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In this study, we have calculated the structural, mechanical, elastic anisotropy, electronic, optical, and thermal properties of Ba3SbI3 perovskite using first-principles-based DFT calculations. We have computed the crystal structure and lattice parameters (a = 7.05 Å) which consisted with previous theoretical and experimental results. The Ba3SbI3 is stable as checked by the standards of mechanical stability criteria, ductile in nature, and elastically anisotropic. Semiconductor feature of Ba3SbI3 is ensured from the band structure, total density of states (TDOS) and partial density of states (PDOS) calculations as the difference of conduction band (CB) and valence band (VB) in the Fermi level. From the electron charge density mapping, it exhibits ionic bond nature. Furthermore, optical properties have investigated in details. The Debye temperature (123.776 K), thermal conductivity (0.247 Wm−1 K−1), and melting temperature (123.776 K) of the Ba3SbI3 compound were calculated and analyzed, which is potential candidates of thermal barrier coating (TBC) material. [ABSTRACT FROM AUTHOR]

This article presents a highly sensitive plasmonic sensor with a focus on enhancing its capabilities through innovative design and simple geometric structure. A hexagonal-shaped photonic crystal fiber (PCF) based surface plasmon resonance sensor is designed and proposed for external sensing applications. The plasmonic material is made of gold and positioned on the outer side of the designed PCF. For detection purposes, the flow of the testing analyte is introduced on the exterior section of the PCF. The sensing capability of this innovative sensor is meticulously examined using the finite element technique facilitated by the COMSOL Multiphysics software. The suggested sensor, with a refractive index of 1.38, has a maximum amplitude sensitivity and wavelength sensitivity of 765.86 RIU−1 and 8,000 nm/RIU respectively. At the same refractive index, the sensing resolution of the sensor is 1.31 × 10–5 for amplitude sensitivity and 1.25 × 10–5 for wavelength sensitivity. Additionally, the sensing capability of the sensor lies in the range of the analyte refractive indices from 1.33 to 1.39. Furthermore, the sensing performance of the designed sensor is analyzed by optimizing the values of several design parameters including air-hole diameter, pitch, and gold layer thickness. The suggested sensor can recognize biological analytes with high sensitivity, improved sensing resolution, and appropriate linearity. [ABSTRACT FROM AUTHOR]

In this study, the dissipation problem of nonlinear pulse in mono mode optical fibers which is governed by the Fokas system (FS) is considered. The solutions of this system have an important role in comprehending the different wave structures in physical settings. Therefore, a new version of the trial equation method (NVTEM) is employed to present the new exact wave solutions of the FS. The advantage of the NVTEM is to use different root possibilities of a polynomial which shape the solutions of the related model. Primarily this system is converted to a nonlinear ordinary differential equation (NODE) via the traveling wave transform to apply the proposed method. Various exact wave solutions to the FS are obtained such as rational function, exponential function, hyperbolic function, and Jacobi elliptic function solutions. Thus, we have revealed solutions featly which are unlike the wave solutions previously found by other analytical methods. The present results depict the formation and development of such waves and their interactions. The exhibition of the solutions is given by 3D plots together with the corresponding 2D plots. The outcomes have shown that the proposed technique is abundant in achieving different wave solutions of many nonlinear differential equations in the field of optics. [ABSTRACT FROM AUTHOR]

This work searches the new wave solutions of the time-fractional ion sound and Langmuir waves (ISLWs) equation and the time-fractional Date–Jimbo–Kashiwara–Miwa (DJKM) equation with the conformable derivative. The m + 1 G ′ -expansion method is employed for these models for the first time. Getting support from symbolic software, some new solutions are presented, which will be constructive for studies in the field of nonlinear physical phenomena. New wave solutions obtained by using the m + 1 G ′ -expansion method have applications in engineering, physics, and other scientific fields. The regarded method may provide a framework for the exact solutions of several evolution equations in applied sciences. Moreover, the graphical illustrations are also demonstrated to observe the dynamical behaviours of the solutions, which may benefit the development of new technologies. [ABSTRACT FROM AUTHOR]

For accurate bio-sample identification, we present a unique optimized surface plasmon resonance sensor based on an X-shaped exposed-core photonic crystal fiber. Applications are made easier by the placement of the target analyte and plasmonic material on the fiber's exterior surface. The sensor has four separate silica channels that reach from the core to the metallic outer surface creating X-shape. These channels were intentionally placed to provide the highest sensitivity while maintaining the sensor's ability to be manufactured. Within a refractive index range of 1.33 to 1.40, our optimized sensor demonstrates improved detecting abilities, including a wavelength sensitivity of 8000 nm/RIU and amplitude sensitivity of - 1175.12 R I U - 1 . The suggested sensor also exhibits exceptional performance parameters, such as a resolution of 1.25 × 10 - 5 , a maximum signal-to-noise ratio (SNR) of 2.041 dB, a figure of merit (FOM) of 160.0 R I U - 1 , a detection accuracy (DA) of 0.02 nm−1, and minimum full width half maxima (FWHM) of 50 nm. When examining variations in the optical properties of the PCF due to different RIs of normal and cancer cells using finite element analysis, we achieve amplitude sensitivities of - 844.91, - 418 and - 1221.8 R I U - 1 for HeLa, Basal and MDA-MB-231 cell lines, respectively. [ABSTRACT FROM AUTHOR]

