Non-linear optical materials

h i g h l i g h t s " In this article we are reporting the single crystal growth of L-lysine acetate. " The sated material is grown by Slow Evaporation Solution growth Technique (SEST). " To the best of our knowledge there is no report is available in the literature. " It is a potential material for NLO devices.

h i g h l i g h t s " In this article we are reporting the single crystal growth of L-lysine acetate. " The sated material is grown by Slow Evaporation Solution growth Technique (SEST). " To the best of our knowledge there is no report is available in the literature. " It is a potential material for NLO devices.

A new nonlinear optical material L-Arginine doped potassium penta borate (LAKB 5) Single Crystals have been grown by slow evaporation solution growth technique from its aqueous solution. The synthesized compound was subjected to single crystal X-ray diffraction analysis to recognize the morphology and structure. An assortment of modes of vibrations there in the crystal was identified with FTIR. The linear and nonlinear optical investigations were recorded in identification of optical transmission spectrum and Second Harmonic Generation (SHG). The mechanical strength have been checked by Vicker's microhardness tester and consequently various parameters such as yield strength (σ v), elastic stiffness constant (C 11), fracture toughness (K c) and brittleness index (B i) were calculated and reported for the first time.

In this paper, we investigate the linear and nonlinear (NL) optical properties of gold nanoparticles (Au-NPs) with different sizes. A colloidal gold nanoparticles solution has prepared to utilize the chemical reduction method by interacting gold chloride solution HAuCl4 with trisodium citrate solution. By using a hotplate and vigorous stirring the flask, which has the mixture solution, was heated to produce a 0.05 mg/ml of colloidal gold nanoparticles. The characterization of gold nanoparticles is executed by the utilization of different techniques. The information about nanoparticles size was achieved from the spectra measured by transmission electron microscopy (TEM). As well as the compositional characteristics are obtained using FTIR and XRD techniques. Finally, the Surface Plasmon Resonance (SPR) peaks were measured using a UV-Vis spectrophotometer. A Z-scan technique was utilized to study the nonlinear optical properties of Au nanoparticles. From the preparation of the nanoparticles, the shape of gold nanoparticles was almost spherical and has two different sizes. The nonlinear refractive index of Au nanoparticles was obtained in the order of 10-10 cm 2 /w extracted from a closed aperture z-scan. The nonlinear absorption of these nanoparticles was measured at 10-5 cm/w range obtained from an open aperture z-scan technique.

Some bismuth borate glasses containing an equal concentration of both ZnO and CaO were prepared using the fast cooling method, in the air. X-ray diffraction and Fourier transform infrared techniques were used to characterize these glasses. All samples showed amorphous natures, with short-range order networks. Introducing of both ZnO and CaO caused BO 4 groups to convert to BO 3 with an observable decreasing in the molar volume. Linear refractive index decreased with increasing the wavelength of the incident light, while the nonlinear refractive index increased. Linear and nonlinear susceptibilities decreased with introducing ZnO and CaO.

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• Sr 2+ doped ZnO nanostructures were synthesized by chemical precipitation method. • Third-order NLO properties of the nanostructures have studied by a Z-scan technique at 532 nm. • Experimental results from the samples show the existence of saturable absorption behavior. • The better NLO response from the samples could be used for NLO device applications.

Some bismuth borate glasses containing an equal concentration of both ZnO and CaO were prepared using the fast cooling method, in the air. X-ray diffraction and Fourier transform infrared techniques were used to characterize these glasses. All samples showed amorphous natures, with short-range order networks. Introducing of both ZnO and CaO caused BO 4 groups to convert to BO 3 with an observable decreasing in the molar volume. Linear refractive index decreased with increasing the wavelength of the incident light, while the nonlinear refractive index increased. Linear and nonlinear susceptibilities decreased with introducing ZnO and CaO.

Using the density functional theory (DFT), the molecular geometry and vibrational spectrum are predicted with accuracy. Using B3LYP/6-31 (d,p) the vibration frequencies are calculated. Using KBr pellet, the FT-IR spectra of LVPCl is recorded between the range 4000 cm-1 to 400 cm-1.The NLO test is performed and a second harmonic efficiency is found to be nearly 2.3 times that of KDP. The single crystals of LVPCl crystal are subjected to thermo gravimetric analysis (TGA) and differential thermal analysis (DTA). To estimate the hardness, Vickers microhardness measurement is carried out on the grown crystal.

We investigated the Onsager relations in the context of electromagnetic constitutive relations of linear, homogeneous materials. We determined that application of the Onsager relations to the constitutive equations relating P and M to both E and B is in accord with Lorentz reciprocity as well as the Post constraint.

