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Amorphous perovskite CoSnO3 has attracted significant attention due to its unique properties and various modification methods. However, modifying metal‐oxygen bonds on the nonlinear optical (NLO) characteristics remains uncharted. In this study, a dehydration method is employed to convert the metal‐hydroxyl bonds (M─OH) of hydroxide CoSn(OH)6 into metal‐oxygen bonds (M─O), successfully preparing amorphous CoSnO3 with oxygen vacancies. Subsequently, effective regulation of the metal‐oxygen bonds in amorphous CoSnO3 is achieved through an ion exchange strategy, yielding Fe‐doped CoSnO3 (Fe‐CoSnO3). Comprehensive characterization and analysis revealed that the regulation of metal‐oxygen bonds accelerated the electron transition rate, resulting in a fast recovery time of ≈245.1 fs for Fe‐CoSnO3, accompanied by a significant boost in broadband NLO properties. Notably, when Fe‐CoSnO3 is utilized as a saturable absorber (SA), it exhibited superior mode‐locking characteristics compared to CoSnO3 in the range of 1–2 µm. Specifically at the communication band of 1.5 µm, the dynamic switching between single‐wavelength and dual‐wavelength mode‐locking operations is achieved. With the ultrafast laser state manipulation, a digital encoding is also demonstrated. This work confirmed that the tailoring of metal‐oxygen bonds makes Fe‐CoSnO3 an excellent NLO material for ultrafast optical applications, and this tailoring strategy provides new insights for designing advanced NLO materials. [ABSTRACT FROM AUTHOR]

This study investigates the optical properties of carbon nanotubes (CNTs) and silicene nanotubes (SiNTs) under the influence of external magnetic fields, focusing on their linear and nonlinear optical responses. A tight-binding model is employed to analyze the effects of magnetic fields on the electronic band structure, dipole matrix elements, and various optical susceptibilities of zigzag CNTs and SiNTs. The results reveal significant magnetic field-induced modifications in both linear and nonlinear optical spectra. Key findings include the splitting of optical peaks, red-shifting of spectral features, and distinct differences between CNTs and SiNTs in their response to magnetic fields. Notably, SiNTs consistently exhibit lower-energy spectral features and enhanced magnetic field sensitivity compared to CNTs. The magnetic field serves as an effective parameter for tuning the position, intensity, and number of peaks in various optical susceptibilities, including linear susceptibility, quadratic electro-optic (DC Kerr) response, and third-harmonic generation. These findings provide valuable insights into the magneto-optical properties of selected nanostructures and highlight the potential of SiNTs for applications in tunable nonlinear optical devices and magneto-optical sensors. [ABSTRACT FROM AUTHOR]

This study analyzes the nonlinear optical properties exhibited by graphene, focusing on the nonlinear absorption coefficient and the nonlinear refractive index. The evaluation was conducted using the Z-scan technique with a 532 nm wavelength laser at various intensities. The nonlinear optical absorption and the nonlinear optical refractive index were measured. Four machine learning models, including linear regression, decision trees, random forests, and gradient boosting regression, were trained to analyze how the nonlinear optical absorption coefficient varies with variables such as spot radius, maximum energy, and normalized minimum transmission. The models were trained with synthetic data and subsequently validated with experimental data. Decision tree-based models, such as random forests and gradient boosting regression, demonstrated superior performance compared to linear regression, especially in terms of mean squared error. This work provides a detailed assessment of the nonlinear optical properties of graphene and highlights the effectiveness of machine learning methods in this context. [ABSTRACT FROM AUTHOR]

Due to their strong molecular hyperpolarizability, organic push–pull materials are gaining interest for nonlinear optical applications. We were able to characterize the intramolecular charge transfer and the distribution of the electron cloud within the molecular unit by exciting these materials under the influence of an electric field. The series products of conjugated monomers derived from acrylo–azobenzene containing in the para position the attracting groups (–H, –NO2, –COOC2H5, –SO3H and –COOH) exhibit good nonlinear optical activity. We computed the nonlinear optical characteristics of these compounds as well as exploiting the theoretical calculations of DFT and AM1 to determine their hyperpolarizabilities. Besides, we investigated the increase in hyperpolarizability in the push–pull model of organic compounds under the effect of the strength of attracting groups, the existence of the conjugated π -electron and the azo bridge. [ABSTRACT FROM AUTHOR]