The sewage water is tested as a source of hydrogen production with a high efficiency value of 25.44% using Cu/CuFeO2 (delafossite)/CZTS (Cu2ZnSnS4, kesterite) as an investigated photocatalyst. The X-ray diffraction (XRD) analysis of the investigated photocatalyst (Cu/CuFeO2/CZTS) revealed a compact crystalline material, as witnessed by the diffraction peaks with high intensities. From the optical characterization, the recorded band gap values of Cu/CuFeO2/CZTS, Cu/CuFeO2, and CZTS are 1.15, 1.97, and 1.43 eV, respectively, inferring an obvious enhancement in the optical properties of the investigated photocatalyst, Cu/CuFeO2/CZTS. The photoelectrochemical (PEC) performance of the investigated photocatalyst for hydrogen (H2) generation was examined in wastewater. The current–time characteristic and the PEC behavior of Cu/CuFeO2/CZTS in dark and under light illumination using various power densities, monochromatic wavelengths, and different temperatures were studied. The current densities (JPh) under light illumination and (Jo) in the dark were − 8.0 and − 0.7 mA cm−2, respectively. The H2 generation rate for the Cu/CuFeO2/CZTS electrode was 0.049 mA/h. The thermodynamic parameters, respectively, ΔS*, ΔE, and ΔH* were 28.76 kJ mol−1 K−1, 21.0, and 18.28 kJ mol−1 at 390 nm. The findings of the work hold great promise for addressing energy production and the hindrances of sewage treatment at the same time. [ABSTRACT FROM AUTHOR]

The current work aims to produce of new nanostructured films from cobalt oxide (Co2O3)/iron oxide (Fe2O3) nanostructures doped polyvinyl alcohol (PVA) as a promising nanocomposites materials to utilize in numerous quantum electronics and optical nanodevices. The structure, optical, and electronic characteristics of PVA/Co2O3/Fe2O3 nanostructured films were investigated. The structure properties included optimization, FTIR and optical microscope. The optical characteristics results indicated that the absorption increased of 91.3% at UV-spectra (λ = 360 nm) with rising of the Co2O3/Fe2O3 NPs content to 5.7 wt%. The energy gap decreased of 55.3% when the Co2O3/Fe2O3 NPs content reached of 5.7 wt% where it reduced from 4.03 to 1.8 eV, this performance make them appropriate for may optoelectronics nanodevices like transistors, photovoltaic cell, electronic gates, diodes and other applications. The optical parameters: absorption coefficient (α); refractive index (n); extinction coefficient (k); real (ε1) and imaginary (ε2) dielectric constants and optical conductivity (σop) of PVA enhanced with an increase in the Co2O3/Fe2O3 NPs content. Finally, obtained results showed that the PVA/Co2O3/Fe2O3 nanostructured films have excellent electronic and optical properties which make them as promising nanomaterials to employ in many quantum electronics and optical nanodevices. [ABSTRACT FROM AUTHOR]

The current research aims to create of novel nanostructured films from silicon sarbide(SiC)/cerium oxide (CeO2) doped polyvinyl alcohol (PVA) as a promising nanocomposites materials to utilize in numerous quantum electronics and optical nanodevices. The fabricated nanostructures have great properties compared of other nanomaterials comprised few cost, excellent optical characteristics, flexible and lightweight. The structure, optical, and electronic features of PVA/SiC/CeO2 nanostructures were investigated. The structure properties included optimization, FTIR and optical microscope (OM). The optical characteristics were tested at wavelength ranged (200–800) nm. The optical characteristics results indicated that the absorbance of PVA rises about 76.9% at (λ = 240 nm, UV-spectra) while rises of 87% at (λ = 540 nm, VIS-spectra) when the SiC/CeO2 NPs content reached of (5.7 wt%).%. The energy gap decreased when the SiC/CeO2NPs content reached of 5.7wt% where it reduced from 4.5 to 2.7 eV, this performance make them appropriate for may optoelectronics nanodevices like transistors, photovoltaic cell, electronic gates, lasers, diodes and other applications. The optical parameters of PVA; with an increase in the SiC/CeO2 NPs content, the optical conductivity(σop), real (ε1) and imaginary (ε2) dielectric constants, absorption coefficient (α), refractive index (n), extinction coefficient (k), and other properties improved. Finally, the obtained results demonstrated that the PVA/SiC/CeO2 nanostructures are promising nanomaterials to employ in many quantum electronics and optical nanodevices. [ABSTRACT FROM AUTHOR]

The goal of current work includes the creation of new nanohybrid structures from SiC–In2O3 nanostructures doped (PS) as a potential nanomaterials have superior qualities, such as low cost, superior optical properties, flexibility, and lightweight nature to be used in a variety of optical and quantum electronic devices. The optical, electronic and structural properties of PS–SiC–In2O3 nanostructures' were examined. The structural properties comprised: FTIR, optical microscopy, and optimization. The findings of the optical characteristics showed that an increase of 3.6% SiC–In2O3 NPs lead to an increase of 83.3% in the absorption at λ = 560 nm. When the SiC–In2O3 NPs content reached 3.6%, the energy gap shrank from 3.7 to 2.62 eV. The optical factors of PS increased with a rise in the SiC–In2O3 NPs content are including the dielectric constants' real (ε1) and imaginary (ε2) components, optical conductivity (σop), absorption coefficient (α), refractive index (n), and extinction coefficient (k). The PS–SiC–In2O3 nanostructures are potentially useful nanomaterials for use in a variety of quantum electronics and optical nanodevices, according to the final results. [ABSTRACT FROM AUTHOR]