Photochromic quartz-like glasses (PCQGs) were successfully synthesized by an impregnation of silica nanoporous glasses (SNPGs) with photosensitive phases (AgCl, AgBr, AgI) in or without the presence of CuO as a sensitizer followed by sintering of the samples. Characterization of PCQGs was carried out using the transmission electron microscopy (TEM), X-ray powder diffraction (XRPD) and UV-VIS-NIR spectroscopy methods. According to TEM, images revealed that the size of the individual isolated particles and agglomerates, which are contained silver-phases inside a silica matrix, is from 10 to 100 nm. It was shown that PCQGs preferably contain the crystalline phase of AgBr. In the spectral curves of optical density of the PCQG subjected to UV laser irradiation, the plasmon resonance peaks of the quasi-metallic silver nanoparticles were found.

Europium doped bismuth borate glasses have been prepared by melt quenching technique, the structural and optical properties have been studied before and after the gamma radiation. The X-ray diffraction pattern confirms the amorphous nature of the prepared samples. Fourier transform infrared spectra show structurally it is not changed with few bands slightly red shifted. In the UV-Visible studies there are no extra peaks. The band gap energies determined are in the range 2.7512.563 eV for direct and 2.303-1.911 eV for indirect transition before irradiation. The band gaps and Urbach energy have been changed a little in rare earth and silver doped samples. The base glass and with 0.3 mol% of Eu2O3 exhibit no significant change after the gamma radiation. The most absorbing bismuth borate glass catches importance as a radiation protection or shielding material.

A fast and general Partial Element Equivalent Circuit (PEEC) method based on the Fast-Fourier-Transform (FFT) is proposed for the first time. The numerical tool only requires common CAD data input files (e.g. .stl format), then the discretization process is performed automatically by means of a fast voxelization technique based on ray intersection, thus drastically reducing the human effort required to setup the model. The method allows for considering at the same time inductive and capacitive effects, and is focused on power electronics applications where propagation effects can be neglected, whereas all the other electromagnetic phenomena are considered. Specifically, the proposed method is particularly suited for problems where both electric and magnetic fields are equally important and therefore quasistatic approximations do not apply. An ad-hoc preconditioner which significantly speeds-up the solver is also proposed and, thanks to the FFT, both memory and computation time are significantly reduced, without the need of applying data compression. Both linear and non-linear materials are considered by the proposed FFT-PEEC method. Sample implementation of the method is made publicly available.

 The successful codoping of Er 2+ and Yb 3+ ions into SrWO 4  Enhancement of green emission intensities by the Yb 3+ ions codoping  Obvious temperature-dependence of green emission on temperature  The sensitivity value of 0.01282 K-1 at 489 K for SrWO 4 :1%Er 3+ /6%Yb 3+

h i g h l i g h t s " In this article we are reporting the single crystal growth of L-lysine acetate. " The sated material is grown by Slow Evaporation Solution growth Technique (SEST). " To the best of our knowledge there is no report is available in the literature. " It is a potential material for NLO devices.

We report here the results obtained in surface ablation of RbTiOPO 4 single crystals by femtosecond laser. We fabricated and characterized one-dimensional (1D) diffraction gratings with different lattice spacings of 15 and 20 lm, and with a sub-modulation of the period introduced in the later. The optical and electronic microscopy characterization and filling factor analysis of these diffraction gratings are reported. We also show that the roughness generated on the grooves by the ablation process can be improved by chemical etching.

Europium doped bismuth borate glasses have been prepared by melt quenching technique, the structural and optical properties have been studied before and after the gamma radiation. The X-ray diffraction pattern confirms the amorphous nature of the prepared samples. Fourier transform infrared spectra show structurally it is not changed with few bands slightly red shifted. In the UV-Visible studies there are no extra peaks. The band gap energies determined are in the range 2.7512.563 eV for direct and 2.303-1.911 eV for indirect transition before irradiation. The band gaps and Urbach energy have been changed a little in rare earth and silver doped samples. The base glass and with 0.3 mol% of Eu2O3 exhibit no significant change after the gamma radiation. The most absorbing bismuth borate glass catches importance as a radiation protection or shielding material.

The sodium zinc borate glasses with silver and copper doped glasses were synthesized by the traditional melt quench technique. Their structural behaviour was studied by powdered x-ray diffraction and Fourier transforms infrared spectroscopy. The optical properties were analysed by the use of UV-Visible spectroscopy. The XRD study confirms the non-crystalline environment of the glasses. Densities were found to change hardly by 0.1gm/cm 3 .The FTIR spectra depicts the presence of BO 3 and BO 4 units in the matrix. Optical energy band gaps were found to decrease which in turn increased the refractive indices by doping. The glasses were perceived to be highly transparent to infrared and highly opaque for the ultraviolet radiation. Hence they find place in the applications of optical limiters and UV filters.

