MEASUREMENT OF THE DIFFERENTIAL POCKELS AND KERR COEFFICIENTS OF THIN FILMS BY A TWO-BEAM POLARIZATION INTERFEROMETER WITH A REFLECTION CONFIGURATION

摘要

A simple procedure for the measurement of the linear and quadratic electrooptic coefficients of thin films by two-beam polarization (TBP) interferometery is developed. Differential electrooptic coefficients that allow clear mathematical definition and can be measured using a modulation method are introduced. It is shown that a TBP interferometer allows measuring both differential Pockels and Kerr coefficients of a thin film with a strong Fabry-Perot (FP) effect that is already present in thin films without special antireflection coating. The measured values of the electrooptic coefficients of PZT thin film are in agreement with the known data.