This article delves into the study of the perturbed cubic-quartic Kudryashov's equation having the Kudryashov's law of refractive index which is recently introduced to the literature. Utilizing the extended rational sine/cosine and sinh/cosh methods, optical solutions such as dark, periodic, and singular are successfully extracted. The two- and three-dimensional plots of these solutions are demonstrated. Besides, the behavior of solitons and the effects of parameters on wave properties are vividly illustrated to explore how the model's parameters influence these solutions. The findings herein can serve as a positive contribution to future research in nonlinear optics, while the methodology employed can be leveraged for similar nonlinear models in real life. [ABSTRACT FROM AUTHOR]

The simplified modified Camassa Holm (SMCH) equation is an essential nonlinear model for classifying several wave phenomena in physical science. In this study, the new m + 1 / G ′ -expansion method has been applied to the SMCH equation. Based on the given method, we have obtained some typical analytical solutions, such as exponential and rational function and complex function solutions of the SMCH equation. The three-dimensional and contour graphs of the obtained results are drawn for appropriate values of parameters. Getting the results and graphic drawings have been made using the Wolfram Mathematica. All the obtained solutions are crucial for understanding the nonlinear phenomena of dispersive waves. The solutions have shown that the presented method is powerful, practical, and suitable for investigating nonlinear models. [ABSTRACT FROM AUTHOR]

The optical soliton solutions of the time-fractional higher-order nonlinear Schrödinger equation in the presence of the Kudryashov nonlinear refractive index are studied in this paper using the new Kudryashov approach and Bernoulli's equation approach. The current model specializes in discerning the propagation of optical soliton pulses within optical fibers. Obtaining the optical solutions for this model, particularly the sextic power, is an essential yet challenging task. To generate the nonlinear ordinary differential equation, we insert the complex wave transformations into the present time-fractional nonlinear Schrödinger equations. Here, a system of linear equations in polynomial form using the proposed approach is acquired. By solving the linear system of equations, various solution sets were generated, each containing different values for the parameters of the studied equation. Additionally, the process yielded distinct approaches for solving the problem. Several novel optical soliton solutions are constructed for the time-fractional Schrödinger equation with the Kudryashov nonlinear refractive index, and the obtained soliton solutions satisfy the model. The visual representations of the obtained solution functions through contour, three-dimensional, and two-dimensional depictions in various simulations are shown, as presented in the figures. The results suggest that the employed methods are efficient and powerful tools to be applied to various differential equations with fractional and integer orders. [ABSTRACT FROM AUTHOR]

Fractional calculus is a field that is currently used in the world's applications in many science and engineering fields where many models are still being developed and researched. The conformable time-fractional gives the full history of this function, which is the advantage of using fractional calculus to solve physical problems. In this study, the conformable time-fractional extended (2 + 1)-dimensional quantum Zakharov-Kuznetsov and the time-fractional modified Korteweg-de Vries equations are investigated by using the the modified exp (- Ω (ξ)) -expansion function approach. Some new prototype analytical solutions such the hyperbolic and trigonometric function solutions are successfully reached. The importance of current research is to derive new solutions using a strong analytical approach. All the reported solutions in this study have verified their corresponding model. Under the choice of suitable values of the parameters involved, the 3D and 2D to the obtained solutions are successfully plotted. [ABSTRACT FROM AUTHOR]

In this study, the analytical solution of the Hirota equation by using the rational sine–Gordon expansion method (RSGEM) has been investigated. For this purpose, the mentioned model is converted into an ordinary differential equation by using a wave transformation. After the balancing procedure, a set of equation system is found. The solutions of the equation system give coefficients both in the considered solution form and in the model. The proposed technique gives new analytical solutions including the dark soliton solutions, bright soliton solutions and periodic wave solutions corresponding to the appropriate coefficient values. We also give geometric interpretations of the obtained solutions to understand the physical meaning better. [ABSTRACT FROM AUTHOR]

The effect of annealing temperature on the structure and linear/non-linear optical properties of CdS-NPs was studied. The structural, optical properties and crystallite size were investigated using X-ray diffraction, Fourier Transform Infrared technique, ultraviolet–Visible absorption spectroscopy and scanning electron microscopy. The calculation shows that the CdS crystallized in cubic phase and formed NPs with average crystallite sizes of 17.2, 20.1 and 23.3 nm and the microstrain is about 0.034, 0.030 and 0.026, for CdS films annealed at 300 °C, 400 °C and 500 °C respectively. The non-linear refractive indices ( n 2 ) of the CdS-NPs are determined using open and closed Z-scan techniques. The optical limiting (OL) behaviors have been also investigated. It has been shown that the OL efficiency depended on the CdS-NPs temperature. Under laser irradiation, self-diffraction rings were seen in CdS-NPs-300 °C, CdS-NPs 400 °C, and CdS-NPs 500 °C as increased input power, each pattern is created by a rise in the number of rings and the diameter of the outermost rings. The assessment of the figure of merit (W > 1) and thermal figure of merit demonstrates that, the CdS-NPs films are highly sufficient for use in nano-optical technology. The potential of CdS-NPs can be used in photonic and holographic devices as shown by this studying. The aim of the present study is to find fresh applications for CdS-NPs in the world of optical modulators. [ABSTRACT FROM AUTHOR]