The design of optical materials in nonlinear devices represents a fundamental step for their optimization and miniaturization, that would significantly contribute to the progress of advanced nanophotonics and quantum technologies. In this work, the effect of geometry and composition of multilayer hyperbolic metamaterials on their third-order nonlinear optical properties, i.e. the optical Kerr effect, is investigated. One figure of merit is provided to be used as a predictive tool to design and best exploit the local intensity enhancement in low-loss metamaterials to be used for various applications in nonlinear nanophotonics. [ABSTRACT FROM AUTHOR]

In this study, the density functional theory (DFT) method is used to theoretically investigate the nonlinear optical (NLO) properties of natural carbazoles. The selected carbazoles have significant NLO characteristics. Using the B3LYP/6‐311++G(d,p) and CAM‐B3LYP/6‐311++G(d,p) level theories, the linear optical absorption, HOMO‐LUMO energy gap, molecular electrostatic potential (MEP), and dipole moments were calculated. The first hyperpolarizability (β0), second hyperpolarizability (γ), and static and dynamic linear polarizability (α0) components were computed. Electron correlation was obtained, which was compared with NLO and docking studies showing good relation with both. All carbazole compounds demonstrate good optoelectronic qualities that promote their potential use in electronic devices, as demonstrated by the frequency‐dependent dynamic hyperpolarizabilities of the B3LYP/6‐311++G(d,p) and CAM‐B3LYP/6‐311++G(d,p) functionals at 532 and 1064 nm wavelengths. The results of the molecular docking study shows that CBZ molecules exhibit a strong affinity for both Malassezia globosa (SMG1) lipase targets. The docking data demonstrated a strong binding ability, with CBZ7 and CBZ3. This indicates that CBZ7 and CBZ3 outperform all other compounds and have a high binding capability to the target protein. [ABSTRACT FROM AUTHOR]

In non-Hermitian open quantum systems, such as polariton condensates, the local tailoring of gains and losses opens up an interesting possibility to realize functional optical elements. Here, we demonstrate that deliberately introducing losses via a photonic defect, realized by reducing the quality factor of a DBR mirror locally within an ultrahigh-quality microcavity, may be utilized to create directed polariton currents towards the defect. We discuss the role of polariton–polariton interactions in the process and how to tailor the effective decay time of a polariton condensate by coupling it to the defect. Our results highlight the far-reaching potential of non-Hermitian physics in polaritonics. [ABSTRACT FROM AUTHOR]

Novel graphdiyne (GDY) materials with tunable electronic and nonlinear optical (NLO) properties are always desirable for material development. Herein, we conducted a comprehensive prediction of silagraphdiyne (SiGDY) with the adsorption of alkali metals (M) and superalkalis molecules (M2F) onto its surface, and their geometric structures, electronic properties, charge transfer and nonlinear optical responses were systematically studied. Our calculations demonstrate that the M/M2F molecules can be adsorbed stably on large delocalized SiGDY surfaces reflected by high binding energies. Notably, the SiGDY can accept almost an electron transferred from M/M2F, forming strong intramolecular charge-transfer (CT) process, while the reduced vertical ionization potentials (VIP) create the necessary conditions for enhancing the NLO response. Furthermore, it is found that both the substitution of silicon atoms within GDY and the adsorption of M/M2F onto SiGDY significantly modulate electronic properties, and narrow the HOMO–LUMO gaps of complexes. More interestingly, the adsorption of M/M2F on SiGDY enhances remarkably the first hyperpolarizability (βtot) of complexes, especially for M@SiGDY, of which Li@SiGDY possesses the exceptionally large βtot value (~7.65 × 105 a.u.), further explained by two-level model. The present findings show that the functionalized SiGDY materials can be considered as promising candidate of novel carbon-based NLO nanodevices for future applications. [ABSTRACT FROM AUTHOR]

