Novel Thermally Stable Ionic Polymers for Electrooptic Applications

Electrooptic (EO) materials with large optical nonlinearities (electrooptic coefficients) and high thermal and temporal stabilities are crucial components in many photonics applications for aircraft avionics systems. Although polymeric NLO materials are excellent candidates for these applications, current materials experience dielectric relaxation of the aligned structure which prevents them from being used in practical devices. Laser Photonics Technology, Inc. proposes the development of a new class of second-order NLO ionic polymers with large nonlinearities, and exceptional thermal, temporal and photophysical stabilities. The second-order NLO chromophores are designed to possess a zwitterionic structure enhancing molecular hyperpolarizability that is obtained through the use of novel sultone chemistry. These chromophores are then covalently attached to a high glass transition temperature polyimide backbone. Ionic structures have been shown to exhibit large B values, but their alignment by electric field poling has been complicated (hindered) by Coulombic (repulsive) interactions. The proposed approach circumvents these problems because ionic structures are formed only during the high temperature poling process. It thus ensures the ease of material processing, effectiveness of electric field poling and great thermal stability of induced noncentrosymmetry.