Good Nonlinear Optical Material Research Articles

Effect of Co2+ on the growth and physical properties of potential nonlinear optical l-Asparaginium picrate crystal

l-Asparaginium picrate (LASP) is a good nonlinear optical material having large second harmonic generation (SHG) efficiency. In the present study LASP crystal is grown with metallic dopant cobalt (Co2+) for different molar concentrations by a low temperature solution growth using slow evaporation technique. The grown crystals are subjected to single crystal and powder X-ray diffraction studies to identify the morphology and structure. The addition of Co2+ at different molar concentration improves the morphology of LASP crystal considerably. The dopant concentration in the doped crystal is estimated by inductively coupled plasma emission analysis (ICP-OES). The UV cut of range is determined by optical absorption study. The NLO behavior of Co2+ doped LASP crystals is tested by Kurtz–Perry technique. The TG-DTA studies showed that the doped crystal exhibit better thermal stability than pure LASP.

Synthesis, structure, growth and characterization of an organic crystal: 1,5-diphenylpenta-2,4-dien-1-one

1,5-Diphenylpenta-2,4-dien-1-one (DDO) chalcone single crystals, synthesized by a base-catalysed aldol condensation reaction between cinnamaldehyde and acetophenone, have been grown by the slow evaporation of an ethanol solution. The crystals belong to the orthorhombic system with centrosymmetric space groupPbca. The DDO crystals are transparent in the visible region and have a lower optical cut-off at ∼445 nm with a band-gap energy of 2.87 eV. Thermogravimetry/differential scanning calorimetry thermal analysis shows that the crystal is stable up to 375 K and it has a good chemical stability. The vibrational patterns of the chalcone have been investigated by Fourier transform IR and Fourier transform Raman spectroscopy. Microhardness studies were also carried out to elucidate the mechanical behaviour. Theoretical calculations were performed using the Hartree–Fock method with 6-31G(d,p) as the basis set, and the first-order hyperpolarizability is 7.077 × 10−30electrostatic units, which is >25 times that of urea. The crystalline perfection evaluated by high-resolution X-ray diffraction analysis reveals multiple peaks. The molecular packing leads to a centrosymmetric arrangement, resulting in zero second harmonic generation [χ(2)= 0] efficiency. Interestingly, the bromo- and chloro-substituted chalcones are good nonlinear optical materials.

Study on Optical Nonlinearities of the Excited-State Proton Transfer Organic Molecule３-Hydroxyflavone

3-hydroxyflavone (3-HF) is a kind of organic molecule with excited state proton transfer (EFPT) effect, and is a good performance nonlinear optical material. In this paper, the nonlinear refractive index and two-proton absorption coefficient of 3-HF were measured by using z-scan technique with ps pulsed laser at 355nm and 532nm respectively. In the experiment, we observed that the two-proton absorption coefficient was decreased as the incident intensity was increased.

Electrochemical and Nonlinear Optical Studies of New D–A Type π-Conjugated Polymers Carrying 3,4-Benzyloxythiophene, Oxadiazole, and 3,4-Alkoxythiophene Systems

Abstract We investigated the nonlinear optical (NLO) properties of two newly synthesized conjugated polymers P1 and P2 carrying 1,3,4-oxadiazole, 3,4-dibenzyloxythiophene, and 3,4-dialkoxythiophene moieties along the main chain, as potential NLO active materials. Their structures have been well characterized. The nonlinear measurements were performed by Z-scan using 532 nm, 7 ns laser pulses. Calculated values of figure of merit and β follow the criteria for good NLO materials. These results suggest that polymers are promising materials for applications in photonics.

Experimental Investigation on Surface Roughness of KDP Crystal Pro-Cessed with Rotary Ultrasonic Face Milling

KDP crystal is a good nonlinear optical and electro-optical crystal material. However, KDP crystal is considered to be one of the most difficult machining materials due to its inherent properties. This paper presents a preliminary experimental study on surface roughness of KDP crystal processed with rotary ultrasonic face milling. The study shows that the process variables (spindle speed, feedrate, and milling depth) have significant influence on the surface roughness in processing KDP crystal. It discusses the effects of the mechanical properties of KDP crystal on the processing performance. The experimental investigation reveals that the rotary ultrasonic face milling method can obtain smoother surface, which means the method is available for processing KDP crystals with a proper machining conditions. This preliminary research affords a guiding significance for precision processing KDP crystals.

