Nonlinear Optical Applications Research Articles

Solvent effect, DFT and NLO studies of A–π–D–π–A and A–π–D–π–D push–pull chromophore of 1,2-diazepin-4-ol based derivatives with optical limiting application

The nonlinear optical properties of push–pull chromophores, namely (E)-7-(4-bromophenyl)-2,5-bis(4-nitrophenyl)-3,4,5,6-tetrahydro-2H-1,2-diazepin-4-ol (A–π–D–π–A) and (E)-7-(4-bromophenyl)-5-(4-nitrophenyl)-2-phenyl-3,4,5,6-tetrahydro-2H-1,2-diazepin-4-ol (A–π–D–π–D), have been investigated using the z-scan technique. NMR, FT-IR, and UV–visible spectral analysis have been performed. The results were compared with density functional theory calculations employing the B3LYP/6-311++G (d, p) basis set. Geometry optimization, frontier molecular analysis, and TD-DFT calculations were conducted in various solvent environments to elucidate solute–solvent interactions. Gaussian 09 software was employed for natural bond orbital analysis, natural population analysis, and molecular electrostatic potential exploration. This comprehensive approach provides insights into the molecular structure and electronic properties of the investigated chromophores, shedding light on their potential applications in nonlinear optics. Normal coordinate analysis using the MOLVIB software has been used to assign the vibrational mode unambiguously. Theoretical second-order hyperpolarizability was computed, and NLO investigations have been employed to determine the second-order hyperpolarizability in both the polar and non-polar solvents. Further, the optical limiting capability was also examined.

Comparative study on structural, morphological, and optical properties of MS/Fe3O4 nanocomposites and M-doped Fe3O4 nanopowders (M = Mn, Zn)

In the present work, the un-doped, M-doped magnetite (Fe3O4); (M = Mn, Zn), and MS/Fe3O4 composite nanopowders with a cubic spinel-type structure and average crystallite size range from 8.30 to 12.33 nm were synthesized by co-precipitation method. The FESEM images revealed the shape of particles are spherical with a grain size in the range of 33.44–49.77 nm. Through the analysis of reflectance data using Tauc’s model, the direct band gap energies of 2.98 eV, 2.93 eV, 3.01 eV, 2.85 eV, and 2.95 eV were determined for Un-doped Fe3O4, Mn-doped Fe3O4, Zn-doped Fe3O4, MnS/Fe3O4 composite, and ZnS/Fe3O4 composite NPs respectively. The parameters such as extinction coefficient and refractive index of the nanoparticles were computed by the Kramers–Kronig (K–K) method. Non-linear optical (NLO) parameters were computed from DRS data using the Wemple–Di-Domenico (WDD) model. The calculated third-order NLO susceptibility χ(3)\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\chi }^{(3)}$$\\end{document} and also electrical susceptibility χe\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\chi }_{\\left(e\\right)}$$\\end{document} represented the maximum value for MnS/Fe3O4 composite NPs compared to the other samples. Considering the advanced optical parameters of MS/Fe3O4 composite samples, these particles can be suitable candidates for non-linear optical applications.

Soliton solutions of cubic quintic septimal nonlinear Schrödinger wave equation with conformable derivative by two distinct algorithms

This paper investigates the cubic-quintic-septimal nonlinear Schrödinger wave equation with a conformable derivative, which governs the evolution of light beams in a weak nonlocal medium. The analysis utilizes the Kudryashov method and the enhanced modified tanh expansion method. By utilizing these analytical integration schemes, various optical wave solutions are derived within the present conformable model. The paper demonstrates the significance of these optical soliton solutions by illustrating different soliton solutions, including kink-type, bell-shaped, singular, dark, and wave soliton solutions, depicted via contour, three-dimensional, and two-dimensional representations. Moreover, it is crucial to emphasize the importance of analyzing the cubic-quintic-septimal nonlinear Schrödinger wave equation, which finds utility across a spectrum of fields including optics, quantum mechanics, and the study of nonlinear wave propagation. Moving forward, these approaches hold promise for investigating diverse sets of differential equations within multiple domains of applied sciences. This governing equation also has numerous applications in nonlinear optics, such as describing the propagation of laser beams through materials with nonlinear optical properties. The inclusion of these nonlinearities illustrates the interaction and behavior of light beams in weakly non-local media.

