Value Of Nonlinear Susceptibility Research Articles

An in-depth investigation of physical properties of Nd doped CdS thin films for optoelectronic applications

The different contents (0 wt.%, 1 wt.%, 3 wt.% and 5 wt.%) of Nd @CdS films were casted using spray pyrolysis deposition procedure. The preferential orientation of crystallites along (002) for all films was noted by XRD profiles. The mean crystalline size (Davg), strain (ɛavg) and dislocation density (δavg) have also been evaluated using XRD results and discussed. The spherical shape morphology of nanoscale particles of Nd@CdS films were analyzed by FE-SEM, exhibits the increased grain sizes with Nd doping concentration. The optical band gaps (2.4–2.36 eV) were found to be decreased with increasing Nd doping content upto (3 wt.%) and increased at 5 wt.% The PL profile displays a stout intensity peak observed at 532 nm and week emission band at 638 nm. The dielectric constant, loss and loss tangent of pristine and Nd@CdS thin films were investigated by dielectric measurements. The optimum values of non-linear refractive index 1.06 × 10−10, 4.41 × 10−11, 3.44 × 10−11 and 1.85 × 10−10 were observed for Nd content varies from pristine to 5 wt.% respectively. Furthermore, optimum non-linear susceptibility values 7.31 × 10−12, 1.079 × 10−12, 4.53 × 10−13 and 1.36 × 10−11 were observed for 0, 1, 3 and 5 wt.% of Nd contents respectively in CdS. Such type of characteristics of Nd doped CdS thin films can be useful for optical devices.

Growth and Z-scan analysis of semi-organic Bis(picolinic acetate) Zinc(II) single crystal for third order NLO applications

Here, we report a new semi-organic single crystal namely Bis(picolinic acetate) Zinc(II) (BPZ) which was grown by a conventional slow evaporation method at room temperature. Structural studies were carried out by single crystal XRD and the results show that Bis(picolinic acetate) Zinc(II) belongs to monoclinic crystal system with space group P21/n. The presence of functional groups in the grown crystal was identified by FTIR spectral analysis. UV-Vis spectral studies reveal that the grown crystals are transparent in the wavelength region of 200-1200 nm. In order to analyze the mechanical strength of the grown crystal, Vickers micro hardness tester was employed. The dielectric properties with respect to different frequency at room temperature were also studied to analyze the dielectric response. The third order nonlinear optical properties were determined by Z-scan studies which shows significant higher values of nonlinear absorption coefficient (β) and third order nonlinear susceptibility (χ3). The enhanced third order nonlinear behavior suggests that the title compound is suitable for nonlinear optical applications.

Influence of bismuth nitrate doping towards the characteristics of L-Alanine nonlinear optical crystals

In the present study, an amino acid derivatives, L-alanine (LA) and Bismuth nitrate-doped L-alanine (BNLA) crystals were grown by the slow evaporation technique. The crystal structure and quality of the grown crystal were examined by single-crystal X-ray diffraction (XRD) and powder XRD. The X-ray diffraction analysis of LA and BNLA crystals confirmed the orthorhombic crystal system without any internal structural grain boundaries. The optical properties of the LA and BNLA crystals have been determined using UV-Visible spectroscopy and Photoluminescence (PL). The second harmonic generation (SHG) efficiency of the crystal was measured using Kurtz powder technique. The dielectric constant measurement was performed at room temperature for different frequencies. Photoconductivity tests show that the LA and BNLA crystals have negative photoconductivity value. On testing of the retentivity or remanent magnetization, the BNLA crystal has increased values as compared to the pure LA crystals, in addition to the observation of changes in coercivity. Further, the observation of maximum intensity peak for the BNLA crystal at 346.9 nm pointed out that the crystal has blue fluorescence emission. The third-order nonlinear optical properties of the grown crystal were studied using Z-scan technique. The enhancement in nonlinear refractive index and third-order NLO susceptibility value shows that the grown BNLA crystals may be of good quality and less in defect than that of pure LA crystals.

