Universal model for splice loss in few-mode fibers

Area of Science:

• Optical Fiber Communications
• Photonics
• Wave Propagation

Background:

• Accurate splice loss prediction is crucial for few-mode fiber (FMF) performance.
• Conventional methods for single-mode fibers are inadequate for FMFs due to modal complexity.

Purpose of the Study:

• To develop a general theoretical model for splice loss in FMFs.
• To unify the splice loss estimation for all LP modes based on fiber parameters.
• To demonstrate the limitations of the backscattering method for FMFs.

Main Methods:

• Employing confluent hypergeometric functions to simplify modal field expressions.
• Developing a theoretical model based on the ratio of axial offset to fundamental mode field radius (d/ω₀).
• Comparing model predictions with experimental results and backscattering measurements.

Main Results:

• The model unifies splice loss for all LP modes as a function of d/ω₀.
• It was proven that the conventional backscattering method is not applicable to FMFs.
• Model predictions showed a maximum error of <0.24 dB, while backscattering deviated by up to 2.45 dB.

Conclusions:

• The developed model provides accurate and rapid splice loss prediction for FMFs.
• It enables the derivation of axial offset tolerance for specified loss constraints.
• The model guides splicing parameter optimization and quality control in FMF systems.