Order Nonlinear Optical Material Research Articles

Crystal growth, dielectric studies, charge transfer and ionic hydrogen-bonding interactions of L-arginine hydrobromide monohydrate single crystal: A novel third order nonlinear optical material for optoelectronic applications

DFT computations supported by B3LYP/cc-pVTZ level theory have been employed to derive equilibrium geometry, vibrational wavenumbers and the hyperpolarizability values of the nonlinear optical (NLO) material L-Arginine Hydrobromide monohydrate (LAHBr). Changes in the atomic charge distribution among different groups due to the presence of strong electronegative atoms and the attenuation of O-H bonds of water molecule have been analyzed. H-bonding effects of LAHBr are examined with the aid of structural analysis, IR, Raman vibrations and NBO analysis. The occurrence of strong intra- and intermolecular NH⋯O, NH⋯Br and OH⋯O ionic hydrogen bonding and non-bonded interactions in making the LAHBr unit NLO active has been discussed. The charge transport mechanism is analyzed by using dielectric measurements and the obtained results suggest good quality of the crystal.

Growth and characterization of a new chlorine substituted chalcone: A third order nonlinear optical material

In this present study, the structural, molecular, electronic, thermal studies, and the nonlinear optical (NLO) properties of a newly synthesized chalcone derivative 3-(2-chloro-phenyl)-1-[3-(2-oxo-2-phenyl-ethoxy)-phenyl]-propan-1-one (CPPO) were performed. The molecular structure of titled compound was described by single crystal X-ray diffraction, nuclear magnetic resonance spectroscopy (1H and 13C NMR) and thermal analysis (TGA-DTG analysis). The supramolecular arrangement in solid state was confirmed by Hirshfeld surface analysis and 2D-fingerprint plots. The CPPO compound was crystallized on non-centrosymmetric monoclinic space group P21 and the supermolecule approach (SM) at DFT/CAM-B3LYP/6-311++G(d,p) level was used to analyze the nonlinear optical properties in crystalline environment. The total moment of dipole, the averages of linear polarizability α(−ω;ω) and first and second hyperpolarizabilities, linear refractive index and the third-order nonlinear susceptibility (χ(3)) were calculated as function of the electric field frequency. The χ(3)-value of the CPPO crystal at 532 nm is 266 times greater than the experimental result of organic crystal (2E)-1-(3-bromophenyl)-3-[4(methylsulfanyl)phenyl]prop-2-en-1-one [1], demonstrating that CPPO crystal has good potential for use as NLO material.

Growth and characterization of L-histidinium fumarate fumaric acid monohydrate single crystal: A promising second and third order nonlinear optical material

L-histidinium Fumarate Fumaric acid Monohydrate (LHFFAM), an organic nonlinear optical single crystal[C14H19N3O11], has been synthesized and grown using aqueous solution by slow evaporation technique at room temperature. Crystal structure details were obtained from single crystal XRD. The coordination of functional groups was identified in the grown crystal by FTIR analysis. The UV-absorption studies evince the transparent nature of the crystal is in the visible region and the optical band gap energy Eg was evaluated. The TG/DSC analyses confirm the thermal stability for the as-grown crystal. The Vickers microhardness test was carried out on the grown crystals and there by Vickers hardness number (Hv), work hardening coefficient (n), yield strength (σy), stiffness constant C11 were evaluated. The dielectric behaviour of LHFFAM has been determined in the frequency range 50 Hz to 5 MHz at various temperatures. Kurtz-Perry and Z-scan techniques were performed for the acentric crystal LHFFAM which highlighted good nonlinear response and hence proves it appropriate for frequency conversion process and photonic device fabrications.

