Good Nonlinear Optical Material Research Articles

Integrating simulated and experimental studies on novel single crystal bis(guanidininium) n-carboxylatephenylalanine towards enhanced antitumor effect

A novel organic crystal bis(guanidininium) n-carboxylatephenylalanine (GUPA) was synthesized and X-ray diffraction outcomes exposed P21, triclinic space group with cell dimensions a = 6.6492(3) Å, b = 16.2440(7) Å, c = 7.8985(3) Å, β = 0.127(2) °, V = 853.11(6) Å3, Z = 2 and possess good agreement with experimental data. Intermolecular interactions were revealed through hirshfeld and major contribution from O-H interaction confirms the presence of intermolecular hydrogen bonds. Through B3LYP algorithm with set 6–311++ G (d, p), chemical reactivity forms and molecular structure of GUPA was investigated, confirming a good stability and hard electrophilic nature. While first order hyperpolarizability value (35.37 × 10−31 esu) was indicative of good nonlinear optical material and hyperconjugate interactions and charge delocalization was further confirmed by natural bond orbitals. To further investigate the electronic properties theoretical (TD-DFT) and experimental absorption wavelengths were compared and excitation energies, oscillator strength and type of electronic transition with contributions have also been studied. The topological properties were evaluated using ELF/LOL maps and RDG with NCI were used to establish the type of interaction present in the GUPA molecular system. The anti-breast cancer effect of GUPA was computationally studied through molecular docking against p53 gene and was further investigated through in vitro MDA-MB-231 cell line studies and GUPA showed better inhibition of cancer cells and their expression.

Determination of the Electronic Structure, Charge-transfer, and Optical Properties of Neutral, Anionic, and Cationic Perfluoropentacene

Perfluoropentacene ( is an n-type organic semiconductor made by fluorination of p-type semiconductor Pentacene and can find applications in molecular thin film devices. In this work, a theoretical study of Perfluoropentacene was carried out based on density functional theory (DFT) and time dependent (TD-DFT) as implemented in Gaussian 09 package using B3LYP/6-311++G (d, p) and B3LYP/6-31+G(d) basis sets. The electronic, charge transfer, Linear and nonlinear optical properties of the molecule were calculated and reported for the neutral, anionic, and cationic forms of the molecule. The results show that the cationic state of the molecule has the strongest bond length at R(28,32) using the basis sets B3LYP/6-311++G (d,p) and the weakest bond length was found at R(4,6) in the ionic state with 6-31+G (d) basis set. The energy gap obtained for the neutral molecule using 6-31+G (d) and 6-311++G (d,p) basis sets are 2.00eV, 1.99eV respectively. The results show a strong agreement with a previously related work that reported the energy gap as 2.02eV thus indicating high stability of the molecule. Perfluoropentacene has the highest value of chemical hardness of 1.3929eV in its anionic state (Beta MO), so is considered to be harder and more stable than the neutral and cationic. The findings also revealed that with toluene as solvent, the strongest absorption was found at wavelength of 738.38, highest oscillator strength of 0.0599 and the lowest excitation energy of 1.6791eV. The calculated results of polarizability, first and second hyperpolarizability confirm that this molecule is a good non-linear optical material. On the whole, the molecule could be a good material for optoelectronic applications.

The impact of the nitrogen atom on the optoelectronic, nonlinear optical, and thermodynamic properties of graphene quantum dots derived from dibenzocoronene: A DFT investigation

Because of their potential applications in electricity and photonics, graphene quantum dots (GQDs) with intriguing physical characteristics have attracted a lot of attention. Here we use density functional theory (DFT) with the B3LYP functional associated with the 6–31++G(d,p) basis to explore the effect of the nitrogen atom on the optoelectronic, nonlinear optical, and thermodynamic properties of dibenzocoronene (DBC) isomers. The pristine molecules of the DBC isomers have HOMO-LUMO energy gaps of 3.39 eV (DBCa), 3.39 eV (DBCb) and 3.65 eV (DBCc). Inserting a nitrogen atom into the DBC molecular structure considerably reduces the energy gap between these two orbitals. The materials thus obtained after nitrogen doping are DBCa-N, DBCb-N, and DBCc-N and have respective gap energies of 2.05, 1.80, and 1.65 eV (in other words, less than 3 eV). It can therefore be deduced that the compounds studied will be used as semiconductors in electronics. The static polarizabilities α of the N-doped DBC isomers obtained are 442.960, 443.523, and 455.657 au, respectively, each of these values being 4 times higher than that of the organic reference molecule for non-linear optical properties (para-nitroaniline pNA α = 114.7 au), while the first-order hyperpolarizabilities β obtained are 2689.838, 5572.137, and 12717.472 au, respectively. These values are approximately 2.5, 5, and 12 times higher than those of para-nitroaniline (β = 1072.44 au). Our results confirm that the investigated DBC nitrogen derivatives are good non-linear optical materials for photonics, data storage, dynamic imaging, optical signal processing, and computer systems. All the calculated thermodynamic properties show that the proposed molecules can be easily produced. This manuscript thus stands out as a good compass in the rational design of organic semiconductors for efficient electronic devices.

