Anisotropy in Thermo-Optic Coefficient of Different Polymer Systems by Attenuated Total Reflection Configuration

Thermo-optic coefficient dn/dT as well as volume expansion coefficients β of different polymer systems are measured for both TE and TM polarizations in an attenuated total reflection (ATR) configuration. Experimental results indicate that cross-linked polymer systems exhibit the thermal expansion coefficients smaller than those of the original side-chain systems. Moreover, the anisotropies in thermo-optic coefficients of the polymer systems with small birefringence exhibit linear relationship with the anisotropies in volume expansion coefficients, but the polymer systems with larger birefringence exhibit more complicated relationship.