Monte Carlo simulation of surface plasmon polariton excitation on U-bent multimode optical fibers

Abstract

Sharply bent optical fibers can be used as sensory systems. At first instance, application of curved optical fiber is refractometric, but after immobilizing a metal layer on the stripped core of the optical fiber its usage can be much more sophisticated. On the metal layer surface, it is possible to excite a special electronic oscillatory mode, surface plasmon polariton (SPP). In the paper we present combination of the classic Drude model of free electron gas, the optical ray tracing approximation and the Monte Carlo method to calculate the probability and estimate the real possibility of excitation of SPP in a metal layer coating prepared on core of a U-bent multimode optical fiber. The calculated results allow for direct assessment of the optimized metal layer position on the semi-toroidal optical fiber waveguide in dependence on the model parameters.