Finite element analysis of an optical fibre electric field sensor using piezoelectric polymer coating

A novel approach for analysing an optical fibre electric field sensor by using the finite element method is presented. A singlemode optical fibre carrying a transversely poled piezoelectric poly(vinylidene fluoride) polymer coating was successfully modelled by using three-dimensional analysis. The response of the optical fibre electric field sensor was determined over a wide frequency range from 100 Hz to 50MHz. The modelling predicts a phase shift of 0.019 rad V−1 m−1 in the low frequency (axially unconstrained) region and 0.000 82 rad V−1 m−1 in the high frequency (axially constrained) region. At frequencies higher than 7 MHz the optical response is dominated by radial resonances of the fibre—jacket composite. Good agreement exists between the resonance peaks predicted by the simulation and those theoretically calculated using composite theory.