Donor-π-Acceptor-π-Donor class of 2,5-dibenzylidenecyclopentan-1-one analogues as efficient third order nonlinear optical and photoluminescent materials – An experimental investigation

In the present work, nonlinear optical (NLO) and optoelectronic investigations of four 2,5-dibenzylidenecyclopentan-1-one (bischalcone) analogues 1 (4-F), 2(4-Cl), 3(4-Br) and 4(3-NO2) with push-pull substituents (Donor-π-Acceptor-π-Donor) are studied. The third-order nonlinear optical measurements of bischalcone analogues carried out by Z-scan technique, which revealed that these compounds possess strong third-order nonlinear absorption (NLA), negative nonlinear refraction (NLR) and optical limiting behaviour under the illumination at 532 nm continuous wave laser beam (200 mW). The magnitude of third order NLA coefficient β, NLR index n2, and effective susceptibility χ(3) are found to be in the order of 10−5 cm/W, 10−12 cm2/W, and 10−7 e.s.u respectively. The β value varied with substitution at the phenyl ring which contributed immensely on the variation. Even though the deactivating effect of 4-F, 4-Cl, 4-Br and 3-NO2 groups contributed on polarization, the presence of electron rich cyclopentanone ring ameliorated the effect of deactivation. Hence these molecules are found to possess moderate NLA and NLR properties. In addition, photoluminescence activity of these flourophores(1–4) is observed as emission spectra in the range of 307–554 nm on shining at 279 nm with relative quantum yield of 1.81%, 3.8%, 1.62% and 0.89% respectively with reference to tryptophan. The HOMO-LUMO analysis for optical band gap ranged between 2.89 eV and 3.13 eV indicating polarizing nature varied with substituents.

Synthesis, growth and characterization of a long-chain π-conjugation based methoxy chalcone derivative single crystal; a third order nonlinear optical material for optical limiting applications

Organic material (chalcone derivative 4-[(1E)-3-(4-methoxyphenyl)-3-oxoprop-1-en-1-yl]phenyl 4-methylbenzene-1-sulfonate {4MPMS}) has been grown by solvent evaporation technique. The structural properties have been carried out by powder XRD and single crystal XRD data. The linear optical properties (band gap, extinction co-efficient, optical conductivity and complex dielectric constant) were studied by UV-VIS-NIR spectrometer. In addition, defect states were identified and analyzed by creation of color center mechanism using photoluminescence spectroscopy. In Thermal analysis, crystal (4MPMS) is found to be stable up to 158 °C. Hence it may be used for the fabrication of device below the melting point. The electrical properties (dielectric constant and dielectric loss factor) have been carried out. The electronic polarizability is the major contribution for the high frequency dielectric constant values. Therefore, using theoretical aspects, the electronic polarizability values were calculated using Clausius–Mossotti relation as well as band structure approach of Penn model. Laser damage threshold for 4MPMS crystal was determined by using Nd:YAG laser with 532 nm. The nonlinear optical absorption coefficient and third order nonlinear optical susceptibility (χ(3)) values are reasonably larger than those of the other chalcone derivative crystals. High second order molecular hyperpolarizability enhances the third order optical nonlinear efficiency. Increased χ(3) and coupling factor (less than 1/3) indicates that the optical nonlinearity is electronic in origin. The behavior of nonlinear optical absorption curve confirms that the mechanism belongs to reverse saturable absorption (RSA).

Studies on structure, NLO properties of a new organic NLO crystal: guanidinium 3,5-dihydroxybenzoate

A new organic nonlinear optical (NLO) crystal, guanidinium 3,5-dihydroxybenzoate (GDH), was synthesized and grown by solvent evaporation technique. The crystal structure was determined by single crystal X-ray diffraction. Noncovalent interaction analysis and molecular electrostatic potential analysis were conducted which found the structure is stabilized by strong hydrogen bond network, π–π interaction, and electrostatic interactions. The obtained GDH crystal was characterized by using FTIR, Raman, UV–Vis-NIR spectra, TG/DTA, and DSC. GDH crystal shows good transparency of about 95% in the entire NIR region. Furthermore, systematic theoretical DFT calculations at B3LYP level including HOMO–LUMO analysis, static polarizability, and hyperpolarizability density analysis were carried out. The results suggest that GDH crystal is a promising third order NLO material.

Growth and Optical, Mechanical, Electrical Behaviour of Zinc Formate Dihydrate Single Crystal: A Third Order Nonlinear Optical Material

Optically good quality single crystals of Zinc Formate Dihydrate (ZFD) were grown by slow evaporation technique. The grown crystals were characterized by various characterization techniques such as single crystal XRD, FT-IR, UV-Vis, dielectric, microhardness and Z-scan studies. The monoclinic crystal system of the grown crystal was confirmed by Single crystal X-ray Diffraction analysis. The functional groups present in the crystal were identified by FT-IR analysis. The transparency of the crystal was identified using UV-Vis spectral studies. Dielectric studies were measured for the crystal from 50 Hz to 5 MHz at room temperature. Mechanical behaviour of the crystal was measured using Vickers microhardness tester and this study confirms that the grown crystal belongs to soft material category. The nonlinear absorption coefficient (β), nonlinear refractive index (n2) and third harmonic generation studies were also carried out for the title crystal.

