Nonlinear Optical Research Articles

Self-induced transparency of long water waves over bathymetry: the dispersive shock mechanism

The shoreline hazard posed by ocean long waves such as tsunamis and meteotsunamis critically depends on the fraction of energy transmitted across the shallow near-shore shelf. In linear setting, bathymetric inhomogeneities of length comparable to the incident wavelength act as a protective high-pass filter, reflecting long waves and allowing only shorter waves to pass through. Here, we show that, for weakly nonlinear waves, the transmitted energy flux fraction can significantly depend on the amplitude of the incoming wave. The basis of this mechanism is the formation of dispersive shock waves (DSWs), a salient feature of nonlinear evolution of long water waves, often observed in tidal bores and tsunami/meteotsunami evolution. Within the framework of the Boussinesq equations, we show that the DSWs efficiently transfer wave energy into the high wavenumber band, where reflection is negligible. This is phenomenologically similar to self-induced transparency in nonlinear optics: small amplitude long waves are reflected by the bathymetric inhomogeneity, while larger amplitude waves that develop DSWs blueshift into the transparency regime and pass through. We investigate this mechanism in a simplified setting that retains only the key processes of DSW disintegration and reflection, while the effects such as bottom dissipation and breaking are ignored. The results suggests that the phenomenon is a robust, order-one effect. In contrast, the increased transmission due to the growth of bound harmonics associated with the steepening of the wave is weak. The results of the simplified modelling are validated by simulations with the FUNWAVE-TVD Boussinesq model.

Deep learning with photonic neural cellular automata.

Rapid advancements in deep learning over the past decade have fueled an insatiable demand for efficient and scalable hardware. Photonics offers a promising solution by leveraging the unique properties of light. However, conventional neural network architectures, which typically require dense programmable connections, pose several practical challenges for photonic realizations. To overcome these limitations, we propose and experimentally demonstrate Photonic Neural Cellular Automata (PNCA) for photonic deep learning with sparse connectivity. PNCA harnesses the speed and interconnectivity of photonics, as well as the self-organizing nature of cellular automata through local interactions to achieve robust, reliable, and efficient processing. We utilize linear light interference and parametric nonlinear optics for all-optical computations in a time-multiplexed photonic network to experimentally perform self-organized image classification. We demonstrate binary (two-class) classification of images using as few as 3 programmable photonic parameters, achieving high experimental accuracy with the ability to also recognize out-of-distribution data. The proposed PNCA approach can be adapted to a wide range of existing photonic hardware and provides a compelling alternative to conventional photonic neural networks by maximizing the advantages of light-based computing whilst mitigating their practical challenges. Our results showcase the potential of PNCA in advancing photonic deep learning and highlights a path for next-generation photonic computers.

Unveiling the NLO Potential of New Zn (II) Complex of 6‐Methylpyridine‐2‐Carboxaldehyde: Experimental/DFT Study on Spectral, Static, and Frequency‐Dependent Linear/Nonlinear Optical Parameters