Synthesis, molecular conformation, vibrational and electronic transition, isometric chemical shift, polarizability and hyperpolarizability analysis of 3-(4-Methoxy-phenyl)-2-(4-nitro-phenyl)-acrylonitrile: A combined experimental and theoretical analysis

This work presents the synthesis and characterization of a novel compound, 3-(4-Methoxy-phenyl)-2-(4-nitro-phenyl)-acrylonitrile (abbreviated as 3-(4MP)-2-(4-NP)-AN, C 16H 12N 2O 3). The spectroscopic properties of the compound were examined by FT-IR, UV–vis and NMR ( 1H and 13C) techniques. FT-IR spectrum in solid state was observed in the region 4000–400 cm −1. The UV–vis absorption spectrum of the compound which dissolved in chloroform was recorded in the range of 200–800 nm. The 1H and 13C NMR spectra were recorded in CDCl 3 solution. To determine lowest-energy molecular conformation of the title molecule, the selected torsion angle is varied every 10° and molecular energy profile is calculated from 0° to 360°. The structural and spectroscopic data of the molecule in the ground state were calculated using density functional theory (DFT) employing B3LYP/6-31G(d,p) basis set. The dipole moment, linear polarizability and first hyperpolarizability values were also computed using the same basis set. A study on the electronic properties, such as HOMO and LUMO energies, were performed by time-dependent DFT (TD-DFT) approach. The HOMO and LUMO analysis were used to elucidate information regarding charge transfer within the molecule. The vibrational wavenumbers were calculated and scaled values were compared with experimental FT-IR spectrum. The complete assignments were performed on the basis of the experimental results and total energy distribution (TED) of the vibrational modes, calculated with scaled quantum mechanics (SQM) method. Isotropic chemical shifts were calculated using the gauge-invariant atomic orbital (GIAO) method. Comparison of the calculated frequencies, NMR chemical shifts, absorption wavelengths with the experimental values revealed that DFT and TD-DFT method produce good results. The linear polarizabilities and first hyperpolarizabilities of the studied molecule indicate that the title compound can be used as a good nonlinear optical material. The thermodynamic properties of the studied compound at different temperatures were calculated, revealing the correlations between standard heat capacity, standard entropy, standard enthalpy changes and temperatures.

Role of Terminal Positions of Aryl Ring Towards Second-Order Nonlinearity in Arylimido-Substituted Molybdates: An Interesting Quantum Study of Organic-Inorganic Hybrid Composites

The role of lateral terminal (X2 and X3) and terminal (X1) positions of aryl ring on the second-order nonlinear optical (NLO) properties of arylimido derivatives of hexamolybdates have been examined by using time-dependent density functional response theory (TD-DFT). This group of organic-inorganic hybrid compounds holds considerable large molecular second-order NLO response, especially [Mo6O18 (NC6H2 (NH2)3)]2- (system 4) with the static secondorder polarizability (βvec) computed to be 4406.60 au. Hence, [Mo6O18 (NC6H4NH2)]2- (system 2) and [Mo6O18 (NC6H2 (CH3)2 NH2)]2- (system 3) have also possibility to be good second-order nonlinear optical materials as compared to [Mo6O18 (NC6H5)]2- (system 1). The study of the major contribution to the βvec value suggests that the charge transfer from arylimido to molybdate (D – A) along the z-axis plays an important part in the NLO response, arylimido acts as a donor (D) whereas molybdate (POM-cluster) acts as an acceptor (A) in all the studied systems. The computed βvec values increase by incorporation of an electron donor (-NH2) at the terminus of phenyl ring. Moreover, substitution of amino (-NH2) at the lateral terminal positions and the terminus of aryl ring is simultaneously dominant to increase the optical nonlinearity. The present exploration offers significant physical insight into the considerable large NLO properties of arylimido substituted hexamolybdates. Keywords: Polyoxometalates, inorganic-organic hybrid composites, second-order polarizability, charge transfer, density functional calculations (DFT), Aryl Ring, second-order nonlinear optical, arylimido, (POM-cluster), Si-O bonds, zero-order regular approximation (ZORA), generalized-gradient approximation (GGA), sum-over-states (SOS), HOMO-LUMO energy gap, hexamolybdates

