High-precision inter-core skew measurement for multi-core fiber using incoherent interferometry based on sliced-ASE...

Area of Science:

• Optical Fiber Communications
• Metrology
• Photonics

Background:

• Inter-core skew in multi-core fibers (MCFs) is a critical parameter affecting signal integrity.
• Existing measurement methods often require complex setups or lack robustness.
• Accurate and reliable skew monitoring is essential for high-performance optical networks.

Purpose of the Study:

• To propose and demonstrate a novel, simple, and robust method for measuring inter-core skew in MCFs.
• To achieve high-precision, sub-picosecond accuracy in skew measurements.
• To provide a solution for non-intrusive, online monitoring of MCFs.

Main Methods:

• Broadband incoherent interferometry using spectrum-sliced amplified spontaneous emission (ASE) noise.
• Utilizing a calibrated interference spectrum for delay extraction via cascaded filtering and fitting.
• Experimental validation using back-to-back and 41-km MCF configurations.

Main Results:

• Achieved sub-picosecond measurement accuracy with root mean square errors below 60 fs.
• Demonstrated stable performance in both back-to-back and deployed fiber experiments.
• The method avoids narrow-linewidth lasers and tolerates power fading.

Conclusions:

• The proposed inter-core skew measurement technique is simple, robust, and highly accurate.
• It offers a practical solution for online, non-intrusive monitoring of MCFs.
• This method is comparable in performance to vector network analyzer-based schemes.