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Mixed lead–tin halide perovskites, as highly sensitive materials in the near-infrared region, hold significant potential for optoelectronic device applications. Here, mixed lead–tin halide perovskite saturable absorbers (SAs) have been developed by coupling with the side-polished surfaces of the single-mode fibers and excellent saturable absorption effects of the mixed lead–tin halide perovskite SAs have been demonstrated in the near-infrared region. By constructing the in-gap site assisted carrier transfer mode, the saturation absorption process of the mixed lead–tin halide perovskite SAs can be well explained, in which defects as in-gap sites can help the photon-generated carriers transfer into the conduction band and promote the Pauli-blocking-induced absorption bleaching in the SA. Moreover, ytterbium-doped fiber lasers based on perovskite SAs have been fabricated, and mode-locked operations at 1040 nm are achieved using the mixed lead–tin halide perovskite SA, generating ultra-short pulses with a pulse width of 683 fs, 3 dB bandwidth of 4.88 nm, signal-to-noise ratio exceeding 49.74 dB, and a repetition rate of 3.74 MHz. Our findings demonstrate that the mixed lead–tin halide perovskite SAs have excellent optical modulation capability and promising applications in the field of ultrafast photonics. [ABSTRACT FROM AUTHOR]

The in‐plane anisotropic properties of 2D group IV monochalcogenides offer an additional degree of freedom which can be advantageous in optoelectronic applications. Here, it is demonstrated that the third harmonic generation (THG) produced by ultrathin tin (II) sulfide (SnS) is in‐plane anisotropic with respect to the direction of the excitation linear polarization. The polarization‐resolved THG (P‐THG) measurements are described with a nonlinear optics model, which accounts for the orthorhombic crystal structure of the 2D SnS. The relative magnitudes of the χ(3) tensor components are calculated by recording and simultaneously fitting two orthogonal polarization components of the P‐THG signals. Furthermore, the "THG anisotropy ratio" is introduced, which compares the THG intensity produced when the excitation linear polarization is along the armchair crystallographic direction, with the case when it is along the zigzag direction. The experimental findings provide quantitative information on the anisotropic nature of the THG process in various SnS flakes. Nonlinear anisotropic 2D materials can be used in future optoelectronic devices, where anisotropic polarization sensitivity is required. Having an optical tool that quantitatively probes the effect of the in‐plane anisotropy among different 2D materials, could be of considerable importance for evaluating the performance of such materials and devices. [ABSTRACT FROM AUTHOR]

In this article, based on the effective mass approximation and the density matrix formalism, we have performed a quantitative analysis of the quantum and dielectric confinement effect on the optical properties in a spherical core multishell quantum dot (MSQD) incorporated into six oxides (TiO2, ZrO2, HfO2, MgO, Si3N4, and SiO2). Formulas for the third-order nonlinear susceptibility χ(3), the optical absorption coefficients (OACs) and alterations in refractive index (RICs) are established using the density matrix formalism applied to a two-level system. Our findings indicated that the investigated coefficients exhibit significant sensitivity to variations in geometrical parameters, incident optical intensity, relaxation time, and the surrounding dielectric oxides. The dielectric discrepancy between the nanosystem and its new environment provides a manual-like guidance for the (MSQD) nanosystem which can be valuable in experimental applications. [ABSTRACT FROM AUTHOR]

Low‐dimensional lead halide perovskites demonstrate remarkable nonlinear optical characteristics attributed to their distinctive physical structures and electronic properties. Nevertheless, the investigation into their nonlinear optical properties remains in its incipient stages. This study addresses this gap by precisely controlling solvent volumes to synthesize both 0D Cs4PbBr6 and Cs4PbBr6/CsPbBr3 perovskites. Remarkably, as saturable absorbers, both pure Cs4PbBr6 and Cs4PbBr6/CsPbBr3 composites exhibit favorable nonlinear optical properties within the C‐band, showcasing modulation depths of 9.22% and 16.83%, respectively. Moreover, for the first time, Cs4PbBr6 and Cs4PbBr6/CsPbBr3 composites have been successfully integrated into erbium‐doped fiber lasers to realize the mode‐locking operations. The utilization of the Cs4PbBr6/CsPbBr3 composites as a saturable absorber that enables the generation of conventional soliton mode‐locked laser pulses with a pulse duration of 688 fs, and a repetition frequency of 10.947 MHz at a central wavelength of 1557 nm. Cs4PbBr6 is instrumental in generating laser pulses at a frequency of 10.899 MHz, producing pulse widths of 642 fs at the central wavelength of 1531.2 nm and 1.02 ps at the central wavelength of 1565.3 nm, respectively. The findings of this investigation underscore the potential utility of 0D Cs4PbBr6 and Cs4PbBr6/CsPbBr3 composites as promising materials for optical modulation within fiber laser applications. [ABSTRACT FROM AUTHOR]

