Thermal Relaxation Processes and Stability in Poled Electro-Optic Polymers

摘要

We developed a new experimental technique based on electric field induced secondharmonic generation in the frequency domain to probe the polymer over many decades of time. This technique is best applied near the glass transition to probe frequencies from mHz to tens of kHz. We used this technique along with others to study a variety of polymers. Applying an Adams-Gibb model to the temperature dependence of the characteristic frequency, prediction of long term behavior at any temperature based on quick measurements near the glass transition temperature is possible. We also developed a new ultrafast laser source for studying nonlinear optical susceptibilities, and contributed to the study of cross-linked polyimide materials as stable and processable hosts for poled electro-optic polymers.