Excess loss caused by the outer layer in a multimode step-index optical fiber: theory

Area of Science:

• Optical Fiber Communications
• Electromagnetic Theory
• Materials Science

Background:

• Multimode step-index fibers are crucial in optical communication systems.
• Outer jacket layers can introduce signal loss, affecting performance.
• Quantifying this excess loss is essential for fiber design and optimization.

Purpose of the Study:

• To derive an equation for evaluating excess loss in optical fibers caused by the jacket.
• To numerically analyze the impact of various parameters on this excess loss.
• To identify key factors influencing jacket-induced loss in multimode fibers.

Main Methods:

• Derivation of an equation based on electromagnetic theory.
• Numerical calculations using the derived equation for LP modes.
• Systematic variation of fiber parameters, jacket properties, wavelength, and mode power distribution.

Main Results:

• The derived equation accurately evaluates jacket-induced excess loss.
• Excess loss is sensitive to jacket refractive index and cladding thickness.
• Mode power distribution within the fiber significantly influences the calculated excess loss.

Conclusions:

• The study provides a theoretical framework for understanding jacket-induced loss in optical fibers.
• Key parameters influencing excess loss have been identified, aiding in fiber design.
• This research contributes to minimizing signal degradation in multimode fiber systems.