Synthesis, DFT calculations, intermolecular interactions and third order nonlinear optical properties of new organoammonium tetrabromocadmate (II): (C5H6N2Cl)2[CdBr4]·H2O

A new hybrid compound (C5H6N2Cl)2[CdBr4]·H2O abbreviated CdACP was grown by slow evaporation from an aqueous solution at room temperature. The compound was characterized by single crystal X-ray diffraction, FTIR and Raman spectroscopies. The structural study proved that this compound crystallizes in a triclinic unit-cell with space group P1¯. To investigate the crystal packing, the structure has been analyzed using the Hirshfeld surface approach. Electronic behavior was analyzed using HOMO–LUMO analysis by density functional theory (DFT) at (DFT/B3LYP/LanL2DZ) level and UV–Vis absorption. The linear optical and electrical parameters (complex dielectric constant and optical and electrical conductivities) of our compound were analyzed using UV–Vis–NIR diffuse reflectance spectroscopy. The higher magnitude of optical conductivity of order 109 s−1 confirms the usefulness of the crystal’s photo response for information processing devices. The direct and indirect band gap values were found to be 4 and 3.8 eV, respectively, which are wide enough to exploit the CdACP crystal for optoelectronics device applications. The dispersion parameters (static refractive index, single oscillator energy (E0) and dispersion energy (Ed)) were discussed using theoretical Wemple Di-Domenico (WDD) model. The third order nonlinear parameters were investigated using empirical approximations. The sufficient transparency in the visible region, low cut off wave length and the higher values of nonlinear susceptibility χ(3) and nonlinear refractive index n2 make the title crystal suitable for third order NLO applications.

A Simple Approach for Determination of Numerical Values of Ferrite Nonlinear Susceptibilities

This article presents a straightforward approach for determination of numerical values of nonlinear susceptibilities of soft magnetic ferrites. It is shown that numerical values of susceptibilities can be calculated from the measured amplitudes of harmonics in the output voltage of ferrite core transformer. For this purpose, useful expressions for the susceptibilities are derived and as example, numerical values of the largest nonlinear susceptibilities those of the third and fifth orders are calculated. Additionally, errors of the measured susceptibilities also are determined. Based on the expressions obtained, the analysis of phase shifts between components of flux density on different frequencies and the magnetic field strength also is performed. The comparison of the calculated and measured output voltage waveforms allows concluding that in the frequency range where losses are small and can be neglected, the susceptibility of the third order is negative but that of the fifth order is positive.

Resonant and Non-resonant Nonlinear Optical Properties of Er3+ modified BaO-ZnO-B2O3 Glasses at 532 and 1550 nm

Er2O3 doped Barium-Zinc-Borate glasses with compositions xEr2O3-(100-x)[0.1BaO-0.4ZnO-0.5B2O3]; x = 0.5, 1.0, 1.5 and 2.0 have been prepared by melt quench technique. The amorphous nature of glasses has been ascertained by X-ray diffraction patterns. Fourier Transform Infrared (FTIR) spectra of the prepared glasses indicate that Er2O3 acts as glass modifier. With the increase in Er2O3 content, BO4 structural units start converting into BO3 structural units. The values of optical energy band gap (Eg) are observed to decrease with the increase in Er2O3 content. The values of nonlinear absorption coefficient (β) and nonlinear refractive index (n2) have been estimated by fitting of experimental data with theoretical models and both are found to increase with the increase in Er3+ ions concentration at 532 nm as well as 1550 nm excitation wavelengths. The calculated values of total third order nonlinear susceptibility (χ(3)) are observed to increase with the increase in Er3+ ions concentration.