Unidirectional growth ofL-cysteine hydrochloride monohydrate: first time observation as nonlinear optical material and its characterization

A bulk size (∼60 mm length and 20 mm diameter) single crystal of L-cysteine hydrochloride monohydrate has been successfully grown for the first time by the unidirectional Sankaranarayanan–Ramasamy method and found to be a nonlinear optical material by observing the second harmonic generation (SHG). The crystal structure has been confirmed by single-crystal as well as powder X-ray diffraction analysis. The Fourier transform–Raman technique was used to study the vibrational modes and functional groups. The grown crystal was found to be highly transparent. The crystalline perfection has been evaluated by high-resolution X-ray diffractometry and the grown crystal was found to be free from macroscopic defects such as structural grain boundaries. The relative SHG efficiency and laser damage threshold values were found to be 1.2 and 5.5 times that of a potassium dihydrogen phosphate crystal, respectively. The dielectric constant, dielectric loss and alternating current conductivity were measured by an impedance analyser over a wide range of frequency between 100 Hz and 5 MHz. The dielectric constant was found to be stable for the entire range of frequency with very small dielectric loss, making this material suitable for device applications. The present investigation reveals that the title compound, since it can be grown with desirable size along a predetermined direction and it is a good nonlinear optical material with the prerequisite optical and dielectric properties, is a good candidate for photonic or opto-electronic applications.

Growth and characterization of organic molecular single crystal ethyl p-amino benzoate by selective self seeding from vertical Bridgman technique

Single crystal growth of ethyl p-amino benzoate (EPAB), a good nonlinear optical material, from the melt using nanoresolution translation by the Bridgman technique is reported. The unit cell dimensions were determined from single crystal X-ray diffraction studies. Fourier transform infrared (FTIR) spectral studies have been performed to identify the functional groups. Using differential thermal analysis (DTA) and differential scanning calorimetry (DSC) technique, EPAB has been studied. The melting point and solidification temperature of EPAB were determined. The EPAB crystal was characterized by UV–vis–NIR spectra. The dielectric constant and dielectric loss of the specimen were also studied. The second harmonic generation efficiency of EPAB was determined using the Kurtz powder technique. The high SHG is due to one dimensional charge transfer between amino and ester group.

Single crystal growth of 4-aminobenzophenone using nanoresolution translation by the Bridgman technique and its characterization

The single crystal growth of 4-aminobenzophenone (4ABP), a good nonlinear optical material, from the melt using nanoresolution translation by the Bridgman technique is reported. Powder X-ray diffraction analysis reveals that 4ABP crystallizes in monoclinic system. Using the differential thermal analysis (TG/DTA) and differential scanning calorimetry (DSC) technique, 4ABP has been studied. The melting point and solidification temperature of 4ABP were determined. Fourier transform infrared spectra were used to assign various modes and identify the functional groups present in the crystal. The 4ABP crystal was characterized by UV–vis–NIR spectra. The optical band gap ( E g), absorption coefficient ( α) and refractive index ( n) were also calculated as a function of energy. The dielectric constant and dielectric loss of the specimen were also studied. The second harmonic generation efficiency of 4ABP was determined using the Kurtz powder technique.