The thermal and nonlinear optical (NLO) properties of alizaringelb R solution are investigated experimentally and numerically. The thermal conductivity, K, of alizaringelb R solution is calculated by constructing a device and found to decrease with the increase in absolute temperature. The change in refractive index, Δ n, of alizaringleb R solution and its nonlinear index of refraction (NLIR), n2, are estimated via diffraction patterns (DPs) under irradiation with a 473 nm cw laser beam. As high as 4.73 × 10–3 and 4.81 × 10–11 m2/W of Δ n and n2 are determined. The collapse of DPs phenomenon through the deformation of the resulted DPs seen to occur. The resulted DPs are numerically calculated via the use of a mathematical model that is solved using the diffraction integral. [ABSTRACT FROM AUTHOR]

This work has studied some nonlinear optical properties of Al0.3Ga0.7As/GaAs quantum dot system with tangent-square potential (TSP), with special emphasis on the role of second harmonic generation (SHG) coefficient under hydrostatic pressure and temperature. Due to the strain of external application conditions, the changes of the energy level and wave function of the neutron band in the system structure provide valuable insights into the optical properties of the quantum dot structure. In this paper, we report the effects of structural parameters, temperature and hydrostatic pressure on the SHG coefficient. According to the results obtained in the work, it can be reported that the nonlinear optical properties of the quantum dot system can be improved by adjusting the hydrostatic pressure and temperature. At the same time, the interaction of various parameters has produced some interesting observations, which are relevant in relevant research fields. [ABSTRACT FROM AUTHOR]

Context: Nonlinear optics (NLO) is an interesting field that discloses the interaction between intense light and matter, leading to a deeper understanding of NLO phenomena. Organic chromophores are considered as promising materials for NLO due to their exceptional structural versatility, ease of processing, and rapid response to NLO effects. Functional materials based on thiophene have been indispensable in advancing organic optoelectronics. Specifically, dithiophene-based compounds display weaker aromaticity, reduced steric hindrance, and additional sulfur–sulfur interactions. Hence, by utilizing dithieno[2,3-d:2′,3′-d′]benzo[1,2-b:4,5-b′]dithiophene (DTBDT) as the core structure, designing of a set of organic compounds with D1–π–D2–π–A-type framework, namely ZR1D1–ZR1D8, was carried out in this study. The analysis of frontier molecular orbitals (FMOs) revealed that compound ZR1D2 has the lowest band gap of 1.922 eV among all the investigated chromophores. The correlation of global reactivity parameters (GRPs) with the band gap values indicates that ZR1D2 displays a hardness of 0.961 eV and a softness of 0.520 eV−1. Among the studied compounds, ZR1D2 demonstrated a broad absorption spectrum that extended across the visible region. The maximum absorption wavelengths were observed at 766.470 nm for ZR1D2 and 749.783 nm for ZR1D5. These DTBDT-based dyes exhibit a remarkable NLO response with exceptionally high first hyperpolarizability (βtot) values. Among them, compound ZR1D2 stands out with the highest average linear polarizability (⟨α⟩ = 3.0 × 10−22 esu), first hyperpolarizability (βtot = 4.1 × 10−27 esu), and second hyperpolarizability (γtot = 7.5 × 10−32 esu) values. In summary, this investigation offers valuable insights into the potential use of DTBDT-based organic chromophores, particularly ZR1D2, for advanced applications in NLO. These findings suggest promising opportunities for researchers to synthesize these molecules and utilize these compounds in hi-tech NLO-based applications. Methodology: The density functional theory computations were performed at the M06/6-311G(d,p) functional to explore their structural effects on electronic and NLO findings. Various analyses like highest occupied molecular orbital–lowest unoccupied molecular orbital energy gaps, absorption maxima, density of states, open circuit voltage, binding energies of electrons and holes, and transition density matrix are employed to investigate photovoltaic efficiencies of the derivatives. Different software packages like Avogadro, Multiwfn, Origin, GaussSum, PyMOlyze, and Chemcraft were used to deduce conclusions from the output files. [ABSTRACT FROM AUTHOR]