This article investigates the optical soliton solutions of the Kundu–Mukherjee–Naskar (KMN) equation with the help of the enhanced modified extended tanh method (eMETEM). The equation is crucial for simulating the bending of light beam, rogue waves in the seas, and fiber pulses in optics. Some different kinds of solitons such as singular-periodic, dark and singular for the KMN equation have been successfully obtained by the used method. Utilizing Maple, we confirm that all acquired solutions satisfy the considered equation. We have also analyzed the impact of the parameters graphically in the considered equation. The results shown in the figures reveal that the parameters of the considered equation have an important effect upon soliton dynamics. It is anticipated that the gained solutions and used approach would create remarkable chances for future work in a variety of science areas. [ABSTRACT FROM AUTHOR]

The aim of this study is to peruse the dispersive Schrödinger–Hirota equation (SH equation) with parabolic law linearity to get optical soliton solutions by utilizing the generalized Kudryashov method (GKM). Firstly, we introduced the solution algorithm of GKM. Then, we substituted the traveling wave transform to dispersive SH equation with parabolic law and gained nonlinear ordinary differential equation (NODE) form of real and imaginary parts. We successfully applied GKM to the NODE form of dispersive SH equation and obtained the appropriate solution sets. Using these sets, the solution of differential equation and necessary transformations, we created the analytical solution functions of dispersive SH equation and demonstrated the graphical simulations. Optical soliton solutions were obtained, graphical representations were made and interpreted, at the same time, it was observed that some parameters had an effect on the soliton behavior. The parabolic law form of the examined model has not been studied, and the obtained results have not been reported. [ABSTRACT FROM AUTHOR]

CdSe Quantum dots (QDs) are cytotoxic cadmium and selenide-based (II–VI) semiconductor nanocrystals with a few nanometer diameters and unique optical and electrical properties. The cytotoxicity of CdSe QDs should not be underestimated and has raised considerable concern. That toxicity is mostly determined by the surface characteristics and size of the particles. The core/shell configuration thus becomes a popular technique to modify the activity of quantum dots by enhancing biocompatibility and stability. The most common and effective synthesis method of those shell-free and core/shell-based CdSe QDs is organometallic and water-based synthesis. Those synthesis frequently requires high temperatures, an oxygen-free atmosphere, and highly poisonous substances like trioctylphosphane (TOP) or trioctylphosphane oxide (TOPO), which may be inefficient, harmful to the environment, and even deadly. Because of this, a biogenic synthesis method was made to get around its limits. Biosynthesis of quantum dots by microorganisms (bacteria, actinomycetes, fungus, and algae) is an environmentally friendly and cost-effective green technology where production may occur intracellularly or extracellularly. The enzyme NADH-dependent nitrate reductase has been reported to have an important role in reducing cadmium and selenide ions to CdSe QDs by several researchers. When synthesizing CdSe QDs, factors such as pH, temperature, synthesizing route, and substrate concentration affect the final product's size and form. They have attracted interest because of their potential usage in a wide range of applications, including photovoltaics, solar cells, LEDs, photocatalyst, optical sensors, medical, medicines, and optical amplifiers. In this review, we focus on the cytotoxicity of non-shell and core/shell-based CdSe QDs, the synthesis using a consortium of different microorganisms from both prokaryotes and eukaryotes, affecting factors, application, challenges, and future prospects of CdSe-based QDs. [ABSTRACT FROM AUTHOR]

The modified exponential function method is used to obtain some new analytical solutions of the nonlinear Gerdjikov–Ivanov equation with the M-fractional operator. The novel obtained solutions are expressed in hyperbolic, trigonometric, and exponential function forms. Moreover, the instability modulation and gain spectra of the Gerdjikov–Ivanov equation are also analyzed. Constraints conditions are utilized to verify the existence of the solutions. Presented solutions are novel, satisfy and verify the M-fractional Gerdjikov–Ivanov equation. [ABSTRACT FROM AUTHOR]

We use the m + 1 G ′ -expansion method in reaching the exact solution of the (3+1)-dimensional B-type Kadomtsev-Petviashvili-Boussinesq, Newel-Whitehead-Segel, and Zeldovich equations. New solutions in form of the kink, complex and singular solutions are reported. On the other hand, the Adomian decomposition method is employed to find approximate solutions to the the (3+1)-dimensional B-type Kadomtsev-Petviashvili-Boussinesq equation. The three-dimensional figures and their corresponding contour plots for the reported solutions are drawn. Also, a table is presented for the approximate solutions. The reported results may be useful in studying physical features of various nonlinear mathematical models. [ABSTRACT FROM AUTHOR]

We aim to determine the analytical solutions for the Davey–Stewartson (RDS) equations in (2+1)-dimensions using the extended sine-Gordon equation expansion method. It is a natural two-dimensional form of the nonlinear Schrödinger equation. As a first step, we change the imaginary (2+1)-dimensional RDS model to a system of nonlinear ordinary differential equations, then we apply the sine-Gordon method. With the use of Wolfram Mathematica software, we try to find novel solutions to the resulting system of the nonlinear differential equation. Constructed solutions are drawn in 2D and 3D-dimensions graphs to more realize their characteristics. [ABSTRACT FROM AUTHOR]

