The second-order nonlinear optical properties of four polyureas with large positive birefringence are presented. The temporal stability of the poling-induced orientations at different temperatures were estimated by in-situ second harmonic generation (SHG) measurements. For the polyurea prepared from aliphatic diamines, the optical transparency was down to 300 nm. The most interesting aspect of these polyureas is in their refractive indices: the refractive indices of TE modes before poling are higher than those of TM modes. This indicates that the polymer chains were stretched along the substrate surface. This work represents the first example of an increase of poling-induced refractive indices in TE modes.

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A novel cyclic carbazole oligomer, which contains the EL chromophore in the main-chain, for organic light-emitting diodes is described. The device structure of glass substrate/indium tin oxide/hole transport layer/cyclic oligomer (electron transport layer)/Al was employed. The EL device exhibited green light with a luminance of 60 cd/m2 at 15 V.

The electric field‐induced dynamic phase‐matching of second harmonic generation (SHG) waveguide was demonstrated by using a main chain polyarylamine. The linear and nonlinear optical properties of this polymer are presented. The optimum phase‐matching thickness was controlled by applying an electric field to the polymer waveguide. The effective phase‐matching thickness variation induced by poling is about 0.025 μm that is six times larger than full width at the half‐maximum (FWHM) of phase‐matching thickness in conventional slab waveguide. The efficient phase‐matched SHG was observed from a taperless slab wave‐guide. The optical loss of poled polymer on glass substrate at 632.8 nm was 2.7 dB/cm. © 1995 John Wiley & Sons, Inc.

We report the second harmonic generation and electroluminescent (EL) properties of a soluble metal complex polyurethane (PU). The PU was prepared by the reaction of a zinc Schiff base with 4,4′-diphenylmethane-diisocyanate. The polymer film has been effectively poled under a corona field and its linear and nonlinear optical (NLO) properties were characterized. The results indicated that the NLO effects of the polymer are mainly originated in the distorted coordination tetragonals formed by the central zinc atoms and coordination atoms. The polymer shows strong photoluminescence under a ultraviolet-lamp illumination and can be used as a luminescent material for EL devices.