Structures and nonlinear optical properties of polar 2-amino-1,2,3-triazolequinone derivatives

A series of phenyldialkylamine, dimethoxyphenyl, and nitrothiophene derivatives of 2-amino-1,2,3-triazolequinones was characterized by NMR, IR, mass spectroscopy, cyclic voltammetry, and chemical analyses. The solvatochromic procedure was used to evaluate the potential of nine compounds for nonlinear optical applications, and the possible failure of this model is discussed. The crystal structures of seven compounds were determined: (4) P2₁/c, a = 15.430(3) Å, b = 7.633(2) Å, c = 15.940(3) Å, = 105.19(3)° (5) P2₁/c, a = 20.201(2) Å, b = 9.6579(9) Å , c = 18.517(2) Å, = 95.907(2)° (6) P-1, a = 7.769(2) Å, b = 8.515(3) Å, c = 17.312(5) Å, = 89.347(7)°, = 83.219(6)°, = 86.001(7)° (7) P-1, a = 8.1365(7) Å, b = 8.9605(8) Å, c = 11.630(1) Å, = 79.553(2)°, = 75.048(2)°, = 82.080(2)° (8) P-1, a = 8.298(3) Å, b = 9.720(3) Å, c = 10.033(3) Å, = 84.803(6)°, = 83.735(6)°, = 77.659(5)° (10) P2₁/n, a = 8.4300(7) Å, b = 13.980(1) Å, c = 13.975(1) Å, = 106.590(2)° (12) P2₁/n, a = 7.715(2) Å, b = 14.206(3) Å, c = 12.758(3) Å, = 91.016(5)°.     

Linear and nonlinear optical properties of tris thiourea zinc sulphate single crystals

Optical absorption of tris thiourea zinc sulphate (ZTS) single crystals has been measured and its direct band gap was found to be 3.6 eV. Theoretical calculations were carried out to determine the linear optical constants such as extinction coefficient and refractive index. Further the optical nonlinearties of ZTS have been investigated by Z‐scan technique with He‐Ne laser at 632.8 nm. The nonlinear refractive index, absorption coefficient and third order susceptibility is found to be in the order of –5.36 ± 0.26 × 10^–12 cm²/W, 4.24 ± 0.21 × 10^–4 cm/W, 3.5 ± 0.17 × 10^–4 esu respectively. Thus optical characterization of ZTS reveals the various industrial application oriented properties of the material. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Structural,electrical, thermal and optical properties of the nonlinear optical crystal L‐Arginine Fluoride

Single crystals of L‐Arginine Fluoride (LAF) have been grown by the slow evaporation technique, and the crystalline perfection was studied by HRXRD. Optical absorption studies reveal the lower cut off wavelength (280 nm) and the band gap (5.1 eV). The dielectric constant and dielectric loss have been measured as a function of frequency (42 Hz–5 MHz) and temperature (307‐368K) and the activation energy is 77 μeV. The thermal transport properties such as thermal conductivity (0.88 ± 0.02 W/mK) and specific heat capacity (482±24 J/kg/K) have been estimated by the photopyroelectric technique. The nonlinear refractive index n₂, is found to be of the order of 10⁻¹³ cm²/W by the Z‐scan technique.     

Single crystal growth and properties of semiorganic nonlinear optical L‐arginine hydrochloride monohydrate crystals

L‐arginine hydrochloride monohydrate (LAHCl.H₂O) has been synthesized and single crystals have been grown from its aqueous solution by slow evaporation and slow cooling methods. The solubility of the material was measured at various temperatures and bulk crystals of size 26×13×11 mm³ have been grown by optimizing the growth parameters. The grown crystals have been subjected to single crystal XRD studies to confirm the structure and to estimate the lattice parameters. FTIR analysis indicate the mode of vibrations of different molecular groups present in LAHCl and confirm the protonation of guanidyl, amino groups and deprotonation of COO^‐ groups. UV‐Vis transmission spectrum revealed the linear optical properties of the grown crystals with a transparency of 65% over the entire visible range upto 300 nm. Thermal behavior of the grown crystal was investigated from DTA and TGA measurements. Dielectric studies have been carried out on the grown crystals. Kurtz and Perry powder SHG technique confirms the NLO property of the grown crystal. The SHG efficiency of LAHCl was found to be 0.38 with respect to KDP. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Substituted imidazolium phenylphosphonate salts for nonlinear optical applications

Three candidates for potential applications as new nonlinear optical materials were investigated using x-ray crystallography to probe the structure and powder second harmonic generation to elicidate the nonlinear response of the materials. Three structures are reported: 1-benzylimidazolium phenylphosphonate, 2-ethylimidazolium phenylphosphonate, and 2-methylimidazolium phenylphosphonate. Of these three salts two, 2-ethylimidazolium phenylphosphonate and 2-methylimidazolium phenylphosphonate, are noncentrosymmetric and therefore display a nonlinear optical response.     