Preparation of amorphous silicon-doped Y2O3 aerogel enabling nonlinear optical features for ultrafast photonics

Abstract Amorphous aerogels with the microscopic nanoscale three-dimensional meshes provide superb platforms for investigating unique physicochemical properties. In order to enhance the physical, thermal and mechanical performances, one efficient and common approach is integrating diverse functional materials. Herein, we report a simple strategy to fabricate the amorphous silicon doped Y2O3 aerogels with the post-gelation method under the N2/EtOH supercritical atmosphere. The impact of Si concentration on the nonlinear optical properties is investigated for the first time. The maximum modulation depth is 1.65 % with a saturation intensity of 0.78 MW cm−2 with the 1-ps laser excitation at 1590 nm. Finally, we incorporated the silicon-doped Y2O3 aerogel based saturable absorber (SA) into an erbium-doped fiber laser (EDFL) and achieved various mode-locking operations at different wavelengths in the super C band, in terms of the conventional soliton, harmonic soliton molecules pulses, and dual-wavelength soliton mode-locking. Overall, this work confirms that amorphous silicon-doped Y2O3 aerogels are good nonlinear optical materials and pave a way for the ultrafast photonic and nonlinear optical applications with amorphous materials in near future.

Deciphering ethynyl single crystal for NLO applications: Synergistic studies on the structural, Hirshfeld surface, photophysical and DFT assessment

In this contribution, we have integrated multiple approaches in investigating the profiles and behaviour of simple ethynyl derivative, 1-[4-(4-(dimethylaminophenyl)ethynyl)phenyl]ethanone (4DME) tolane which is known to be integrated widely in molecular electronics as conjugated building block in functional molecules. Prepared via simplified aerobic Sonogashira cross-couping reaction, symmetrical chromophore of 4DME crystallizes in monoclinic with complex framework containing the space group of P21/n and includes four molecules within a unit cell. The fingerprint plots and Hirshfeld surface analyses demonstrate the presence of synergism between molecules supporting nonlinear optical response of the compound. It was shown that C⋯H contact (44.5 %) is the major contribution of intermolecular interaction executed by Hirshfeld surface area. The investigation on their spectroscopic, thermal analysis and density functional theory (DFT) analysis operating under B3LYP/6-31G (d,p) were conducted to determine the energies of the LUMO and HOMO level, NLO behaviour, intermolecular charge transport facilitated by global chemical reactivity descriptors, molecular electrostatic potentials (MEP) and hyperpolarizability analyses. From the simulated DFT calculation, it shows that 4DME has good polarizability properties with HOMO-LUMO energy gap of 3.89 eV. Calculated total first hyperpolarizability βtot of 4DME were 1261.40 × 10−30 esu which can be potentially applied as good nonlinear optical materials. The preliminary outcomes prove that this simple ethynyl derivative is capable of being used in optoelectronic industry as NLO-based products. A CW diode laser operating at 532 nm wavelength was used to perform the Z-scan measurements and 4DME showed an effective value of χ(3) in order of 10−6, indicating good nonlinear properties.