Syntheses and characterization of ferrocenylthiocarboxylate-containing coordination compounds for nonlinear optics

Four metal-organic coordination compounds containing ferrocenylthiocarboxylate components, [Cd 2(η 2-SOCFc) 2(η 1-μ 2-SOCFc) 2(4,4′-bpy)] n ( 1), [Cd(SOCFc) 2(tmp)] n (tmp = 4,4′-trimethylene-dipyridine) ( 2) [Zn(SOCFc) 2(2,2′-bpy)] ( 3), and {[Hg(SOCFc) 2(phen)] · (0.5CH 3OH)} ( 4) (Fc = (η 5-C 5H 5)Fe(η 5-C 5H 4)), have been prepared in search of good nonlinear optical (NLO) materials. Investigation of the NLO properties shows that Hg-containing compound 4 exhibits very strong third-order NLO absorptive and refractive effects. The NLO absorptive coefficient α 2 value (2.11 × 10 −10 m W −1) is larger than those of all the reported ferrocenylcarboxylate-containing coordination compounds and comparable to the well-performing Hg-containing complexes. Additionally, we further analyzed their NLO behaviors through studying electrochemical properties of the four compounds.

Two cobalt(II) one-dimensional ribbon of rings polymers: Syntheses, structures and non-linear optical properties

Two cobalt(II) coordination polymers {[Co(SCN) 2(3-bpit) 2] · 2CH 3OH} n ( 1) (3-bpit = N,N′-bis(3-pyridylformyl)imidazolidine-2-thione) and {[Co(SCN) 2(4-bpit) 2] · CH 3OH · CH 3CN} n ( 2) (4-bpit = N,N′-bis(4-pyridylformyl)imidazolidine-2-thione) have been synthesized for study of the third-order non-linear properties. X-ray crystal structural analyses reveal that the two polymers show the same topological motif: a ribbon of rings. Their third-order non-linear optical (NLO) properties in DMF solution have been studied by Z-scan techniques with a linearly polarized laser light ( λ = 532 nm; pulse widths = 7 ns). Both of them exhibit strong self-focusing effect. The third-order NLO susceptibility χ (3) values are calculated to be 2.61 × 10 −11 esu ( 1) and 2.76 × 10 −11 esu ( 2), respectively. The values are comparable to those of the reported good NLO materials.

Synthesis, characterization and third-order nonlinear optical properties of bromo[tri-α-(2,4-dimethyl-3-pentyloxy)subphthalocyanine]boron complex

A new subphthalocyanine complex, bromo[tri-α-(2,4-dimethyl-3-pentyloxy)subphthalocyanine]boron, has been synthesized and characterized by elemental analysis, MALDI-TOF-MS, FT-IR and UV–vis spectroscopy. Its third-order nonlinear optical (NLO) properties in ethanol solution have been studied by Z-scan technique using 8 ns laser pulses at 532 nm. The results reveal that the new complex exhibits strong NLO absorption effect ( α 2 = 3.7 × 10 −10 m W −1) and self-focusing refractive performance ( n 2 = 2.1 × 10 −17 m 2 W −1). The effective third-order NLO susceptibility ( χ (3)) and the molecular second-order hyperpolarizability ( γ) value were calculated to be 1.12 × 10 −11 and ∼6.8 × 10 −28 esu, respectively. All of the values are comparable to those of the reported good NLO materials. In addition, the effects of cone-shaped molecular structure and axially heavy-atom (Br) substitution on third-order NLO properties are discussed.

Crystal structures and third-order NLO properties in DMF solution of Co(II)-bpfp coordination polymers (bpfp= N, N′-bis(pyridylformyl)piperazine)