Novel axially substituted lanthanum phthalocyanines: Synthesis, photophysical and nonlinear optical properties

Materials with excellent nonlinear optical (NLO) properties are usually applied in optoelectronics and optical limiting devices. Photoinduced intramolecular electron transfer (PET) and energy transfer (ET) play an important role in enhanced NLO properties. Through axially connected anthraquinone to phthalocyanine, two types of novel lanthanum phthalocyanine (LaPc-Aqn and HLaPc-Aqn) were designed to effectively improve PET/ET process, and thus leading to excellent NLO properties. Hyperbranched phthalocyanines possess enhanced NLO properties owing to their special three-dimensional structures that have more donor–acceptor (D–A) systems in their cell structure than lanthanum phthalocyanines. The uniform polyphenylsulfone composite film(HLaPc-Aqn-PPSU) was prepared by a simple solution casting method according to the “like dissolves like” theory. The values of large third-order nonlinear susceptibility (Im[χ(3)]) and low limit threshold (Ilim) were 1.51 × 10−9 esu and 0.015 J/cm2, respectively, demonstrating that the film had great optical limiting performance. Such research can contribute to the development of novel phthalocyanine materials for nonlinear optics and optical limiting devices.

Structural, linear and nonlinear optical characterization of Ni and Al Co-Doped CdO semiconductor nanostructures for nonlinear optical device applications

The effects of metallic doping (Ni and Al) on thin film CdO nanostructures have been investigated and their morphological, structural, linear and nonlinear optical properties have been studied. Thin films were grown using spray pyrolysis method with a substrate temperature of 300 °C for different Ni and Al doping concentrations (0, 1, 3, 5 and 10 wt%). Studies of films with Powder X-ray diffraction confirm the polycrystalline nature with the cubic crystal structure. The Scherer rule was employed to determine the crystallite size and found to be enhanced. The elemental analysis confirms the incorporation of Ni and Al into the host CdO matrix. The surface morphology was analysed using the Field Emission Scanning Electron Microscope and the grain size was found to be altered by increasing the doping content. To understand the characteristics of the defect state, open and closed aperture Z-scan measurement was performed using the DPSS continuous wave (532 nm) laser excitation and nonlinear absorption, refractive index and nonlinear susceptibility values of third order were calculated and found to be increasing with the increased concentration of the dopants. The encouraging findings of the nonlinear optical parameters with the increasing concentration of Ni and Al on CdO nanostructures indicate that doped films are a promising source for nonlinear device applications.

An analysis of spectroscopic, computational and biological activity studies of L-shaped sulfamoylbenzoic acid derivatives: A third order nonlinear optical material

The current article focuses mainly on investigation of structural, reactivity, topology studies, and third order nonlinear optical properties of the synthesized 2-(benzylamino)-4-chloro-5-sulfamoylbenzoic acid (BACSBA) with the aid of spectroscopic techniques and computational methods. The structure in the solid state was obtained unambiguously by SCXRD study that revealed that BACSBA has L-shaped structure stabilized by N–H⋯O intramolecular hydrogen bond. Further, the two dimensional sheet like architecture formation by linking of molecules via O–H⋯O and N–H⋯O hydrogen bonds, were visualized both qualitatively and quantitatively by Hirshfeld surface analysis. Also, a topological analysis made through Quantum Theory of Atoms In Molecules (QTAIM) highlights the observations N–H⋯O bonds on solid state. The quantum chemical calculation was performed at DFT/6–311++G (d,p) level of basis set. The analysis of each vibrational wave number was performed with the help of potential energy distribution (PED) using VEDA4 software and correlation with experimental data shows good concurrence. The reactive sites have been predicted and visualized by molecular electrostatic surface potential (MESP) and Fukui function calculation, together with hydrogen bond dissociation energy (H-BDE) for the BACSBA compound. Frontier molecular orbitals (FMO), global reactivity parameters, natural bond orbital analysis (NBO), localized orbital locator (LOL) and electron localization function (ELF) properties have also been studied for the titled compound. The super molecule (SM) approach with 372,680 atoms at the DFT/CAM-B3LYP/6–311++G (d,p) level was used for calculating the nonlinear optical properties of the crystal. The electrical parameters such as total dipole moment, average linear polarizability and average second IDRI hyperpolarizability were calculated. In addition, the linear refractive index and the nonlinear third order macroscopic susceptibility of the crystal was estimated as a function of the frequency of the applied electric field. The value of third order nonlinear susceptibility for the BACSBA crystal at 532 nm was found to be 45.57 times greatest than the experimentally measured result of organic crystal (2E)-1-(3-bromophenyl)-3-[4 (methylsulfanyl)phenyl]prop-2-en-1-one (3Br4MSP) demonstrating that BACSBA crystal could be a good potential candidate for nonlinear optical applications. In addition, the thermal stability was studied showing that the crystal as potential optical devices at temperature up to 234 °C. Furthermore, preliminary studies revealed that BACSBA compound displayed promising antifungal and antioxidant activities compared with the standard drugs.

