Search

We investigate the plasmon-mediated nonlinear dynamics and the optics of a laser emission of random nanoemitters (NEs) embedded in a two-dimensional (2D) lattice of conducting nanorings (NRs) enhanced by plasmon–polariton (PP) excitations. The interaction of quantum NEs with the PP field in the NRs perturbs the dynamics of the electronic populations in NEs, leading to a significant dependence of laser generation (dynamics) on the plasma frequency ωp of PP. This results in a strong coupling of NE field emission with the PP field and sharp variations of the average current in the NR lattice. The phase transition in the system was found when the macroscopic structures of PP fields are excited simultaneously in different regions of the system if ωp (control parameter) reaches critical value ωc. We have established the analytical dependence of the PP current I = I(ωp/ωc) on the plasma frequency, which is in excellent agreement with the results of numerical simulations. This effect may allow the design of new types of PP active devices with the use of conducting NRs in modern nanoelectronics. [ABSTRACT FROM AUTHOR]

A bipartite system is defined as two microscopic entities being able to exchange energy. When excited by light, the complete optical response functions at first (polarizabilities) and second orders (first hyperpolarizabilities) of such a system are determined using the diagrammatic theory of optics. The generality of the method is ensured by the free choice of light–matter and matter–matter interaction Hamiltonians and by the arbitrary number of quanta involved in the energy exchange. In the dipolar approximation, the optical response functions of the system (i.e., of the interacting entities) are linked to the responses of the interaction-free entities by transfer matrices. These universal matrices identically modify the optical response functions at all orders in the electromagnetic field, allowing the implementation of matter–matter interactions in higher-order processes, such as stimulated or spontaneous Raman scattering and four-wave mixing. This formalism is then applied to various composite systems: dimers, multimers and lattices of nanoparticles and molecules, dense molecular layers, and substrate-induced image dipoles. [ABSTRACT FROM AUTHOR]

Optical metasurfaces, artificial planar nanostructures composed of subwavelength meta-atoms, have attracted significant attention due to their ability to tailor optical nanoscale properties, making them a versatile platform for shaping light in both linear and nonlinear regimes. This paper reports on the realization of second harmonic generation (SHG) enhancement based on a dolmen-type gold metasurface containing two resonances. Nonlinear scattering theory is employed to numerically investigate the SHG enhancement phenomenon in the resonant metasurface. The periodic dolmen-type gold metasurface introduces a diffraction coupling effect between Fano resonance and surface lattice resonance (SLR), providing strong local-field enhancement and significantly enhancing the nonlinear effect. We analyze the influence of the coupling between Fano resonance and SLR on the SHG intensity and achieve a 230-fold enhancement in SHG intensity compared to the single resonance case by adjusting the periodicity of the metasurface. The SHG-enhanced gold metasurface may find applications in sensing, imaging, optical computing, and integrated nonlinear optics. [ABSTRACT FROM AUTHOR]

Second-order nonlinear processes like Sum-Frequency Generation (SFG) are essentially defined in the electric dipolar approximation. However, when dealing with the SFG responses of bulk, big nanoparticles, highly symmetric objects, or chiral species, magnetic and quadrupolar contributions play a significant role in the process too. We extend the diagrammatic theory for linear and nonlinear optics to include these terms for single objects as well as for multipartite systems in interaction. Magnetic and quadrupolar quantities are introduced in the formalism as incoming fields, interaction intermediates, and sources of optical nonlinearity. New response functions and complex nonlinear processes are defined, and their symmetry properties are analyzed. This leads to a focus on several kinds of applications involving nanoscale coupled objects, symmetric molecular systems, and chiral materials, both in line with the existing literature and opening new possibilities for original complex systems. [ABSTRACT FROM AUTHOR]

Optical metamaterials, sensing, nonlinear optics, and surface-enhanced spectroscopies have witnessed the remarkable potential of the anapole mode. While dielectric particles with a high refractive index have garnered significant attention in recent years, the exploration of plasmonic anapole modes with intense localized electric field enhancements in the visible frequency range remains limited. In this study, we present a theoretical investigation on the relationship between the strongest near-field response and magnetic anapole modes, along with their substantial enhancement of Raman signals from probing molecules. These captivating findings arise from the design of a practical metallic oblate spheroid–film plasmonic system that generates magnetic anapole resonances at frequencies within the visible–near-infrared range. This research not only sheds light on the underlying mechanisms in a wide range of plasmon-enhanced spectroscopies but also paves the way for innovative nano-device designs. [ABSTRACT FROM AUTHOR]

Second harmonic generation (SHG) is used to characterize the interfaces of centrosymmetric materials typically used in microelectronic/optoelectronic devices. For such applications, the materials are actually multi-layer stacks, and in this case, the SHG can be difficult to interpret and model. This paper presents the theory of the second harmonic light generated from multilayer structures. The focus is on describing the nonlinear boundary conditions at the interfaces between two different materials, taking into account the distinct contributions of bulk and interface regions. Using these conditions, it is possible to calculate the second harmonic signal from any stack of materials. In this paper, we address stacks containing silicon (100) because it is a material with numerous applications. The nonlinear polarization expressions of the surface and bulk of Si(100), according to Sipe et al. [Phys. Rev. B 35, 1129 (1987)], were integrated into nonlinear boundary conditions in order to determine transmitted and reflected second harmonic waves. An analytical validation was performed on the simple case of an air–silicon interface. For multilayered stacks, the model was compared with experimental results obtained on samples corresponding to pragmatic substrates widely used in microelectronic and optoelectronic applications. [ABSTRACT FROM AUTHOR]

[Display omitted] Inversion symmetry broken 3R phase transition metal dichalcogenides (TMDs) show fascinating prospects in spintronics, valleytronics, and nonlinear optics. However, the controlled synthesis of 3R phase TMDs is still a great challenge. In this work, two-dimensional 3R-NbSe 2 single crystals up to 0.2 mm were synthesized for the first time through chemical vapor deposition method by designing a space-confined system. The crystal size and morphology can be controlled by the location of the stacked substrates and the amount of the Nb 2 O 5 precursor. Scanning transmission electron microscopy and Raman measurements reveal the NbSe 2 exhibits a pure 3R stacking mode with relatively weak interlayer van der Waals interactions. Importantly, 3R-NbSe 2 shows obvious second harmonic generation signal which intensity intensified as thickness increases. Density functional theory calculations and optical absorption demonstrate the coexistence of metallic and semiconducting optical properties of 3R-NbSe 2. We designed a NbSe 2 /WS 2 /NbSe 2 photodetector utilizing the metallicity of 3R-NbSe 2 , which shows good performance especially an ultrafast response (6–7 μs, 0.5 ms − 7.9 s for Au electrodes in literature). The proposed strategy and findings are of great significance for the growth of many other 3R-TMDs and applications of nonlinear optical and ultrafast devices. [ABSTRACT FROM AUTHOR]

