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Abstract: Two novel two-dimensional spindle-type fluorinated chromophores with fluorinated phenyl as side groups connecting to the π conjugated bridge were prepared for second-order nonlinear optical applications. The detailed synthetic procedure was reported. Thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC) revealed that the spindle-type fluorinated chromophores have excellent thermal stability. Host–guest doped materials had been used to prepare the second-order nonlinear optical films. The nonlinear electro-optic (EO) coefficient of the poled films was measured by Teng–Man technique at the fundamental wavelength of 1310nm, and the r 33 up to 28pm/V was achieved. [Copyright &y& Elsevier]

Abstract: This work focused on the development of a novel method for molecular level assembly and processing of inorganic–organic hybrid second-order nonlinear optical (SONLO) multilayer films. Aromatic diazo group linked silicon sol was first synthesized and used as a polycation. This oligomer was assembled into inorganic–organic hybrid SONLO multilayer films by electric-field-induced layer-by-layer assembly technique with a low molecular weight chromophore molecule as an anion. After UV irradiation, the electrostatic interaction between layers converted to covalent bonds. Large second-harmonic generation signal of the assembled film was observed, which confirmed that the chromophore in the film had a high degree of molecular orientation as assembled under the electric field. As the cross-linked structure and silicon oxygen meshwork in the films, the resulting inorganic–organic hybrid multilayer films displayed good thermal and chemical stability, and excellent NLO properties. [Copyright &y& Elsevier]

Abstract: A photo-cross-linked stable organic–inorganic hybrid second-order nonlinear optical (NLO) film was fabricated by sol–gel process with silicon sol linking aromatic diazonium group (SOD) and Chromophore molecule 2-({4-[4-(2-carboxy-2-cyano-vinyl)-phenylazo]-phenyl}-methyl-amino)-ethyl acid (DRCB). The films were poled under 50DC voltage electric field at room temperature at the existence of solvents. After the solvents volatilized completely and upon UV irradiation under the electric field, the ionic bonds converted to stable covalent bonds in the system, the orientations of the chromophores were fixed by the photo-cross-linked structures. The order parameter of the fabricated film can retain 99% after 17days at room temperature. The stable organic–inorganic hybrid photo-cross-linked NLO films fabricated in this paper had large potential to be applied in electric-optic devices. [Copyright &y& Elsevier]