Exploring the impact of CuCl2 modification on structural variations and dielectric constant in bismuth borate tellurite glasses

Copper chloride doped boro-tellurite-based glass series with compositions 60TeO2-(25-x) Bi2O3–15B2O3-xCuCl2 (x = 0, 5, 10, 15, and 20) were synthesized using the traditional melt-quench procedure. The X-ray diffraction patterns of the examined glasses reveal their amorphous nature. The effect of CuCl2 addition on the glass network/structural units was studied using vibrational (FTIR/Raman) spectroscopy, and CuCl2 inclusion in the glass matrix resulted in a transformation from compact TeO4 to TeO3 structural units This shows that copper chloride acts as a modifier in the examined glass series, resulting in the creation of non-bridging oxygen (NBOs), meaning that the loosening of the glass network is further supported by a decrease in the glass transition temperature as CuCl2 content increases. UV–Vis DRS spectra of examined glasses reveal an absorption band corresponding to the typical transition of Cu2+ ions from 2B1g → 2B2g, situated in deformed octahedral sites in absorption spectra. As Cu+ concentration rises, the indirect optical band gap values drop from 2.94 eV to 1.75 eV. The metallization criterion values lie between 0.383 and 0.300 suggesting that these glasses are potential candidates for nonlinear optical applications. With an increase in Cu+ concentration, the values of molar refractive index (Rm) and molar electronic polarizability αm increases from 22.412 to 26.205 and 8.894 to 10.398 respectively, which correlate with increasing dielectric constant (ε′) values as the Cu+ amount increases. Further dielectric studies reveal non-Debye-type relaxation behaviour.

Investigation of thermally induced nonlinear optical response of polyurethane-graphene composite by SSPM method

We conducted a study on composites made of polyurethane and graphene (PU-G). We synthesized these composites and then examined their far-field diffraction patterns at various concentrations of dimethylformamide (DMF) using the spatial self-phase modulation (SSPM) method. By analyzing the intensity-dependent far-field ring patterns, we were able to estimate the samples' thermally induced nonlinear refractive index and thermo-optical coefficient. We found that these variables, as well as other observable phenomena such as the “diffraction ring collapse effect” and “variation in nonlinear refractive index,” depended on the sample's concentration rate. Our results indicate that the laser-induced thermal effect is a significant factor in the SSPM phenomena observed in our experiments. Furthermore, our findings suggest that the PU/G combination in DMF has promising nonlinear optical properties that could be beneficial in a variety of nonlinear optics applications.

DFT/TD-DFT study of novel triphenylamine-based dyes with azo moieties and π-spacer variations for enhanced dye-sensitized solar cell performance

This study involves a computational analysis of new D-π-A dyes obtained from triphenylamine (TPA), which contain various azo-dye components. The structural, molecular, electrical, and optical properties of these dyes were computed using Density Functional Theory (DFT) and Time-Dependent DFT, utilizing the B3LYP/6–31 G model. Our research specifically aimed to investigate the effects of incorporating different azo dye constituents in the para position of two phenyl groups of TPA. The results indicate that these alterations lead to notably broadened and red-shifted absorption spectra, as well as improved optoelectronic properties that are subject to additional tuning through the manipulation of the π-spacer. The excitation energies and HOMO-LUMO energy levels that have been estimated indicate the presence of effective electron injection and dye regeneration mechanisms. The results concerning the nonlinear optical (NLO) properties suggest that these dyes are likely to demonstrate superior performance in NLO applications. The factors encompassed in this study consist of light-harvesting efficiency (LHE), open-circuit photovoltage (VOC), electron injection driving force (ΔGinj), dye regeneration driving force (ΔGreg), excited state lifetime (τ) and reorganization energy (λtotal), which has a strong correlation with the electrical current density in a short-circuit (JSC) and DSSC's overall effectiveness. This scientific attempt contributes to the systematic advancement of efficient dyes, demonstrating the possibility for enhanced efficiency in DSSCs. Further validation of computational forecasts and advancement of renewable energy technology necessitate future experimental synthesis and testing.

