185 research outputs found

    Third harmonic generation in LiKB4O7 single crystal

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    The third order nonlinear optical properties of the lithium potassium borate (LiKB4O7) single crystal have been investigated by means of the rotational Maker fringe technique using Nd:YAG laser at 1064 nm working in picosecond regime. The value of the third order nonlinear optical susceptibility was calculated using the theoretical model of Kajzar et al. and was found to be about 1.4 × 10−21 m2 V−2 that is one order higher than that of fused silica

    Characterization and investigation of NLO properties of electrodeposited polythiophenes

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    In this work we study the electronic properties of ClO4- doped polythiophenes and discuss the nonlinear optical properties of these organic compounds galvanostatically electrodeposited on ITO glasses. The investigation on the electronic properties (band gap, flat band potential) was performed by means of a non-destructive optical technique, photocurrent spectroscopy (PCS). The investigation on the nonlinear optical response was carried out by means of second and third harmonic generation measurements. In particular, the effect of the oxidation state of the polymeric films was studied by comparing the NLO response of oxidized and reduced polythiophenes. Reduced polymeric films show higher values of the second (χ<2>) and third (χ<3>) order nonlinear susceptibilities

    Influence of Ag, Cu dopants on the second and third harmonic response of ZnO films

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    Silver- 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

    Characterization and Investigation of NLO Properties of some Selected Electrodeposited Polythiophenes

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    In this work we study the electronic properties of ClO 12 doped polythiophenes and discuss the nonlinear optical properties of these organic 4 compounds galvanostatically electrodeposited on ITO glasses. The investigation on the electronic properties (band gap, \ufb02at band potential) was performed by means of a non-destructive optical technique, photocurrent spectroscopy (PCS). The investigation on the nonlinear optical response was carried out by means of second and third harmonic generation (SHG and THG) measurements. In particular, the effect of the oxidation state of the polymeric \ufb01lms was studied by comparing the NLO response of oxidized and reduced polythiophenes. Reduced poly- meric \ufb01lms show higher values of the second (\u3c7 h2i) and third (\u3c7 h3i) order nonlinear optical susceptibilitie

    Spin-coated Tin-doped NiO thin films for third order nonlinear optical applications

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    A self-made spin-coater was employed to deposit pure and Sn doped nickel oxide thin films on glass substrates. The tin doping impact on the structural, linear and nonlinear optical properties of the spin-coated NiO thin films was studied. The XRD analysis showed that undoped and Sn doped NiO thin films have a cubic structure and are preferentially oriented along the (200) direction. The increase of doping concentration leads to a modification in the values of certain parameters such as the crystallite size and the structural strain as well as affecting the nonlinear optical properties of the doped nickel oxide thin films. The values of the third order nonlinear optical susceptibility, found to be between 2.25 × 10−21 m2/V2 and 3.13 × 10−21 m2/V2, were obtained and analyzed depending on the concentration of the doping

    Functionalized azo-based iminopyridine rhenium complexes for nonlinear optical performance

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    Two new TTF-pi-acceptor dyads that contain p-nitrophenyl group as acceptor and bis-(styryl)benzene system as an efficient π−conjugated bridge have been synthesized by multistep synthetic procedure and their electrochemical behavior has been studied by cyclic voltammetry (CV). The occurrence of an intramolecular charge transfer (ICT) in these molecules has been evidenced by UV–Visible electronic absorption spectroscopy and these studies were completed by DFT calculations in both gas phase and in solution. The nonlinear optical parameters obtained via SHG and THG measurements are described and indicate that these materials are valuable candidates for the construction of optoelectronic and photonic devices. The Optical Kerr Effect measurements indicate that these materials exhibit a great potential in the field of optical switchers construction, where the material\u27s photoresponse time is a crucial parameter

    Comparison of structural, morphological, linear and nonlinear optical properties of NiO thin films elaborated by Spin-Coating and Spray Pyrolysis

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    The paper reports on a comparative study of nickel oxide thin films prepared via two different elaboration methods spin-coating and spray pyrolysis. The structure and the surface topography of the NiO thin films have been studied by X-ray diffraction and the atomic force microscope. The optical properties of the deposited films were characterized with the analysis of the experimentally recorded optical transmittance data in the spectral wavelength range of 300–850 nm, via a JENWAY6715 UV–vis spectrophotometer. To complete the comparison, the third order nonlinear optical susceptibility was determined from the third harmonic generation experiment, which in turn were explored by the rotational Maker fringe technique using the beam of Nd:YAG laser at 1064 nm in picoseconds regime. The present work is aimed to exhibit the influence of the elaboration method on the physical properties through analyzing the obtained experimental results

    Second and third order nonlinear optical properties of nanostructured ZnO thin films deposited on α-BBO and LiNbO3

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    The nanocrystalline ZnO films were deposited on α-BaB2O4 (0 0 1 2) and LiNbO3 (0 0 0 1) single crystals by RF-magnetron sputtering technique. Their structure was studied using X-ray diffractometry, scanning electron microscopy and atomic force microscopy. Besides, the optical absorption spectra were investigated. The second and third harmonic generation measurements were performed by means of the rotational Maker fringe technique using Nd:YAG laser at 1064 nm in picoseconds regime. Finally, the second and third order nonlinear susceptibilities were determined and their values have been found and compared

    Linear and nonlinear optical properties of ZnO/PMMA nanocomposite films

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    The nanoscale crystals (NCs) of ZnO were embedded into polymethylmethacrylate (PMMA) 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 THG) studies of ZnO/PMMA nanocomposite films with different concentrations of ZnO NCs were carried out at λ=1.064 Όm 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

    Quadratic nonlinear optical parameters of 7% MgO-doped LiNbO3 crystal

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    Pure and 7% MgO-doped lithium niobate (LiNbO3) single crystals were grown by the Czochralski technique. The shift of optical absorption edge in 7% MgO-doped crystal in direction of shorter wavelength compared to undoped crystal was observed. The second harmonic generation measurements of 7% MgO-doped LiNbO3 crystal were performed at room temperature by means of the rotational Maker fringe technique using Nd:YAG laser generating at 1064 nm in picoseconds regime. Experimentally obtained value of nonlinear optical coefficient d33 for 7% MgO-doped LiNbO3 was found to be less than for undoped crystal but higher than for 5% MgO-doped. I-type phase-matched second harmonic generation was achieved and the value of phase-matched angle was calculated. High quadratic nonlinearity together with tolerance to intensive laser irradiation makes 7% MgO-doped LiNbO3 crystal interesting for application in optoelectronics
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