Interpretation of structural, spectral and nonlinear optical properties of a new semiorganic crystal: Rubidium bis(2-methyllactato) borate monohydrate

Rubidium bis (2-methyllactato) borate monohydrate (RbMB) was developed by adopting slow solvent evaporation technique. Good crystalline nature of RbMB is confirmed by powder X-ray diffraction analysis. The optical transparency window is observed from 190 nm to 1100 nm. FTIR and FT-Raman spectral analysis endorses the formation of RbMB crystal. Thermal stability of RbMB extends upto 134 °C. Molecular structure of RbMB crystal is interpreted through the observed chemical shifts through 1H NMR and 13C NMR spectroscopy. The intermolecular interactions between organic and inorganic moieties are well established. These intermolecular interactions and electron delocalization enhances the third order nonlinear susceptibility (χ3) value and is found as 3.75354·X10−6 esu. The self-defocusing and reverse saturable absorption nature gives negative non-linear refractive index (n2) and positive nonlinear absorption co-efficient (β). This made RbMB a suitable candidate for using in Q-switching, optical pulse shorteners and optical energy limiters applications.

An investigation on structural, morphological, optical and third order nonlinear properties of facilely spray pyrolysis fabricated In:CdS thin films

Owing to the tremendous applications of cadmium sulphide (CdS), the fabrication of different content of In doped (0.0, 0.5, 1.0, 2.5 and 5.0 wt%) CdS thin films has been carried out facilely by spray pyrolysis technique. X-ray diffraction and FT-Raman studies confirm the single phase of CdS with hexagonal crystal system. The Scherrer rule was employed to determine the crystallite size and found to be reduced from 20 to 18 nm. The elemental composition and mapping studies shows that the prepared films contain In in CdS which is homogeneously distributed all over the film. The surface morphology was studied and noticed to be modified with increasing the content of In doping. The emission spectra were recorded at λexc = 450 nm and an intense green emission was observed at 529 ± 16 nm for pure and In:CdS films. The optical study reveal that the optical transparency is enhanced from 65% to 75% with In doping. The refractive index was noticed in range from 1 to 2.8. The direct optical energy gap was estimated in the range from 2.31 to 2.46 eV and shows reduction with In content. The open and closed aperture Z-scan measurement was carried out and nonlinear absorption, third order nonlinear susceptibility and refractive index values were determined and found in range from 3.12 × 10−3 to 5.37 × 10−3 cm/W, 4.67 × 10−1 to 7.01 × 10−1 esu and 2.14 × 10−7 to 5.99 × 10−7 cm2/W, correspondingly.

Probing the structure–property relationship of a new semiorganic nonlinear optical crystal: catena-poly[bis(4-methylbenzylammonium) [[dibromidocadmate(II)]-di-l-bromido