ABSTRACTOngoing exploration focuses on synthesizing and characterizing coordination compounds to improve the design of nonlinear optical (NLO)‐based materials. In this regard, to examine spectral and static/frequency–dependent linear/NLO parameters, the new Zn (II) complex {[Zn(6‐MePyAld)2(Cl)]; 6‐MePyAld: 6‐methylpyridine‐2‐carboxaldehyde} was synthesized and characterized by using 1H and 13C NMR, mass (LC‐HRMS), powder XRD, and FTIR spectra. The electronic features of synthesized complex were investigated by considering the TD‐CAM‐B3LYP/ and TD‐M06L/6‐311G(d,p)//LanL2DZ levels of time‐dependent density functional theory (TD‐DFT). Moreover, the theoretical linear optical (LO), second‐, and third‐order NLO susceptibility tensors/polarization (χ(1)/P(1), χ(2)/P(2), χ(3)/P(3)) parameters for the Zn (II) complex were computed using the DFT/M06L and DFT/CAM‐B3LYP levels. The external electric field (E), polarization (P), and electric displacement (D) values of the Zn (II) complex were also calculated using the same DFT levels. To investigate microscopic LO (isotropic polarizability <α(0;0)>/<α(−ω;ω)>, and anisotropic polarizability (∆α (0;0)/∆α (−ω;ω)) and second‐/third‐order NLO (<β(0;0,0)>/<β(−ω;ω,0), <β(−2ω;ω,ω)>/<γ(0;0,0,0)>/<γ(−ω;ω,0,0)> and <γ(−2ω;ω,ω,0)>) parameters for the Zn (II) complex, the DFT/M06L and DFT/CAM‐B3LYP levels in the gas phase were used. The ∆α (0;0), ∆α (−ω;ω), <β(0;0,0)>, <β(−ω;ω,0)>, and <β(−2ω;ω,ω)> for Zn (II) complex were computed at 17.288 × 10−24, 21.782 × 10−24, 14.692 × 10−30, 466.80 × 10−30, and 210.79 × 10−30 esu, respectively, by using the DFT/CAM‐B3LYP level. Moreover, the <γ(0;0,0,0)>/<γ(−ω;ω,0,0)> and <γ(−2ω;ω,ω,0)> in the gas phase computed at the DFT/CAM‐B3LYP level for Zn (II) complex were obtained at 129.74 × 10−36, 3997.6 × 10−36, and −886.60 × 10−36 esu, in turn. According to the CAM‐B3LYP level, the <γ(0;0,0,0)> value is 8.65 and 18.53 times higher than the values of para‐nitroaniline (pNA) and urea, respectively. The obtained static/dynamic β and γ values of Zn (II) complex are greater than those of urea and pNA. Zn (II) complex exhibited remarkably microscopic second‐order and particularly third‐order NLO features. It is predicted that our study will shed light on NLO materials that might be used in telecommunication and optoelectronics.

Surface-near domain engineering in multi-domain x-cut lithium niobate tantalate mixed crystals

Lithium niobate and lithium tantalate are among the most widespread materials for nonlinear, integrated photonics. Mixed crystals with arbitrary Nb–Ta ratios provide an additional degree of freedom to not only tune materials properties, such as the birefringence but also leverage the advantages of the singular compounds, for example, by combining the thermal stability of lithium tantalate with the larger nonlinear or piezoelectric constants of lithium niobate. Periodic poling allows to achieve phase-matching independent of waveguide geometry and is, therefore, one of the commonly used methods in integrated nonlinear optics. For mixed crystals, periodic poling has been challenging so far due to the lack of homogeneous, mono-domain crystals, which severely inhibit domain growth and nucleation. In this work, we investigate surface-near (<1μm depth) domain inversion on x-cut lithium niobate tantalate mixed crystals via electric field poling and lithographically structured electrodes. We find that naturally occurring head-to-head or tail-to-tail domain walls in the as-grown crystal inhibit domain inversion at a larger scale. However, periodic poling is possible if the gap size between the poling electrodes is of the same order of magnitude or smaller than the average size of naturally occurring domains. This work provides the basis for the nonlinear optical application of lithium niobate tantalate mixed crystals.

Toward Strong UV-Vis-NIR Second-Harmonic Generation by Dimensionality Engineering of Zinc Thiocyanates.

The precise modulation of the spatial orientations and connection modes of primitives is vital for certain critically important optical functions for nonlinear optical (NLO) materials (specifically, second-harmonic generation (SHG) and optical bandgap); however, we are yet to achieve a sufficient level of control for the designed construction of efficient broadband NLO materials. Exploiting the changes in microscopic polarization that may result from dimensional increase, we propose herein a zero-dimensional (0D)-to-three-dimensional (3D) dimensionality-increase strategy to realize strong broadband SHG responses for the first time. The novel 3D pseudo diamond-like Zn(SCN)2 has been synthesized by removing SHG-inactive [NH4]+ counter cations and H2O molecules that are located between the adjacent discrete [Zn(SCN)4] building blocks within the 0D (NH4)2Zn(SCN)4·3H2O. The 0D-to-3D dimensionality engineering, proceeding from (NH4)2Zn(SCN)4·3H2O to Zn(SCN)2, results in significantly enhanced SHG responses and efficient broadband activity (8 × KH2PO4 @ 1064 nm, 4.18 eV bandgap for the former c.f. 2 × β-BaB2O4 @ 380 nm, 30 × KH2PO4 @ 1064 nm, 2 × KTiOPO4 @ 2100 nm, 4.78 eV bandgap for the latter) from the UV to the NIR regions (SHG@300-1050 nm). Theoretical calculations and crystal structure analyses reveal that the coordination-bond-connected [Zn(SCN)4] building blocks within the diamond-like structure of Zn(SCN)2 are responsible for its giant broadband SHG responses.