Growth, effect of protonation and hydrogen bonding interactions of L-Histidine nitrate monohydrate, a potential semi organic third order nonlinear optical material

Single crystal of l-Histidine Nitrate monohydrate (LHNM) has been grown from aqueous solution by evaporation technique. A comprehensive investigation of the NIR FT-Raman and FT-IR spectra was carried out with the aid of normal coordinate analysis following the scaled quantum mechanical force field methodology supported by the density functional theory (DFT) computations to analyze the effects of intramolecular charge transfer on the geometries and the vibrational modes contributing to the linear electro-optic effect of the organic NLO material. Effect of protonation and hydrogen bonding interactions has been analyzed using structural analysis, natural bond orbital analysis, and spectral analysis. The HOMO-LUMO energy gap value suggests the possibility of charge transfer within the molecule. Hyperconjugative interactions responsible for second hyperpolarizabilities have been described by NBO and AIM analyses. Hirshfeld surface analysis reveals that the van der Waals H⋯H (32.3%) contact plays a significant role in crystal packing and that a variety of NH⋯O intermolecular contacts and hydrogen bonds leads to the formation of intermolecular charge transfer occurring in LHNM. The nonlinear refractive index (n2), nonlinear absorption coefficient (β) and third-order nonlinear susceptibility (χ3) of LHNM have been determined by Z-scan technique, which points to its potential application in the field of optical limiting. The calculated value of laser damage threshold was 2.04 GW/cm2.

Synthesis Growth, structural, optical, SHG and characterization a new organic potential novel material Z-scan studies third order nonlinear optical material on single crystal of N-(tert-butyl)-2

Synthesis Growth, structural, optical, SHG and characterization a new organic potential novel material Z-scan studies third order nonlinear optical material on single crystal of N-(tert-butyl)-2

Growth and characterization of L-phenylalanine nitric acid (LPN) and tris L-(phenylalanine)-phenylalanininum nitrate (TPLPN) as second and third order nonlinear optical materials

We synthesized noncentrosymmetric single crystals of L-phenylalanine nitrate (LPN) and tris L-(phenylalanine) L-phenylalaninium nitrate (TPLPN) by slow solvent evaporation technique. Both crystallized in monoclinic system with different acentric space groups namely P21 (LPN) and C2 (TPLPN) respectively. The IR and Raman spectral investigation was done for LPN and TPLPN and discussed. The UV-vis-studies accomplished the excitation wavelength of the grown crystals suitable to exhibit second harmonic generation signal. From the absorption data, remarkable optical properties such as direct band gap energy, Urbach energy, extinction coefficient were evaluated. The mechanical strength of the grown crystal was examined by Vickers micro hardness test. The temperature of decomposition was confirmed by TG/DSC analysis. Fluorescence emission spectrum of LPN and TPLPN were recorded and lifetime was also studied. The dielectric constant and dielectric loss of LPN and TPLPN has been determined as a function of frequency and temperature. Also the surface topologies of the crystallized salts were assessed by SEM studies. The third-order nonlinearities of LPN and TPLPN were determined by Z-scan technique with Nd: YAG at 532 nm and thereby from closed and open Z-scan data, third-order susceptibilities were calculated to be χ(3) = 8.826 × 10−6 esu for LPN and χ(3) = 2.552 × 10−7 esu for TPLPN.