Growth,thermophysical and electrical properties of the nonlinear optical crystal BPO4

Bulk BPO₄ crystals have been successfully grown from high temperature solution of BPO₄, Li₂O, and MoO₃ in the molar ratio of 2.3:1:1.3 by the top‐seeded solution growth (TSSG) method using [101]^c orientation seeds. There are no visible scattering centers and impurity of Mo in the as‐grown BPO₄ crystals, whose optical homogeneity reaches up to 1.6×10^–5/cm. BPO₄ possesses a specific heat of 0.50–1.00 J·g^–1·K^–1 in the temperature range from 298 to 698 K and exhibits strong anisotropic thermal expansion behavior with α_a = 14.2 × 10^–6 K^–1 and α_c = ‐4.0 × 10^–7 K^–1. Moreover, the thermal conductivity coefficients are calculated to be κ_a = 62.4 W·m^–1·K^–1 and κ_c = 51.5 W·m^–1·K^–1, which are remarkably larger than those of some commonly used borates. The measured dielectric constants, ε_a and ε_c, are 4.8 and 6.1, respectively, and the ionic conductivity coefficients, σ_a = 4.3 × 10^–8 S/cm and σ_c = 9.5 × 10^–8 S/cm, are several orders of magnitude lower than that of LiB₃O₅ (LBO). (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Synthesis,crystal growth,spectral, thermal and optical properties of acenaphthene picrate

The crystalline material of acenaphthene picrate (ACP) was synthesized and the single crystals of the title compound grown by slow evaporation solution growth technique. The solubility of the complex compound was estimated using different solvents as chloroform, ethanol, (1:1) chloroform ‐ acetone mixture. The material was characterized through elemental analysis; powder XRD, NMR and FTIR techniques. The various planes of reflection have been identified from the XRD powder pattern. The formation of the charge transfer complex was confirmed by UV‐VIS spectroscopy. The thermal stability of the crystals was studied using TG/DTA analyses techniques. The second harmonic generation (SHG) of the material was confirmed by using Nd: YAG laser. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Growth and characterization of L‐valine ‐ a nonlinear optical crystal

The growth of a new nonlinear optical material L‐valine by solvent evaporation method is reported here. To grow good quality crystals pH value of growth solution has been optimized and solubility of L‐valine in different solvents and different pH values was determined. The grown crystals were characterized by IR, single crystal XRD, DTA and TGA, optical transmission and second harmonic generation (SHG) efficiency measurement. SHG efficiency of L‐valine was found equivalent to KDP and its transmission is 75%‐80% from ultraviolet to near IR region. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Synthesis,growth and characterization of a new nonlinear optical crystal: l‐arginine maleate dihydrate

A new nonlinear optical material L‐arginine maleate dihydrate, C₆H₁₄N₄O₂,C₄H₄O₄,2H₂O (LAMD) was synthesized and single crystals were grown by slow cooling and also by slow evaporation method at constant temperature from its aqueous solution. Quality and size of the crystals are found to be dependent on pH of the solution and best crystals were obtained at pH = 4. Single crystal X‐ray diffraction analysis reveal that the crystal lattice of LAMD is triclinic with unit cell parameters a = 5.264(3)Å, b = 8.039(3)Å, c = 9.784(3)Å, α = 106.19(3)°, β = 97.24(3)°, γ = 101.66(2)°. Second harmonic generation efficiency is found to be about 6.8 times that of quartz. It is optically transparent down to 300 nm and possesses a large optical window between 300–2000 nm. The compound is thermally stable up to 93.4 °C. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Growth,optical and thermal studies of nonlinear optical L‐arginine perchlorate single crystals

