From molecules to opto-chips: organic electro-optic materials

Recent advances in polymeric electro-optic materials and device fabrication techniques have significantly increased the potential for incorporation of these materials and devices into modern high bandwidth (fiber and wireless) telecommunication, information processing, and radar systems. Charge transfer π-electron chromophores characterized by molecular first hyperpolarizability (second order optical non-linearity) values approaching 3000×10 –30 esu have been synthesized. Elucidation of the role of intermolecular electrostatic interactions in inhibiting the efficient translation of molecular optical non-linearity to macroscopic electro-optic activity has permitted systematic modification of materials to achieve electro-optic coefficients approaching 100 pm V –1 . Improvements in the optical loss of polymeric materials at wavelengths of 1.3 and 1.55 µm have been effected. Mode matching of passive transmission and active electro-optic waveguides has been addressed, permitting a dramatic reduction in insertion loss. The putative ability of polymeric electro-optic materials to be efficiently integrated with very large scale integration semiconductor electronic circuitry and with passive optical circuitry has been demonstrated. Several devices of varying degrees of complexity have been fabricated and evaluated to operational frequencies as high as 150 GHz. The operational stability of polymeric devices is very competitive with devices fabricated from lithium niobate and gallium arsenide.