Analysis of a Mach-Zehnder interferometry measurement of the Pockels coefficients in a poled polymer film with a reflection configuration

Mach-Zehnder interferometry is employed to measure the Pockels coefficients in a poled thin polymer film, which serves as a reflection mirror in the sample arm of the interferometer. As a complete optical characterization of the electro-optic polymer film, the modulated light intensity of the Mach-Zehnder interferometer is investigated as a function of the optical bias in the reference arm, the modulation voltage applied to the film, the polarization angle of the incident light, and the angle of incidence on the film. The Mach-Zehnder interferometry measurement of the Pockels coefficients in the reflection configuration has an advantage over single-beam polarization interferometry in permitting the independent determination of the Pockels tensor components, r₁₃ and r₃₃. Particularly, in a reflection configuration two-beam interferometric measurement, a proper consideration of the optical path change due to the refractive angle change is found to be critical in determining the absolute values of the Pockels coefficients.