Wide‐Bandgap RBa3(B3O6)3 (R = Nd, Sm, Tb, Dy, and Er) Single Crystals for Ultraviolet Nonlinear Optics

AbstractDiscovery of new materials with enhanced optical properties in the visible and UV‐C range can impact applications in lasers, nonlinear optics, and quantum optics. Here, the optical floating zone growth of a family of rare earth borates, RBa3(B3O6)3 (R = Nd, Sm, Tb, Dy, and Er), with promising linear and nonlinear optical (NLO) properties is reported. Although previously identified to be centrosymmetric, the X‐ray analysis combined with optical second harmonic generation (SHG) assigns the noncentrosymmetric P space group to these crystals. Characterization of linear optical properties reveals a direct bandgap of ≈5.61–5.72 eV and strong photoluminescence in both the visible and mid‐IR regions. Anisotropic linear and nonlinear optical characterization reveals both Type‐I and Type‐II SHG phase matchability, with the highest effective phase‐matched SHG coefficient of 1.2 pm V−1 at 800‐nm fundamental wavelength (for DyBa3(B3O6)3), comparable to β‐BaB2O4 (phase‐matched d22 ≈ 1.9 pm V−1). Laser‐induced surface damage threshold for these environmentally stable crystals is 650–900 GW cm−2, which is four to five times higher than that of β‐BaB2O4, thus providing an opportunity to pump with significantly higher power to generate about six to seven times stronger SHG light. Since the SHG arises from disorder on the Ba‐site, significantly larger SHG coefficients may be realized by “poling” the crystals to align the Ba displacements. These properties motivate further development of this crystal family for laser and wide bandgap NLO applications.

New insights into non-linear optical properties, photocatalytic activity, and applications of ZnSe:Cu nanoparticles prepared by microwave-assisted hydrothermal method

In the present work, semiconducting ZnSe:Cu (0, 0.1, 0.75, 1.5, 2.25 and 3 mol%) nanoparticles (NPs) were prepared by microwave-assisted hydrothermal (MAH) method at the fixed pH of 11.2. XRD patterns certified the formation of nanocrystals with the size of about 2.04–2.21 nm. Also, FESEM and TEM images confirmed the formation of round-shape NPs. UV–Vis spectra showed that the energy gap of nanoparticles decreased from 3.615 to 3.342 eV by the increment in copper impurity content. The exact value of the energy gap of NPs was determined by the absorption spectrum fitting derivative method (DASF). Results revealed that these NPs have a high potential in optical and optoelectronic applications; specially, the samples owing 1.5 and 2.25 mol% of Cu-impurity, as the best candidates for optical fiber applications, showed the highest third order non-linear optical susceptibility (χ(3)). Also, for all synthesized NPs, the optical characteristics such as the optical transition index (m), Urbach energy (Etail), dielectric constant (ε) and the refractive index (n) at the absorption edge were determined. Moreover, the amount of metallization factor was also calculated, which decreases with the increase of impurity and microwave irradiation, indicating the increase of metal affinity of the samples. Photoluminescence (PL) spectra of ZnSe NPs demonstrated a general reduction in the intensity upon the introduction of Cu. This anticipated quenching further supports their heightened photocatalytic activity. The results of photocatalytic tests indicate that the sample containing 2.25 mol% of Cu exhibits the highest rate constant value (0.0255 min−1) and achieves the maximum efficiency (75.7 % after 60 min) for degrading the DB71, establishing it as the prime candidate for photocatalytic applications.

