The nanoscale crystals ͑NCs͒ of ZnO were embedded into polymethylmethacrylate ͑PMMA͒ polymeric matrix and nanocomposite films were prepared by modified spin coating method. The surface of the ZnO/PMMA nanocomposite films has been investigated using atomic force and scanning electron microscopy. The prepared films are highly transparent, the ultraviolet-visible spectra show their high optical quality. The second and third harmonic generation ͑SHG and THG͒ studies of ZnO/PMMA nanocomposite films with different concentrations of ZnO NCs were carried out at = 1.064 m and the effective values of the second and third order nonlinear susceptibilities were estimated to be higher than that of ZnO bulk for the films at low concentration of ZnO NCs. This could indicate that surface effects in ZnO/PMMA nanocomposite films have a dominant role over bulk effects for the SHG and THG processes.

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International audienceOptical and nonlinear optical properties of difluoroboradiazaindacene (BODIPY) models with attached dimethylaminostyryl substituents were studied. The optical absorption and fluorescence emission of BODIPY compounds were found to be dependent on the number of dimethylaminostyryl substituents. In order to investigate the nonlinear refraction and absorption activity, the Z-scan technique was used employing a laser generating a wavelength at 532 nm with 30 ps pulse duration. The studied dimethylaminostyryl containing BODIPY compounds showed considerable nonlinear refraction and reverse saturable absorption. The BODIPY containing a pair of dimethylaminostyryl substituents demonstrated an increased third order nonlinear optical response mostly due to the extension of its conjugated length. © 2016 The Royal Society of Chemistry

a b s t r a c tSilver-and copper-doped ZnO films were prepared by radio-frequency (RF)-magnetron sputtering on glass and quartz substrates. The influence of dopants content on the microstructural evolution and optical as well as nonlinear optical (NLO) properties were investigated. It has been found that the grain sizes were enlarged with increasing of Ag, Cu dopants amount in ZnO films. The Ag or Cu doping leads to the optical band gap narrowing. Besides, the second-order NLO response of Ag-and Cu-doped ZnO films is lower than that of undoped ZnO film. The second harmonic generation (SHG) efficiency of the ZnO:Ag film was found to be higher than that of the ZnO:Cu film at the similar concentration of dopant. In addition, the decrease of the third harmonic generation (THG) response is observed in ZnO films with increasing of Ag or Cu dopant amount.

We report the preparation of microcrystalline ZnO thin films on sapphire substrates using a simple method based on the thermal evaporation of metallic Zn in vacuum with further annealing process. The aim of annealing in the oxygen atmosphere in the range of 800–850°C was to obtain the high quality ZnO films. The surface morphology was studied by scanning electron microscopy and atomic force microscopy. The polycrystalline films with ZnO microrods at different stages of their growth were investigated. Second and third harmonic generation measurements were performed by means of the rotational Maker fringe technique using Nd:YAG laser at 1064nm in picosecond regime. The obtained values of second and third order nonlinear susceptibilities were found to be high enough for the potential applications of the investigated materials in the optical switching devices based on refractive index changes.

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