Flexible or wearable devices are of great interests in the modern technologies, and oxide thin films are critical components for such applications. In this work, epitaxial LiNbO 3 (LNO) thin film integrated on flexible mica substrate has been achieved. Al-doped ZnO (AZO) layer has been first deposited as buffer layer to obtain the epitaxial LNO film, furthermore AZO serves as bottom electrode for electrical measurement. The as-deposited LNO film exhibits high epitaxial quality with c-direction growth. The transmittance measurement indicates the high transparency of the film, ～85 % in visible range and ～90 % in near infrared region up to 1500 nm. The second harmonic generation (SHG) measurement confirms the nonlinearity of the flexible LNO film. The LNO/AZO/mica film also presents apparent ferroelectric response. Overall, the high-quality LNO integrated on flexible mica could be potentially applied in wearable optical and electrical devices. [ABSTRACT FROM AUTHOR]

Highly efficient off‐diagonal THz generators based on novel organic nonlinear optical single crystals with optimal polar axis orientation in the as‐grown crystal morphology are introduced. The newly developed fluorinated and non‐fluorinated cationic chromophores exhibit a non‐centrosymmetric crystal structure with P21 space group symmetry in the crystalline phase. In particular, PB5FB‐T (5‐fluoro‐2‐(4‐(2‐(hydroxymethyl)pyrrolidin‐1‐yl)styryl)‐3‐methylbenzothiazol‐3‐ium 4‐methylbenzenesulfonate) crystals have an in‐plane polar axis, along with a top‐level off‐diagonal component of the nonresonant effective first hyperpolarizability of ≈100 × 10−30 esu. This stands in stark contrast to previously reported organic THz crystals, which either show a small off‐diagonal optical nonlinearity with an in‐plane polar axis or a large off‐diagonal optical nonlinearity with an almost out‐of‐plane polar axis. Employing an off‐diagonal THz generation configuration, PB5FB‐T crystals generate a THz electric field approximately four times higher than previously reported benchmark analogous crystals with a polar axis nearly out‐of‐plane. Moreover, PB5FB‐T crystals yield smooth THz spectral shapes without significant absorption dimples up to 6 THz when utilizing 130‐fs pump pulses at the wavelength of 1300 nm. [ABSTRACT FROM AUTHOR]

The design and experimental demonstration of double‐step, 1D amorphous germanium grating structures supporting quasi bound‐states‐in‐continuum (quasi‐BIC) resonance at 3.2 µm wavelength and its application to third‐order sum‐frequency generation‐based up‐conversion are reported. Linear transmission measurements on the fabricated metasurface with loosely focussed excitation spanning 0–3° angles show very good agreement with ideal plane‐wave excitation of the periodic photonic structure. TSFG measurements performed on the same structures with tightly focusing mid‐infrared signal and pump beams using a reflective‐type objective with 15–40° angular excitation show ≈375 times enhancement with significant blue‐shift in the resonance feature by ≈300 nm. To understand this excitation angle dependence of the resonance characteristics, a generalized plane‐wave expansion (PWE) model is developed by considering varying excitation angle plane‐waves incident on the metasurface with a discretized angular spectrum representation used to coherently combine the resultant electric and magnetic fields to obtain the linear transmission characteristics and nonlinear TSFG spectra. The PWE method is found to be particularly effective in modeling linear and nonlinear responses under realistic illumination conditions while ensuring optimal utilization of computational resources. Good agreement is obtained between the PWE simulations, linear transmission, and nonlinear TSFG measurements by considering appropriate angular excitation. [ABSTRACT FROM AUTHOR]

In this paper, we succeed to obtain the new optical wave solutions to the truncated M-fractional (2+1)-dimensional nonlinear Schrödinger's complex hyperbolic model by utilizing the Sardar sub-equation method. The obtained solutions are in the form of trigonometric, hyperbolic and mixed form. These solutions have many applications in nonlinear optics, fiber optics, and other areas of physics and engineering where the propagation of nonlinear waves is important. Achieved solutions are verified with the use of Mathematica software. Some of the achieved solutions are also described graphically by two-dimensional, three-dimensional and contour plots. The gained solutions are helpful for the further development of concerned model. Finally, this technique is simple, fruitful and reliable to handle the nonlinear PDEs. [ABSTRACT FROM AUTHOR]

A theory of degenerate four‐wave mixing (DFWM) and phase conjugation is developed for metallic nanohybrids, which consist of an ensemble of interacting metallic nanoshells and noninteracting quantum dots (QDs). It is considered that three incident waves are applied to the metallic nanohybrid, and they produce a fourth output mixed wave. These waves induce dipoles in metallic nanoshells, generating surface plasmon polaritons, and interact with each other via the dipole–dipole interactions (DDI). In DFWM, the input and output waves travel in opposite directions, and this retroreflective nature is responsible for the phenomenon of phase conjugation. The analytical expressions for the input transmitted and output reflected wave intensities are calculated in the presence of the surface plasmon polaritons (SPPs) and the DDI polaritons. It is demonstrated that the phase conjugation, the phase coherent phenomena, and the intensities of both input transmitted and output reflected waves are enhanced due to SPPs and DDI polaritons. These findings indicate that the nanohybrid acts as a phase conjugate device and a phase coherent optical amplifier, which can be applied to fabricate optical nanoamplifiers, phase conjugate mirrors, and nanosensors by measuring the intensity of the output reflected wave. [ABSTRACT FROM AUTHOR]

