Stability of second-order nonlinear optical properties in sol–gel matrix bearing silylated chalcone and disperse red 1

Abstract

We report the syntheses of two triethoxysilanes for thin film fabrication. One silane (SGDR1) contains disperse red 1 (DR1) which is a second-order nonlinear optical (NLO) active chromophore. The other silane (SGCHC) bears a chalcone derivative. In order to improve the poor temporal stability of second-order NLO effects in the resulting poled sol–gel film, photo-crosslink was induced between the double bonds in chalcone units after mixing SGDR1 and SGCHC. Under UV exposure, the photocrosslink was studied with UV–visible absorption and IR vibrational spectroscopy. The decaying behavior of the molecular order parameter ( A 2) after corona poling was investigated using polarized absorption spectroscopy (PAS). Second-order non-linear optical properties of the sample were studied using second-harmonic generation (SHG) and linear electro-optic (E/O) signal measurement. Poled and UV-cured film of SGDR1/SGCHC exhibited much better stability than thermally poled sample with respect to the molecular order parameter and linear electro-optic effect.