Octave-wide broadening of ultraviolet dispersive wave driven by soliton-splitting dynamics

Coherent dispersive wave emission, as an important phenomenon of soliton dynamics, manifests itself in multiple platforms of nonlinear optics from fibre waveguides to integrated photonics. Limited by its resonance nature, efficient generation of coherent dispersive wave with ultra-broad bandwidth has, however, proved difficult to realize. Here, we unveil a new regime of soliton dynamics in which the dispersive wave emission process strongly couples with the splitting dynamics of the driving pulse. High-order dispersion and self-steepening effects, accumulated over soliton self-compression, break the system symmetry, giving rise to high-efficiency generation of coherent dispersive wave in the ultraviolet region. Simultaneously, asymmetric soliton splitting results in the appearance of a temporally-delayed ultrashort pulse with high intensity, overlapping and copropagating with the dispersive wave pulse. Intense cross-phase modulations lead to octave-wide broadening of the dispersive wave spectrum, covering 200–400 nm wavelengths. The highly-coherent, octave-wide ultraviolet spectrum, generated from the simple capillary fibre set-up, is in great demand for time-resolved spectroscopy, ultrafast electron microscopy and frequency metrology applications, and the critical role of the secondary pulse in this process reveals some new opportunities for all-optical control of versatile soliton dynamics.

Magnetic field-engineered optical nonlinearity in germanene nanotubes

Abstract The linear and nonlinear optical properties of germanene nanotubes (GeNTs) under the influence of magnetic fields are investigated through theoretical analysis. By employing a tight-binding model beyond the Dirac cone approximation, the electronic band structure, density of states, dipole matrix elements, and third-order nonlinear optical susceptibilities are calculated. The application of a magnetic field induces a Zeeman splitting of the energy levels, breaking the band degeneracy. Consequently, the dipole matrix elements exhibit a magnetic field dependence, altering the intensity and number of allowed transitions. In the infrared and ultraviolet energy regions, the linear optical absorption spectrum displays the splitting of peaks into dual neighboring peaks, with the splitting distance linearly dependent on the magnetic field strength. The third-order nonlinear optical susceptibilities, χTHG(3)3ω and χIDIR(3)ω, reveal the emergence of multiple resonance peaks in different energy regions due to two-photon and three-photon absorption processes. The magnetic field significantly influences the number, position, and height of these optical peaks, enabling effective control over the nonlinear optical response. By investigating the scaled energy (E/E_g) dependence, a universal behavior is observed for the three- and two photon resonance peaks, where their positions remain constant, but their peak intensities are significantly enhanced under the influence of the magnetic field. These findings demonstrate the potential of GeNTs as tunable nonlinear optical materials, with the magnetic field serving as an effective parameter for engineering their optical properties for various applications in optoelectronics, photonics, and related fields.

High-order solitary waves, fission, hybrid waves and interaction solutions in the nonlinear dissipative (2+1)-dimensional Zabolotskaya-Khokhlov model

The Zabolotskaya-Khokhlov model (ZKm) is a widely used nonlinear model in the fields of sound, ultrasound, and shock waves. The aims of this paper stems from its examination and rectification of earlier results concerning the N-soliton solutions of nonlinear dissipative (2+1)-dimensional ZKm. By recognizing and incorporating the non-zero values of the dispersion coefficient , this study addresses a significant omission in current research. The findings enhance the comprehension of higher-order soliton behaviors, encompassing bifurcation solitons, higher-order breathers, rogue waves, periodic lumps, and their interactions, which are crucial for both theoretical studies and practical applications in areas like nonlinear optics and fluid dynamics. Subsequent detailed numerical simulations are conducted to elucidate the complex behaviors of the obtained solutions. This thorough exploration provides crucial insights into the intricate patterns exhibited by the nonlinear dissipative (2+1)-dimensional ZKm under different conditions, enhancing our understanding of the underlying physical phenomena.