A new semiorganic single crystal, catena-Poly[bis(4-methylbenzylammonium) [[dibromidocadmate(II)]-di-l-bromido]],[4MLBDCB], has been developed by evaporating the solvent at a 37 °C. It crystallizes in centrosymmetric space group Pnma. In the crystal structure, 4-methylbenzylammonium cation and tetrabromido cadmate anion are connected by N–H⋯Br and C-H⋯Br hydrogen bonds. Functional groups vibrations of 4MLBDCB were analysed by FT-Raman and FTIR spectroscopy. The stretching vibration of NH and CH shifted towards lower frequency side and their bending vibrations (–NH, –CH) to higher frequency when compared with pure 4 methylbenzylamine (4MLBA) vibrations. The observed variations in CH bond length are discussed. Presence of Raman active CdBr42− vibrations ensures the formation of the molecule. Transmittance bandwidth of the crystal extends from 260 and 1100 nm. In 1H and 13C NMR spectra, the observed variations in the chemical shifts are interpreted through intermolecular interactions. The presence of hydrogen bonds enhances the third order nonlinear susceptibility (χ3) value of the grown crystal and found to be 5.04 × 10−6 esu. The third order nonlinear optical parameters such as absorption coefficient (β) and refractive index (n2) are also determined using Z-scan technique.

Synthesis and characterization of nickel doped zinc selenide nanospheres for nonlinear optical applications

Phase purity plays an important role in determining the properties of the material and its subsequent applications which depends on the synthesis conditions and dopant concentrations. Phase pure zinc selenide and nickel doped zinc selenide nanoparticles were synthesized by hydrothermal method using sodium selenite as precursor. Calculated crystallite size for various compositions showed a decrease with dopant concentration with the values around 10 nm and less. Morphological analysis showed the formation of spherical particles which is distinct in the micron scale image. SAED pattern showed the formation of nanocrystalline particles with particles size varying between 10 and 20 nm. Quantum confinement effect due to reduced size was corroborated with increased band gap values as measured from diffuse reflectance spectra. Photoluminescence spectra showed the presence of dominant near band-edge emission along with certain defect level emissions for all the samples. Nonlinear optical studies carried out using a continuous wave laser showed an increase in nonlinear refractive index and susceptibility values with dopant concentration signifying the role of defects and the structural modifications occurring due to doping. The nonlinear optical properties exhibited by this material has been utilized for device applications like optical limiting and the results show enhancement in limiting efficiency with dopant concentrations.

Non-linear optical response of meso substituted dipyrromethene boron difluoride dyes: Synthesis, photophysical, DFT and Z scan study

2-(Naphthalen-2-yl)benzo[d]thiazole meso fused dipyrromethene boron difluoride dyes are synthesised and their linear and non-linear optical properties are studied. The third order nonlinear susceptibility (χ3) value obtained from the Z-scan experiment is 11.21 × 10−13 and 13.30 × 10−13 esu. The global hybrid (B3LYP and BHHLYP) and range-separated hybrid (CAM-B3LYP) functional with the basis set 6-311++G(d,p) performed better in computing the linear and non-linear optical properties. The computed β0 value (56.36 × 10−30 esu and 48.64 × 10−30 esu for Kr-OH-BDY and Kr-OMe-BDY respectively) of both the dyes are superior to that of urea (βo = 0.371 × 10−30 esu). Thermal and reorientational study display the dominating electronic contribution to the linear polarizability (α) whereas for first-order hyperpolarizability (β), pure vibrational contributions found to be more operative in both the dyes. The geometries of the dyes were optimized by using B3LYP/6-311++ G(d,p) level of theory.

Influence of thiophene spacer and auxiliary acceptor on the optical properties of 4-(Diethylamino)-2-hydroxybenzaldehyde based D-π-A-π-D Colorants with N-alkyl donors: Experimental, DFT and Z-scan study

