We demonstrate a hybrid nanocomposite combining mesoporous silica, p , as a host medium and guest lithium niobate nanocrystals embedded into tubular silica nanochannels by calcination of the precursor mixed solution of lithium and niobium salts. High-resolution transmission electron microscopy, X-ray diffraction and Raman scattering techniques reveal trigonal nanocrystals within the p nanochannels, indicating their random texture morphology. Annealing at high temperatures ( 950 C) during calcination also leads to partial crystallization of the p matrix with the formation of trigonal - nanocrystals.
View Article and Find Full Text PDFThe presented work concerns computational investigations of the physical properties of composite materials based on polymer matrix and nonlinear optical (NLO) active chromophores. The structural, electronic, and optical properties of selected tetrathiafulvalene (TTF)-based chromophores have been calculated using quantum chemical methods. The polymer matrix changes the physical properties of the inserted chromophores influencing their optical parameters.
View Article and Find Full Text PDFThe synthesis of high-quality thin films through spin coating deposition on meticulously cleaned glass substrates is presented. Optical band gaps of both samples using the Kubelka-Munk function are determined. The data analysis uncovers the presence of optical allowed direct transition for AZnGeO (A = K, Li).
View Article and Find Full Text PDFThe optimal geometries of vector phase matching are determined for the cases of second harmonic generation, sum frequency generation, and difference frequency generation in a number of orthorhombic nonlinear optical crystals: KTP, KTA, KB5, , LBO, CBO, and LRB4. The extreme surface method was used to define the wave vector directions of highest possible generation efficiency. As shown, in a significant number of cases vector phase matching ensures higher efficiencies than the scalar one.
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