Abstract

The linear electro-optic (EO) effect, in conjunction with second harmonic generation (SHG) has been used to study temperature and electric field effects on dye-doped guest-host systems. An interferometric technique with in-situ poling was used to probe the poling field- induced molecular alignment of the chromophores as a function of temperature. The doped polymer systems were thin films of 4-dimethylamino-4'-nitrostilbene or disperse red 1 chromophores doped into poly(methyl methacrylate). For small poling fields, this technique revealed the linear dependency of the electro-optic-coefficient, r, and thus the second order susceptibility χ⁽²⁾ of the material, on low poling fields. It was also possible to detect the β-relaxation, the secondary transition occurring below the glass transition temperature, which until now has not easily been seen in studies using optical techniques.

© 1995 Optical Society of America