Emissively enhanced novel azo compounds featuring with ESIPT core

This study presents the synthesis and detailed characterization of novel azo compounds featuring Excited State Intramolecular Proton Transfer (ESIPT) cores derived from orcinol, resorcinol, and 2-naphthol. Using a comprehensive suite of spectroscopic techniques, including Nuclear Magnetic Resonance (NMR), Liquid Chromatography-Mass Spectrometry (LC-MS), Ultraviolet-Visible (UV–Vis) spectroscopy, and fluorescence spectroscopy, we explored the unique photophysical properties of these compounds. Notably, the synthesized compounds exhibited exceptionally large Stokes shifts, with values recorded at 204 nm, 251 nm, and 168 nm for compounds 1A, 2A, and 3A, respectively. These shifts indicate significant potential for applications in areas such as optical sensing and fluorescent imaging. Furthermore, Density Functional Theory (DFT) calculations were employed to investigate the nonlinear optical (NLO) properties of the enol and keto tautomeric forms of these compounds. The findings revealed that compound 2A, in particular, demonstrated impressive first-order hyperpolarizability, especially in chloroform, underscoring its suitability for advanced nonlinear optical applications. The study highlights the pivotal role of the ESIPT mechanism, where efficient intramolecular hydrogen bonding facilitates proton transfer upon excitation, leading to enhanced fluorescence properties. This phenomenon is particularly pronounced in compound 2A, where dual O—H interactions contribute to its remarkable fluorescence behavior, making it a standout candidate for use in high-performance optical materials. These findings not only advance our understanding of azo compounds and their versatile photophysical characteristics but also open new avenues for their application in cutting-edge technologies such as optical sensors, imaging agents, laser materials, and other fluorescence-based devices. By strategically leveraging the ESIPT process and the unique structural features of these compounds, this research paves the way for future innovations in the field of advanced optical materials and photonic devices.

Ferroelectric nematic fluids as spontaneous polarization field for enhanced orientational-dependent second-harmonic generation

ABSTRACT Second-order nonlinear optical effects have piqued researchers’ interest in fundamental physics and practical perspectives. The ferroelectric nematic liquid crystals (NF LCs) have recently drawn attention to LC nonlinear optical applications due to their relatively high second-harmonic generation output. Further improving the nonlinear optical properties to get closer to the performance of inorganic nonlinear optical materials is challenging. Here, we take a blending strategy to enhance the nonlinear optical response of a prototype NF LC, DIO. We mixed an organic nonlinear optical crystalline material, 3,5,5-trimethyl (cyclohex-2-enylidene) malononitrile (TCM), with DIO and investigated the effects of TCM doping at various concentrations. We quantitatively determined the second-harmonic generation and spontaneous polarization as functions of temperature and concentration. We found that, compared with the pure DIO, the second-harmonic generation performance increased by about 130% at maximum, 93% in maximum for the nonlinear optical coefficient, and 10% in maximum for spontaneous polarization.

Cascaded multi-phonon stimulated Raman scattering near second-harmonic generation in a thin-film lithium niobate microdisk.

High-quality microresonators can greatly enhance light-matter interactions and are excellent platforms for studying nonlinear optics. Wavelength conversion through nonlinear processes is the key to many applications of integrated optics. The stimulated Raman scattering (SRS) process can extend the emission wavelength of a laser source to a wider range. Lithium niobate (LN), as a Raman active crystalline material, has remarkable potential for wavelength conversion. Here, we demonstrate the generation of cascaded multi-phonon Raman signals near the second-harmonic generation (SHG) peak in an X-cut thin-film lithium niobate (TFLN) microdisk. Fine tuning of the specific cascaded Raman spectral lines has also been made by changing the pump wavelength. Raman lines can reach a wavelength up to about 80 nm away from the SHG signal. We realize the SFG process associated with Raman signals in the visible range as well. Our work extends the use of WGM microresonators as effective optical upconversion wavelength converters in nonlinear optical applications.