We report here design and synthesis of four new D-π-A-π-D type dyes (4 and 5) with triphenylamine/N-ethyl carbazole as fixed rotor/donor and N, N-diethyl amine as a secondary donor having dicyanovinylene as a common acceptor. The Influence of π-linker (thiophene) along with an auxillary cyano group on the nonlinear and linear optical properties is investigated. Molecules with thiophene spacer (4b and 5b) exhibit progressive variation in their absorption and emission profiles reflecting the effect of π-linker, compared to those devoid of thiophene spacer (4a and 5a). The dyes display solvent dependent emission [e.g. 4b (toluene = 689 nm) and 5b (DMSO = 795 nm)] suggesting a more polarized photo-excited state arising as a result of enhanced intramolecular charge transfer in the excited state. The solvatochromic nature is supportive of a general solvent effect, which is confirmed by solvent polarity plots (Weller’s and Rettig’s plot). The trends in the optical properties were also validated by time dependent density functional theory computations which further reveals charge transfer (from secondary donor to acceptor) for the long wavelength absorption. Dye with the highest charge transfer dipole moment relatively has the maximum two-photon absorption cross-section area (4b = 246–399 GM) which was established using theoretical two-level model. Non-linear optical properties were investigated using solvatochromic two-level model and computationally using global and range separated hybrid functionals. The dyes show high first-order hyperpolarizability (β0) in the range of 191–1162 × 10−30 e.s.u. and second-order hyperpolarizability (γ0) in the range of 491–6,704 × 10−36 e.s.u. Z-scan results show 4a (3.79 × 10−13 e.s.u.) possesses a higher value of third order nonlinear susceptibility in DMSO. Thus, the dyes can be considered as promising candidates for NLO application in material science.

Effect of Gamma Radiation Induced on Structural, Electrical, and Optical Properties of N, N′-Dimethyl-3,4,9, 10-Perylenedicarboximide Nanostructure Films

N,N′-Dimethyl-3,4,9,10-perylenedicarboximide (PTCDI-C1) thin films were first prepared by thermal evaporation technique. Then, the prepared films were irradiated with gamma rays at room temperature with different absorbed doses. The structure of PTCDI-C1 films at different doses of gamma radiation was elucidated by x-ray diffraction. The results confirmed that PTCDI-C1 film has a nanostructure morphology. The grain size was observed to decrease slightly with increasing the gamma radiation doses. The temperature dependence of the electrical conductivity was measured in the temperature range of 293–423 K. It was found that the obtained activation energy of PTCDI-C1 films decreased with increasing gamma radiation dose. The optical parameters were obtained using spectrophotometric measurements. The single oscillator model of Wemple–Didomenico was adopted to study the normal dispersion of refractive index. The optical dispersion parameters of PTCDI-C1 films such as dispersion energy, oscillator energy and the high frequency dielectric constant were calculated. Furthermore, the nonlinear susceptibility values of PTCDI-C1 films at different gamma radiation dose were calculated. Also, the dielectric constants of the films were investigated in a large range of frequencies. The fundamental band gap energy values (3.91 eV Eg2 > 50 kGy).

Optical second harmonic generation in encapsulated single-layer InSe

We report the observation of optical second harmonic generation (SHG) in single-layer indium selenide (InSe). We measure a second harmonic signal of > 103 cts/s under nonresonant excitation using a home-built confocal microscope and a standard pulsed pico-second laser. We demonstrate that polarization-resolved SHG serves as a fast, non-invasive tool to determine the crystal axes in single-layer InSe and to relate the sharp edges of the flake to the armchair and zigzag edges of the crystal structure. Our experiment determines these angles to an accuracy better than ± 0.2°. Treating the two-dimensional material as a nonlinear polarizable sheet, we determine a second-order sheet polarizability |χsheet(2)|=(17.9 ± 11.0)×10−20 m2 V−1 for single-layer InSe, corresponding to an effective nonlinear susceptibility value of |χeff(2)|≈(223 ± 138)×10−12 m V−1 accounting for the sheet thickness (d ≈ 0.8 nm). We demonstrate that the SHG technique can also be applied to encapsulated samples to probe their crystal orientations. The method is therefore suitable for creating high quality van der Waals heterostructures with control over the crystal directions.

Fluorescent meso-benzyl curcuminoid boron complex: Synthesis, photophysics, DFT and NLO study

Curcumin based fluorescent NLOphore was synthesized. Solvent polarizability (SP) was found to be responsible for the solvatochromic nature of dye as confirmed from the multilinear regression analysis. DFT computations using global hybrid (B3LYP and BHHLYP) and range-separated hybrid (CAM-B3LYP) functionals with the basis set 6-31 + G(d,p) were performed to determine the linear as well as NLO properties. NLO response was measured using Z scan technique. The computed NLO values (βo = 426.64 × 10−30 esu) were found to be superior to that of urea (βo = 0.371 × 10−30 esu). The value of nonlinear absorption coefficient (β) and third-order nonlinear susceptibility (χ)3 were found to be 2.19 × 10−12 (m/W) and is 2.09 × 10−13 (e.s.u) respectively. The result of present work might be useful for the designing of curcumin based NLOphores for industrial applications.