Experimental and quantum chemical studies on N[sbnd]H[sbnd][sbnd][sbnd]O hydrogen bonded helical chain type Morpholinium 2-chloro-4-nitrobenzoate: A phasematchable organic nonlinear optical material

We report on the studies performed on Morpholinium 2-chloro-4-nitrobenzoate (M2C4N), a second order nonlinear optical (NLO) material, which has been proved to crystallize with chiral structure as compared to its other two variants. The synthesized powder was studied for its composition, crystalline phase and NLO efficiency and phasematchability. The solubility and the metastable zone width (MSZW) of the title compound were measured for the growth of bulk crystals of M2C4N. A smoky pattern observed in the middle region of the crystals that could prevent it from optical applications was greatly reduced, through suitable modifications in the growth process. The optical properties such as luminescence and laser damage threshold resistance were studied for the bulk crystals whereas the molecular vibrations of M2C4N were studied through Fourier transform infrared (FTIR) and FT-Raman spectral analysis using the polycrystalline powders derived from the single crystals. In addition, quantum chemical studies on M2C4N molecule were performed by using density functional theory (DFT) at the B3LYP/6-311++G (d, p) basis set. These studies showed that the M2C4N is a phasematchable NLO crystal and could be used for device fabrication.

Growth, spectral, optical, laser damage threshold and DFT investigations on 2-amino 4-methyl pyridinium 4-methoxy benzoate (2A4MP4MB): A potential organic third order nonlinear optical material for optoelectronic applications

In present investigation, single crystals of organic charge transfer complex, 2-amino-4-methyl pyridinium-4-methoxy benzoate (2A4MP4MB) was grown by controlled slow evaporation solution growth technique using methanol as a solvent at room temperature. Single crystal XRD analysis confirmed the crystal system and lattice parameters of 2A4MP4MB. The crystalline nature, presence of various vibrational modes and other chemical bonds in the compound have been recognized and confirmed by powder X-ray diffraction, FT-IR and FT-Raman spectroscopic techniques respectively. The presence of various proton and carbon positions in title compound was confirmed using 1H NMR and 13C NMR spectral studies. The wide optical operating window and cut-off wavelength were identified and band gap value of the title compound was calculated using UV-vis-NIR study. The specific heat capacity (cp) values of the title compound, 1.712 J g−1·K−1 at 300 K and 13.6 J g−1 K−1 at 433 K (melting point) were measured using Modulated Differential Scanning Calorimetric studies (MDSC). From Z-scan study, nonlinear refractive index (n2), nonlinear absorption (β) and third order nonlinear susceptibility (χ(3)) values were determined. The self-defocusing effect and saturable absorption behavior of the material were utilized to exhibit the optical limiting action at λ = 532 nm by employing the same continuous wave (cw) Nd: YAG laser source. The laser damage threshold (LDT) study of title compound was carried out using Nd: YAG laser of 532 nm wavelength. The Vickers’ micro hardness test was carried out at room temperature and obtained results were investigated using classical Meyer’s law. In addition, DFT calculations were carried out for the first time for this compound. These characterization studies performed on the title compound planned to probe the valuable and safe region of optical, thermal and mechanical properties to improve efficacy of 2A4MP4MB single crystals in optoelectronic device applications.

Insight on the growth and property studies of inorganic hydrated borate (Na6 [B4O5 (OH)4]3. 8H2O) single crystal – An effective third order nonlinear optical (NLO) material for optical limiting application

A new alkali metal borate with formula Na6 [B4O5 (OH)4]3. 8H2O single crystal has been grown by slow evaporation method under room temperature condition for the first time. The structural analysis reveals that the grown crystal crystallizes in the rhombohedral space group R32 with cell parameters a = 11.27 Å, b = 11.27 Å, c = 21.27 Å and α = β = 90°, γ = 120°. The intermolecular interactions of symmetric stretching of BO3 and asymmetric stretching of BO4 were identified by Fourier-transform infrared spectroscopy (FT-IR). Optical investigation on the hydrated borate shows that the material possessed a high transmittance of about 60% in the entire UV- visible region with an optical absorption edge at 220 nm and the band gap was found to be 4.972 eV. The theoretical calculations were performed in order to find the linear optical constant such as linear absorption coefficient, extinction coefficient and reflectance etc. Thermogravimetric (TG)/Differential scanning calorimetry (DSC) analysis for the grown crystal displayed that the material is stable up to 116 °C and having the melting point of 145 °C. The frequency independent dielectric constant and dielectric loss were performed at different temperature. AC conductivity was studied by means of electrical relaxation process and it is due to the presence of water molecules in the compound. The third order nonlinear susceptibility (χ3), nonlinear refractive index (n2) and the absorption coefficient (β) are found to be in the order of 1.36 × 10−6 esu, 3.88 × 10−8 cm2/W and 0.026 × 10−4 cm/W respectively. The strong optical limiting behaviour of the material could be attributed to the two photon absorption mechanism and negative nonlinearity due to self-defocusing effect.