Investigation of synthesis, spectroscopic characterization, crystal structure, and computational studies of 3-(4-(dimethylamino)phenyl)-1,5-di(thiophen-2- yl)pentane-1,5-dione as potent against Cathepsin S

The chief purpose of this work was to synthesize and characterize 3-(4-(dimethylamino)phenyl)-1,5-di(thiophen-2-yl)pentane-1,5-dione (4) whose structure was subsequently confirmed by single-crystal X-ray analysis. This molecule adopts a conformation approximating a three-bladed fan. In the crystal, C–H···O and C–H···S hydrogen bonds, together with C–H···π(ring) interactions form corrugated layers parallel to the bc plane. Electronic structure calculations were performed at the ωB97xd/def2tzvp level to explore the reactivity and topology of the molecule. Quantum theory of atoms in molecule (QTAIM) and NBO studies provide bonding characteristics and the extent of charge transfer with orbital energies computed from FMO theory together with optical and nonlinear optical (NLO) properties. A Hirschfeld surface analysis was performed to explore the nature of interactions in the crystal packing and the dispersion interactions were found to have a significant role in stabilizing the crystal structure. The H···H interactions are the most significant among the intermolecular interactions. Compound 4 was subjected to structural activity relationship analysis and exhibited potency against Cathepsin S. Molecular docking and molecular dynamics analysis were carried out to understand the binding interaction mechanism and stability of 4 in its complex with Cathepsin S.

Near-field enhancement of light by higher-order multipole excitations in a metal nanodisc trimer

Near-field enhancement of light by dipole excitations in plasmonic nanoparticles plays an important role in many applications of optical nanotechnology, including solar cells, plasmonic sensors, and nonlinear optical devices. Recently, we have shown that a seemingly weak octupole resonance in a pair of metal nanospheres can provide a higher near-field enhancement than the dipole resonance. Being motivated by this discovery, we now design a plasmonic nanodisc trimer that supports hybridized higher-order excitations and simultaneously suppresses the dipole excitation. We show that, under these conditions, the near-field enhancement can reach a high level, exceeding the value achievable with a corresponding dimer structure. The interference of the electric currents belonging to different multipole moments is found to play an important role in the enhancement. We believe that arrays of similar metal nanostructures can be designed to enhance optical fields via higher-order resonances for many applications, e.g., in nonlinear optics and optical sensing based on surface-enhanced fluorescence or Raman scattering.

Bismorpholin-4-ium tetrabromo-cadmium metal-organic single crystal delivering Crystal structure, physicochemical properties and Characterizations for Optoelectronic Applications

For the development of nonlinear optical (NLO) materials, compositions of cadmium chloride (CC) and Morpholinium bromide (MB) molecules were utilized to form metal-organic materials. Morpholinium bromide was incorporated with cadmium metal to have electron charge transfer by constructing acentric structures that take advantage of strong third-order nonlinear optical properties. Bis Morpholinium cadmium bromide (BMCB) crystals were synthesized by a slow evaporation method (SEST). The BMCB crystal belongs to monoclinic P21/c space group with four molecules in the unit cell (a=6.7607(4) Å, b=16.5811(2) Å, c=14.9744(2) Å, β=94.136(3) ° and Z=4). The grown BMCB crystal phase purity and crystallinity were further investigated using powder X-ray diffraction (PXRD) analysis. Using Fourier transform infrared (FTIR) spectroscopy, the functional groups and their vibrational states were evaluated. From the results obtained from UV-vis-NIR spectral analysis, it is clear that the title compound is transparent in the visible range with the lower cut-off wavelength of 254 nm. The TG-DTA measurement has been used to evaluate thermal stability. Microhardness measurements were carried out to evaluate the mechanical stability of the grown crystal. The third-order nonlinear optical (NLO) characteristics were studied using Z-scan technique. The grown crystal exhibits outstanding third-order NLO response and wide laser damage threshold (LDT), which are crucial characteristics for developing practical NLO devices. The findings consequently open a novel path for the logical design of enormous, thermally stable and NLO-active metal-organic complexes for NLO applications.

