ENHANCED LINEAR ELECTROOPTIC RESPONSE AND ENHANCED STABILITY OF THERMO-POLED GUEST HOST POLYCARBONATE THIN-FILMS

Fixed electrode poling of 20% DAN doped bisphenol-A polycarbonate at moderate poling temperature (80-degrees-C) gives a linear electro-optic (EO) coefficient, r33, of 1.12 pm V-1 for an applied poling field, E(p), of 27 V-mu-m-1. This value is found to be ten times larger than that predicted using a simple thermodynamic model. The long term stability of the EO response was found to be unexpectedly good for a guest-host system and approaches that of some side-chain-type materials. At room temperature, a decrease of only 25% was seen in the linear EO response over a period of 21 days. The enhanced response and its unexpected stability is thought to be due to guest-host interactions and particularly to hydrogen bonding. Poling is performed 70-degrees-C below the glass transition temperature of the host and is assisted by a beta-relaxation process identified at 80-degrees-C.