Experimental and theoretical perspectives on 2-amino 5-bromopyridinium salicylate: a third order nonlinear optical material

Organic charge–transfer complex of 2-amino 5-bromopyridinium salicylate (2A5BPSA) single crystals were grown by slow evaporation solution growth technique using methanol as a solvent. The phases and functional groups of 2A5BPSA have been identified and confirmed through powder X-ray diffraction and Fourier transform infrared. The optical transmittance window and the lower cutoff wavelength of the 2A5BPSA have been identified by UV–Vis–NIR studies. Dielectric studies were carried out for the grown crystals at various temperatures from the frequency ranging from 50 Hz to 5 MHz. Photoconductivity and microhardness studies were also performed for the 2A5BPSA crystal sample. The nonlinear refractive index, nonlinear absorption coefficient have been measured through the Z-scan technique. In addition to that, the quantum chemical calculations on 2A5BPSA have been performed by density functional theory calculations using Hartee–Fock method with HF/6-311++G basis set.

Synthesis, crystal structure, growth, optical and third order nonlinear optical studies of 8HQ2C5N single crystal - An efficient third-order nonlinear optical material

A neoteric organic third order nonlinear optical material 8-hydroxyquinolinium 2-chloro-5-nitrobenzoate dihydrate (8HQ2C5N) was grown by slow cooling technique using ethanol: water (1:1) mixed solvent. The calculated low value of average etch pit solidity (4.12 × 103 cm−2) indicated that the title crystal contain less defects. From the single crystal X-ray diffraction data, it was endowed that 8HQ2C5N crystal belongs to the monoclinic system with centrosymmetric space group P21/c and the cell parameters values, a = 9.6546 (4) Ǻ, b = 7.1637(3) Ǻ, c = 24.3606 (12) Ǻ, α = γ = 90°, β = 92.458(2)° and volume = 1683.29(13) Ǻ3. The FT-IR and FT-Raman spectrum were used to affirm the functional group of the title compound. The chemical structure of 8HQ2C5N was scrutinized by 13C and 1H NMR spectral analysis and thermal stability through the differential scanning calorimetry study. Using optical studies the lower cut-off wavelength and optical band gap of 8HQ2C5N were found to be 364 nm and 3.17 eV respectively. Using the single oscillator model suggested by Wemple – Didomenico, the oscillator energy (Eo), the dispersion energy (Ed) and static dielectric constant (εo) were estimated. The third-order susceptibility were determined as Im χ(3) = 2.51 × 10−5 esu and Re χ(3) = 4.46 × 10−7 esu. The theoretical third-order nonlinear optical susceptibility χ(3) was calculated and the results were compared with experimental value. Photoluminescence spectrum of 8HQ2C5N crystal showed the yellow emission. The crystal had the single shot laser damage threshold of 5.562 GW/cm2. Microhardness measurement showed that 8HQ2C5N belongs to a soft material category.

NLOphoric mono-azo dyes with negative solvatochromism and in-built ESIPT unit from ethyl 1,3-dihydroxy-2-naphthoate: Estimation of excited state dipole moment and pH study

Five mono-azo dyes were synthesized using different diazotized aromatic amines followed by coupling with 1, 3-dihydroxy-2-naphthoate and characterized by proton and carbon NMR and elemental analysis. DFT optimized geometries of all the dyes suggest that dyes are present in the hydrazone form in the ground state and not in the azo form. They showed strong negative absorption solvatochromism and were studied using various solvent polarity scales and multilinear regression analysis using Kamlet – Taft and Catlan scales. Dyes are weakly fluorescent in solvents. Dyes were compared with a parallel series of dyes using 2-naphthol and azo dyes based on benzothiazole unit to investigate the effect of hydroxyl naphthalene ester moiety on the photophysical properties. Solvatochromism was used to calculate the excited state dipole moment, linear and nonlinear optical properties of these dyes. The excited state dipole moments found higher than the ground state dipole moments in case of dye 3a, 3b and 3c while lower than the dyes 3d and 3e respectively. The dyes were also found to be sensitive to pH. Positive and negative values are found for second hyperpolarizability. All these features indicates that present dyes have potential for the advanced applications such as third order nonlinear optical materials.

