Third harmonic generation in LiKB4O7 single crystal

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

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

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

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

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

Forecasting the Dynamics of Stockbreeding Development Using Time Series

The construction of time series using historical data is one of the urgent problems of management in the agrarian sector, since the analysis and forecasting of processes related to the food security of the State, of region, and of economic entities is crucial. With the help of forecasts, businesses can adjust their production activities in such a way as to meet demand and deliver products to consumers on time. The aim of this study is to forecast the dynamics of the development of stock of cattle and cows and to determine the optimal forecasting period. For this type of analysis, statistical methods related to autoregression are used: autoregressive models, moving average models, or combinations of both; integrated models with a variable structure, and models that include seasonal effects and exogenous factors with an autoregressive and moving average component in the model. Monthly statistics on the number of cattle and cows are provided: mean, standard deviation, minimum and maximum values, asymmetry and excess. The dynamics of decline in the number of stock of cattle and cows is shown. The studied series were tested for stationarity. To the time series of the number of cattle, the Box–Cox transformation was applied. The optimal parameters of the models used are presented. Forecast values for time intervals (months) have been obtained and changes in the number of stock of cattle over the past 17 years have been analyzed. The built time series are compared with the actual values, which is illustrated in the graphs. Estimates of standard deviation, mean absolute error for different forecasting terms are provided. When comparing these estimates for different time intervals, the optimal time period for the forecast (24 months) was determined. This study allows farms and enterprises of the industry to realize how much products (milk, meat) can be harvested or obtained in the future. This assists in taking the necessary managerial steps: plan for resource needs, improve efficiency, increase profits, reduce costs, and adapt to changes in the market

Functionalized azo-based iminopyridine rhenium complexes for nonlinear optical performance

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

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

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

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 μm 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