Enhancement of nonlinear optical properties of nanocarbon cluster C60 by aluminum doping

AbstractThe search for good nonlinear optical (NLO) materials is of utmost importance in laser technology and optical information science, making it a popular research topic in materials science. It is reported that the introduction of alkali metal Li can enhance the NLO properties of nanocarbon materials. Here, metal Al, which exhibits similar electron transfer characteristics to Li, was used for the first time to enhance the NLO properties of nanocarbon cluster C60, which possesses a large delocalized π structure and the highest yield in the fullerene family. Density functional theory calculations in combination with Boltzmann distribution showed that the most thermodynamically stable Al@Ih(1812)‐C60 exhibited good second‐order NLO properties, which originated from the noncentrosymmetry geometry and one extra delocalized electron on Ih(1812)‐C60 from the 3p shell of inner Al. Density of state analysis indicated that the molecular orbitals of Al@Ih(1812)‐C60 were primarily formed by Ih(1812)‐C60 with minimal Al participation, and the presence of Al always resulted in an antibonding orbital effect. Bond critical point and electron localization function analyses indicated almost no covalent interaction between Al and Ih(1812)‐C60. Exohedral functionalization was employed to further stabilize Al@Ih(1812)‐C60 with radical character, and the infrared spectrum was also analyzed in detail. This study has promising implications for expanding the potential applications of fullerenes in optical devices.

Efficient Approach for the Synthesis of Aryl Vinyl Ketones and Its Synthetic Application to Mimosifoliol with DFT and Autodocking Studies.

An efficient and elegant method was developed for the preparation of substituted phenyl vinyl ketones using low-cost and commercially available ethyl chloroformate and diisopropylethylamine as reagents. This methodology was also applied to the synthesis of natural products such as mimosifoliol and quinolines. Frontier molecular orbital (FMO) studies on mimosifoliol were carried out to understand its chemical reactivity. Electron localization function (ELF) and localized orbital locator (LOL) analysis gave information about localized and delocalized electrons. Reduced density gradient (RDG) analysis gave information on steric, van der Waals, and hydrogen-bonding interactions. Molecular electrostatic potential (MEP) and Fukui functions gave information about nucleophilic and electrophilic attack. Nonlinear optical (NLO) analysis represented the mimosifoliol good NLO material. Molecular docking showed that the mimosifoliol compound had effectively inhibited the aspulvinone dimethylallyltransferase enzyme.

Direction dependent crystalline perfection, Z-scan studies and fabrication of Type-I and Type-II SHG elements using imidazolium L-tartrate crystals for optical modulator applications

Monoclinic phase (P21) imidazolium l-tartrate (IMLT) has received considerable research interest because of its wide transparency range, good SHG efficiency and phase matchable non-linear optical (NLO) materials. Organic single crystals of IMLT have been grown via a slow cooling method. The grown crystals were oriented using powder X-ray diffraction. The quality of the grown crystals was evaluated using HRXRD studies. Polarized Raman spectroscopy was carried out on b-cut and c-cut IMLT wafers. The third order NLO characteristics of the <1 0 0>, <0 1 0> and <0 0 1> orientated IMLT crystals have been studied using Z-scan measurements with a Hi-Ne laser (632.8 nm). The second-harmonic generation (SHG) intensity was measured for the powdered grown crystals with various particle sizes to explore the second order NLO properties and phase matchability in the crystals. Furthermore, the type-I and type-II phase-matching angle of the XY and XZ (θ <Ω) planes were calculated.

Effects of Mono-Halogen-Substitution on the Electronic and Non-Linear Optical Properties of Poly(3-hexylthiophene-2,5-diyl) for Solar Cell Applications: A DFT Approach

