High-capacity phase-sensitively amplified transmission in a field-deployed fiber cable

Area of Science:

• Optical Communications
• Signal Processing
• Materials Science

Background:

• Phase-sensitive amplifiers (PSAs) offer superior signal-to-noise ratio (SNR) enhancement over conventional amplifiers by selectively amplifying signals based on phase.
• Practical application of PSAs in deployed fiber transmission systems is limited, despite their theoretical advantages.

Purpose of the Study:

• To evaluate the performance of phase-sensitive amplification in a real-world, deployed optical fiber transmission system.
• To demonstrate high-capacity, wavelength-division-multiplexing (WDM) signal transmission using PSAs.

Main Methods:

• Conducted a field trial using same-wavelength, bi-directional WDM transmission in a deployed optical fiber cable.
• Employed a wideband PSA, built using periodically poled lithium niobate waveguides, as a receiver pre-amplifier.
• Mitigated interference crosstalk, primarily from Rayleigh backscattering, to improve SNR.

Main Results:

• Achieved a net transmission capacity of 10.944 Tb·s⁻¹.
• Reached a net capacity-distance product of 541.728 Tb·s⁻¹·km.
• Exceeded performance benchmarks of previous phase-sensitively amplified transmission studies.

Conclusions:

• PSA-based pre-amplification is effective for large-capacity optical fiber transmission in real deployment scenarios.
• The field trial validates the practical benefits of PSAs for enhancing SNR and transmission capacity.