Measuring the Electro-Optic Coefficients of Bulk-Poled Polymers

Abstract : This report describes the construction of an optical test system to measure the electro-optic coefficients of poled polymers directly. The poling process in polymers is the spontaneous orientation of the dissolved dye molecule, the chromophore, in the presence of an applied electric field. This spontaneous orientation confers upon the poled polymer a variety of useful optical effects, the linear electro-optic effect being chief among them. The optical test system measures the electro-optic coefficient directly by measuring the relative retardance of one polarization, the p-polarization, relative to the other polarization present, the s-polarization. This method has advantages over previous methods that have relied on measuring the very weak second-harmonic signal emitted from poled polymers. This report describes the measurement of the electro-optic coefficient of a number of electro-optic chromophores synthesized in the Weapons and Materials Research Directorate (WMRD) and intended for use in electro-optic modulation devices.