Mixed‐halide perovskites (MHPs) have emerged as important semiconductor materials for optoelectronic devices due to the bandgap tunability by halide composition. However, their device applications are hampered by light‐induced ion migration and halide segregation, leading to the formation of lower bandgap domains with red‐shifted photoluminescence. Previous studies of phase segregation in MHPs have predominantly focused on their linear optical properties. Herein, nonlinear absorption (NLA) properties of MAPbBr2I films before and after femtosecond laser irradiation are investigated using the Micro‐I‐scan technique. An unusual NLA switching from reverse‐saturable absorption (RSA) to saturable absorption (SA) under intense laser illumination is found. It is unveiled that the initial RSA originates from two‐photon absorption in uniform bromide‐rich regions of as‐prepared film whereas the SA occurs due to state filling effect in the newly generated low bandgap I‐rich phases under laser irradiation. The switching threshold and effective NLA coefficient are highly dependent on the distribution of halide ions, which is controllable through the laser illumination time. Furthermore, an all‐optical logic gate scheme is demonstrated based on the unusual NLA switching. The results not only unveil that halide segregation results in NLA switching in MHPs but also pave the way for the realization of MHPs‐based nonlinear photonic devices. [ABSTRACT FROM AUTHOR]

We present a theoretical study of the incidence of nonuniform waves between two dissipative media with finite conductivity and with a nonlinear response to the applied electric field, which is associated with the Kerr effect. From the Adler–Chu–Fano formulation, the complex propagation vectors, transmitted and reflected angles, and Fresnel coefficients are obtained for the two linear polarization states. In addition, the modification of the total internal reflection, the phase shift, the Goos–Hänchen effect, as well as the interface interaction with bright solitons are explored. Calculations are performed for fused silica, the chalcogenide As2S3 glass, and gold in glass media. [ABSTRACT FROM AUTHOR]

In this paper, we address a newly nonlinear Schrödinger equation (NLSE) in (2 + 1) -dimensions influenced by cubic–quintic–septic law nonlinearity and spatial dissipations effects. We properly construct the dark and bright optical soliton solutions for our governing model. Furthermore, periodic, other singular solutions, multiwave, homoclinic breather, M-shaped rational and their interaction with kink waves of various structures will be derived. In addition to this, some 3D, 2D and contour profiles will be added to anticipate the wave dynamics. [ABSTRACT FROM AUTHOR]

In the present work, we explored the impact of doping concentration and applied electric field on both linear and nonlinear optical properties based upon the intersubband transitions of CdSe/MgSe single quantum wells (QWs) in the framework of the effective mass approximation (EMA) using the compact density matrix approach. The energy levels and their relative wave functions were obtained by solving the coupled Schrödinger–Poisson equations by the finite difference method (FDM) under the envelope wave function approximation. The third-order nonlinear optical susceptibility, the refractive index changes (RIC), and the absorption coefficients (AC) were investigated as a function of doping concentration. The numerical results revealed that an increase in the doping concentration ND results in a blue shift of the peak position of the linear and nonlinear optical properties, with a substantial enhancement of their magnitudes. The same behavior related to the third-order nonlinear susceptibility was noted when the considered structure was subjected to an external electric field. [ABSTRACT FROM AUTHOR]

Discovery 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 P6¯$\overline{6}$ 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. [ABSTRACT FROM AUTHOR]

This article aims to study the time fractional coupled nonlinear Schrödinger equation, which explains the interaction between modes in nonlinear optics and Bose-Einstein condensation. The proposed generalized projective Riccati equation method and modified auxiliary equation method extract a more efficient and broad range of soliton solutions. These include novel solutions like a combined dark-lump wave soliton, multiple dark-lump wave soliton, two dark-kink solitons, flat kink-lump wave, multiple U-shaped with lump wave, combined bright-dark with high amplitude lump wave, bright-dark with lump wave and kink dark-periodic solitons are derived. The travelling wave patterns of the model are graphically presented with suitable parameters in 3D, density, contour and 2D surfaces, enhancing understanding of parameter impact. The proposed model's dynamics were observed and presented as quasi-periodic chaotic, periodic systems and quasi-periodic. This analysis confirms the effectiveness and reliability of the method employed, demonstrating its applicability in discovering travelling wave solitons for a wide range of nonlinear evolution equations. [ABSTRACT FROM AUTHOR]

We provide a rigorous justication of nonlinear geometric optics expansions for reflecting pulses in space dimensions n > 1. The pulses arise as solutions to variable coefficient semilinear first-order hyperbolic systems. The justification applies to N × N systems with N interacting pulses which depend on phases that may be nonlinear. The coherence assumption made in a number of earlier works is dropped. We consider problems in which incoming pulses are generated from pulse boundary data as well as problems in which a single outgoing pulse reflects off a possibly curved boundary to produce a number of incoming pulses. Although we focus here on boundary problems, it is clear that similar results hold by similar methods for the Cauchy problem for N × N systems in free space. [ABSTRACT FROM AUTHOR]

Nonlinear optics of structured light carrying orbital angular momentum (OAM) has recently led to intriguing fundamental physical effects in light–matter interactions and advanced applications from classical imaging to quantum informatics. However, the mutual interaction between spatial mode and frequency conversions in nonlinear processes is still elusive. In this work, we go beyond only considering OAM and frequency in nonlinear structured light conversion and investigate the complex mode evolution in cascaded nonlinear frequency conversion and spatial astigmatic mode conversion. In particular, we unveil a generalized law of nonlinear structured light from experiments and theories, that the converted modes are highly related to the sequence of frequency and spatial mode conversions, obeying an inherent (non)commutative rule in which. This effect not only creates extended structured laser modes but serves as regular rules in nonlinear optics. [ABSTRACT FROM AUTHOR]

With the advancement of laser technology, searching for new nonlinear optics (NLO) active units is necessary for designing NLO materials with excellent performance. In this study, an amino substitution strategy is proposed to explore new planar π‐conjugated groups as functional building units (FBUs) for NLO and birefringent materials. Accordingly, a new NLO‐active molecule melem C6N7(NH2)3 is identified, which is characterized by significant polarization anisotropies and large hyperpolarizabilities. Subsequently, C6N7(NH2)3·H3PO4 is screened out and successfully synthesized through a simple aqueous method. The compound exhibits a strong second harmonic generation (SHG) response of 8.9 times that of KDP and a large birefringence of 0.609 at 1064 nm. As far as is known, the calculated birefringence of C6N7(NH2)3·H3PO4 is the largest among the organic–inorganic hybrid crystals in which the birefringence originates from π‐conjugated groups. The theoretical computation supports that the amino (─NH2) substitution strategy is effective for designing and synthesis of materials with strong SHG response and large birefringence. [ABSTRACT FROM AUTHOR]

