Diffraction Ring Patterns Research Articles

Preparation, DFT and optical nonlinear studies of a novel azo-(β)- diketone dye

New azo compound containing an antipyrine moiety is prepared via interaction of 4-aminoantipyrine with benzoylacetone. The coupling reaction of diazonium salt with benzoylacetone is employed to prepare the azo compound. The FTIR, 1H NMR and mass spectroscopies are used for the characterization of the new azo compound. Density function theory DFT calculations are carried out to study the electronic structure and vibrational frequencies of the prepared azo compound. A linear correlation appeared between the Mulliken atomic charge of oxygen atoms and the values of calculated wavenumbers. The nonlinear optical NLO properties of the prepared compound solution are studied using 473 nm, continuous wave cw, single fundamental mode, low power laser beam via the diffraction ring patterns DRPs and the Z-scan techniques. The optical limiting OLg property of the compound solution is examined. The DRPs are simulated numerically using the Fresnel-Kirchhoff integral with reasonable accord compared to the experimental findings.

Modification to axial tracking for mobile magnetic microspheres

Three-dimensional particle tracking is a routine experimental procedure for various biophysical applications including magnetic tweezers. A common method for tracking the axial position of particles involves the analysis of diffraction rings whose pattern depends sensitively on the axial position of the bead relative to the focal plane. To infer the axial position, the observed rings are compared with reference images of a bead at known axial positions. Often the precision or accuracy of these algorithms is measured on immobilized beads over a limited axial range, whereas many experiments are performed using freely mobile beads. This inconsistency raises the possibility of incorrect estimates of experimental uncertainty. By manipulating magnetic beads in a bidirectional magnetic tweezer setup, we evaluated the error associated with tracking mobile magnetic beads and found that the error of tracking a moving magnetic bead increases by almost an order of magnitude compared with the error of tracking a stationary bead. We found that this additional error can be ameliorated by excluding the center-most region of the diffraction ring pattern from tracking analysis. Evaluation of the limitations of a tracking algorithm is essential for understanding the error associated with a measurement. These findings promise to bring increased resolution to three-dimensional bead tracking of magnetic microspheres.

All optical switching and the optical nonlinear properties of 4-(benzothiazolyldiazenyl)-3-chlorophenyl 4-(nonylthio)benzoate (EB-3Cl)

Chemical computational calculations are carried out to investigate the molecular structure of 4-(benzothiazolyldiazenyl)-3-chlorophenyl 4-(nonylthio)benzoate (EB-3Cl) via the density functional theory (DFT) method. The B3LYP method is used to optimize the geometrical structure of the EB-3Cl compound with 6–31G(d,p) basis set level. HOMO-LUMO energies and some nonlinear optical (NLO) properties are calculated via the same method used in geometry optimization. The results show that the synthesized compound has good optical properties. Good agreement correlations of experimental and theoretical findings are found. The index of nonlinear refraction (INR) of EB-3Cl is determined via two methods, the diffraction ring pattern (DRP) and the Z-scan. High INR value of 5.92×10−7 cm2/W is obtained via the first method. Optical limiting (OLg), of the synthesized compound is studied with OLg threshold value of 8 mW is obtained. All optical switching technique is tested in the prepared compound with good results are obtained and DRPs are simulated numerically based on the Fresnel-Kirchhoff integral.

Nonlinear optical properties investigation of a newly synthesised Azo-(β)- diketone dye

Azo-β-diketone compound is prepared via coupling reaction of dizonium salt of sulfanilamide with acetylacetone. The compound is characterized by FTIR, Mass and 1H NMR spectrocopies. The optimization of synthesized azo-β-diketone is carried out using B3LYP method 6-31G (d,p) basis sets. Nonlinear optical properties of synthesized azo-β-diketone is investigated via some quantum chemical descriptors calculation using DFT/B3LYP method with 6‐31G(d,p) basis set. The UV–vis spectrum of the synthesized azo-β-diketone is also calculated using TD-DFT with same optimization method and level. The nonlinear index of refraction of the azo-β-diketone at 473 nm is calculated using the spatial self-phase modulation and Z-scan techniques where as high as 3.259 × 10−7 cm2/W is obtained due to the first technique and 2.4 × 10−8 cm2/W due to the second technique. The compound optical limiting property is tested at the same wavelength with limiting threshold of 12 mW is obtained. The diffraction ring patterns are theoretically simulated based on the Fresnel-Kirchhoff diffraction integral with results agree well with experimental findings.