Exploring nonlinear optical properties of RbPbI3 nanorods using SSPM technique: Implications for all-optical switching applications

Nowadays, nanomaterials' nonlinear optical (NLO) properties are a fascinating topic for developing a novel all-optical switching application. Spatial self-phase modulation (SSPM) is an important technique to determine the laser-induced coherent light-matter interaction to determine the NLO properties of nanomaterials. This study successfully synthesized RbPbI3 nanorods (NRs) via a low-cost, less complicated chemical route with all the basic characterizations to confirm its structural and compositional analysis. For the first time, we conducted a comprehensive analysis of the nonlinear refractive index (n2) and third-order susceptibility (χ(3)) for RbPbI3 NRs dissolved in two different solvents, namely N-Methyl-2-pyrrolidone (NMP) and 2-propanol, utilizing the SSPM technique. Our investigation revealed significant nonlinear optical (NLO) responses with n2 = 6.19 × 10−5 cm2 W−1 and χmonolaer(3) = 2.38 × 10−8 esu for RbPbI3. We elucidated the factors contributing to this pronounced NLO behaviour, including variations in parameters such as solvent type, viscosity, wavelength, and cuvette length. Additionally, we successfully demonstrated optical information transfer through an all-optical switching application. This research sheds light on the NLO properties of Perovskite materials and holds promise for the development of advanced all-optical device applications.

Electronic structure, global reactivity descriptors and nonlinear optical properties of glycine interacted with ZnO, MgO and CaO for bacterial detection

Modern laboratory medicine relies on analytical instruments for bacterial detection, focusing on biosensors and optical sensors for early disease diagnosis and treatment. Thus, Density Functional Theory (DFT) was utilized to study the reactivity of glycine interacted with metal oxides (ZnO, MgO, and CaO) for bacterial detection. Total dipole moment (TDM), frontier molecular orbitals (FMOs), FTIR spectroscopic data, electronic transition states, chemical reactivity descriptors, nonlinear optical (NLO) characteristics, and molecular electrostatic potential (MESP) were all investigated at the B3LYP/6–31G(d, p) level using DFT and Time-Dependent DFT (TD-DFT). The Coulomb-attenuating approach (CAM-B3LYP) was utilized to obtain theoretical electronic absorption spectra with the 6-31G(d, p) basis set to be more accurate than alternative quantum chemical calculation approaches, showing good agreement with the experimental data. The TDM and FMO investigation showed that glycine/CaO model has the highest TDM (10.129Debye) and lowest band gap (1.643 eV). The DFT computed IR and the experimental FTIR are consistent. The calculated UV-vis spectra showed a red shift with an increase in polarity following an increase in the absorption wavelength due to the interaction with ZnO, MgO, and CaO. Among the five solvents of water, methanol, ethanol, DMSO and acetone, the water and DMSO enhances the UV-Vis absorption. Glycine/CaO model showed high linear polarizability (14.629 × 10−24esu) and first hyperpolarizability (23.117 × 10−30esu), indicating its potential for nonlinear optical applications. The results showed that all model molecules, particularly glycine/CaO, contribute significantly to the development of materials with potential NLO features for sensor and optoelectronic applications. Additionally, MESP confirmed the increased electronegativity of the studied structures. Additionally, glycine/ZnO nanocomposite was synthesized and characterized using IR and UV-visible spectroscopy to determine their structural and spectroscopic features. It was discovered that there was good agreement between the DFT computed findings and the related experimental data. The antibacterial activity of glycine/ZnO nanocomposites against Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa were studied in terms of concentration and time. The results showed that increasing the concentration of glycine/ZnO nanocomposite significantly enhanced its antibacterial efficacy by lowering optical density. Notably, Pseudomonas aeruginosa exhibited lower susceptibility to the nanocomposite compared to S. aureus, requiring higher concentrations for effective bactericidal action. In summary, this study contributes novel insights into the dual functionality of glycine-metal oxide complexes, with significant implications as optical biosensor for microbial detection.