This study focuses on the investigation of the perturbed Chen–Lee–Liu model with conformable fractional derivative by the implementation of the generalized projective Riccati equations technique. The proposed method uses symbolic computations to provide a dynamic and powerful mathematical tool for addressing the governing model and yielding significant results. Numerous analytical solutions of the governing model, including bell-shaped soliton solutions, anti-kink soliton solutions, periodic solitary wave solutions and other solutions, have been constructed effectively utilizing this effective technique. The findings acquired from the governing model utilizing the suggested technique demonstrate that all results are novel and presented for the first time in this study. Solitons are of immense significance in the domain of nonlinear optics due to their inherent ability to preserve their shape and velocity during propagation. The study of the propagation and the dynamical behaviour of the derived results have been explored by representing them graphically through 3D, density, and contour plots with different selections of arbitrary parameter values. The solitons acquired from the proposed model can provide significant advantages in the field of fiber-optic transmission technology. The obtained results demonstrate that the suggested approach is extremely promising, straightforward, and efficient. Furthermore, this approach may be effectively used in numerous emerging nonlinear models found in the fields of applied sciences and engineering. [ABSTRACT FROM AUTHOR]

Graphene is a unique platform for tunable opto‐electronic applications thanks to its linear band dispersion, which allows electrical control of resonant light‐matter interactions. Tuning the nonlinear optical response of graphene is possible both electrically and in an all‐optical fashion, but each approach involves a trade‐off between speed and modulation depth. Here, lattice temperature, electron doping, and all‐optical tuning of third‐harmonic generation are combined in a hexagonal boron nitride‐encapsulated graphene opto‐electronic device and demonstrate up to 85% modulation depth along with gate‐tunable ultrafast dynamics. These results arise from the dynamic changes in the transient electronic temperature combined with Pauli blocking induced by the out‐of‐equilibrium chemical potential. The work provides a detailed description of the transient nonlinear optical and electronic response of graphene, which is crucial for the design of nanoscale and ultrafast optical modulators, detectors, and frequency converters. [ABSTRACT FROM AUTHOR]

Over the past decade, there has been a pronounced research emphasis on leveraging the advantageous defect states inherent in metal dichalcogenide nanostructures to intricately modulate and tailor their optoelectronic characteristics. Here, we demonstrate how defects significantly impact the linear and nonlinear optical properties of pristine FeS2 nanomaterials (NMs), ionic liquids (DMII) passivated FeS2 NMs, and CoFeS2 NMs. These NMs were synthesized using a low-cost hot-injection process, and their structure was validated via X-ray diffraction analysis. The oval-like structure of the NMs is revealed by high-resolution transmission electron microscopy, and X-ray photoelectron spectra demonstrate the presence of the divalent oxidation state of iron (Fe) and cobalt (Co). After the treatment of DMII on the pristine NMs, a decrease in the Urbach energy (Eu) was found, with values reducing from 0.77 to 0.27 meV. This phenomenon may potentially be associated with the passivation of surface imperfections in pristine NMs. The treatment of DMII further enhances the lifetime of charge carriers (1.25 ns) and conductivity by one order compared to pristine FeS2 NMs. On the other hand, introducing Co in FeS2 alters the conductivity of pure FeS2 NMs, shifting them from p-type to n-type and significantly enhancing their electrical characteristics by 3 orders of magnitude. The open aperture z-scan study revealed that the CoFeS2 NMs have an effective nonlinear absorption coefficient (βeff) of 160 cm GW–1, which is superior to that of the pristine NMs with a βeff of 130 cm GW–1. The optical limiting threshold value (1.01 J cm–2) of CoFeS2 NMs is much higher than those of both pristine and DMII-treated FeS2 NMs, indicating superior optical limiting performance. The current work presents a comprehensive analysis of pristine, DMII-treated, and Co-alloyed FeS2 NMs, focusing on their potential for linear and nonlinear optoelectronic applications. [ABSTRACT FROM AUTHOR]

We consider the Cauchy problem for the stochastic nonlinear Schrödinger equation augmented by nonlinear energy-critical damping term arising in nonlinear optics and quantum field theory. Through examining the behavior of the momentum and energy functionals, we almost surely prove the existence and uniqueness of global solutions with continuous H 1 (R d) valued paths. The results cover either defocusing nonlinearity in the full energy critical and subcritical range of exponents or focusing nonlinearity in the full subcritical range, as in the deterministic case. [ABSTRACT FROM AUTHOR]

Ultrafast lasers have significantly contributed to the advancement of research and technology; however, high‐intensity lasers bring potential risks to precision instruments and the human eye. Developing optical limiting (OL) devices capable of reasonably controlling laser energy to an acceptable energy level is imperative. Nevertheless, achieving both exceptional OL performance and broad‐spectrum laser intensity tunability proves highly challenging. In this work, the synthesis of a porphyrin‐based 2D polymer (Por‐2DP) using a template‐assisted self‐coupling polymerization, constructing a 2D framework through the carbon‐carbon single bond coupling of porphyrin monomer is presented. The resultant Por‐2DP demonstrates remarkable broadband nonlinear absorption performance, spanning the visible and near‐infrared spectral regions under an ultrafast pulse laser (35 fs) for the first time. OL thresholds at excitation wavelengths of 515, 800, and 1550 nm are determined to be 1.44, 0.48, and 0.54 mJ cm−2, respectively, surpassing reported 2D materials to date. Additionally, the Por‐2DP exhibits prominent photostability, enabling sustained operation under intense light conditions for a long time, thereby enhancing OL practical applicability. This study not only introduces a novel OL material and device but also promotes the application of innovative 2D organic polymers in NLO field. [ABSTRACT FROM AUTHOR]