Investigating the optical nonlinear properties and limiting optical of eosin methylene blue solution using a cw laser beam

Diffraction patterns and Z-scan methods are used to measure the nonlinear refractive index, NRI, of the eosin methylene blue in the solvent ethanol using a continuous wave laser beam of 473 nm wavelength. Experimental results of the former and latter methods showed the appearance of rings and the self-defocusing SDF effect respectively, and these results may be due to phase modulation. It is demonstrated that the eosin methylene blue solution have a high NRI. Also the limiting optical properties of the sample are investigated. It is observed that the sample has the optical limiter properties OLPs. It is proved that the origin of the OLPs is thermal. The NRI and threshold limiting values of the eosin methylene blue solution are −1.1 × 10−8 cm2 W−1 and 12 mW, respectively. A thermal lens model and the Fresnel–Kirchhoff integral are used to calculate the self-defocusing and the diffraction ring patterns results respectively.

Synthesis and diffraction ring patterns of 8-hydroxyquinolin-1-ium 4-aminobenzenesulfonate

8-hydroxyquinolin-1-ium 4-aminobenzenesulfonate solution was synthesized via conventional chemical method. Different spectroscopies techniques utilized to characterize the new organic salt molecule. The spatial self-phase modulation technique was employed to obtain the nonlinear optical parameters of the new salt. The diffraction ring patterns used to deduce the nonlinear refractive index (10−6 cm2/W) n2 and thermo-optic coefficient [dn/dT]. Our results have indicated that the number of diffraction rings is related to the laser beam intensity. The all optical switching effect was realized as function to the laser beam frequency.

Liquid–Liquid Demonstrations: Spinodal Decomposition

Under most conditions, a liquid mixture does not have long-range structural order and may be considered to be a homogeneous collection of molecules in random motion. However, if a single-phase critical mixture of a partially miscible liquid–liquid system is subjected to a small temperature jump into the two-phase region, then structural coherence across macroscopic distances can form in the liquid. The process is called spinodal decomposition and results because the temperature jump has made the entire sample thermodynamically unstable. This process is fundamentally different from the more typical phase-separation mechanism of nucleation and growth, which involves localized droplet formation. Here, a benchtop setup is described for showing students a critical isobutyric acid + water mixture undergoing spinodal decomposition using only ambient cooling and a low-power laser. When structural order within the phase-separating sample reaches the micron scale, students see a diffraction ring pattern formed by the transmitted laser. The pattern persists for up to 30 s, and students can use Bragg’s law to estimate the size of structural order within the liquid mixture. The critical temperature of the isobutyric acid + water sample is just above room temperature, so the experiment is easily repeated. Preparation of a four-phase immiscible liquid mixture is also described; when this mixture is vigorously shaken, the resulting emulsion separates in a manner visually analogous to spinodal decomposition.

Linear and nonlinear optical properties of potassium dichromate in solution and solid polymer film

A film with polyvinyl alcohol and aqueous solution of potassium dichromate are prepared where various linear optical constants and nonlinear properties are determined via the measurements of the film optical absorbance and transmittance spectra in the wavelength range 312–900 nm and via the diffraction ring patterns by transmitting a visible, 473 nm, continuous wave with single fundamental transverse mode, low power laser beam. As high as 1010 sec−1 optical conductivity and nonlinear refractive index of 10−13 cm2/W of the film are obtained due to the linear parameters and 10−7 cm2/W of the aqueous solution due to the diffraction ring patterns. Fraunhofer approximations of the Fresnel-Kirchhoff theory are used to simulate the diffraction ring patterns.