Design, growth and characterization of D-π-A-π-D based efficient nonlinear optical single crystal for optical device applications

Third order nonlinear material of 4-[(1 E)-3-(5-chlorothiophen-2-yl)-3-oxoprop-1-en-1-yl]phenyl4-methylbenzene-1-sulfonate (4 TP MS) was synthesized by Claisen Schmidt condensation reaction method and single crystals were grown by slow evaporation technique. The functional groups corresponding to the vibrational frequencies has been confirmed through FT-IR and FT-RAMAN spectroscopic techniques. The single crystal XRD analysis revealed the crystal is belonging to monoclinic crystal structure with P21/n space group. The optical properties were studied by UV-VIS spectroscopy and photoluminescence spectroscopy. The cut-off wavelength of 4 TPMS is found to be 432 nm and the crystal is transparent in entire visible and near IR region. Using absorbance data, the parameters like extinction co-efficient, reflectance, electrical conductivity, optical conductivity, complex dielectric constant, lattice dielectric constant and ratio of carrier concentration to effective mass has been analyzed. The crystal has blue light emission property with less defects were observed from photoluminescence studies. The 4 TPMS is thermally stable up to 254 °C. The dielectric properties like dielectric constant and dielectric loss were studied. The low value dielectric loss at high frequency region enhances the optical quality of the material. The third order nonlinear properties of nonlinear absorption and nonlinear refraction were studied through open/closed aperture Z-Scan technique. The high value nonlinear absorption co-efficient of 4 TPMS makes the material suitable for optical limiting application. These optical limiting properties were extracted from open aperture Z-Scan data and this behavior is due to reverse saturable absorption. The large value of third order nonlinear susceptibility is of the order of 10−11 esu and material has better capability to be used optical device applications.

Effects of Mn doping on the structural, linear, and nonlinear optical properties of ZnO nanoparticles

In this study, the synthesis and characterization of undoped and Mn-doped ZnO nanoparticles with 2%, 5%, and 15% Mn/ZnO prepared using the hydrothermal method were reported. The structural, morphological, and chemical-bond properties of the Mn-doped ZnO nanoparticles were studied by using x-ray diffraction, field emission scanning electron microscopy (FESEM), energy dispersive x-ray analysis, and Fourier transform infrared spectroscopy analysis. X-ray diffraction patterns indicate that all of the samples have hexagonal wurtzite structures. The average diameters of the Mn-doped ZnO nanoparticles with different Mn/ZnO ratios were estimated to be about 20–38 nm from the FESEM images. The linear absorption coefficient and optical band gap energy of ZnO and Mn-doped ZnO nanoparticles were calculated using UV-Vis spectroscopy. A decrease in Eg was observed by an increase in Mn concentration. The nonlinear optical measurements have been performed using a nanosecond Nd:YAG pulse laser by the Z-scan technique. Both the undoped and Mn-doped ZnO nanoparticles exhibited a negative nonlinear optical index of refraction at 532 nm relating to the self-defocusing phenomenon. The nonlinear optical absorption of ZnO and Mn-doped ZnO nanoparticles is attributed to two-photon absorption combined with free carrier absorption. Furthermore, the third-order nonlinear susceptibility values of the undoped and Mn-doped ZnO nanoparticles varied between 1.2−2.5×10−9 esu, depending on the Mn contents. The results suggest that a Mn dopant can improve the nonlinear optical properties of ZnO nanoparticles, and Mn-doped ZnO nanoparticles synthesized through the hydrothermal method may be a promising candidate for nonlinear optical applications at 532 nm.