Theoretical investigation of enhanced nonlinear optical properties of silicene and carbon nanotubes: Potential applications in infrared and ultraviolet optoelectronics

This theoretical study investigates the linear and nonlinear optical properties of zigzag carbon nanotubes (CNTs) and silicene nanotubes (SiNTs) with varying radii, focusing on their behavior in the infrared and ultraviolet energy ranges. In the infrared region, absorption spectra exhibit several peaks resulting from allowed transitions between valence and conduction bands. The number of absorption peaks increases with radius for both nanotube types, with SiNTs showing peaks at lower energy ranges and higher intensities compared to CNTs. Conversely, CNTs display markedly higher absorption intensities in the ultraviolet region. The quadratic electronic optic (DC Kerr) effect reveals sharp peaks near the band gap with multiple sign changes, attributed to allowed optical transitions at band edges. The third-order optical susceptibility for both CNT and SiNT structures show several peaks below the band gap energy due to multiphoton resonance absorption. In the infrared region, two highest and lowest subbands near to the Fermi level play a dominant role in the χTHG(3)(3ω) peaks formation. The position and intensity of χTHG(3)(3ω) peaks demonstrate a strong dependence on nanotube radius and type with higher intensity for the SiNTs. The tunable nature of the optical properties of CNTs and SiNTs by their radius and the enhanced nonlinear optical response of SiNTs, characterized by lower energy peaks and higher intensities, show their significant potential for advanced applications in nonlinear optics, optical detection, and high-energy optical systems.

Tuning the photophysical and NLO properties of β-diketonates derived from coumarin-triphenylamine-chalcones: effect of the BF2 group.

Herein the synthesis of three difluoroboron β-diketonate complexes (7a-c) and one chalcone (7d) with coumarin and triphenylamine fragments is described. The effect of the inclusion of the difluoroboron (BF2) group and a phenyl linker on the photophysical properties, intramolecular charge transfer (ICT) and nonlinear optical (NLO) properties was studied. These dyes exhibited excellent ICT properties due to their A-π-D and D-π-A-π-D type push-pull configuration. Thus, all compounds presented a strong solvatochromism, given the absorption and emission maxima shifted to red because of the increase in the polarity of the medium. In addition to this, 7a-d showed the formation of a twisted intramolecular charge transfer (TICT) state, which quenched fluorescence in polar solvents. Compounds 7a, 7b and 7d exhibited aggregation-induced emission (AIE) in MeCN/H2O mixtures, while 7c did not have this behavior. In addition, all compounds showed emission in the solid state. Using DFT and TD-DFT calculations, the molecular geometries of the ground state S0 and the first excited state S1 were elucidated, which confirmed the formation of a TICT state. Furthermore, the theoretical and experimental absorption electronic transitions were correlated by testing different functionals: B3LYP, CAM-B3LYP, PBE0, wB97XD, HSEH1PBE and M062X. Frontier molecular orbitals (FOMs) and molecular electrostatic potentials (MEPs) supported the ICT from the donor to the acceptor group. The global reactivity descriptors were studied and the NLO properties were predicted by calculating first (βtot) and second-order (γave) hyperpolarizabilities, revealing that 7a-d would present promising NLO behavior.

Effect of alkyl chains on the structural and optical properties of nH6BiN orthoconic antiferroelectric liquid crystals: Insights from DFT calculations

This research presents a detailed computational study of a homologous series of orthoconic antiferroelectric liquid crystalline compounds, nH6BiN (where n = 1 to 6), employing Density Functional Theory (DFT) with the B3LYP functional and 6-311G(d,p) basis set. We optimized the molecular geometry and used it as an input file for analyzing thermodynamic properties, vibrational spectroscopy, and evaluating non-linear optical (NLO) properties to investigate the impact of terminal chain length on these compounds. The electronic structure analysis, including HOMO-LUMO gap and reactivity parameters, indicated consistent electronic properties across the series. Raman spectroscopy confirmed structural regularity, with characteristic vibrational modes. Notably, non-linear optical properties enhanced with chain length, as evidenced by increasing dipole moments, polarizabilities, and hyperpolarizabilities. The results highlight the influence of terminal chain length on the structural, electronic, and optical properties of the nH6BiN compounds, providing valuable insights for material design. This comprehensive study provides insights into the influence of terminal chain length on the molecular properties of the nH6BiN series, offering a foundation for their potential application in advanced material science.

