GENERATION OF NONCENTROSYMMETRIC STRUCTURES IN GLASSY LIQUID-CRYSTALLINE SILOXANES

Photoisomerization has been used to induce polar order in ate-dye-cont aining polymeric liquid crystalline oligosiloxanes at room temperature . The extent of the induced polar order was probed using a Maker fring e analysis at 1064 and 1542 nm. All samples studied at 1064 nm gave as ymmetric fringe maxima, which was ascribed to a gradient in the induce d polar order. The benefits of this poling mechanism, which operates o n the combined effect of both light and static electric fields, was hi ghlighted via poling of a defined area of the liquid crystal. This abi lity to selectively write polar structures into the liquid crystals ma y lead to electro-optic diffractive devices.