Real-time measurement for the electr0-optic coefficient of a poled-polymer film in ATR configuration

摘要

A new method which based on the attenuated total reflection(ATR) technique is developed to determine the electrn-optic coefficient of a poled-polymer film. THe proposed ATR arrangement consists of a cuppling prism, and four film layers deposited directly onto the base of the prism in sequence. The four film layers are metal film(which serves as a top electrode), poled polymer film, buffer and base electrode, respectively. A convenrgent light beam covering a suitable angular range is incident onto the prism base to excided wave mode and the reflected light beam is imaged by a CCD array. TShen resonance angle of the guided wave mde can be determined from the position of the reflectance minimum. It is demonstrated that the applying electrical field will cause a minute change in the refractive indes of a pled-polymer film, due to the Prockes effect, which will result in a shift of the resonance angle. In order to make the measurement more successful, computer image processing method and optical image spatial filter technology are used in our measurement.