Third-order optical nonlinearity of poly(thienylene vinylene)/silica sol-gel composite

In order to improve the optical quality, poly(thienylene vinylene)/silica composite was prepared by sol-gel processing techniques, and its optical nonlinearity was determined. The soluble methoxy pendant poly(thienylene vinylene)(PTV) precursor and the silica sol were homogeneously mixed in tetrahydrofuran and converted to the final composite material by heat-treatment. The resulting material have been characterized by UV-visible absorption spectra, and thermal analysis. The blue shift of λ_max in the UV-visible spectra of composite materials was observed which provides an evidence of interaction between the PTV and the silica components. The third-order optical nonlinearities, χ⁽³⁾, were measured as 4 × 10^-9 esu and 3 × 10^-9 esu for the pure PTV and PTV/silica sol-gel composite, respectively.