Synthesis and NLO properties of hybrid inorganic–organic films containing thiophene ring

A family of second-order nonlinear optical sol–gel films with a pendent thiophene chromophore has been developed. The key step in preparation these hybrids was the syntheses of alkoxysilane dye containing thiophene ring, which was accomplished by utilizing the urethane forming reaction. Molecular structural characterization for the resultant was achieved by FTIR, 1H NMR and UV–Visible spectra. The microscopic optical nonlinearity of the thiophene chromophore was evaluated to be 7646 × 10− 30 esu D by solvatochromic method and second harmonic coefficients (d33) of the hybrid film was also calculated to be 41.2 pm/V by second harmonic generation (SHG) measurements, respectively. Furthermore, the stability of optical nonlinearity in poled film was also investigated through a depoling experiment.