Poly(3-hexylthiophene-2,5-diyl) with the acronym P3HT and its derivatives are p-type conjugated semiconductor polymers that have been proved to be good organic semiconductors. They have several applications in many areas, such as photovoltaic systems, organic light-emitting diodes, and so on. The instability of organic molecules under ambient conditions is one factor deterring the commercialization of such organic semiconductor devices. Here we present a theoretical study using density functional theory (DFT) approach with Gaussian 09 and GaussView 5.0, to investigate the effects of halogens (Bromine, Chlorine, Fluorine and Iodine) on the electronic and nonlinear optical properties of poly(3-hexylthiophene-2,5-diyl) (P3HT). This is to enable us to address the issue of instability in the molecule. The bond lengths and bond angles of the mono-halogenated molecules were found to be less than that of the isolated Poly(3-hexylthiophene-2,5-diyl). Iodine doped P3HT was found to be the most stable amongst the studied molecule for having the least bond angles and bond lengths. The calculated band gap for iodine doped P3HT and fluorine doped P3HT were observed to have the lowest energy gap of 3.519 eV and 3.545 eV respectively thus proving that iodine doped P3H is the most stable and this makes it more suitable for photovoltaic applications. The molecule with the highest value of chemical hardness was obtained to be the isolated P3HT with a chemical hardness of 1.937eV. This is followed by bromine doped P3HT, chlorine doped P3HT, fluorine doped P3HT and iodine doped P3HT with values as 1.925 eV, 1.813 eV, 1.773 eV, and 1.7595 eV respectively. All the substituted molecules results were found to be more reactive than their isolated form for having lower values of chemical hardness. The results for the nonlinear optical (NLO) properties show that the first-order hyper-polarizability of chlorine doped P3HT and iodine doped P3HT as and respectively were found to be about eight times more than that of the urea value (0.3728 x10-30 esu), which is commonly used for the comparison of NLO properties with other materials. This makes them very good NLO materials. The open circuit voltage was also calculated. The highest values of the calculated open circuit voltage were found to be (PCBM C60) in chloroP3HT and 1.3134 eV (PCBM C60) in flouroP3HT. The results of the IR frequency show that the doped molecules are more stable than the isolated molecule. Zero-point vibrational energy (ZPVE), total entropy (S) and molar heat capacity (Cv) were also calculated and presented. We also observe that the entropy and heat capacity of the doped materials are higher than those of the original molecule, which confirms that the charge dynamics of the doped molecules are higher than those of the original molecule at the same temperature. This result further demonstrates that these doped materials have a high chemical reactivity and a high thermal resistivity, hence their application in the fields of organic electronics. By and large the overall results confirm that there is a good electron transfer within the doped molecules which makes them have potential applications in photovoltaic devices.

Crystal structure, intermolecular interactions and NLO properties for imidazolium hydrogen sulfate ionic liquid

Crystal structure, intermolecular interactions and nonlinear optical behavior for the ionic liquid imidazolium hydrogen sulfate (ImHS) were presented in the current paper for the first time. This was achieved applying a combined experimental (single crystal X-ray diffraction) and theoretical (Quantum theory of atoms in molecules (QTAM), Hirshfeld surface (HS), natural bond orbital (NBO) analysis) method. The quantum chemical calculations were conducted via density functional theory at B3LYP/6–311++G(2d,2p) level. Important nonlinear optical parameters such as dipole moment (μ), polarizability (α), anisotropy of polarizability (∆α) and first-order hyperpolarizability (β) are calculated at B3LYP/6–311++G(2d,2p) level of theory as well.It was shown that fragments with different molecular geometry present in the ImHS structure. Formation of hydrogen bonds (O···H) between the imidazolium cation and hydrogen sulfate anion stabilizes the ImHS structure. It was confirmed by means of QTAM, HS and NBO, where intensive electron density distribution between aromatic ring and inorganic anion due to O···H interactions was registered. Pronounced charge transfers between imidazolium cycle and hydrogen sulfate anion were found to be responsible for highly polarizable nature of ImHS, registered as high values for μ, α and β. Based on these, the studied ionic liquid was denoted as a good nonlinear optical material.

Impact of L-Leucine on the structural and optical properties of potassium dihydrogen phosphate (KDP) crystals

IntroductionPotassium Dihydrogen Phosphate (KDP) is an exceptionally good non-linear optical (NLO) material used for optoelectronics, electro-optics, etc. The inclusion of amino acids enhances the properties of KDP because amino acids have properties like molecular chirality and zwitterionic nature. ObjectiveIn this study, our primary goal was to describe the effects of L-Leucine doping on KDP and to study the changes in its optical and structural properties for different applications related to non-linear optics. MethodsPure KDP and L-Leucine doped KDP (1 mol% and 2 mol%) crystals were grown using the slow evaporation method at room temperature. The crystals have been characterized using Powder X-ray Diffraction (XRD), Fourier Transform Infrared (FT-IR) Spectroscopy, Ultraviolet-Visible (UV-Vis) Spectroscopy, Photoluminescence (PL) Spectroscopy and Relative Second Harmonic Generation (SHG) measurement. ResultThe FTIR spectroscopy confirms the presence of amino acid, L-Leucine in KDP as implied by functional groups. The UV-Vis spectroscopy helps with the optical transparency of crystals and the bandgap of pure KDP was observed to be enhanced with the addition of L-Leucine. The PL spectra confirm the existence of point defects in the grown crystals. Furthermore, L-Leucine doping in KDP improves its relative SHG efficiency. ConclusionIt has been seen those optical properties of pure KDP is immensely improved with the addition of L-Leucine without altering the KDP lattice.

