Zouheir Sekkat, Jonathan Wood, et al.
American Chemical Society, Polymer Preprints, Division of Polymer Chemistry
We report on both polar and nonpolar light-induced orientation of a polyimide of high glass transition temperature (Tg ≈ 210°C) with nonlinear optical azo dye molecules in the side chain. This photoinduced orientation is shown to occur at room temperature, i.e., at least 190°C below the Tg value of the polymer, which indicates that the photoisomerization-induced movement of the nonlinear optical chromophores induces, in turn, a movement of the polyimide main chain. This allows for an efficient orientation of the dye molecules in spite of the stiffness of the polyimide main chain. A nonpolar orientation is induced by polarized light irradiation alone, whereas polar orientation is achieved by application of a dc field during the photoisomerization process. Further light irradiation in the absence of a dc field destroys the previously induced stable polar order. A detailed theoretical study of this light-induced depoling process is also presented. © 1996 Optical Society of America.
Zouheir Sekkat, Jonathan Wood, et al.
American Chemical Society, Polymer Preprints, Division of Polymer Chemistry
Zouheir Sekkat, Jonathan Wood, et al.
American Chemical Society, Polymer Preprints, Division of Polymer Chemistry
Zouheir Sekkat, Andre Knoesen, et al.
Optical Science, Engineering and Instrumentation 1997
Zouheir Sekkat, Jonathan Wood, et al.
Journal of the Optical Society of America B: Optical Physics