Modeling relaxation processes in poled electro-optic polymer films

Chielectric spectroscopy, which is frequency-domain electric-field-induced second-harmonic generation, was developed to study the nonlinear optical response near the glass-transition temperature on short time scales. These measurements, along with time-domain second-harmonic generation and time- and frequency-domain dielectric measurements, were used to characterize the decay of poling-induced electro-optic properties of guest–host and side-chain methacrylate polymers that have glass-transition temperatures in the range 90< Tg<125 °C. Time- and frequency-dependent data were fitted with a three-level model. The temperature dependences of the time constants from the polymeric systems were then compared, and a scaling model for predicting useful lifetimes of poled electro-optic media is discussed.