In this work, we investigate the Fokas system which expresses the nonlinear pulse propagation in mono-mode optical fibers. We use the m + 1 G ′ -expansion scheme and the novel modified generalized exponential rational function scheme to generate soliton solutions to the proposed model. As a result, some exact solutions are constructed including hyperbolic, exponential, dark, singular, and periodic singular solutions. In order to analyze the physical behavior of the absolute, and real parts of the obtained solutions we present the 3-D surfaces, 2-D graphs, and their contour graphs. [ABSTRACT FROM AUTHOR]

In this study, some solitary wave solutions of the Wu-Zhang system are analyzed using the modified expansion function method and the sine–Gordon expansion method. Solitary wave solutions of this non-linear mathematical model consisting of hyperbolic and trigonometric function structures are get. Two and three dimensional, density graphics of the solitary solutions of the mathematical models are drawn by choosing the appropriate parameters. It was seen that all solution functions found as a result provide the mathematical model. In this study, Wolfram Mathematica software program was used for all mathematical calculations. [ABSTRACT FROM AUTHOR]

In this research, we analyze travelling wave solutions of the conformable resonant nonlinear Schrödinger's equation with Kerr-law nonlinearity by using an analytical approach which is the rational sine-Gordon expansion method. The purposed technique is a significant method to solve nonlinear evolution equations having high nonlinearity. We found some explicit solutions, including bright soliton and dark soliton, which have important roles in fields such as quantum physics, optical fibres by this way. We illustrate some graphics corresponding to the obtained wave solutions under the appropriate coefficients to help better understand their physical meaning of them. [ABSTRACT FROM AUTHOR]

A newly developed pentagonal photonic crystal fiber (P-PCF) with high nonlinearity and birefringence has been introduced in this work. Numerical analysis is carried out across the broader wavelength spectrum from 1.0 to 2.0 μm within the inferred region (IR). Furthermore, using the finite element method (FEM) with smaller mesh, a numerical examination of several optical characteristics such as effective mode area (EMA), nonlinearity, numerical aperture (NA), birefringence, and V-parameter was carried out. By using a circular completely matched layer (PML), the proposed P-PCF's optical transmission qualities have been guided. For the x-polarization mode, the suggested P-PCF exhibits high nonlinearity of 1.6 × 104 W−1 Km−1 at the working wavelength of λ = 1.4 µm. Furthermore, the proposed structure offers strengthening birefringence 2.5 × 10–6 at 1.6 μm wavelength including numerical aperture (NA) of 0.44 for the X-polarization mode. Based on the outstanding advantages, it can be asserted that the suggested model will find a promising domain of application in the area of all optical signal processing, sensing applications, and coherent optical communications. [ABSTRACT FROM AUTHOR]

In this paper, we find new soliton solutions of the Sasa-Satsuma equation according to the Sardar sub-equation scheme. Different forms of soliton solutions, including the optical dark, optical bright, and optical singular function solutions are formally extracted. To better realize the physical phenomena of the gained solutions, some physical explanations of the exhibited solutions under suitable parameters for the physical values via the contour and 3D simulations are given. The confrontation between the dispersion and nonlinear terms has permitted survey the treatment of the Modulation Instability gain spectra. [ABSTRACT FROM AUTHOR]

Past few decades, light absorbing materials based on CuInGaSe2 and CdTe have been used for fabrication of thin film solar cells. But main issues arising from these absorbers are the limited availability and toxicity of some of their constituents, viz. In, Cd, and Te. At present, light absorbing materials based on Cu2ZnSnS4 (CZTS) is a best alternative to develop low cost and environmentally friendly component for next generation thin film solar cells. CZTS and their selenium alloy based devices showed the necessary potential for the development of thin film solar cells (TFSCs). There have been numerous attempts to synthesize TFSCs based on CZTS absorber. Various techniques available to deposit thin film absorber layer rely on vacuum and non-vacuum based methods. In this review, we focused on various deposition methods, their shortcomings and potential improvement for deposition of CZTS thin film. We have also addressed various parameters that affect CZTS thin film and its device performance including condition of annealing, variation of composition and doping of different elements. Finally, we have discussed the challenges and approaches for resolving the issue in the synthesis of CZTS based thin film solar cell. [ABSTRACT FROM AUTHOR]