Nonlinear optical response and application of indirect narrow-bandgap SbTe nanosheets

The nonlinear optical properties of antimony telluride (SbTe) crystal with indirect narrow bandgap are investigated, which exhibits superior performance for nonlinear laser modulation in the infrared band. The nonlinear optical coefficients of SbTe nanosheets are determined to be −3.3 cm/GW, −2.3 cm/GW, −1.9 cm/GW and the modulation depths are 5.5 %, 2.0 %, 1.5 % at 400 nm, 800 nm, 1064 nm, respectively. Based on the SbTe-SA, a Yb:GdScO3 laser centered at 1064 nm is achieved with 633 mW maximum output power, 56 fs pulse width and 104 MHz repetition rate. The damage threshold of the SbTe nanosheets is calculated to be exceed 338 GW/cm2, revealing the great potential in high-power laser modulation. This investigation marks the inaugural theoretical and experimental analysis of SbTe’s optical properties and its application in laser modulation, laying the groundwork for future research into indirect narrow-bandgap materials in laser technology.

Optical nonlinearity and all-optical switching in pumpkin seed oil based on the spatial cross-phase modulation (SXPM) technique

Nonlinear optics (NLO) and its applications have attracted increasing research interest in recent years owing to their contribution to the development of photonic technology. Accordingly, in this study, we investigated the NLO response of pumpkin seed oil using the spatial self-phase modulation (SSPM) method. Significant NLO characteristics have been experimentally studied at 405nm\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$405\\,{\ ext{nm}}$$\\end{document} and 532nm\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$532\\,{\ ext{nm}}$$\\end{document} continuous wave (CW) laser wavelengths, yielding second-order nonlinear refractive index (n2,th\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$n_{2,\\,th}$$\\end{document}) values of 6.54×10-5cm2/W\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$6.54 \ imes 10^{ - 5} \\,{{{\ ext{cm}}^{2} } \\mathord{\\left/ {\\vphantom {{{\ ext{cm}}^{2} } W}} \\right. \\kern-0pt} W}$$\\end{document} and 2.73×10-5cm2/W\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$2.73 \ imes 10^{ - 5} \\,{{{\ ext{cm}}^{2} } \\mathord{\\left/ {\\vphantom {{{\ ext{cm}}^{2} } W}} \\right. \\kern-0pt} W}$$\\end{document}, respectively. The findings suggest that the absorption of the material leads to higher optical nonlinearity at shorter wavelengths owing to higher thermal effects. Furthermore, we implemented a light-controlled-light system based on the spatial cross-phase modulation (SXPM) technique employing pumpkin seed oil. We successfully achieved all-optical switching by designing the 'ON' and 'OFF' modes. The results of this study can be considered for the future development of NLO applications. Moreover, our work investigates the potential of pumpkin seed oil for designing low-cost and high-efficiency NLO devices, and this contribution opens up a novel practical avenue for oil-based optical devices.

Optical imaging of ferroelectric domains in periodically poled lithium niobate using ferroelectric liquid crystals

Ferroelectric liquid crystals exhibiting a chiral smectic C* phase are deposited on z cut periodically poled lithium niobate substrates and investigated by polarized optical microscopy. While the pure substrates placed between crossed polarizers and observed in transmission appear dark, uniformly aligned liquid crystal films deposited on these substrates show alternating domains with varying brightness. This effect can be attributed to the well-known coupling between the direction of the spontaneous polarization and the optical axis in the birefringent ferroelectric smectic C* phase. Quantitative measurements of the tilt angle between the local optical axis and the smectic layer normal confirm antiparallel orientations of spontaneous polarization of the liquid crystal from domain to domain, as expected by the periodic poling of the lithium niobate substrate. This effect provides a valuable non-destructive method of optical inspection of the quality of periodically poled ferroelectric substrates, which plays an important role in achieving quasi-phase-matching in non-linear optical applications.