High-Temperature and Large-Polarization Ferroelectric with Second Harmonic Generation Response in a Novel Crown Ether Clathrate.

Molecular ferroelectrics of high-temperature reversible phase transitions are very rare and have attracted increasing attention in recent years. In this paper is described the successful synthesis of a novel high-temperature host-guest inclusion ferroelectric: [(C6 H5 NF3 )(18-crown-6)][BF4 ] (1) that shows a pair of reversible peaks at 348 K (heating) and 331 K (cooling) with a heat hysteresis about 17 K by differential scanning calorimetry measurements, thus indicating that 1 undergoes a reversible structural phase transition. Variable-temperature PXRD and temperature-dependent dielectric measurements further prove the phase-transition behavior of 1. The second harmonic response demonstrates that 1 belongs to a non-centrosymmetric space group at room temperature and is a good nonlinear optical material. In its semiconducting properties, 1 shows a wide optical band gap of about 4.43 eV that comes chiefly from the C, H and O atoms of the crystals. In particular, the ferroelectric measurements of 1 exhibit a typical polarization-electric hysteresis loop with a large spontaneous polarization (Ps ) of about 4.06 μC/cm2 . This finding offers an alternative pathway for designing new ferroelectric-dielectric and nonlinear optical materials and related physical properties in organic-inorganic and other hybrid crystals.

A density functional theory (DFT) study of the doping effect on 4-[2-(2-N, N-dihydroxy amino thiophene) vinyl] benzenamine

In the present work, density functional theory was used at the B3LYP, CAM-B3LYP and B3PW91 levels with the 6–311 + + G (d, p) basis set, in other to study the structural, optoelectronic, nonlinear optical, piezoelectric and thermodynamic properties of 4-[2-(2-N, N-dihydroxy amino thiophene) vinyl] benzenamine (DATVB) molecule doped with chlorine and fluorine respectively. The results obtained show that doping significantly improves the properties of this material. The materials obtained after doping 4-[2-(2-(5-(bis (chlorooxy) amino) thiophene) vinyl] benzenamine (BCATVB) and 4-[2-(2-(5-(bis (fluorooxy) amino) thiophene) vinyl] benzenamine (BFATVB) are good semiconductors because their gap energy is range between 1 and 1.5 eV which is less than 3 ev. Their first order hyperpolarizabilities ({beta }_{mol}) are very high compared to para-nitroaniline (p-NA) known as reference molecule for nonlinear optical properties. The obtained results predisposes them as good nonlinear optical materials with applications in photonics, optical signal processing devices, dynamic imaging, data storage and computer devices. The piezoelectric and pyroelectric coefficients of the fluorinated molecule are higher than those of the reference organic molecule polyvinylidene fluoride. This led us to the conclusion that, these molecules can also be used for applications in piezoelectricity.

Suzuki–Miyaura Reactions of (4-bromophenyl)-4,6-dichloropyrimidine through Commercially Available Palladium Catalyst: Synthesis, Optimization and Their Structural Aspects Identification through Computational Studies

5-(4-bromophenyl)-4,6-dichloropyrimidine was arylated with several aryl/heteroaryl boronic acids via the Suzuki cross-coupling reaction by using Pd(0) catalyst to yield novel pyrimidine analogs (3a-h). It was optimized so that good yields were obtained when 5 mol % Pd(PPh3)4 was used along with K3PO4 and 1,4-Dioxane. Electron-rich boronic acids were succeeded to produce good yields of products. Density functional theory (DFT) calculations were also applied on these new compounds to analyze their reactivity descriptors and electronic and structural relationship. According to DFT studies, compound 3f is the most reactive one, while 3g is the most stable one. As per DFT studies, the hyperpolarizability (β) values of these compounds do not show them as very good non-linear optical (NLO) materials. Compound 3f has the highest β value among all the compounds under study but still it is not high enough to render it a potent NLO material.