Optical materials with non‐π‐conjugated units usually can exhibit large bandgaps, which are conducive to a wide ultraviolet (UV) transparency window. However, the relatively small structural anisotropy hinders the application of these materials as nonlinear optical (NLO) and birefringent materials. Herein, a universal strategy of dissimilating non‐π‐conjugated units is proposed to enhance birefringence, optimize phase‐matching (PM) wavelength, and maintain a large bandgap. The functionality of the series of hetero‐anionic units is distinguished in terms of optimizing birefringence and PM wavelength. In particular, the dimeric hetero‐anionic unit N(SO2F)2− with the dual‐heteroatom dissimilation is found to be a novel superior optical hereto‐gene. In addition, AN(SO2F)2 (A = Li, Na‐I, K‐I/II, H) and Ba(SO3CF3)2 are identified with large birefringence of approximately 0.051–0.106 at 546 nm, which are much larger than those of corresponding sulfates. HN(SO2F)2 exhibits a short PM wavelength (208 nm), a large NLO coefficient (≈ 2 × KDP), and an extremely short UV cutoff edge (149 nm). Experimental polarizing microscope measurement confirms that the birefringence of Pbca‐KN(SO2F)2 is significantly enhanced to 0.06 at 546.1 nm, which is 12 times higher than that of K2SO4. Finally, this strategy offers direction for the design and synthesis of novel NLO or birefringent materials in the future. [ABSTRACT FROM AUTHOR]

An azo compound, T-3OCH3, is synthesized and diagnostics using 1H and 13C NMR and mass spectroscopies. The compound theoretical structure is optimized via the DFT/WB97XD approach with a 6-31+G(d,p) basis set level. The compound nonlinear optical properties are studied under irradiation with a visible CW laser beam via diffraction patterns and the Z-scan. As high as 6.739 × 10−11 m2/W of the nonlinear refraction index is obtained. Static and dynamic all-optical switching are tested in the synthesized compound using two visible CW laser beams. [ABSTRACT FROM AUTHOR]

This study was planned to prepare new mixed ligand chelates derived from N‐(4,6‐dimethylpyrimidin‐2‐yl)‐3a,4,5,6,7,7a‐hexahydro‐1H‐benzimidazol‐2‐amine (BIP), and imidazole (I). They identified through CHN study, spectroscopic (NMR, FT‐IR, and UV–Vis), conductivity, magnetic susceptibility, mass analysis, and thermal analysis. Correlation between all results exposed that the BIP ligand performed as a bi‐dentate ligand through NN donation locations, where the co‐ligand shows as N–H monodentate. The optimization for the studied chelates led to the formation of distorted octahedral geometry for BIPICu and BIPIVO chelates, distorted (tetrahedral and square planar) geometry for BIPIAg and BIPIPd chelates, respectively, around the metal salt. The B3LYP level, B3LYP/6‐311G** level for the free ligand, and B3LYP/6–311G**‐LANL2DZ functional level for the solid chelates were used in density functional theory (DFT) calculations. The findings showed that DFT calculations produce conclusions that are consistent with those of the experiments. The resulting compounds' nonlinear optical properties were examined by calculating the hyperpolarizability (β) and molecular polarizability (α) parameters, which gave rise to several unexpected optical properties for the synthesized compounds. Using the agar well diffusion method, the antimicrobial activity of the produced compounds was experimentally confirmed against a subset of G+ and G− bacteria. To ascertain how these substances attach to the targeted protein binding sites, a molecular docking mechanism between the microbially resistant chelates and their suppressed microbial protein pocket receptors was investigated. Also, DNA binding estimated for studied structures was tested by electronic absorption spectrum, viscosity estimation, and gel electrophoresis. Data proposed that all tested compounds link with DNA using an intercalation, electrostatic, and covalent binding mechanism. Moreover, antioxidant performance for studied compounds was governed by radical scavenging techniques in vitro. In addition, an MTT assay has been worked out to explore in vitro cytotoxic impending. All the tested chelates assumed antimicrobial, antitumor, and antioxidant performances that cause them to suggest drugs. [ABSTRACT FROM AUTHOR]

