Modelling of standard and specialty fibre-based systems using finite element methods

TL;DR

This paper demonstrates the use of finite element methods to model light transmission in complex fibre systems, validating the approach against analytical models and applying it to novel fibre configurations.

Contribution

It introduces FEM as a versatile tool for modelling complex optical fibre systems, surpassing limitations of traditional analytical methods.

Findings

FEM results closely match analytical models with less than 0.4% deviation.

FEM can model complex geometries and materials beyond analytical capabilities.

Application to a hollow core photonic crystal fibre system shows qualitative agreement with experiments.

Abstract

We report on the investigation of an approach for modelling light transmission through systems consisting of several jointed optical fibres, in which the analytical modelling of the waveguides was replaced by Finite Element Modelling (FEM) simulations. To validate this approach we first performed FEM analysis of standard fibres and used this to evaluate the coupling efficiency between two singlemode fibres under different conditions. The results of these simulations were successfully compared with those obtained using classical analytical approaches, by demonstrating a maximum loss deviation of about 0.4 %. Further, we performed other more complex simulations that we compared again to the analytical models. FEM simulations allow addressing any type of guiding structure, without limitations on the complexity of the geometrical waveguide cross section and involved materials. We propose as example of application the modelling of the light transmitted through a system made of a hollow core photonic crystal fibre spliced between two singlemode standard optical fibres, and qualitatively compare the results of the simulation with experimental results.