NLO response as a function of structural water presence: A comparative experimental (UV-vis) and DFT (structural, NPA, MEP) study on Cs2Ni(SeO4)2•4H2O and Cs2Ni(SeO4)2

A comparative experimental (UV–vis) and theoretical (DFT) study on the nonlinear optical (NLO) response of the double salts Cs2Ni(SeO4)2•4H2O and Cs2Ni(SeO4)2 is presented in the current paper. For that purpose, a detailed analysis on the electronic absorption behavior of the compounds under investigation in the range from 200 to 1100 nm is conducted. The position of the experimentally registered electronic transitions is compared with that of the corresponding theoretical ones (calculated by means of DFT at B3LYP/6–311+G(d,p) level of theory). A time-dependent variant of DFT is applied to calculate the oscillator strengths and absorption maxima. Moreover, structural parameters, net atomic charges and molecular electrostatic potential surface are accomplished at B3LYP/6–311+G(d,p) level of theory as well.Results showed that the NLO response depends strongly on the structural water presence. Hence, the ionic salt Cs2Ni(SeO4)2•4H2O is a good NLO material in the middle ultraviolet (MUV), near ultraviolet (NUV) and near infrared (NIR) regions, while MUV and NUV areas characterize Cs2Ni(SeO4)2. However, it was revealed that Cs2Ni(SeO4)2 possesses considerably better NLO properties within 200–400 nm than Cs2Ni(SeO4)2•4H2O. These findings were related to a different electron density rearrangement in the Cs2Ni(SeO4)2•4H2O and Cs2Ni(SeO4)2, a consequence of the metal-oxygen interactions strength.

The structure-property studies and mechanism of optical limiting action of methyl 4-((4-aminophenyl)ethynyl)benzoate crystal under continuous wave laser excitation

This study focuses on the design of the new dye of donor-π-acceptor (D−π−A) system of methyl 4-((4-aminophenyl)ethynyl)benzoate (MAPEB) to highlight its structural-property relation through a combined experimental and quantum chemical calculation approaches for optical limiting applications. MAPEB was synthesized via aerobic condition palladium-catalysed Sonogashira cross-coupling reaction with good yield. This molecular structure was confirmed by single crystal X-ray crystallographic analysis and the crystal exhibits monoclinic non-centrosymmetric space group of Pc. The existence of intermolecular interactions was confirmed by Hirshfeld analysis, showing high contribution of C⋯H contact which suggested the high nonlinear optical response of the compound. The experimental spectroscopic data including Fourier Transform Infrared (FT-IR), 1H and 13C Nuclear Magnetic Resonance, electronic absorption spectra, HOMO-LUMO energy gap were compared with Density Functional Theory (DFT) at 6–311++G (d,p) basis set. The experimental results complement the theoretical findings in supporting anticipated electronic properties of the molecule. Additionally, the z-scan analysis unveils an excellent value of χ3 of MAPEB in the order of 10−6 esu which indicate good nonlinear optical material under 532 nm continuous wave laser. Low optical limiting action was measured at 110 kW/cm2 which is suitable for various continuous wave laser applications. These findings prove that MAPEB has the potential to be employed as NLO materials for photonic applications.

Orange-Red Fluorescent (Partially Rigidified) Donor-π-(rigidified)-Acceptor System - Computational Studies.

D-π-A chromophore derived coumarins are studied using "DFT and TD-DFT" to compute vertical excitation as well as NLO properties using "global hybrid" (GH) functionals B3LYP and BHandHLYP and "range separated hybrid" (RSH) functionals CAM B3LY', wB97, wB97X, and wB97XD with basis set 6-311++G(d,p) and "correlation consistence polarized valence double and triple zeta" cc-pVDZ and cc-pVTZ respectively in the gas phase and two solvents, N,N-Dimethylformamide (DMF) and ethyl acetate (EA). The trends in absorption and emission values calculated by TD-DFT using all the above mentioned functional and basis sets were studied and it was observed that the trends seen in the computed parameters using B3LYP, BHandHLYP and CAM B3LYP are in good agreement with the trends in experimental values. DFT calculations were performed to determine "static dipole moment" (μ), "linear polarizability" (α), "first order hyperpolarizability" (β0), "second order hyperpolarizability" (γ). We have calculated the mean average errors in dipole moment, linear polarizability, first and second hyperpolarizability and vertical excitation. We have observed large values of 'first order hyperpolarizability' (301-938 × 10^-30 e.s.u) and 'second order hyperpolarizability' (684-2498 × 10^-34) and they can act as good nonlinear optical materials. Also, vibrational contribution indicates the red shifted absorption and emission in 2c. They show higher values of electrophilicity index which indicates the stability and reactivity of molecules.

