Multiple reflection correction in the determination of the complex electro-optic constant using a Mach-Zehnder interferometer

The effect of multiple reflection was corrected in the measurement of the complex electro-optic (EO) tensor of polymer films doped with dye molecues using a Mach-Zehnder interferometer. The oscillations due to multiple reflection were clearly observed for the incidence-angle dependence of the amplitude ratio and the phase difference between the total light intensity and the EO-modulated signal intensity. An analytical expression was derived for the transmitted light intensity including multiple reflection in order to obtain the correct EO constant. Theoretical and experimental results show that the systematic error due to multiple increases with the transmittance.