Coupled power equations for lossy fibers

Area of Science:

• Optical Fiber Communications
• Wave Propagation in Guided Structures

Background:

• Traditional coupled power equations for multimode fibers often neglect mode losses or introduce them phenomenologically.
• This simplification can affect the accuracy of theoretical models, particularly in scenarios with significant loss.

Purpose of the Study:

• To derive time-independent coupled power equations for multimode fibers that inherently account for mode losses from the initial formulation.
• To analyze the impact of incorporating mode losses on the coupling coefficients and the resulting theoretical framework.
• To compare the steady-state losses predicted by this new model with those of fiber resonators.

Main Methods:

• Derivation of time-independent coupled power equations with integrated mode loss considerations.
• Analysis of the resulting changes in coupling coefficients and matrix asymmetry.
• Comparative study of steady-state losses between multimode fibers and fiber resonators under varying differential mode loss conditions.

Main Results:

• The derived equations maintain the form of traditional coupled power equations but feature modified coupling coefficients.
• Mode losses introduce asymmetry into the coupling coefficient matrix.
• Fiber resonator losses are found to equal randomly coupled mode losses only at the extremes of very low or very high differential mode losses; otherwise, resonator losses are significantly higher.

Conclusions:

• Incorporating mode losses from the beginning provides a more accurate representation of coupled power dynamics in multimode fibers.
• The asymmetry introduced by mode losses in the coupling matrix has significant implications for power transfer and loss analysis.
• The findings offer a refined understanding of loss mechanisms in optical fibers and resonators, with practical implications for device design and performance optimization.