Ternary Boron Carbon Nitride nanosheets with improved and controllable linear and nonlinear optical response for efficient photocatalytic performance

This work reports the systematic variation of linear and nonlinear optical (NLO) properties of ternary boron carbon nitride (BCN) nanosheets with varying carbon concentrations. These nanosheets are synthesized by the thermal substitutional method to modulate the band-gap of BCN nanosheets by varying the hBN and graphene domain ratios which is confirmed through UV-Vis absorption spectroscopy. The third-order optical nonlinearity of nanosheets was explored through the Z-scan technique. With increases in both carbon content and laser power, samples' NLO properties have shifted from saturable absorption to reverse saturable absorption. The enhanced nonlinearity with carbon concentration in BCN samples was responsible for higher photoinduced charge separation time. In UV-Vis driven photoreduction of organic pollutants, BCN nanosheets with a decreased bandgap and an increased charge separation time show higher catalytic efficiency. Therefore, based on the combined effect of many processes, the results revealed that the BCN nanosheets displayed greater potential for photoinduced reduction.

A systematic evaluation of Random Lasing, Third Harmonic Generation, and quantum chemical calculations in multifunctional perylene derivatives

The quest for multifunctional materials in the field of optoelectronics has become increasingly imperative, as it offers a pathway toward the development of highly versatile and efficient devices. In this study, we present a comprehensive overview of our achievements in the characterization of perylene derivative-based materials. This group of chromophores exhibits remarkable multifunctionality including Third Harmonic Generation (THG), Z-scan results, and excellent Random Lasing (RL) capabilities. Theoretical quantum chemical calculations (QCC) were conducted to investigate dipole moments, frontier molecular orbital HOMO and LUMO energies, optical band gap energies, as well as second hyperpolarizabilities (γ). The study revealed how groups attached to the perylene core influence the chromophore's dipole moment and, consequently, the nonlinear optical (NLO) properties of the investigated compounds. The combined theoretical and experimental analyses provide valuable insights for the design of various optoelectronic devices using thin films of perylene derivatives, enhancing the understanding of their nonlinear and laser action behavior.

Novel schiff base as potent antimalarial: Synthesis, single crystal x-ray structure, spectroscopic analysis, theoretical investigation and molecular docking studies

The title compound N’-[(E)-(2-Hydroxy-1-naphthyl)methylene]benzohydrazide was compounded completely by the condensation reaction between 2-hydroxynaphthaldehyde and benzhydrazide. The Schiff base obtained was attributed by single-crystal X-ray diffraction (SCXRD), FT-IR, UV–Visible spectroscopy, and mass spectrometry. Computational validation was performed using DFT- B3LYP/6–311 + G(d,p) theory to ascertain the optimal geometry of the compound. Thermodynamic parameters and nonlinear optical (NLO) plots were also investigated. The HOMO-LUMO energy gap was found to be 3.6380 eV. Mulliken charges were found and electrostatic field surface mapping conducted to explore various properties. Theoretical findings were consistent with experimental results. Molecular docking studies revealed that the Schiff base exhibits antimalarial activity against Plasmodium falciparum, with the LibDock score and binding energy assessed for the malaria-causing protein 4WZ3. ADMET analysis indicated favorable pharmacokinetic properties of the synthesized ligand compared to current antimalarial drugs, highlighting its potential for malaria treatment.

ANALYTICAL SOLUTIONS OF THE NONLOCAL NONLINEAR SCHRÖDINGER-TYPE EQUATIONS

In physics, nonlinear equations are applіed to characterize the varied phenomena. Usually, the nonlinear equations are presented by nonlinear partial differential equations, that can be received as conditions for the compatibility of two linear differentіal equations, named the Lax pairs. The presence of the Lax pair determines integrability for the nonlinear partial differentіal equation. Linked to this development was the realization that certаіn coherent structures, known as solіtons, which play a fundamental role in nonlinear phenomena as lattice dynamics, nonlinear optіcs, and fluіd mechanics. One of the famous equations is the nonlinear Schrödinger equation which is associated with various physical phenomena in nonlinear optics and Bose-Einstein condensates. This equation allows the Lax pair thus it is integrable. This work investigates nonlocal nonlinear Schrödinger-type equations with PT symmetry. Nonlocal nonlinear equations arise in various physical contexts as fluid dynamics, condensed matter physics, optics, and so on. We introduce the Lax pair formulation for the nonlocal nonlinear Schrödinger-type equations. The method of the Darboux transformation is applied to receive analytical solutions.