Growth, optical, thermal, mechanical and dielectric studies of sodium succinate hexahydrate (β phase) single crystal: A promising third order NLO material

A third order nonlinear optical (NLO)single crystals of sodium succinate hexahydrate (SSH) (β phase) has been grown by a slow evaporation growth technique using aqueous solution at ambient temperature. The lattice parameters and morphology of SSH were determined by single crystal X-ray diffraction analysis. SSH crystallizes in centrosymmetric monoclinic system with space group P21/c and the crystalline purity was analyzed by powder X-ray diffraction analysis. The UV–vis–NIR spectrum reveals that the crystal is transparent in the entire visible region. The recorded FT-IR spectrum verified the presence of various functional groups in the material. NMR analysis of the grown crystal confirms the structural elucidation and detects the major and minor functional groups present in the title compound. ICP-OES analysis proved the presence of sodium in SSH. TG-DTA/DSCanalysis was used to investigate the thermal stability of the material. The dielectric permittivity and dielectric loss of SSH were carried out as a function of frequency for different temperatures and the results were discussed. The mechanical stability was evaluated from Vicker's microhardness test. The third order nonlinear optical properties of SSH has been investigated employing Z-scan technique with He-Ne laser operating at 632.8nm wavelength.

Nonlinear optical switching and optical limiting in colloidal CdSe quantum dots investigated by nanosecond Z-scan measurement

The semiconductor nanocrystals are found to be promising class of third order nonlinear optical materials because of quantum confinement effects. Here, we highlight the nonlinear optical switching and optical limiting of cadmium selenide (CdSe) quantum dots (QDs) using nanosecond Z-scan measurement. The intensity dependent nonlinear absorption and nonlinear refraction of CdSe QDs were investigated by applying the Z-scan technique with 532nm, nanosecond laser pulses. At lower intensities, the nonlinear process is dominated by saturable absorption (SA) and it is changed to reverse saturable absorption (RSA) at higher intensities. The SA behaviour is attributed to the ground state bleaching and the RSA is ascribed to free carrier absorption (FCA) of CdSe QDs. The nonlinear optical switching behaviour and reverse saturable absorption makes CdSe QDs are good candidate for all-optical device and optical limiting applications.

Growth and characterization of benzaldehyde 4-nitro phenyl hydrazone (BPH) single crystal: A proficient second order nonlinear optical material

The crystals (benzaldehyde 4-nitro phenyl hydrazone (BPH)) appropriate for NLO appliance were grown by the slow cooling method. The solubility and metastable zone width measurement of BPH specimen was studied. The material crystallizes in the monoclinic crystal system with noncentrosymmetric space group of Cc. The optical precision in the whole visible region was found to be excellent for non-linear optical claim. Excellence of the grown crystal is ascertained by the HRXRD and etching studies. Laser Damage Threshold and Photoluminescence studies designate that the grown crystal contains less imperfection. The mechanical behaviour of BPH sample at different temperatures was investigated to determine the hardness stability of the grown specimen. The piezoelectric temperament and the relative Second Harmonic Generation (for diverse particle sizes) of the material were also studied. The dielectric studies were executed at varied temperatures and frequencies to investigate the electrical properties. Photoconductivity measurement enumerates consummate of inducing dipoles due to strong incident radiation and also divulge the nonlinear behaviour of the material. The third order nonlinear optical properties of BPH crystals were deliberate by Z-scan method.

Metal–organic frameworks for electronics: emerging second order nonlinear optical and dielectric materials

Metal–organic frameworks (MOFs) have been intensively studied over the past decade because they represent a new category of hybrid inorganic–organic materials with extensive surface areas, ultrahigh porosity, along with the extraordinary tailorability of structure, shape and dimensions. In this highlight, we summarize the current state of MOF research and report on structure–property relationships for nonlinear optical (NLO) and dielectric applications. We focus on the design principles and structural elements needed to develop potential NLO and low dielectric (low-κ) MOFs with an emphasis on enhancing material performance. In addition, we highlight experimental evidence for the design of devices for low-dielectric applications. These results motivate us to develop better low-dielectric and NLO materials and to perform in-depth studies related to deposition techniques, patterning and the mechanical performance of these materials in the future.