Design and optimisation of long period fibre grating devices for sensing applications by using Python

Abstract

Nowadays Long period fiber grating (LPFG) devices have been more and more popular as surrounding refractive index sensor and it has been widely implemented in chemical, biomedical, environment as well as food industries. In order to investigate the sensing parameters to make it suitable for certain applications, it is necessary to numerically model the device before fabrication. In this report, a cost-saving and efficient way was presented to achieve such purpose. This report describes how to design and optimize a simple three layer step index Long Period Fiber Grating device using the open source Python programming language. It covers theory and concepts behind this projects, the formulas and techniques used to model the light propagations in the LPFGs device, approaches to analyze the sensitivity characteristics and to predict the parameters based on the simulated power spectrums, GUI design, results verifications etc. This work can be served as a good guideline for developing highly sensitive long period grating fiber devices for refractive index sensing in different applications.