Preparation of sol-gel films containing thiazole-based chromophore and their nonlinear optical performances

A push-pull thiazolylazo chromophore and alkoxysilane-terminated chromophore have been synthesized. Their structures were verified by elemental analysis, FTIR, UV-Visible spectra and 1H NMR. Followed by a hydrolysis and copolymerization process of the alkoxysilane with poly(3-(trimethoxysilyl)propyl methacrylate) (PTMSPM), transparent hybrid films were obtained by spin-coating. From TGA thermogram the initial decomposition temperature of the hybrid film was determined to be 231 deg. C. The molecular hyperpolarizability of thiazolylazo chromophore was evaluated by solvatochromic method and the nonlinear optical coefficient value of the hybrid film was also calculated to be 56.8 pm/V by second harmonic generation (SHG) measurements. The poled film exhibits fairly high stability of optical nonlinearity in depoling experiment, implying its suitability for device applications