Synthesis, characterization and the nonlinear optical properties of newly synthesized 4-((1,3-dioxo-1-phenylbutan-2-yl)diazenyl)benzenesulfonamide

The dye of azo compound is prepared by coupling reaction of dizonium salt of sulfanilamide with benzoylacetone. The product is characterized by FTIR spectroscopy, Mass spectroscopy and 1H NMR spectroscopy. The geometries of the synthesized dye is optimized using B3LYP method and 6-31G (d,p) basis sets. Nonlinear optical properties are investigated theoretically by calculation of some quantum chemical descriptors using the DFT/B3LYP method with a 6‐31G(d,p) basis set in comparison with urea as a standard. The UV–visible spectrum of synthesized azo dye are calculated using TD-DFT with B3LYP/6-31G(d,p) level. The nonlinear refractive index of the prepared dye is calculated via the diffraction ring patterns and Z-scan techniques using 473 nm visible, continuous wave laser light. The diffraction ring patterns are numerically simulated using the Fresnel-Kirchhoff theory with reasonable agreements. The property of optical limiting of the azo dye is tested.

Synthesis and optical nonlinear properties performance of azonaphthol dye

Azonapthol dye viz., (E)-4-(phenyldiazenyl)naphthalen-1-ol (C16H11N3O3) is synthesized via diazotization of p-nitro aniline and subsequent coupling with α-naphthol. 1H NMR spectrum is used to identify the position of protons in obtained compound. FTIR spectrum is used to assign the absorption bands of vibration bonds at the expected regions. Mass spectrum proved a good agreement with structure of the prepared azonaphthol dye. The third order optical nonlinear properties of the azonaphthol dye 4 dissolved in acetone viz., the nonlinear index of refraction and the nonlinear absorption are obtained using 473 nm laser beam via diffraction ring patterns at 42 mW and Z-scan at 5 mW techniques separately. High nonlinear refractive index, 10−6 cm2 W−1, is obtained via diffraction ring pattern. Optical limiting property of azonapthol dye 4 solution is tested and a limiting threshold value of 17 mW is obtained, and prove that the sample can be used as an optical limiter. The Fraunhofer approximations of the Fresnel-Kirchhoff theory have led to the diffraction ring patterns simulation where very good agreement have been obtained.

Investigating the Nonlinear Optical Response of Pepper Oil under Low Power Irradiation with Continuous Wave Visible Laser Beam

The nonlinear optical properties of pepper oil are studied by diffraction ring patterns and Z-scan techniques with continuous wave beam from solid state laser at 473 nm wavelength. The nonlinear refractive index of the sample is calculated by both techniques. The sample show high nonlinear refractive index. Based on Fresnel-Kirchhoff diffraction integral, the far-field intensity distributions of ring patterns have been calculated. It is found that the experimental results are in good agreement with the theoretical results. Also the optical limiting property of pepper oil is reported. The results obtained in this study prove that the pepper oil has applications in nonlinear optical devices.

Measurement of the thermo-optic coefficient and Ring surface profile of sulfadiazine azo dye by using milli watts cw laser beams

We report on the observation of thermal lens as well as multiple diffraction ring patterns due to the irradiation of the azo dye “1.8-Dihydroxy-naphthalin-3, 6 disulfonic acid [2-(4-Azo)]-N-(5-methyl-3-isoxazolyl)-benzene sulfonamide” at same time by three continuous wave, green (λ=532 nm), red (λ=635 nm) and blue (λ=473 nm), laser beams. This effect we observed at power input less than 10 mW for the pump 532 nm green laser and as low as 50 μW of beams from other two wavelengths. The number of rings for all three beams is totally controlled by the level of pump input power. The optical limiting of the azo dye solution using the 532 nm green laser beam is also demonstrated. The change in the material refractive index, Δn, the nonlinear refractive index, n 2, and the thermo-optical coefficient dn/dT are calculated based on thermal lens and diffraction ring techniques. The three quantities are found to be in the range of 10−4, 10−7 cm 2/W and 10−5 K −1 respectively by both techniques.

