PREPARATION AND CHARACTERIZATION OF CROSS-LINKED LIQUID-CRYSTALLINE POLYMER-FILMS AS NONLINEAR-OPTICAL MATERIALS

Liquid crystalline monomers have been synthesized and characterized in purpose to make polymeric second-order nonlinear optical (NLO) materi als. Crosslinked polymers have been made to thermally stabilize the or ientation created in aligned samples. The orientation has been measure d by means of x-ray scattering and infrared dichroism. Oriented, cross linked poly(vinyl ether)s were made by cationic polymerization whereas crosslinked, nonlinear optical poly(acrylate)s were made by radical p olymerization. Polymerization was initiated both thermally and photoch emically. The NLO activity of the poly(acrylate)s was measured as the Pockels effect and the second harmonic generation signal, giving value s of 0.15 pm/V and 0.40 pm/V, respectively.