This work focuses on the electronic, optoelectronic, and nonlinear optical properties of the cyclo[2N]carbon series (C10, C12, C14, C16, C18, C20, C22, and C24), and their derivative systems (C8BN, C10BN, C12BN, C14BN, C16BN, C18BN, C20BN, and C22BN) obtained by functionalizing each molecule of the series with the boron–nitrogen (B–N) binomial. The results were obtained from density functional theory and time-dependent density functional theory at the B3LYP-D3, CAM-B3LYP-D3, and ωB97XD/6–31 + G(d) levels of theory. The study found that the cumulative B–N effects on the molecules studied break the centrosymmetry of these molecules while, lowering the energy gap (from 3.11 eV for C18 to 2.80 eV for its derivative C16BN) making these molecules good materials for electronics. The C2N molecules (2N = 4n), namely C12, C16, C20, and C24, and their derivatives C10BN, C14BN, C18BN, and C22BN, are found to have high chemical softness (s), electronegativity (η), and electrophilic index (ω), making them useful materials in optoelectronics. An impressive impact of the B–N cumulative effect on the cyclo[2N]carbon's series is that it significantly generates the first-order hyperpolarizability values. Like C24 of which β = 0.00 a.u. and its derivative C22BN of which β = 8812.77 a.u., value 8 times higher than that of paranitroaniline (β = 1072.44 a.u.), which is the reference compound in nonlinear optics, rendering these molecules interesting for linear and non-linear optical applications. [ABSTRACT FROM AUTHOR]

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 405 nm and 532 nm continuous wave (CW) laser wavelengths, yielding second-order nonlinear refractive index ( n 2 , t h ) values of 6.54 × 10 - 5 cm 2 / W and 2.73 × 10 - 5 cm 2 / W , 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. [ABSTRACT FROM AUTHOR]

Light‐induced electron dynamics in monolayer hexagonal boron nitride is theoretically investigated under the influence of two‐color linearly‐polarized laser fields at frequencies ω and 2ω, by solving the time‐dependent Schrödinger equation with a tight‐binding model. In the weak field regime, it is confirm that the injection of ballistic current arises from the breakdown of time‐reversal symmetry. This phenomenon is attributed to quantum interference between two distinct excitation paths: a one‐photon (2ℏω) absorption path and a two‐photon (ℏω) absorption path. In a strong field regime, the analysis reveals that the two‐color laser fields may generate a substantial population imbalance within momentum space, consequently facilitating the injection of ballistic current even in a deeply off‐resonant regime. The findings demonstrate that a pronounced population imbalance exceeding 30% of excited electrons can be realized without relying on the ellipticity of the fields. This highlights the potential of linearly polarized light for efficient photovoltaic effects and valley population control in 2D systems and heterostructures. [ABSTRACT FROM AUTHOR]

A strategic approach to develop efficient ultra‐broadband terahertz (THz) crystals involves the incorporation of different electron donating groups (EDGs) into cationic chromophores. In contrast to the widely utilized non‐cyclic 4‐(dimethylamino)phenyl (DA) EDG, cyclic 5‐membered 4‐(2‐(hydroxymethyl)pyrrolidine‐1‐yl)phenyl (PB) and cyclic 6‐membered 4‐(3‐(hydroxymethyl)piperidin‐1‐yl)phenyl (PN) EDGs exhibit an asymmetrical shape with a strongly interacting hydroxymethyl group at the chiral center. Notably, the PB EDG shows narrower intrinsic vibrational states with lower conformational flexibility and smaller ring flips compared to the PN EDG. In the crystalline state, introducing the PB EDG leads to the formation of a new class of nonlinear optical assembly, the so‐called stair‐type cation‐anion assembly. This assembly demonstrates optimal chromophore alignment with state‐of‐the‐art effective first hyperpolarizability (209 × 10−30 esu). Furthermore, the PB EDG‐based crystals exhibit significantly lower THz absorption compared to previously reported benchmark crystals. In THz wave generation experiments, PB EDG‐based crystals demonstrate state‐of‐the‐art efficiency and ultrabroad spectral bandwidth, featuring a cut‐off frequency of up to 16 THz. [ABSTRACT FROM AUTHOR]

Lead‐free halide perovskites is a novel class of environment‐friendly nonlinear optical materials, that already demonstrate high potential for second harmonics generation (SHG). Here a synthesis protocol is optimized to create single‐crystal CsGeI3 nanoparticles (NPs) supporting optical Mie resonances that efficiently convert infrared light to visible both via lasing and SHG mechanisms. Such high‐quality resonant NPs allow us to achieve up‐conversion lasing in the broadband excitation wavelength (1200–1520 nm), which is accompanied by efficient spectrally tunable SHG with intensity comparable with that for lasing depending on temperature. Experimental and theoretical study of linear and nonlinear optical properties of CsGeI3 material in the form of high‐quality thin film and NPs of different sizes reveal that coupling incident light with a magnetic dipole resonance leads to a strong enhancement of SHG by one order of magnitude. As a result, the study provides a novel strategy where individual NPs can support both up‐conversion lasing and SHG in a broad range of excitation wavelengths. [ABSTRACT FROM AUTHOR]

The fabrication related to single-layer Ag/curcumin (Curc) dye nanocomposites on a substrate is described in this paper, along with an examination of optical characteristics that follow, which could be applied to non-linear optics. With the use of a nanosecond pulsed laser method, AgNPs were produced. Using a straightforward solution technique, hybrid Ag/Curc dye nanocomposites have been created with varying concentrations regarding the Curc dye. The impact of concentration on the (non-linear and linear) structural and optical properties was then examined. The following techniques have been examined: FT-IR analysis, FE-SEM microscope, XRD, fluorescence spectroscopy, and UV-Vis spectra. Non linear refractive index as well as non linear absorption coefficients of samples have been utilized in order to explore the non-linear optical (NLO) properties related to the Curc dye nanocomposites and hybrid AgNPs using Zscan method. A nano-second pulsed Neodymium-YAG laser operating at 532 nm has been employed in the Z-scan approach. The findings demonstrate that the size of AgNPs affects their nonlinearity absorption coefficients and non-linearity refractive index. The enhancement of visual qualities was attributed, according to the data, to an increase in Curc content. For AgNPs and raise the strength of surface plasmon resonance (SPR), which will boost NP production and enhance fluorescence. The absorption which emerges near wave number 3451 cm-1 in the infrared Fourier test of AgNPs was researched because it results from the alcohol group's (OH) bond vibration. The aromatic (C-H) bond is the absorption bond 2927 cm-1, indicating that Curc functions as a cover agent. A study was conducted using XRD to examine AgNPs and a hybrid mixture of Curc and AgNPs. XRD data of AgNPs revealed a cubic and polycrystalline crystal structure, with several angles recorded that are exactly the same as the international standard cards for silver. A straightforward platform for improving optical qualities is offered by such hybrid Ag/Curc dye nano composite, which may find use in nanoprobing as well as nano-medical applications, including the antibacterial domain. [ABSTRACT FROM AUTHOR]

