A NUMERICAL MODEL OF THE LASER LIGHT INTENSITY TRANSVERSAL DISTRIBUTION INTO UNDEFORMED/DEFORMED OPTICAL FIBERS

Abstract

Preliminary results obtained in developing a numerical model of laser light intensity transverse distribution into undeformed/deformed step index optical fiber are presented. The main purpose of the presented preliminary numerical modelling results consists in developing a simple method of fiber optical sensors interrogation, especially concerning strain and pressure measurements. It is a potential important matter for aeronautical research and industry because of the more extended use of fibre optic sensors in aircraft manufacturing. The developed numerical model relies on solving the equations of electromagnetic waves propagation into optical fibers by using the finite element method technique (FEM). The results of numerical simulation obtained by considering single mode or multimode and various laser wavelengtsh are presented. One important achievement reported in this paper consists in preliminary experimental results concerning the modification of laser intensity transverse distribution observed for multimode optical fiber with and without perpendicular mechanical load. The reported preliminary experimental results confirm to some extent the predictions of numerical simulations regarding laser intensity distribution under low and medium transverse mechanical load. One important conclusion of this paper consists in the future development of fiber optic sensor interrogation techniques based on the reported preliminary experimental and numerical simulation results.