Polymeric electro-optic modulators: From chromophore design to integration with semiconductor very large scale integration electronics and silica fiber optics

Chromophores with optimized second-order optical nonlinearity to optical loss ratios are synthesized, poled with an electrical field, and coupled into hardened polymer matrixes. Acentric order, which is necessary for electro-optic activity, is optimized by the consideration of chromophore-chromophore electrostatic interactions as well as chromophore-poling field interactions and thermal collisions which randomize chromophore orientations with respect to the applied field direction. Reactive ion etching and/or multicolor photolithography are used to fabricate buried channel waveguide structures out of the resulting polymeric electro-optic materials and to integrate polymeric waveguides with silica optical fibers. Tapered transitions are developed to minimize coupling (insertion) loss. Both vertical and horizontal integration of polymeric electro-optic modulator circuitry with semiconductor very large scale integration circuitry is demonstrated. Modulation to 113 GHz is demonstrated. Polymeric modulators are relevant to cable television, phased-array radar, ultrafast analogue-to-digital conversion, high-speed optical switching in local area networks, optical beam steering, optical backplane interconnects for parallel processors, and voltage sensing.