Amorphous aerogels with the microscopic nanoscale three-dimensional meshes provide superb platforms for investigating unique physicochemical properties. In order to enhance the physical, thermal and mechanical performances, one efficient and common approach is integrating diverse functional materials. Herein, we report a simple strategy to fabricate the amorphous silicon doped Y2O3 aerogels with the post-gelation method under the N2/EtOH supercritical atmosphere. The impact of Si concentration on the nonlinear optical properties is investigated for the first time. The maximum modulation depth is 1.65 % with a saturation intensity of 0.78 MW cm−2 with the 1-ps laser excitation at 1590 nm. Finally, we incorporated the silicon-doped Y2O3 aerogel based saturable absorber (SA) into an erbium-doped fiber laser (EDFL) and achieved various mode-locking operations at different wavelengths in the super C band, in terms of the conventional soliton, harmonic soliton molecules pulses, and dual-wavelength soliton mode-locking. Overall, this work confirms that amorphous silicon-doped Y2O3 aerogels are good nonlinear optical materials and pave a way for the ultrafast photonic and nonlinear optical applications with amorphous materials in near future.

The effective calculation of static nonlinear optical properties requires a considerably high accuracy at a reasonable computational cost, to tackle challenging organic and inorganic systems acting as precursors and/or active layers of materials in (nano‐)devices. That trade‐off implies to obtain very accurate electronic energies in the presence of externally applied electric fields to consequently obtain static polarizabilities (αij) and hyper‐polarizabilities (βijk and γijkl). Density functional theory is known to provide an excellent compromise between accuracy and computational cost, which is however largely impeded for these properties without introducing range‐separation techniques. We thus explore here the ability of a modern (double‐hybrid and range‐separated) Range‐Separated eXchange Quadratic Integrand Double‐Hybrid exchange‐correlation functional to compete in accuracy with more costly and/or tuned methods, thanks to its robust and parameter‐free nature. [ABSTRACT FROM AUTHOR]

The molecular geometry, electronic structure, and absorption spectra of some important phenyl derivatives are investigated by using DFT and TD‐DFT with B3LYP and CAM‐B3LYP functional. The highest HOMO–LUMO energy gap, Non‐linear optical properties of dipole moment, polarizability, and hyperpolarizability are calculated. In both methods hyperpolarizability PDP values (16.77 × 10−30 and 16.59 × 10−30 esu) are higher than PDNA, PDN, and MPAN dye. The Molecular electrostatic potential shows that PDNA dye has more electronegative potential. Comparing all the dyes, PDP dye shows a higher light harvesting efficiency in the UV–vis region. The vibrational frequencies are assigned based on the potential energy distribution (PED) using the VEDA‐4 program. [ABSTRACT FROM AUTHOR]

Molybdenum diselenide/graphene(MoSe2/rGO) composite was synthesized by a facile solvothermal reaction, and the molybdenum diselenide/graphene/polyvinyl alcohol（MoSe2/rGO/PVA) film was further prepared by simple drop casting technique. The structure, morphology, component and absorption characteristics of MoSe2/rGO composite were analyzed by X-ray diffraction, raman spectra, fourier transform infrared spectrometry, transmission electron microscope, X-ray photoelectron spectrometer and ultraviolet visible spectrophotometer. The third order nonlinear optical(NLO) properties of MoSe2/rGO solution and film were investigated using the Z-scan technique at 1064 and 532 nm with 4 ns laser pulses. The results demonstrate that the third order NLO properties of MoSe2/rGO/PVA film was larger than that of the MoSe2 solution, MoSe2/rGO solution and MoSe2 film. The MoSe2/rGO/PVA film exhibits much larger nonlinear absorption coefficient with incident energy of 25 μJ at 532 nm. The results pave the way for the application of transition metal dichalcogenides/graphene composite in the optical limiting and laser mode-locking. [ABSTRACT FROM AUTHOR]

