Fourier decomposition algorithm for leaky modes of fibres with arbitrary geometry

Area of Science:

• Photonics and Optical Engineering
• Computational Electromagnetics

Background:

• Accurate calculation of confinement loss is crucial for designing optical fibres, especially those with complex structures like microstructured fibres.
• Leaky modes in optical fibres represent energy that radiates outwards, contributing to signal loss and impacting device performance.

Purpose of the Study:

• To introduce a new algorithm for calculating the confinement loss of leaky modes in arbitrary fibre structures.
• To implement the algorithm within the scalar wave approximation for efficient computation.

Main Methods:

• The study employs a polar-coordinate Fourier decomposition method.
• Adjustable boundary conditions (ABC-FDM) are utilized to model outward radiating fields.
• The scalar wave approximation is applied for computational tractability.

Main Results:

• The developed algorithm successfully calculates leaky modes in various microstructured fibre designs.
• Demonstrated accuracy in modeling outward radiating fields for confinement loss estimation.
• The method is applicable to fibres with diverse and complex hole geometries.

Conclusions:

• The proposed algorithm provides an effective tool for analyzing confinement loss in leaky-mode optical fibres.
• The polar-coordinate Fourier decomposition method with ABC-FDM offers a robust approach for arbitrary fibre structures.
• This work contributes to the precise design and optimization of advanced photonic fibres.