In the course of past decade, surface plasmon resonance (SPR) based photonic crystal fiber (PCF) sensors have shown phenomenal advancement. Many researchers have proposed a wider range of SPR-based sensors by this time. But many of these proposed sensors either show low sensitivity or it is very difficult to fabricate the sensors for real time applications. We present a simple circular shaped PCF SPR sensor which is easy to fabricate as well as shows high sensitivity in the visible and near-infrared spectroscopy. A chemically stable and inactive plasmonic material, gold is applied to the outer layer of the PCF structure to generate surface plasmon excitation. A perfectly matched layer is used to minimize radiation absorption towards the surface. The guiding properties and analytical evaluation are carried out using commercially available COMSOL Multiphysics version 5.4 on the basis of finite element method. In x-polarization mode, the maximal value of amplitude sensitivity and wavelength sensitivity (WS) of the proposed sensor is 1757.3RIU−1 (Refractive Index Unit) and 32,000 nm/RIU respectively. In addition to that, the proposed design exhibits high sensor resolution of 1.428 × 10–6 and figure of merit of 587.2 indicating a high-performance sensor and demonstrates birefringence of 0.004 RIU. Moreover, the proposed PCF-SPR sensor is composed of only six symmetrical circular air holes, which makes it fabrication friendly. Owing to the high performance of the proposed sensor and high fabrication probability makes the sensor a strong contender to be used in biomedical and biochemical applications. [ABSTRACT FROM AUTHOR]

This study investigates the electrical and photoresponse properties of Nd-YAG annealed Pt/n-PSi/Pt photodetectors. A porous silicon (PSi) layer was deposited on a single crystalline n-type Si via photoelectrochemical etching in aqueous hydrofluoric acid at 45 mA cm−2 for 30 min. Annealing of the n-PSi layer was conducted using a Q-switching Nd:YAG laser at different fluence laser energies (20, 30, 40, 60 mJ cm−2) with a pulse duration of 10 ns. The effect of Nd:YAG laser irradiation on the morphological and structural properties of the deposited n-PSi layer was determined. The n-PSi sample synthesized at 40 mJ cm−2 showed the maximum average discrepancy. The photodetectors fabricated using such materials showed very high sensitivity (1527.9) and low dark current (2.58 × 10−4 A) with an internal photoconductive gain of 16.27, photoresponse of 3.1 A W−1, response time of 0.29 s, and recovery time of 0.45 s. These exceptional properties of the fabricated photodetectors indicate that the laser annealing approach is a viable tool for the synthesis of n-PSi that is suitable for various applications. [ABSTRACT FROM AUTHOR]

An analytical model has been developed to investigate the activation energy profile in Mg-doped p-AlxGa1−xN alloy for the entire range of Al composition. For any Al content, the calculated activation energy quantitatively shows a good agreement with experimental result which has also been confirmed by both Hydrogen atom model and effective Bohr radius model. Through this empirical analysis, a breakthrough is apparent for the hole concentration and sheet resistivity with particular Al concentration. It is found that the hole concentration is < 1017 cm−3 while the Al content, x > 30% in p-AlxGa1-xN. Moreover, the sheet resistivity is found to be < 1 Ω-cm up to the Al content of 30%. Finally, the temperature-induced changing behavior of hole concentration and sheet resistivity have been explored here. These results could be a good insight for fabricating the AlGaN-based real-world devices for future optoelectronics. [ABSTRACT FROM AUTHOR]

This study acquires the wave solutions of the two well-known nonlinear models, namely; the modified Benjamin-Bona-Mahony and the coupled Klein-Gordon equations. The modified Benjamin-Bona-Mahony is a nonlinear model that describes the long surface gravity waves of small amplitude and the coupled Klein-Gordon equation describes the quantized version of the relativistic energy-momentum relation. We successfully acquire some new solutions to these models such as kink-type and soliton solutions in complex hyperbolic functions form. We plot the 3D and 2D surface of the all the obtained solutions in this study. The mathematical approach used in this study is the sine-Gordon expansion method. [ABSTRACT FROM AUTHOR]

This study applies the powerful sine-Gordon expansion method in acquiring some new solutions to the strain wave equation in micro-structured solids arising in mathematical physics. The strain wave equation in micro-structured solids is used in modelling wave propagation in micro-structured materials. We successfully acquire some new solitary wave solutions with hyperbolic function structure. By taking some suitable values of parameters involved in the solutions, we plot the 2D, 3D and contour graphs of all the obtained solutions in this study. [ABSTRACT FROM AUTHOR]

In this article, we employed the powerful sine-Gordon expansion method in obtaining analytical solutions of the Benjamin-Bona-Mahony equation. We obtain some new solutions with the hyperbolic function structures. Benjamin-Bona-Mahony equation has a wide range of applications in modelling long surface gravity waves of small amplitude. We also plot the 2- and 3-dimensional graphics of all analytical solutions obtained in this paper. On the other hand, we analyze the finite difference method and operators, we obtain discretize equation using the finite difference operators. We consider one of the analytical solutions to the Benjamin-Bona-Mahony equation with the new initial condition. We observe that finite difference method is stable when Fourier-Von Neumann technique is used. We also analyze the accuracy of the finite difference method with terms of the errors $$L_{2}$$ and $$L_{\infty }$$ . We use the finite difference method in obtaining the numerical solutions of the Benjamin-Bona-Mahony equation. We compare the numerical results and the exact solution that are obtained in this paper, we support this comparison with the graphic plot. We perform all the computations and graphics plot in this study with the help of Wolfram Mathematica 9. [ABSTRACT FROM AUTHOR]

In this manuscript, we investigate the analytical solutions of the new coupled Konno-Oono equation by using the sine-Gordon expansion method. We successfully obtained some new soliton solutions to this model. We plot the 2D and 3D surfaces of all the found soliton solutions in this study. The Wolfram Mathematica 9 is used in performing all the computations in this study. [ABSTRACT FROM AUTHOR]

