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

Preliminary results obtained in developing a numerical model of laser light intensity transversedistribution into undeformed/deformed step index optical fiber are presented. The main purpose ofthe presented preliminary numerical modelling results consists in developing a simple method offiber optical sensors interrogation, especially concerning strain and pressure measurements. It is apotential important matter for aeronautical research and industry because of the more extendeduse of fibre optic sensors in aircraft manufacturing. The developed numerical model relies onsolving the equations of electromagnetic waves propagation into optical fibers by using the finiteelement method technique (FEM). The results of numerical simulation obtained by consideringsingle mode or multimode and various laser wavelengtsh are presented. One importantachievement reported in this paper consists in preliminary experimental results concerning themodification of laser intensity transverse distribution observed for multimode optical fiber with andwithout perpendicular mechanical load. The reported preliminary experimental results confirm tosome extent the predictions of numerical simulations regarding laser intensity distribution underlow and medium transverse mechanical load. One important conclusion of this paper consists inthe future development of fiber optic sensor interrogation techniques based on the reportedpreliminary experimental and numerical simulation results.