Numerical modeling of multimode optical fibre sensors

Abstract

The numerical modeling of the multimode optical-fiber evanescent-field sensors is described. The work is focused on sensors which employ essentially multimode plastic optical fibers and plastic optical detection elements. The ray-tracing model is employed which is complemented with mode coupling and mode-dependent attenuation obtained from measurements. It is shown that in the case of relatively short optical fibers such as used in sensors, the characteristics of particular light source, evolution of light distribution along the optical fibers, and finite non-homogeneity of plastic material have a significant effect on sensor characteristics.