Dynamically tunable multi-band quasi-permittivity-asymmetric BIC in the GST225 metasurface.

Bound states in the continuum (BICs) on metasurfaces have garnered significant interest for their ultrahigh Q-factor potential in sensing applications. Reconfigurability and multi-band resonance are highly desirable for sensing systems. In this work, we introduce a metasurface comprising four nanocubes with different permittivity asymmetries, which can be dynamically adjusted using Ge2Sb2Te5 (GST225), a phase-change material, in the near-infrared (NIR) region. Additionally, a simulation for a liquid molecule sensor based on the metasurface shows a sensitivity of 1017 nm/RIU. This research introduces a novel, to the best of our knowledge, approach for designing multi-band, dynamically tunable quasi-BIC metasurfaces, which are good candidates for tunable, high-sensitivity biochemical sensing and nonlinear optics applications.

Physicochemical properties of 2-amino-5-methylpyridinium 3-carboxy-4-hydroxybenzenesulfonate single crystal: An efficient material for optoelectronic applications

A novel third-order organic nonlinear optical (NLO) material with promising excellent properties in the crucial NLO application. For the first time high NLO active 2-amino-5-methylpyridinium 5-sulfosalicylic acid (2A5MP3C4H) has been rationally designed and single crystals have been grown by the slow evaporation solution growth technique (SEST). X-ray diffraction analysis revealed that 2A5MP3C4H belongs to the category of triclinic system and has a Centro symmetric space group of P1. Remarkably, the grown crystal exhibits competitive and even superior physical properties including high thermal stability and wider transparency than the standard NLO single crystal. The morphology of the as-grown 2A5MP3C4H crystal was equivalent to the theoretically produced morphology. Fourier transform infrared spectroscopy (FTIR) was used to investigate the molecular vibrations of 2A5MP3C4H. The optical characteristics of 2A5MP3C4H recorded optical transmittance spectrum reveals that the 2A5MP3C4H crystal possesses good optical transparency in the range between ultraviolet (UV) and near-infrared (NIR) regions. Intriguingly, the short cut-off edge of the grown crystal is found to be about 345 nm which is more favourable for developing modern photonic and optoelectronic devices application. The Laser Damage Threshold (LDT), were investigated to understand its effectiveness to be utilized in the area of optoelectronics and photonics. The thermal and mechanical stability of 2A5MP3C4H was tested using Thermo gravimetric Differential Thermal Analysis (TG-DTA) and Vickers hardness test. The third-order nonlinear optical properties of 2A5MP3C4H single crystals were analyzed, which involves studying the absorption coefficient and refractive index behaviour using a continuous wave laser. Additionally, the grown crystal exhibits outstanding third-order NLO response and wide LDT, which are crucial characteristics for developing practical NLO devices. There are various 2-amino-5-methylpyridine (2A5MP) derivative single crystals available in the literature. However 2A5MP3C4H crystal has not been reported earlier. So, we have carried out our researcher on this new novel crystal. Our findings consequently open a novel path for the logical design of enormous, thermally stable and NLO-active organic complexes for true NLO applications.

Silicon‐On‐Silicon Carbide Platform for Integrated Photonics

AbstractSilicon carbide (SiC)'s nonlinear optical properties and applications to quantum information have recently brought attention to its potential as an integrated photonics platform. However, despite its many excellent material properties, such as large thermal conductivity, wide transparency window, and strong optical nonlinearities, it is generally a difficult material for microfabrication. Here, it is shown that directly bonded silicon‐on‐silicon carbide can be a high‐performing hybrid photonics platform that does not require the need to form SiC membranes or directly pattern in SiC. The optimized bonding method yields defect‐free, uniform films with minimal oxide at the silicon–silicon–carbide interface. Ring resonators are patterned into the silicon layer with standard, complimentary metal–oxide–semiconductor (CMOS) compatible (Si) fabrication and measure room‐temperature, near‐infrared quality factors exceeding 105. The corresponding propagation loss is 5.7 dB cm−1. The process offers a wafer‐scalable pathway to the integration of SiC photonics into CMOS devices.