A potentially useful semiorganic nonlinear optical (NLO) material, L‐arginine perchlorate, has been synthesized and bulk crystals have been grown by slow cooling technique. The grown crystals were characterized by single crystal X‐ray diffraction, UV‐Vis‐NIR spectroscopy, FT‐IR, thermal analysis and SHG measurements. The grown crystals were thermally stable upto 153°C and exhibit SHG efficiency of about 0.17 with respect of Urea. The etching studies have been carried out on the grown crystal. LAPC has good optical transmission not only in the visible range, however, also in the near UV part of the spectra and hence it is a potential material for nonlinear frequency conversion. The refractive index was measured by the Brewster's angle method. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Recent advances in rare earth-based borate single crystals: Potential materials for nonlinear optical and laser applications

Due to an increase in the requirement for ultraviolet and visible laser sources nonlinear optical crystals are gaining importance. Borate-based nonlinear optical crystals such as lithium borate LiB₃O₅ (LBO), CsLiB₅O₁₀ (CLBO), SrBe₂B₂O₇ (SBBO), KBe₂BO₃F₂ (KBBF) and K₂Al₂B₂O₇ (KAB) have excellent transmission ranges extending from the ultraviolet into the infrared region. But their hygroscopic nature retards their use in real-time applications. Rare earth-based borate crystals such as rare earth calcium oxy borate RECa₄O(BO₃)₃ (RECOB) and rare earth calcium borate RE₂CaB₁₀O₁₉ (RECB) have excellent nonlinear optical behaviour and also allow the substitution of ‘laser-active’ ions to create ‘laser crystals’. Further they are non-hygroscopic which favours them in practical applications. A review on RECOB and RECB crystals is presented along with a discussion on our attempts to grow yttrium calcium oxy borate YCa₄O(BO₃)₃ (YCOB), lanthanum calcium oxy borate LaCa₄O(BO₃)₃ (LCOB), yttrium calcium borate Y₂CaB₁₀O₁₉ (YCB) and lanthanum calcium borate La₂CaB₁₀O₁₉ (LCB) crystals. These crystals possess excellent transmission properties combined with nonlinear optical behaviour. They also exhibit high laser damage threshold (LDT) values.     

Synthesis and Crystal Structure of Compound 1,5-bis(4-methoxyphenyl)-3a-(2-phenyl-2H-1,2,3-triazol-4-yl)-4,5-dihydro-3aH-benzo[b][1,2,4]oxadiazolo[4,5-d][1,4]thiazepine

Abstract The crystal structure of title compound has been determined. The compound crystallizes in the triclinic system with space group P-1, lattice parameters; a = 9.2938 (5) ?, b = 11.9992 (7) ?, c = 25.5918 (13) ?, α = 91.343 (2)°, β = 95.8360 (10)°, γ = 101.005 (2)°, V = 2784.3 (3) ?³, Z = 4, X-Ray analysis reveals that the molecular backbone consists of tricyclic system with the central seven-membered ring in twisted chair-like conformation. Graphical abstract The crystal structure of 1,5-bis(4-methoxyphenyl)-3a-(2-phenyl-2H-1,2,3-triazol-4-yl)-4,5-dihydro-3aH-benzo[b][1,2,4]oxadiazolo[4,5-d][1,4]thiazepine was first determined by single-crystal X-ray diffraction which reveals that the molecular backbone consists of a tricyclic system with the central seven-membered ring in twisted chair-like conformation .     

Hydrogen bonded nonlinear optical γ-glycine: Crystal growth and characterization

Single crystals of γ-glycine(GG) were grown by solvent evaporation technique from a mixture of aqueous solutions of glycine and ammonium nitrate at ambient temperature. X-ray diffraction, thermogravimetric/differential thermal analysis, Fourier transform infrared spectral techniques were employed to characterize the crystal. The lattice parameters were calculated and they agree well with the reported values. GG exists as dipolar ions in which the carboxyl group is present as a carboxylate ion and the amino group as an ammonium ion. Due to this dipolar nature, glycine has a high decomposition temperature. The UV cutoff of GG is below 300 nm and has a wide transparency window, which is suitable for second harmonic generation of laser in the blue region. Nonlinear optical characteristics of GG were studied using Q switched Nd:YAG laser (). The second harmonic generation conversion efficiency of GG is 1.5 times that of potassium dihydrogen phosphate . The X-ray diffraction and Fourier transform infrared spectral studies show the presence of strong hydrogen bonds which create and stabilize the crystal structure in GG. The main contributions to the nonlinear optical properties in GG results from the presence of the hydrogen bond and from the vibrational part due to very intense infrared bands of the hydrogen bond vibrations. GG is thermally stable up to 441 K.     