Amorphous aerogels with the microscopic nanoscale three-dimensional meshes provide superb platforms for investigating unique physicochemical properties. In order to enhance the physical, thermal and mechanical performances, one efficient and common approach is integrating diverse functional materials. Herein, we report a simple strategy to fabricate the amorphous silicon doped Y2O3 aerogels with the post-gelation method under the N2/EtOH supercritical atmosphere. The impact of Si concentration on the nonlinear optical properties is investigated for the first time. The maximum modulation depth is 1.65 % with a saturation intensity of 0.78 MW cm−2 with the 1-ps laser excitation at 1590 nm. Finally, we incorporated the silicon-doped Y2O3 aerogel based saturable absorber (SA) into an erbium-doped fiber laser (EDFL) and achieved various mode-locking operations at different wavelengths in the super C band, in terms of the conventional soliton, harmonic soliton molecules pulses, and dual-wavelength soliton mode-locking. Overall, this work confirms that amorphous silicon-doped Y2O3 aerogels are good nonlinear optical materials and pave a way for the ultrafast photonic and nonlinear optical applications with amorphous materials in near future. [ABSTRACT FROM AUTHOR]

This study investigates the supramolecular interactions between perylene diimides (PDI) and nucleotides, specifically adenosine monophosphate (AMP) and cytidine monophosphate (CMP). Ten complexes (complex 1 (l-ala-PDI-AMP), complex 2 (B-ala-PDI-AMP), complex 3 (GLY-PDI-AMP), complex 4 (IMI-PDI-AMP), complex 5 (PYR-PDI-AMP, complex 6 (l-ala-PDI-CMP), complex 7 (B-ala-PDI-CMP), complex 8 (GLY-PDI-CMP), complex 9 (IMI-PDI-CMP), and complex 10 (PYR-PDI-CMP), were simulated using the B3LYP/6-31G(d,p) level of DFT method. The study explores NMR, IR, UV, hyperpolarizabilities, frontier molecular orbitals (FMOs), density of states (DOS), noncovalent interactions (NCI), iso-surface analysis, atom in molecule (AIM), dipole moment (µ), electron density distribution map (EDDM), transition density matrix (TDM), molecular electrostatic potential (MEP), and electron–hole analysis (EHA) using differential functional theory (DFT). The weak bonds formed were visualized using Discovery Studio Visualizer. The electronic properties of the complexes were examined through natural bond orbital (NBO) and natural population analysis (NPA), leading to nonlinear optics (NLO) study. Complex 6 demonstrates the highest NLO activity with γ static of 17,424,700.00, and complex 10 exhibits the weakest NLO activity with second dipole hyperpolarizability (γ static) at 25,116.10. Moreover, global reactivity factors for complexes 1–5 show EA ranging from 6.53 to 7.7, and ionization potential (IP) spans 7.8–8.8. Global hardness values highlight complex 4 as the hardest (η = 0.55) and complex 1 as the softest (η = 0.51). Electronegativity (X) varies from 7.28 to 8.25, with complex 3 being the most electronegative. Chemical potential (μ) ranges from − 7.9 to − 8.25, global softness (σ) identifies complex 1 as the softest (0.2575) and complex 4 as the hardest (0.435). Electrophilicity (ω) ranges from 33.30 to 61.87. Complexes 6–10 show EA from 6.7 to 7.53. IP values range from 8.4 to 8.6, with complexes 7 and 10 highest. Global hardness spans 0.53 to 0.85. X ranges from 7.55 to 8.06, with complex 7 the most electronegative. μ varies from − 7.55 to − 8.06, and complex 7 has the lowest. From σ values, complexes 9 and 10 are the softest. ω ranges from 35.53 to 60.78, with complex 7 the most electrophilic. [ABSTRACT FROM AUTHOR]