Numerical modeling of a fiber-optic phase modulator using piezoelectric polymer coating

A new approach in analysing an all-fiber phase modulator using a commercially available finite-element software package is presented. A single-mode fiber coated with a radially poled piezoelectric unoriented vinylidene fluoride (73 mol%)/trifluoroethylene (27 mol%) copolymer was successfully modeled using a two-dimensional axi-symmetric approach. The response of the phase modulator was determined over a wide frequency range, from 10 Hz to 50 MHz. Results showed a phase shift of 0.155 rad/V/m in the low-frequency (axially unconstrained) region, and 0.045 rad/V/m in the high-frequency (axially constrained) region. An excellent agreement exists between the simulation results and experimental measurements.