IMPROVED TEMPORAL STABILITY OF THE 2ND-ORDER NONLINEAR-OPTICAL EFFECTIN A SOL-GEL MATRIX BEARING AN ACTIVE CHROMOPHORE

A second-order nonlinear optical (NLO) chromophore (disperse red 1) wa s reacted with (3-isocyanatopropyl)triethoxysilane to form a functiona lized silicon alkoxide precursor (SGDR1). To improve the temporal stab ility of the second-order NLO effect, we employed a thermal cross-link between the organic side groups themselves. (3-Glycidoxypropyl)trimet hoxysilane was mixed with SGDR1 in tetrahydrofuran (SGDR1/GPTS). We co mpared the temporal stability of the poled samples with SGDR1 and SGDR 1/GPTS. We investigated second-order NLO properties of sol-gel films b y virtue of second harmonic generation (SHG) and linear electrooptic ( E/O) coefficient measurements for the purpose. We achieved much improv ement in the temporal stability of second-order NLO effect at high tem perature with the heterogeneous films.