A semi-organic l-glutamic acid cadmium chloride single crystal: preparation, crystal structure, and physicochemical characterization for nonlinear optical applications

A semi-organic l-glutamic acid cadmium chloride single crystal: preparation, crystal structure, and physicochemical characterization for nonlinear optical applications

Synthesis and Investigation of ReSe2 Thin Films Obtained from Magnetron Sputtered Re and ReOx

The promise of two-dimensional (2D) rhenium diselenide (ReSe2) in electronics and optoelectronics has sparked considerable interest in this material. However, achieving the growth of high-quality ReSe2 thin films on a wafer scale remains a significant challenge. In this study, we adopted a two-step method to produce ReSe2 thin films by combining magnetron sputtering of Re and ReOx onto flat substrates with subsequent selenization via atmospheric pressure chemical vapor transport (CVT). After analyzing the produced films using X-ray diffraction to identify the crystalline phase in formed thin film and scanning electron microscopy (SEM) to examine surface morphology, it was determined that the suitable temperature range for the 15 min selenization process with CVT is 650 °C–750 °C. Further investigation of these optimally produced ReSe2 thin films included atomic force microscopy (AFM), X-ray photoelectron spectroscopy, and Raman spectroscopy. The bulk electrical analysis of these films and AFM and SEM surface morphology revealed a strong reliance on the type of precursor material used for their synthesis, whereas optical measurements indicated a potential for the films in non-linear optics applications, irrespective of the precursor or temperature used. This study not only provides a new pathway for the growth of ReSe2 films but also sheds light on the synthesis approaches of other 2D transition metal dichalcogenide materials.

Investigating the optical and magnetic properties of engineered multifunctional graphene oxide and potential application in medical physics and nonlinear optics‏

Herein, the synthesis of multifunctional engineered GOs with the structure of GO@Fe3O4-ligands-CdTe quantum dots (QDs) by an environment-friendly aqueous method was reported. l-cystein (Cys), 3-trimethoxysilyl-propanethiol (TMSP), and glutathione (GSH) were selected as ligands. The as-prepared GO@Fe3O4-ligands-CdTe QDs hybrid nanostructures were characterized by different methods. The findings indicate that the nanocomposites of GO@Fe3O4–ligands–CdTe QDs demonstrate superparamagnetic properties at room temperature. The saturation magnetization values for GO@Fe3O4, GO@Fe3O4-Cys-CdTe, GO@Fe3O4-GSH-CdTe, and GO@Fe3O4-TMSP-CdTe, are 25, 14, 16, and 2 emu g−1, respectively. These nanocomposites show stable and strong luminescence at 580-600 nm. The magnetic nanostructures also reveal the absorption wavelength at 300-490 nm. Using TMSP ligand as a bridge between QDs and magnetic GOs, the luminescence of the nanostructure has not decreased much compared to CdTe QDs. The use of Cys ligand preserves the saturation magnetism of the nanocomposite more than magnetic GO, and the dispersed nanostructure is stable in water. Furthermore, the transverse and longitudinal optical (TO and LO) phonon modes of prepared GO@Fe3O4–ligands–CdTe QDs were obtained by Kramers-Kronig (KK) relations based on fourier-transform infrared (FTIR) spectroscopy. The Z-scan results show that the type of used ligand has a great effect on the nonlinear optical (NLO) properties of the final product. The largest NLO parameters are related to GO@Fe3O4- TMSP -CdTe QDs, and the values of nonlinear absorption coefficient and nonlinear refractive index were obtained as 2.17×10−3(cm/W) and10.27×10−8(cm2/W), respectively. As a result, GO@Fe3O4–ligands–CdTe QDs nanostructures can be considered as promising multifunctional nanostructures for various biomedical applications and NLO devices.