Mach-Zehnder interferometer measurement of the Pockets effect in a poled polymer film with a coplanar electrode structure

Mach-Zehnder interferometry was used to measure the Pockels effect in a poled electro-optic polymer thin film with a coplanar electrode structure. The beam at the sample arm of the Mach-Zehnder interferometer passed through a polymer thin film which had been spin-coated on top of a clear gap between two electrodes patterned on an optical substrate. This unique optical geometry enabled the Pockels coefficients of the poled electro-optic polymer film in the directions of the ordinary and the extraordinary optic axes to be determined independently. As an example, the tensor ratio r₃₃/r₁₃ for a stilbene-dye-doped polyimide guest/host polymer film was determined experimentally the ratio turned out to be 4.6, which was higher than the value of 3 predicted by the thermodynamic model.