21 research outputs found
Propriétés Optiques Non Linéaires de l'Oxyde de Zinc: Elaboration, Charactérisation, Propriétés Optiques, Génération de la troisième Harmonique
Theoretical calculations of second and third-order nonlinear susceptibilities and their corresponding hyperpolarizabilities of a styrylquinolinium dye
The second (Xexp(2)) and third-order (Xexp(3)) susceptibilities of a styrylquinolinium dye (1) have been determined utilizing second-harmonic generation (SHG) and third-harmonic generation (THG) techniques, respectively. The reported measurement findings on Xexp(2) and Xexp(3) have been compared with the theoretical data evaluated here by means of ab-initio quantum mechanical calculations. The electric dipole moments (μ), static dipole polarizabilities (a) and first hyperpolarizabilities (β) have been computed by density functional theory (DFT) at B3LYP/6-311+G(d, p) level. To reveal the frequency-dependent second and third-order microscopic nonlinear optical (NLO) behavior of the title compound, the dynamic dipole polarizabilities, first and second (γ) hyperpolarizabilities have been theoretically investigated using time-dependent Hartree-Fock (TDHF) method. According to the experimental and theoretical results, the values of susceptibilities and the corresponding microscopic coefficients with large non-zero responses make the examined dye promising candidate for NLO applications
Third order non linear optical properties of ZnO:Al thin films prepared by spray pyrolysis
In this study, zinc oxide (ZnO) and aluminium doped zinc oxide (ZnO:Al) thin films were deposited by reactive chemical pulverization spray pyrolysis technique on heated glass substrates at 450degC. X-ray diffraction (XRD), scanning electron microscopy (SEM) and third harmonic generation (THG) are used to characterize their structure , morphology and nonlinear optical properties as a function of Al concentration (0, 3, 5, 7 at %). The intensity of third order non linear optical susceptibility increase by incorporation of aluminium. A strong value of susceptibility chi(3) was found for films with a good crystallinity
Influence of strain/stress on the nonlinear-optical properties of sprayed deposited ZnO:Al thin films
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Ab-initio and DFT methodologies for computing hyperpolarizabilities and susceptibilities of highly conjugated organic compounds for nonlinear optical applications
Z-scan determination and ab-initio computations on third-order optical nonlinearities of a styrylquinolinium dye
In order to elucidate the third-order nonlinear optical (NLO) phenomena of the styrylquinolinium dye (1), the nonlinear absorption parameter (ß) and third-order susceptibility (χ(3)) have been measured using the Z-scan measurements. The one-photon absorption (OPA) and two-photon absorption (TPA) characterizations have been determined by configuration interaction (CI) and time-dependent Hartree-Fock (TDHF) methods, respectively. The averaged (isotropic) second hyperpolarizability (〈γ〉) allows the determination of the third-order optical response. The ab-initio calculation on 〈γ〉 with non-zero value reveals that the title dye has relatively good third-order NLO properties. The calculated results of 1 on OPA wavelength, TPA cross-section (δ(ω)) and third-order susceptibility are in reasonable agreement with its experimental data
Influence of Bi doping on the electrical and optical properties of ZnO thin films Superlattices and Microstructures
Transparent conducting ZnO doped Bi thin films were prepared on glass substrates by ultrasonic spray method. The influence of Bi doping concentration on the structural, optical and nonlinear optical properties of ZnO thin films was studied. The X-ray diffraction (XRD) analysis show that all studied films have a hexagonal wurtzite structure and are preferentially oriented along the c-axis from substrate surface. Optical transmittance measurements show that all samples have average 80% transparency in the visible light. Optical band gap values range between 3.14 and 3.28Â eV. ZnO film with 3Â wt% of Bi showed the highest electrical conductivity. In addition, the second and third order nonlinear susceptibilities were determined and their values have been calculated
Diagnostic study of the roughness surface effect of zirconium on the third-order nonlinear-optical properties of thin films based on zinc oxide nanomaterials
Zinc oxide (ZnO) and zirconium doped zinc oxide (ZnO:Zr) thin films were deposited by reactive chemical pulverization spray pyrolysis technique on heated glass substrates at 500 °C using zinc and zirconium chlorides as precursors. Effects of zirconium doping agent and surface roughness on the nonlinear optical properties were investigated in detail using atomic force microscopy (AFM) and third harmonic generation (THG) technique. The best value of nonlinear optical susceptibility χ(3) was obtained from the doped films with less roughness. A strong third order nonlinear optical susceptibility χ(3) = 20.12 × 10−12 (esu) of the studied films was found for the 3% doped sample
Influence of Roughness Surfaces on Third-Order Nonlinear-Optical Properties of Erbium-Doped Zinc Oxide Thin Films
ABSTRACT Zinc oxide (ZnO) and erbium-doped zinc oxide (ZnO:Er) thin films were deposited on heated glass substrates using the spray pyrolysis technique. Third-order nonlinear-optical properties of the thin films have been investigated using the third harmonic generation (THG) at wavelength of 1064 nm in picosecond regime. The dependence of third-order nonlinear susceptibility and transmission characteristics on the thin films roughness has been evaluated. Third-order nonlinear optical susceptibility (χ(3)) values of the studied materials were in the remarkable range of 10−2 esu. The morphologic properties of the deposited films have been analyzed using x-ray diffraction (XRD) and atomic force microscopy (AFM) and the luminescence properties by cathodoluminescence (CL). A correlation between optical properties and structural properties is given