This study is related to new soliton solutions of Davey-Stewartson equation (DSE) with power-law nonlinearity. The generalized Kudryashov method which is one of the analytical methods has been used for finding exact solutions of this equation. By using this method, dark soliton solutions of DSE have been found. Also, by using Mathematica Release 9, some graphical representations have been done to analyze the motion of these solutions. [ABSTRACT FROM AUTHOR]

Small footprint photonic integrated interferometer based on silicon-on-insulator platform is reported. A passive interferometer comprising small footprint $$4\times 4$$ and $$2\times 2$$ multi-mode interference (MMI) couplers is designed and tested. The $$4\times 4 \,(2\times 2)$$ MMIs feature 0.16 dB (0.06 dB) excess loss, 0.22 dB (0.09 dB) power imbalance, and 1.7 $$^{\circ }$$ (0.12 $$^{\circ }$$ ) phase error. An efficient use of the small design area is accomplished by positioning the input and output ports of the passive interferometer along the same side of the chip with a separation of $$127\,\upmu \hbox {m}$$ between each other (pitch size). A passive-active interferometer terminated with Ge photodiodes has also been designed and tested. Sinusoidal fitting of the phase differences between output port number 1 and all other output ports are estimated to be under 2 $$^{\circ }$$ margin, i.e., $$90^{\circ }\pm 1^{\circ },180^{\circ }\pm 1^{\circ }$$ and $$270^{\circ }\pm 1^{\circ }$$ . [ABSTRACT FROM AUTHOR]

We have presented a method to estimate parameters of the decoy state method based on one decoy state protocol for SARG04. This method has given lower bound of the fraction of single-photon counts ( y), the fraction of two-photon counts ( y), the upper bound QBER of single-photon pulses ( e), the upper bound QBER of two-photon pulses ( e), and the lower bound of key generation rate for both BB84 and SARG04. The numerical simulation has shown that the fiber based QKD and free space QKD systems using the proposed method for BB84 are able to achieve both a higher secret key rate and greater secure distance than that of SARG04. Also, it is shown that bidirectional ground to satellite and inter-satellite communications are possible with our protocol. [ABSTRACT FROM AUTHOR]

The optical and electrical properties of compressively strained GaInSb/GaInAlSb mid-infrared quantum well lasers are numerically studied solving one-dimensional Schrödinger equation using finite difference method. The simulation results demonstrate that band-mixing effects and effective mass of hole are reduced when the well is compressively strained. The strain-dependent optical and differential gains are evaluated for 0.6, 0.9, 1.21, and 1.52% compressively strained quantum well and found maximum when well is strained by 1.52%. The emission wavelength for the proposed laser can be tuned from 2.40 to 2.26 μm due to change in compressive strain from 0.60 to 1.52% at temperature 300 K. For the range of strain, the shift in wavelength is found from 2.38 to 2.24 μm at temperature 275 K. The results obtained from PSPICE simulation indicate that, the optical output power and threshold current are strongly depend on the number of wells and found to be almost constant for the number of wells three and above. [ABSTRACT FROM AUTHOR]

A filter-less millimeter-wave generation scheme consisting of four polarization modulators in series, each followed by a polarizer is proposed to achieve optoelectronic frequency octupling. The cascade of polarization modulator and polarizer provides an intensity modulator whose biasing condition can be set by the polarizer angle and polarization state of the input light to each polarization modulator. A theoretical analysis of the architecture is performed using a transfer function method and validated by industry-standard software simulation tools. The circuit shows high potential in achieving desired performance with lower input RF power when compared to the another configuration based on a generalized Mach–Zehnder interferometer structure. Although the operating range in terms of applied RF drive becomes narrow, low RF input operation can be achieved by this circuit. The effect of imbalances in the key circuit parameters is also investigated in terms of electrical side harmonic suppression ratio. [ABSTRACT FROM AUTHOR]

In the title paper, Zhu et al. presented a technique for generating filter less frequency octo-tupling signal based on a cascade of two dual-polarization modulators. Firstly, the harmonics of order 4 l (l in an integer) are generated in the x -polarization by driving the x-modulators with an RF signal with a 90° phase difference between the two stages. Then the carrier is suppressed using unmodulated y -polarization by means of polarization multiplexing. Accordingly, the demerit of their design is the requirement to reset a precise polarizer angle to suppress the optical carrier every time there is a change in the RF drive amplitude or the modulation index. Nevertheless, the authors claim superior performance to a similar architecture in which the y-branch is modulated with the proper RF drive phases to suppress the carrier for all drive levels with no need to adjust a splitting ratio. The aim of this comment is to show that by modulating the y -polarization with adjusted RF drive phases, same architecture can be used to perform frequency octo-tupling whose performance is neither limited by precise settings of the polarizer angle nor by the proper settings of the modulation index. The carrier is suppressed for a unique value of the polarizer angle for all modulation index. If the modulation index is adjusted to suppress the 4 th harmonics, same circuit can be used to perform frequency 24-tupling generation. [ABSTRACT FROM AUTHOR]