Single crystals of sodium chloride (NaCl) doped organometallic nonlinear optical material L-asparagine cadmium chloride monohydrate (LACCM) were successfully grown by slow evaporation method at room temperature. Grown crystals were characterized by single crystal and powder X-ray diffraction analysis, scanning electron microscopy, energy-dispersive analysis by X-ray and thermal studies. The second harmonic generation was confirmed by the Kurtz and Perry powder technique. The presence of various functional groups was identified from FTIR spectral analysis. The mechanical strength of the grown crystal has been determined with the aid of Vickers hardness test. The second harmonic efficiency and dielectric constant increases significantly due to the introduction of sodium ions into the lattice of l-aspargine cadmium chloride crystal, so that this crystal is a potential material for nonlinear frequency conversion.

Sol-gel SiO2 matrices with Polymethine dyes (РМ1, РМ2 and РМ3) were synthesized using citric acid as a catalyst. There were measured the absorption and luminescence spectra of РМ1, РМ2 and РМ3 dyes (with a concentration of 1·10–5 mole/dm3) in different solvents (ethanol, dimethylformamide, formamide and water) and in sol-gel SiO2 matrices. The said dyes were found to be present in monomeric form in ethanol, dimethylformamide and formamide. PM1 dye did not form dimers in water and in matrices and retained its color. PM2 and PM3 dyes aggregated into the network of SiO2 matrices and in water solution, and the intensity of their coloration reduced in the course of time.

The glass series of samarium nanoparticles (NPs) doped zinc borotellurite glasses were successfully fabricated by using conventional melt-quenching technique. The structural properties of the prepared glasses were investigated by X-ray diffraction (XRD) analysis and FTIR analysis. It was confirmed that the prepared glasses are amorphous in nature. The bonding parameters of the glasses were analyzed by using FTIR analysis and were found the formation of non-bridging oxygen. The density of these glasses were measured and found to be increased with increasing samarium NPs content. The optical absorption spectra of these glasses were revealed that the fundamental absorption edge shifts to higher wavelengths as the content of Sm2O3 (NPs) increases. The optical energy band gap are found to be decreased linearly with an increasing samarium NPs concentration which is due to the formation of non-bridging oxygen in the glass system.KeywordsBorotellurite glass; optical band gap, Samarium nanop...

TeO2 –WO3 –Pb3O4 glasses codoped with Er3+ – Yb3+ ions have been prepared by melting and quenching process. Judd–Ofelt analysis has been performed to calculate the various radiative parameters viz., radiative lifetime , branching ratio and stimulated emission crosssections by using the absorption spectra. The nephelauxetic ratio, bonding and covalency parameters have been determined to get the information about the nature of bonding between the rare earth ions and neighbouring oxygen atoms. The near infrared (NIR) to visible frequency upconversion (UC) study upon excitations with 980 nm and 808 nm diode lasers has been performed. The variations observed in the UC emission intensity arising from the Er 3? ions have been explained on the basis of efficient energy transfer Yb3+ - Er3+ ions and back energy transfer Er3+-Yb3+ processes. On codoping with Yb 3? ions the intensity of the UC emission bands observed in the codoped glass upon excitation at 980 nm has been enhanced by many folds and explained on the basis of the oscillator strengths, UC emission crosssection and temporal evolution analysis. No tuning in the colour emitted from the codoped glass upon excitation at 980 nm is reported. The results suggested that the codoped glass may be suitable in making the NIR to visible upconverter and colour non-tunable optical devices.

Magnesium hydrogen phosphate (MHP) and transition metal doped cadmium magnesium hydrogen phosphate (CdMHP) was synthesized in the form of crystalline material by room temperature solution technique known as gel encapsulation technique. The synthesized crystals were then characterized for their structural, mechanical and electrical investigations using various chemical and physical methods. X - ray diffraction analysis (XRD) establishes magnesium hydrogen phosphate and cadmium magnesium hydrogen phosphate belonging to orthorhombic crystal system with space group Pbca. The mechanical behaviour of these crystals was studied by calculating Vicker’s hardness number. The behaviour of microhardness with applied load was observed to be complex. The electrical behaviour was carried out by calculating dielectric constant at different temperatures and for different frequencies. The dielectric constant (ε/) was found to be strongly dependent on temperature and frequency. The transition metal doping of cadmium in magnesium hydrogen phosphate remarkably decrease the value of dielectric constant from 68 to 23. The transition temperature also decreases from 330˚C in case of magnesium hydrogen phosphate to 310˚C in case of cadmium magnesium hydrogen phosphate. Copyright © 2014 VBRI press.

We have observed polarization-resolved coherent beam combination via nondegenerate two-wave mixing in water-glycerol suspensions of shaped polytetrafluoroethylene microparticles. Experiments detect coherent energy transfer arising from two different types of moving index gratings: translational and orientational. Additionally, the dependence of the two-wave mixing gain coefficient on the frequency-difference of the beams, pump intensity and microparticle volume fraction was measured and found to be in accord with theory. Finally, beam combination was also achieved using degenerate laser beams and moving the suspension relative to the laser interference pattern.