STABILIZATION OF THE DIPOLE ALIGNMENT OF POLED NONLINEAR-OPTICAL POLYMERS BY ULTRASTRUCTURE SYNTHESIS

A new approach to attaining long term and high temperature stability o f second-order nonlinear optical effects has been developed. Two side- chain copolymers containing dipole-end cross-linkable chromophore pend ants were synthesized from a double-end cross-linkable (DEC) chromopho re monomer. The polymer solutions containing a cross-linker were spin cast into optical quality thin films, which were subsequently poled by an electric field, using a corona configuration, and thermally cross- linked. Second-order susceptibilities, chi(2), on the order of 10(-7) esu, of the polymer films were measured by the second harmonic generat ion (SHG) at 1.06-mum fundamental wavelength. The cross-linked films s how no SHG signal decay for thousands of hours at room temperature. Th ermal stability studies demonstrate that long term stability of the se cond-order nonlinear optical effects at 125-degrees-C has been realize d using the DEC approach.