Here, proposed Kretschmann configuration based surface plasmon resonance biosensor shows immense improvement in its performance parameters. This highly sensitive biosensor provides a higher value of quality factor and detection accuracy. We presented a five-layer model of a biosensor with two dimensional transition metal di-chalcogenides Tungsten disulfide (WS2) in addition with Al2O3 layer. By using one layer of WS2 with six layers of Al2O3, the highest sensitivity (227.5 °/RIU), detection accuracy (1.1123), and quality factor (28.26 RIU−1) can be achieved. CaF2 as coupling prism has also played a remarkable role in enhancing the performance parameters for its low refractive index. [ABSTRACT FROM AUTHOR]

Here, proposed Kretschmann configuration based surface plasmon resonance biosensor shows immense improvement in its performance parameters. This highly sensitive biosensor provides a higher value of quality factor and detection accuracy. We presented a five-layer model of a biosensor with two dimensional transition metal di-chalcogenides Tungsten disulfide (WS2) in addition with Al2O3 layer. By using one layer of WS2 with six layers of Al2O3, the highest sensitivity (227.5 °/RIU), detection accuracy (1.1123), and quality factor (28.26 RIU−1) can be achieved. CaF2 as coupling prism has also played a remarkable role in enhancing the performance parameters for its low refractive index. [ABSTRACT FROM AUTHOR]

This study reaches the dark, bright, mixed dark-bright, singular, mixed singular optical solitons and singular periodic wave solutions to the time-fractional Radhakrishnan-Kundu-Lakshmanan equation. The parametric conditions that guarantee the existence of valid solitons and other solutions are stated. By choosing some suitable values of parameters, the 2- and 3-dimensional surfaces to some of the reported solutions are plotted. The reported solutions may be useful in expalining the physical meaning of the Radhakrishnan-Kundu-Lakshmanan equation and other related nonlinear models arising in nonlinear sciences. [ABSTRACT FROM AUTHOR]

In this paper, the effects of interband and intraband transitions on the gain and phase stabilities in quantum dot semiconductor optical amplifier (QD-SOA) are investigated both temporally and spectrally employing electrical and optical pumping schemes. For this purpose, the carrier rate equations in different energy states coupled to the traveling wave optical field equation have been numerically solved to derive the dynamical behavior of QD-SOA. Our results show that the gain and phase response can be stabled under optical pumping (OP) scheme because the role of the interband and intraband transitions on the dynamics of QD-SOA is reduced. This behavior leads to high-speed pattern effect-free cross-phase modulation (XPM) in QD-SOA. It is found that optically pumped QD-SOA can have high performance in phase based applications. Moreover, it is shown that under OP scheme although the QD-SOA has lower gain value and slower gain recovery time, the ultrafast cross-gain modulation (XGM) without pattern effect is possible and the phase is recovered within a shorter time compared to EP scheme. The behavior arises from the different capacity of the carrier reservoir for pumping schemes. [ABSTRACT FROM AUTHOR]

In this paper, we study the generalized higher-order nonlinear Schrödinger equation analytically. We use two integral schemes for conducting this study. Dark, bright, combined dark-bright optical, singular soliton, soliton-like and trigonometric function solutions are successfully constructed. We give the constraint conditions for the existence of valid solutions. The 2D, 3D and the contour graphs for the dark and bright solitons are plotted. [ABSTRACT FROM AUTHOR]

The dynamical systems of soliton propagation through optical fibers for trans-continental and trans-oceanic distances is one of the most interesting areas of study. Optical solitons are restrained electromagnetic waves that stretch in nonlinear dispersive media and allow the intensity to remain unchanged due to the balance between dispersion and nonlinearity effects. In this study, we successfully acquire dark, bright, combined dark-bright, singular and combined singular soliton solutions to the decoupled nonlinear Schrödinger equation arising in dual-core optical fibers by using the extended sinh-Gordon equation expansion method. The constraint conditions for the existence of valid soliton solutions are given. We discuss how change in parameters affect the solitons transmission. We present the 2D, 3D and the contour graphs to some of the reported solutions. [ABSTRACT FROM AUTHOR]

This study constructs bright and singular optical solitons the (2+1)-dimensional NLSE and the Hirota equation by utilizing the new sine-Gordon expansion method. The parametric conditions for the existence of valid solitons are given. We give the variations of solitary and periodic wave solutions that depend on the parameters. We present the 2D, 3D and contour graphs to represent the kind of solutions secured in this study. [ABSTRACT FROM AUTHOR]

This study investigates the Nizhnik-Novikov-Veselov and the Drinfel’d-Sokolov systems by using the extended sinh-Gordon equation expansion method. The Nizhnik-Novikov-Veselov system is an isotropic Lax extension of the one-dimensional Korteweg-de Vries equation and the Drinfel’d-Sokolov system is a nonlinear model that possesses some special forms of Lax pairs. Topological kink-type, topological, non-topological, compound topological-non-topological bell-type and singular soliton solutions are successfully constructed. Under the choice of suitable values of parameters, the 2D, 3D and contour graphs to some of the obtained solutions are plotted. [ABSTRACT FROM AUTHOR]

This study investigates the longitudinal wave equation in a magneto-electro-elastic circular rod by using the extended sinh-Gordon equation expansion method. Topological, non-topological and singular soliton solutions are extracted. To illustrate the physical appearance of the obtained solutions, 2D, 3D and the contour graphs to some of the obtained solutions are plotted. The reported results may be useful in explaining the physical meaning of the studied models and other nonlinear physical models arising in nonlinear sciences. [ABSTRACT FROM AUTHOR]