4-level pulse amplitude modulation (PAM4), demands robust regeneration techniques.

Purpose of the Study:

• To propose and investigate a modified NOLM configuration incorporating polarization-effect optimization (PE).
• To enhance the regeneration region (RR) of all-optical multi-level amplitude regenerators.
• To analyze the synergistic effects of Kerr nonlinearity and PE in a single unit.

Main Methods:

• Modification of the NOLM by integrating a polarization-maintaining optical coupler for PE.
• Theoretical analysis of the collaboration mechanism between Kerr nonlinearity and PE effect.
• Experimental demonstration of the PE-NOLM for multi-level signal regeneration.

Main Results:

• Achieved an 188% enhancement in the regeneration region (RR) compared to conventional NOLMs.
• Observed a 4.5 dB signal-to-noise ratio (SNR) improvement for 4-level pulse amplitude modulation (PAM4) signals.
• Demonstrated the effectiveness of the PE-NOLM in extending regeneration capabilities.

Conclusions:

• The proposed PE-NOLM offers a significant advancement in all-optical signal regeneration.
• The integration of PE with NOLM effectively broadens the operational range for multi-level signals.
• This technology holds promise for improving the performance of future optical communication systems.