Simple reflection technique for measuring the linear electro-optic coefficient of the polymer thin films

The simple reflection technique is usually used to measure the linear elect ro-optic (EO) coefficient (Pockels coefficient) in the development of EO po lymer thin films. But there are some problems in some articles in the deter mination of the phase shift between the s and p light modes of a laser beam waveguided into the polymer film while a modulating voltage is applied acr oss the electrodes, and different expressions for the linear EO coefficient measured have been given in these articles. In our research, more accurate expression of the linear EO coefficient was deduced by suitable considerin g the phase shift between the s and p light modes. The linear EO coefficien ts of several polymer thin films were measured by reflection technique, and the results of the Linear EO coefficient calculated by different expressio ns were compared. The limit of the simple reflection technique for measurin g the linear EO coefficient of the polymer thin films was discussed.