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The incorporation of dye molecules into solid matrixes is an attractive and widely investigated method to prepare dye-doped solid-state devices [1][2][3][4][5]. Large quantum yield of organic dye molecules combined with the advantages offered by the solid host matrix with respect to liquid solutions (bulky volume, flammable, toxic solvents, and difficult to be manageable) indicate that these materials can be good candidates, for solid-state dye laser applications [5,6]. It has been shown that the lifetime and thermal stability of dyes are enhanced when they are entrapped in solid matrices [5]. Solid matrix offers a larger mechanical and thermal stability, reduces the risks of environmental and operator hazards, and allows to increase achievement of larger concentrations of the dye, reducing the formation of H-aggregates responsible for the quenching of the luminescence. Among the investigated possibilities, the embedding of dye molecules into silica materials prepared via sol-gel methods can offer the highest physical and chemical performances.Two different approaches [2] can be used to prepare dye-doped silica materials: post-doping method (the impregnation), where the selected dye is incorporated into the sol-gel prepared porous silica and the pre-doping method, where the dye molecule is introduced at the sol stage in situ of solgel procedure. Post-doping method has disadvantage and some limits: difficult to determine the exact location of the dye molecules, dimension pores, presence of sorption center or defects on the surface, what induce untimely aggregation of the dye molecules. The main

The sol-gel method has been employed in the fabrication of easily processable mesostructured films consisting of a nonionic surfactant and silica as the inorganic component. The ability of the occluded Pluronic P123 mesostructures to solubilize guest molecules made these films ideal host matrices for organic dyes and molecular assemblies, possessing substantial nonlinear susceptibilities. These films were explored for use as the photonic layer in all-optical time-to-space converters and proved successful at increasing the optical response of the intercalated dyes to a point that would make these composite films applicable for use as the photonic layer. Recording of a dynamical grating in a single-pulse regime has been obtained. Since the dynamical grating exhibits the fast relaxation time (up to 10 ns), the nonlinear mechanism represents an electronic excitation of the photosensitive molecules. As far as the dye molecules are distributed in nanoporous silica, a model of ‘gas of molecular dye’ may be rightly used in order to consider nonlinear optical properties in the nanostructured hybrid films. We suppose that further improvement of the nonlinear optical nanomaterials may follow on the way to embed additional inclusions, which will not promote the heat accumulation in the host matrix and will lead to effective dissipation of the heat energy.PACS: 78.20.-e; 42.70 -а; 42.79