Demonstration of the linear electro-optic effect in a thermopoled polymer film

Abstract

We describe an interdigital linear electro-optic modulator produced from a novel polymer. The polymer was formed into a thin phase grating by simultaneous application of heat and a periodic electric field. The first maximum generated by diffraction of 633-nm HeNe laser light passing through the grating was electrically modulated to a depth of over 17%. The performance of the modulator is compared with a quadratic electro-optic modulator having the same electrode structure but where the polymer was replaced by nitrobenzene. It is estimated that the application of a thermopoling field strength of 20 V/μm to the polymer would impart a linear electro-optic coefficient of about 30 pm/V, which is comparable to the largest coefficient of lithium niobate.