Synthesis,crystal growth and properties of the charge transfer complex adduct of 2‐nitro aniline with picric acid – An organic non‐linear optical material

The organic NLO material 2‐nitro aniline and picric acid (2NAP) was synthesized, needle shaped single crystals of dimension 10 × 1 × 0.8 mm^‐3 were grown by slow evaporation solution growth technique from the saturated solution of the title compound in chloroform at ambient temperature. The material was characterized through elemental analysis, powder XRD, ¹H NMR, ¹³C NMR and FTIR techniques. The various planes of reflection have been identified from the XRD powder pattern. The formation of the charge transfer complex was confirmed by UV‐VIS spectroscopy. The thermal stability of the crystals was investigated using TG/DTA analyses techniques. The second harmonic generation (SHG) efficiency of the material was estimated using Nd: YAG laser as source. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Growth,optical, photoluminescence,dielectric, second and third order nonlinear optical studies of benzoyl valine acentric crystal

A nonlinear optical material benzoyl valine (BV) was synthesized by the technique of slow evaporation process at room temperature. The single crystal X ray diffraction analysis evince that crystal corresponds to acentric space group P₂₁ with monoclinic system. The diverse optical properties assured an elevated transparency in BV crystal. Photoluminescence profile revealed the suitability of crystal for fabricating violet lasers. The Laser damage threshold and the dielectric behavior of the grown crystal were analyzed to indicate its practical applications. The second and third order nonlinear optical measurements were studied to prove its potentiality in the domain of nonlinear optical applications.     

Preparation and optical properties of silver nanoparticles induced by a femtosecond laser irradiation

Silver nanoparticles were prepared by a focused femtosecond laser irradiation in a 5 mM AgNO₃ solution in the presence of TiO₂ sol. TEM analysis revealed that the size of silver nanoparticles was less than 20 nm. A mechanism for the precipitation of silver nanoparticles was proposed. Nonlinear absorptions and optical limiting properties of silver nanoparticles contained solution were also measured. It is observed that the composite material showed strong self-focused effect and significant optical limiting property.     

A new nonlinear optical crystal: Bi2O2(OH)(NO3)

The nonlinear optical (NLO) properties of Bi₂O₂(OH)(NO₃) crystals have been reported for the first time. Bi₂O₂(OH)(NO₃) crystals with dimensions of 1.3×1.2×0.1 mm³ have been grown by hydrothermal method, and the crystals characterized by X‐ray powder diffraction (XRD), SEM and IR. The measured second harmonic generation (SHG) effect of Bi₂O₂(OH)(NO₃) was about 7 times that of KDP. The mechanism responsible for the large SHG of Bi₂O₂(OH)(NO₃) was explained according to its structure. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Nonlinear optical properties of lithium sulfate monohydrate

In this paper, all eight tensor components of the nonlinear optical susceptibility tensor for second harmonic generation were determined for monoclinic non‐centrosymmetric lithium sulfate monohydrate, Li₂SO₄·H₂O, using the Maker fringe technique at the wavelength λ=1064 nm. The largest component of the nonlinear optical susceptibility tensor was 0.34 pm/V. This crystal has the maximum effective value 0.13 pm/V along the phase matching directions at type I and 0.10 pm/V at type II. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Anisotropy of optical absorption in layered single crystals

The optical energy gap of Re doped MoSe₂ single crystal Mo_0.995Re_0.005Se₂ has been measured at room temperature near the fundamental absorption edge. The incident light was kept normal to the basal plane i.e. along the c‐axis of the grown crystals. Results have been given on the basis of two and three dimensional models. Both direct and indirect transitions are involved in the absorption process. The indirect transition was found to be allowed with two phonons involved in the process. The three dimensional model and not the two dimensional could be used to describe the optical properties of Re doped MoSe₂ single crystal. Also, the optical energy gaps depend upon the amount of the intercalating Re material. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)