Solvents effect on the optical nonlinear properties of the sudan iv

The optical nonlinear properties of three sudan iv solutions in DMSO, DMF and chloroform solvents are studied under irradiation with low power laser beam work at 473 nm. The diffraction ring patterns and Z-scan experiments were carried out separately to calculate the change in the index of refraction and the nonlinear index of refraction of each solution. The rings number per each pattern, the area of each pattern and the outer most ring diameter in each pattern increased with the increase of input laser beam intensity. Each pattern loses symmetry in the upper part as input intensity increased. The obtained diffraction ring patterns are simulated using Fraunhofer approximation of the Fresnel-Kirchhoff diffraction theory where good theoretical agreements with the experimental findings are obtained. According to both methods it is proved that sudan iv three solutions shows self-defocusing phenomena. Type of solvent appears to control the nonlinearities of sudan iv solutions. Optical limiting property is studied in the three solutions.

Diffraction ring patterns and nonlinear measurements of the Tris(2′,2-bipyridyl)iron(II) tetrafluoroborate

The nonlinear optical properties of the Tris(2,2′-bipyridyl)iron(II) tetrafluoroborate in aqueous solution was investigated by the spatial self-phase modulation (SSPM) technique using CW laser at λ = 532 nm. The experimental results show large nonlinear refractive index (n2) and the thermo-optic coefficient (dn/dT) equal to −3.17 × 10−6 cm2/W and the 3.17 × 10−3 k−1, respectively. The effect of input power of excitation laser and the temporal evolution on the shape of the diffraction patterns were studied. Consequently, the collapse effect of the diffraction ring patterns was explained.

The nonlinear optical properties of two dihydropyridones derived from curcumin.

Two dihydropyridone compounds are synthesized from curcumin using microwave radiation. Both compounds were identified by their melting points and 1HNMR spectra. The nonlinear properties viz., nonlinear absorption coefficients and nonlinear refractive index of both compounds were calculated at wavelength 473nm using the diffraction ring patterns and Z-scan techniques separately. The diffraction ring patterns evolved from circular symmetric to asymmetric due to convection current in the vertical direction. As a result of using Gaussian laser beam, the Fraunhofer approximation of the Fresnel-Kirchhoff diffraction, have led to successful simulation of the diffraction ring patterns with good quantitative and excellent qualitative agreements compared with experimental results. Optical limiting property has been tested in both compounds.

Synthesis, Characterization and Mechanical Behaviour of Al2O3, TiO2, and Cu Reinforced Al 7068 Nanocomposites

This present research work aims at fabrication of AA7068 metal matrix composite reinforced with a different weight percentage of Al2O3, TiO2 and Cu (0 wt.%, 2 wt.%, and 4 wt.%) nanopowders through mechanical alloying of 30 hrs which is produced using powder metallurgy route. The consolidation pressure of 500 MPa was applied for compaction of the composite and sintered at a temperature of 600°C for two hrs in the presence of argon gas flow. An XRD result reveals that there are no intermetallic compounds formed in the milled powder after 30 hr of mechanical alloying. The reinforcement particles were well embedded and uniformly distributed in matrix composites was confirmed by bright-field emission transmission electron microscopy (FETEM) image and selected area diffraction (SAD) ring pattern. From the DSC curve of AA 7068–2.0 wt. % Al2O3, TiO2 and Cu nanocomposite powders after 30 hrs of mechanical alloying., the endothermic peak at 536.85°C corresponds to the melting of aluminium which was followed by a steady-state exothermic reaction at 579.51°C was obtained. The green density and sintered density of prepared nanocomposites were calculated and compared. Brinell hardness test has been conducted and the maximum value of 192 BHN was obtained by adding a weight percentage of 2 wt. % of Al2O3, TiO2 and Cu particles.

