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 °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.