As a rapidly expanding family of 2D materials, MXenes have recently gained considerable attention. Herein, by developing a coating method that enables transfer‐free and layer‐by‐layer film coating, the nonlinear optical absorption (NOA) of Ti3C2Tx MXene films is investigated. Using the Z‐scan technique, the NOA of the MXene films is characterized at ≈800 nm. The results show that there is a strong and layer‐dependent NOA behavior, transitioning from reverse saturable absorption (RSA) to saturable absorption (SA) as the layer number increases from 5 to 30. Notably, the nonlinear absorption coefficient β changes significantly from ≈7.13 × 102 cm GW−1 to ≈−2.69 × 102 cm GW−1 within this range. The power‐dependent NOA of the MXene films is also characterized, and a decreasing trend in β is observed for increasing laser intensity. Finally, the NOA of 2D MXene films at ≈1550 nm is characterized by integrating them onto silicon nitride waveguides, where an SA behavior is observed for the films including 5 and 10 layers of MXene, in contrast to the RSA observed at ≈800 nm. These results reveal intriguing nonlinear optical properties of 2D MXene films, highlighting their versatility and potential for implementing high‐performance nonlinear photonic devices. [ABSTRACT FROM AUTHOR]

Subwavelength gratings play a fundamental and pivotal role in numerous science and applications for wave manipulation, exhibiting distinctive features such as filtering, phase manipulation, and anti‐reflection. However, conventional fabrication methods for ultrasmall periodic structures are constrained by the fundamental optical diffraction limit, making it challenging to produce subwavelength gratings for optics. Here, a novel technique is demonstrated to build a reconfigurable subwavelength photorefractive grating (SPG) in a thin‐film lithium niobate on the platform of an optical microcavity. Such SPGs are optically induced through the photorefractive effect and the subwavelength features originate from the spatial phase modulations of the pump's standing wave. The resulting SPGs lead to the mode splitting of two counter‐propagating modes inside the microcavity, exhibiting an Electromagnetically Induced Transparency (EIT)‐like transmission spectrum. Moreover, the unique subwavelength characteristic of SPGs enables first‐order quasi‐phase‐matching for backward second‐harmonic generation, a long‐standing problem in nonlinear optics. Also, free‐space‐to‐chip vertical nonlinear frequency conversion can be achieved in a similar manner. These results provide a flexible approach toward fabricating subwavelength gratings, which holds significant potential in various applications such as nonlinear frequency conversion, optical communication, sensing, and quantum technologies. [ABSTRACT FROM AUTHOR]

Taking advantage of their unique and tuneable electromagnetic properties, plasmonic metamaterials constitute a versatile platform for a variety of applications ranging from high‐resolution imaging, sensing and spontaneous emission engineering to ultrafast nonlinear optics and light polarization control. Here, recent advances in the design and applications of plasmonic metamaterials based on aligned metallic nanorod assemblies are reviewed, and the fast‐developing trends in their exploitation in nanophotonics are outlined. The fabrication of the nanorod‐based metamaterials is introduced and their linear and nonlinear optical properties are presented from both microscopic and phenomenological considerations. Multiscale structuring allowing precise engineering of the electromagnetic modes supported by the nanorod metamaterials, as well as nonlocal spatial dispersion effects and their impact on nanophotonic performance are discussed. To illustrate the developing field of practical applications of these metamaterials, some of their main application domains in sensing, photochemistry and nonlinear optics are overviewed and novel designs of anisotropic metamaterials directly derived from the nanorod architecture are introduced. [ABSTRACT FROM AUTHOR]

Integrated tunable optical filters are essential components in photonic signal processors, telecom systems, sensors, and quantum optical devices. Two of the most important features of a tunable filter are its dimensions and power consumption. Herein, the design and experimental validation of an on‐chip optical filter composed of a 1D topological photonic crystal cavity based on a hybrid integrated lithium tantalite‐silicon platform is presented. The strong optical confinement of the boundary state allows the fabrication of a tunable filter with an ultra‐compact size of 1.14 × 75 µm2 is demonstrated. Moreover, lithium tantalite has excellent electro‐optic properties and enables ultra‐low‐power wavelength tuning of the topological boundary state. The measured power consumption and tuning efficiency of the device are 0.0218 nW pm−1 and 6.64 pm V−1, respectively. The anisotropy of thin‐film lithium tantalite is verified by evaluating its tuning efficiency at different optical angles. The device can compensate for thermally induced refractive index changes ≈20 °C, exhibiting operational robustness. High‐speed transmission experiments confirm the stability of the developed tunable filter. This optical filter implements a topological structure with a compact size and can potentially be applied in on‐chip quantum optics, nonlinear optics, and optical sensing. [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]