Diffraction Rings Pattern and Nonlinear Optical Properties of Hybrid ZnO-NPs / Epoxy Resin

In this research, the diffraction ring patterns scan and single-beam Z-scan techniques were used to measure the nonlinear refractive index (n2) and nonlinear absorption coefficient (β). Nano-composite sample, which consists of zinc oxide nanoparticles (ZnO-NPs), and epoxy resin polymer. The sample was prepared by the casting method. A second harmonic generation Nd: YAG laser, which operates at 532 nm and intensity 3183 W/cm2 was used for the two techniques. Z-scan results showed that values for nonlinear refractive index n2 and nonlinear absorption coefficient β were obtained of 6.59*10-9 cm2/W and 1.75*10-3 cm/W respectively. While results for the D-scan technique showed that the number of rings increases with the increasing of laser power.

Simultaneous contribution of saturation in absorption and nonlinear photoacoustic effects in CuTPP under blue laser irradiation

The nonlinear optical responses of CuTPP are studied in toluene under the irradiation of a blue laser beam focused using a convergent lens. The z-scan setup is applied in order to determine nonlinear optical responses. Besides the nonlinear absorption response, which indicates reversed saturable absorption, intensity dependence photoacoustic waves are created in both hearable sound and ultrasonic waves. Hearable sound is recorded by a microphone and analyzed by Fourier transform analyzes in order to calculate the sonic frequencies. Because of the high absorption of dye molecules, a dilute solution is prepared to enhance transmittance from the cell to analyze profile of the passing beam. Diffraction rings pattern is observed with about 30 dense rings, in which the number of rings depends on the beam intensity that could be attributed to the higher frequency photoacoustic waves and the corresponding refractive grating induced by the waves. The nonlinear refraction of the solution is a simultaneous contribution of thermal lensing and photoacoustic effects, in addition to the saturation in absorption process which influences the nonlinear absorption behavior. This compound can be proposed as a good candidate in mode locking, Q-switching devises, and short pulse generators where we need a pattern from the activity of the saturable absorber at the cross section of the beam.

Nonlinear photoacoustic response of s-tetrazine as an important azadiene pigment

Photoacoustic (PA) properties of a familiar and important azadiene pigment, 3,6-dichloro-1,2,4,5-tetrazine (DCT), are studied in toluene as solvent. Different aspects of PA signals of this pigment are compared in various frequencies of the produced sonic waves. Using a focused laser beam with 450-nm wavelength and irradiation of 300 mW, audible sonic waves with 15,500-Hz frequency are created in solvents with high densities of DCT. In low concentrations, where the laser beam transmitted from the cell, dense diffraction rings pattern are observed, which is attributed to the PA properties of this pigment. For the first time, simultaneous study of the diffraction rings pattern, optical PA z-scan, and Fourier transform analyzes results in a more comprehensive understanding of the PA phenomenon. In addition, a new method based on diffraction rings number is presented that could lead to the estimation of non-linear optical phase changes. Moreover, the audible PA signals, as a non-linear phenomenon, could be applied as a density sensor for the solution or intensity sensor for the laser beam.

Phase formation and lattice distortion of Lu2O3‐doped ZrO2 in comparison with Y2O3‐doped ZrO2

AbstractLu2O3 and Y2O3 doping of 8, 11, and 18 mol% in ZrO2 were prepared by solid solution reaction, aiming to study the phase stabilization of Lu2O3‐doped ZrO2 and Y2O3‐doped ZrO2 in terms of phase formation and lattice distortion. The Rietveld refinement results indicated that Lu2O3‐doped ZrO2 and Y2O3‐doped ZrO2 followed the same trend in terms of cubic phase fraction, increasing from 25%–30% (8 mol%) to 95%–100% (11 and 18 mol%). This phase formation was confirmed by observing the same diffraction ring pattern observed for the Lu2O3‐doped ZrO2 and Y2O3‐doped ZrO2. The Vickers hardness of the Lu2O3‐doped ZrO2 was 4.3% higher than that of Y2O3‐doped ZrO2 at 8 mol%, but 9.7% and 14.8% lower at 11 and 18 mol%, respectively. This was likely caused by the lattice distortion effect of Y2O3 doping overpowering the field strength difference between Lu3+ and Y3+.