Two novel Co(II) coordination polymers {[Co(H 2O) 2(CH 3OH) 2(4-bpfp)](NO 3) 2} n 1 (4-bpfp= N, N ′-bis(4-pyridylformyl)piperazine) and [Co(NCS) 2(CH 3OH) 2(3-bpfp)] n 2 (3-bpfp= N, N ′-bis(3-pyridylformyl)piperazine) have been synthesized and characterized by single crystal X-ray diffraction. Both the polymers consist of one-dimensional chains constructed by bridging bpfp ligands and Co(II) ions. The existence of O⋯H–O hydrogen bond in 1 and S⋯H–O hydrogen bond in 2 play important roles in creating interesting supramolecular structures. Their third-order nonlinear optical (NLO) properties in DMF solution have been studied by Z-scan technique. The results reveal that polymers 1 and 2 exhibit strong NLO absorption effects ( α 2=9.00×10 −11 m W −1 for 1; 1.41 × 10 −10 m W −1 for 2) and self-focusing performance ( n 2=3.24×10 −16 esu for 1; 3.05 × 10 −16 esu for 2) in DMF solutions. The corresponding effective NLO susceptibilities χ (3) values are 3.08 × 10 −12 esu ( 1) and 4.70 × 10 −12 esu ( 2). All of the values are comparable to those of the reported good NLO materials. Additionally, the TG-DTA results of the two polymers are in agreement with the crystal structures.

Growth and properties of organic nonlinear optical crystals: l-tartaric acid–nicotinamide and d-tartaric acid–nicotinamide

Two novel single crystals of l-tartaric acid–nicotinamide (LTN, 2HOOC HC(OH)HC(OH)COO−·2C5H4NH+CONH2·H2O) and d-tartaric acid–Nicotinamide (DTN, 2HOOCHC(OH)HC(OH)COO−·2C5H4NH+CONH2·H2O), good quality organic nonlinear optical (NLO) materials have been successfully grown by the temperature lowering method from aqueous solution. Solubility curves of both LTN and DTN have been determined in water. The solubility of both LTN and DTN steadily moved upward along with the uninterrupted rise of the solution temperature. Effects of different solvents on growth of LTN and DTN single crystals were compared. The LTN single crystal in size 12×42×2mm3 was grown in the deionized water for 5 days while DTN single crystal in size 28×12×3mm3 was grown for only 12h. The transmission ranges of both LTN and DTN single crystals have been found to be between 280 and 1900nm.

The Third-Order Nonlinear Optical Susceptibility of C60-Derived Nanotubes

Using the extended Su-Schrieffer-Heeger (SSH) model and the sum-over-state (SOS) method, we have calculated the third-order nonlinear polarizability γ and its dispersion spectra for C 60 -derived nanotubes, which is one of the narrowest tubes. Our numerical calculations indicate that both symmetry and size of the nanotubes have great effect on the third-order nonlinear polarizability γ spectra. We find that with increasing size, both static γ values and dynamical response peak values increase. When the atom number of the C 60 -derived nanotubes is 140, the static γ value is about 65 times larger than that of C 60 , and the highest peak value of γ (at 3ω = 3.52 eV) is about three orders larger than that of C 60 , So, C 60 -derived nanotubes may become a kind of good nonlinear optical materials.

Crystal Growth and Structure of 4‐Aminobenzophenone (ABP)

Abstract4‐aminobenzophenone C6H5COC6H4NH2 (ABP) is a good organic Nonlinear Optical (NLO) material. The bulk crystal has been grown by cooling method from organic solution, and the crystal structure determined by X‐ray diffraction.

Phase relations, solubility and growth of potassium titanyl phosphate, KTP

Potassium titanyl phosphate is an unusually good nonlinear optical material whose use is constrained because of the difficulty of growing crystals. Promising new hydrothermal conditions for growth have been discovered. The yield of the reaction: KH 2PO 4+TiO 2 → KTiOPO 4+H 2O is used to deduce the hydrothermal phase diagram KPO 3-TiO 2-H 2O between 500 and 600°C at 10 kpsi in the presence of the mineralizer, 1m K 2HPO 4. It is shown that KTiOPO 4, “KTP”, is congruently saturating above 600°C and crystallizes as the sole solid in an excess of KPO 3 below 600°C. Solubility is appreciable above 600°C. Phase equilibria and solubility results are used to find growth conditions (2m K 2HPO 4, 70% fill, 375–425°C) with rates of KTP crystallization from a new mil/day to ∼27 mil/day (∼0.68 mm/day). Good quality crystal growth takes place at the lower rates. These results hold promise of practical growth at mild conditions where low carbon steel, comparatively inexpensive autoclaves can be used.