Context: In this study, we evaluate the geometrical, absorption, optoelectronic, electronic, nonlinear optical (NLO) and thermodynamic properties of dibenzo[b,def]chrysene molecule derivatives by means of DFT and TD-DFT simulations. In view of the aim of producing new high-performance materials for non-linear optics (NLO) by doping test, two types of doping were used. We obtained six derivatives by doping with organic dopants (Nitro, amide and ticyanoethenyl) and mixed alkali metal (potassium) and organic dopants. Doping with organic dopants produced molecules A, B and C, respectively when substituting one hydrogen with nitro (NO2), amide (CONH2) and tricyanoethenyl (C5N3) groups, while mixed doping involved considering A, B and C and then substituting two hydrogens with two potassiums to obtain compounds D, E and F respectively. The negative values of the various interaction energies calculated for all the doped molecules show that they are all stable, but also that molecules C and F are the most stable in the case of both dopings. The gap energies calculated at the B3LYP level of theory are all below 3 eV, which means that all the molecules obtained are semiconductors. Better still, compounds C and F, with gap energies of 1.852 eV and 1.204 eV, respectively, corresponding to decreases of 35.67% and 58.18% in gap energy compared with the pristine molecule, are more reactive than the other doped molecules. Mixed doping is therefore a highly effective way of narrowing the energy gap and boosting the semiconducting character and reactivity of organic materials. Optoelectronic properties have also been improved, with refractive index values higher than those of the reference material, glass. This shows that our compounds could be used under very high electric field conditions of the order of 4.164 × 109 V.m−1 for C and 7.410 × 109 V.m−1 for F the highest values at the B3LYP level of theory. The maximum first-order hyperpolarizability values for both types of doping are obtained at the CAM-B3LYP level of theory by C: β mol = 92.088 × 10−30esu and by F: β mol = 129.449 × 10−30esu, and second-order values are also given by these same compounds. These values are higher than the reference value, which is urea, making our compounds potential candidates for high-performance NLO applications. In dynamic mode and at a frequency of 1064 nm, at the CAM-B3LYP level of theory, the highest dynamic hyperpolarizability coefficients were obtained by C and F. Hyper-Rayleigh scattering β HRS , coefficients of the electro-optical Pockel effect (EOPE), EFISHG, third-order NLO-response degree four-wave mixing γ DFWM , quadratic nonlinear refractive index n2 were also calculated. The maximum values of n2 are obtained by C (6.13 × 10–20 m2/W) and F (6.60 × 10–20 m2/W), these values are 2.24 times higher than that of fused silica which is the reference for degenerate four-wave mixing so our molecules could also have applications in optoelectronics as wavelength converters, optical pulse modulators and optical switches. Methods: Using the DFT method, we were able to determine the optimized and stable electronic structures of doped dibenzo[b,def]chrysene derivatives in the gas phase. We limited ourselves to using the proven B3LYP and CAMB3LYP levels of theory for calculating electronic properties, and non-linear optics with the 6-311G + + (d,p) basis set, which is a large basis set frequently used for these types of compound. Gaussian 09 software was used to run our calculations, and Gauss View 6.0.16 was used to visualize the output files. TD-DFT was also used to determine absorption properties at the B3LYP level of theory, using the same basis set. [ABSTRACT FROM AUTHOR]

In this study, we investigate the Biswas–Arshed (BA) model, applicable in various fields such as fluid mechanics, laser science, and nonlinear optics. We employ the direct algebraic procedure, the modified rational sine–cosine process, and the 1 G ′ approach to obtain soliton dynamics of the mentioned model. Chaotic behavior and sensitivity analysis of the BA model are also investigated using a planar dynamic system. As a result, periodic, quasi-periodic, and chaotic patterns are obtained from the suggested nonlinear model. We also obtain various soliton solutions from this model with novel properties. From the proposed equation, we can obtain periodic waves with bright solitons, bright-dark solitons, dark solitons, breather waves with singularities, double periodic waves, periodic waves with singularities, bright solitons with singularities, multiple bright dark breather waves with singularities, and multiple bright breather waves with singularities. Certain features of the outcomes are exhibited in 2D, 3D, and density views. The work presented is innovative as it offers valuable insights into the governing model's intricate behaviors and diverse waveforms through extensive analysis. This study also contributes to understanding real-world problems by incorporating waveform properties, bifurcation analysis, chaotic dynamics, and sensitivity tests. [ABSTRACT FROM AUTHOR]

This study introduces a novel numerical method for analyzing the nonlinear behavior of intricate electromagnetic structures, with a specific focus on a metatronic amplifier as a case study. We propose a modified approach that integrates Harmonic Balance (HB) and Finite Difference Frequency Domain (FDFD) methods, tailored for structures featuring anisotropic materials. The combined application of HB-FDFD enables a comprehensive investigation of spatial electromagnetic field distributions and harmonic responses within such structures. Moreover, this method effectively addresses the challenges associated with complex architectures. Additionally, we emphasize the incorporation of effective boundary conditions, as discussed in the paper, to enhance the accuracy of our analysis. Through a comparison with conventional methods, we demonstrate the efficacy of our approach and underscore its broad applicability to various nonlinear electromagnetic devices. [ABSTRACT FROM AUTHOR]

The exact soliton solutions of perturbed Gerdjikov-Ivanov equation with both constant and variable coefficients are constructed in this work through the application of the modified F-expansion method. This method is used for the very first time on the considered equation. As a result, the traveling wave solutions including soliton solutions are obtained. These soliton solutions enhance understanding of nonlinear phenomena in the fields of photonic crystal fibers, fiber optics and nonlinear fiber optics. The explanation of the obtained results is provided by drawing some 2-dimensional and 3-dimensional graphs using Mathematica. Furthermore, this study discusses the modulation instability for the considered model. The considered method is found to be effective, simple and useful to study the perturbed Gerdjikov-Ivanov equation. [ABSTRACT FROM AUTHOR]

In this paper, the Kundu–Eckhaus equation which describes the propagation of ultrashort pulses or femtosecond light pulses in nonlinear optics is investigated using the new mapping method. As a result, different structures of chirped solitary and periodic waves were yielded. The dynamic of the soliton and kink soliton chirp waves were illustrated from which we can conclude that the sign of the Raman parameter identifies the chirp wave function direction. [ABSTRACT FROM AUTHOR]

In this paper, we conducted a detailed investigation on the evolution of a partially coherent generalized Hermite cosh-Gaussian beam (PCGHchGB) through a gradient-index medium. Analytical formula for a PCGHchGB propagating in the gradient-index medium is obtained based on ABCD transfer matrix and generalized diffraction integral formula. We discuss the periodic changes of the corresponding beam through the gradient-index medium by performing numerical examples. Our obtained results demonstrate that the gradient-index parameter of media and the initial beam parameters, such as the coherence width, beam waist width, decentered beam parameter, and beam orders, affect the evolution characteristics on the intensity distribution of the PCGHchGB in the gradient-index medium. The results of this work could be beneficial for applications in optical communication and nonlinear optics. [ABSTRACT FROM AUTHOR]

This article explores a wide range of envelope soliton pulses and their behavior during propagation through a birefringent optical fiber. The propagation of light in such fibers is governed by two coupled non-linear Schrödinger equations (CNLSEs), which account for both coherent and incoherent non-linear couplings. To investigate these solitons, an improved modified extended tanh function scheme (IMETFS) is employed. The study focuses on elliptical core optical fibers and examines the significance of various optical solitons in the presence of group-velocity dispersion and third-order nonlinearity. The findings illustrate that birefringent optical fibers can generate a diverse array of nonlinear periodic waves and localized pulses. The different types of soliton solutions identified include singular, bright, rational, exponential, Jacobi elliptic functions (JEFs), Weierstrass elliptic doubly periodic solutions, and singular periodic solutions. Comparisons with existing literature highlight the novelty and substantive contributions of the discovered wave solutions to current research in nonlinear optics. The success of this approach suggests its potential applicability in addressing nonlinear challenges across different fields, particularly in soliton theory, where similar models are frequently encountered. Additionally, the article presents visual representations of these solutions through 3D and 2D plots, aiding in the understanding of their behaviors. [ABSTRACT FROM AUTHOR]