Nonlinear optical properties of single crystal of L-OOMHCL incorporation with Glycine Oxalic Acid (GOA) with high chemical stability for optoelectronic applications

In this report, a good nonlinear optical material with high criteria such as optical nonlinearity, chemical and thermal stability for life time system capability. The crystallographic orientation belongs to monoclinic crystal structure with the non-centrosymmetric space group, the prominent peaks were observed as (101), (112) and (300). The calculated lattice parameter values are, a = 6.21 Å, b = 3.67 Å, c = 12.12 Å, α = 90°, β = 103.21°, γ = 90° monoclinic space group of P21/n. A broad and strong peak at 3427 cm−1 was assigned to NH stretch, the OH and CH stretching of the compound were confirmed by the peaks present at 3043 cm−1 and 2934 cm−1. Moreover, the peaks at 1398 cm−1 represent the tartaric acid, another strong peak at 1261 cm−1 was assigned to CH2 twisting. In addition, the DTA curve shows a sharp endothermic peak at 109 °C, which corresponds to the melting point of the compound at this stage the sample lost its 20% of weights due to dehydration. From TGA curve, the L-OOMHCL crystal has good thermal stability up to melting point as there is no major weight loss below that temperature. However, it shows the more weight loss of 95% after the melting point due to the removal of volatile substances. Thus, it confirms the full degradation around 600 °C. The dielectric constant and the dielectric loss of L-OOMHCL crystal were carried out at three different temperatures 313 K, (40 °C) 333 K (60 °C) and 353 K (80 °C) for frequencies varying from 50 Hz to 5 MHz. Finally, we have calculated the refractive index value at the cutoff wavelength 214 nm and the 2.012 which is larger than unity, this results in greater development of polarization in the presence of dc electrical fields, hence leading to greater mobility.

Nonlinear optical properties of tungsten disulfide as saturable absorber based on Q-switched fiber laser

In this paper, nonlinear optical properties of tungsten disulfide are studied. Tungsten disulfide (WS2) is prepared as saturable absorber (SA) with the microstructured optical fiber. When the SA based on WS2 is assembled into a fiber laser, Q-switched operation is demonstrated. The 2 nm spectral width is obtained at the central wavelength of 1531 nm. The signal-to-noise ratio is about 80 dB, which indicates that the fiber laser is very stable. The shortest pulse duration is 800 nm at the maximum input power of 650 mW. The conclusion shows that WS2 is a good nonlinear optical material.

Synthesis and characterization of a metal-organic NLO material: Tetrakis(thiourea)cobalt chloride

We investigate the growth of the hybrid complex tetrakis(thiourea)cobalt chloride (TTCoC) from an aqueous solution of thiourea and cobalt chloride through a slow evaporation method that yields good-quality crystals. Different analyses confirmed that TTCoC crystal is a good nonlinear optical material. The crystal system and parameters were determined by X-ray diffraction analysis, which showed that the crystals crystallize in the tetragonal system with non-centrosymmetric space group P42/n. Within this structure, each Co2+ ion is bordered by four sulfur atoms and two chlorine atoms, which allows it to adopt an octahedral coordination geometry. The functional groups in the complex were confirmed by Fourier transform IR spectroscopy. Furthermore, the percentages of the different elements present in this compound were identified through energy-dispersive X-ray analysis. The UV–visible spectrum confirmed that TTCoC crystal has transmittance as high as 59.6%. The optical band gap energy of TTCoC was obtained from the Tauc plot of (αhν)2 versus hν. Its value is equal to 4.6 eV. Thermogravimetric analysis and differential scanning calorimetry revealed stability up to around 110 °C. The nonlinear optical properties of the crystal were studied by the Kurtz-Perry technique, and the efficiency of its second harmonic generation was found to be equal to that of potassium dihydrogen phosphate single crystal. This result was confirmed by theoretical calculations of the polarizability and the first hyperpolarizability. To determine the closest contacts within the crystal, Hirshfeld surface analysis was performed. Finally, according to the fingerprint plots, we can attribute the dominant interaction present within the structure to hydrogen bonds.