This paper investigates the application of the enhanced modified tanh expansion method and the Kudryashov method in deriving optical solutions for a conformable nonlinear Schrödinger equation. This equation includes Kudryashov's arbitrary refractive index and incorporates two distinct nonlocal nonlinearities. The resulting optical solutions are expressed using a combination of exponential and hyperbolic functions, encompassing kink-type, mixed dark-bright, bright, bell-shaped, multi-bright, and wave solitons. Visualization of these solutions is provided through two-dimensional, three-dimensional, and contour plots to elucidate their characteristics. Furthermore, the behavior of these optical solutions is analyzed via illustrative graphs, considering different values of the time parameter and conformable order derivative. The proposed methods are posited as precise approaches for investigating optical solutions across various formulations of Schrödinger equations. The methods proposed in the paper offer precise approaches for studying and understanding the behavior of light in complex optical systems described by Schrödinger equations. This research contributes to advancing our knowledge of nonlinear optics and may have practical applications in fields such as telecommunications, laser technology, and optical signal processing. [ABSTRACT FROM AUTHOR]

The paper introduce a novel auxiliary equation method for the successful derivation of traveling wave solutions for the non-linear Kairat-X (K-X) equation. Along with other novel results, soliton, singular, triangular periodic, and doubly periodic topological solutions are among the solutions obtained. The study revisits the concept of optical solitary waves, enhancing our understanding of the model. Previous studies have already derived analytical solutions using diverse approaches, contributing to the discovery of new soliton solutions within this framework. These solutions are characterized through three-dimensional, contour plot, and two-dimensional profile analyses. Additionally, the impact of time on the propagation of wave patterns is explored. The outcomes show how well our suggested approach works to solve non-linear evolution equations by producing fresh, more thorough solutions, making it a powerful mathematical tool for doing so. Through this article, we elucidate how leveraging NAEM with the Kairat-X equation can lead to optimized optical systems, improved data transmission rates, and the evolution of nonlinear optics towards more efficient and reliable communication technologies. [ABSTRACT FROM AUTHOR]

Under the consideration of computational software Mathematica on the basis of extended simple equation method, constructed the periodic wave soliton solutions for nonlinear Zakharov–Kuznetsov modified equal width equation. In this study, constructed soliton solutions included periodic singular solitons, bright solitons, kink solitons, anti-kink solitons, travelling waves, dark solitons and solitary waves are more interesting, prices and some are novel. The graphical demonstration of some investigated results shown by contour, 2-dim and 3-dim by computing software Mathematica under numerical simulation to visualizing the physical phenomena of obtained results. The demonstrated results will be helpful in the study of nonlinear phenomena in various kinds of domains including nonlinear optics, nonlinear dynamics, solitons wave theory, optical fiber, nonlinear acoustic wave, communications system, networking system and transmission of signals. The extended simple equation technique is a concise, straightforward, powerful and reliable approach for the investigation of different kinds of nonlinear partial evolution equations. [ABSTRACT FROM AUTHOR]

The slow evaporation technique was used to produce nonlinear optical ammonium pentaborate dihydrate (APBDH) single crystals. The crystal lattice parameters and structure of APBDH crystal was determined by single crystal X-ray diffraction (S-XRD) technique with the triclinic space group. The optical band gap of the grown crystal was determined using UV–Vis spectrophotometer. There is no absorption peak was observed in the entire visible region of the spectrum. The functional groups of the APBDH crystal were identified through Fourier transforms infrared (FTIR) and Fourier transform Raman (FR-Raman) analyses. The thermal decomposition and thermal stability of the grown crystal was measured using TG-DTA analyses. The laser damage threshold (LDT) analysis was used to know the ability to withstand the influence of laser on the grown crystal. Photoconductivity of the grown crystal was studied and its photocurrent and dark current behavior was examined. The surface morphology of the APBDH crystal was evaluated using HR-SEM analysis. The APBDH crystal was exhibited second harmonic generation behavior and its efficiency was calculated with different particle sizes. [ABSTRACT FROM AUTHOR]

The organic single crystal of aniline-4-sulphonic acid (A4SA) was synthesized and grown by slow evaporation solution technique (SEST) using distilled water as a solvent. The lattice parameters of the grown crystal were confirmed by single-crystal X-ray diffraction analysis. The X-ray diffraction exposes that the A4SA crystal belongs to an orthorhombic system with space group Pca21. Functional groups of A4SA crystal were confirmed by Fourier transform infrared (FTIR) and FT-Raman spectrum analyses. The optical quality of the grown crystal was identified by the UV-Visible NIR spectrum analysis. The grown crystal has good optical transmittance in the range of 300–900 nm. The photoconductivity analysis was carried out to calculate the photo and dark current values. Photoconductivity study indicates that A4SA crystal shows a negative photoconductivity nature. Intermolecular interactions of A4SA are executed by the Hirshfeld surface analysis. The chemical etching was investigated to calculate the etch pit density. Photoluminescence analysis for grown crystals is obtained. Thermogravimetric, differential thermogravimetric analysis and differential scanning calorimetry (TG, DTA, DSC) measurements investigate the thermal stability of a grown crystal. Vickers microhardness analysis was performed to study the mechanical properties of the material. The Nd:YAG laser, with a wavelength of 1064 nm, was used to examine the LDT analysis. It shows a good LDT value of 5.02 GW/cm2. The third-order non-linear susceptibility was measured and analysed by Z-scan technique using (He–Ne) laser of wavelength 632.8 nm. [ABSTRACT FROM AUTHOR]

A passively Q-switched Er:YAP laser of 2.7 µm, utilizing Au-doped CsPbI3 quantum dots (QDs) as a saturable absorber (SA), was realized. It was operated stably with a minimum pulse width of 185 ns and a maximum repetition rate of 480 kHz. The maximum pulse energy and the maximum peak power were 0.6 μJ and 2.9 W, respectively, in the Q-switched operation. The results show that the CsPbI3 QDs SA exhibits remarkable laser modulation properties at ~3 μm. [ABSTRACT FROM AUTHOR]