Optical Analysis Research Articles

Retraction Note: Explainable AI based wearable electronic optical data analysis with quantum photonics and quadrature amplitude neural computing

Retraction Note: Explainable AI based wearable electronic optical data analysis with quantum photonics and quadrature amplitude neural computing

Retraction Note: Elastic optical network routing analysis using intelligent machine learning architecture with security analysis

Retraction Note: Elastic optical network routing analysis using intelligent machine learning architecture with security analysis

Strong absorptions of thermal neutrons caused by virtual states

Abstract Cross sections of compound nucleus (CN) formation by S-wave neutron scattering, which began to be studied in a pioneering work by Feshbach et al., are reanalyzed by the optical model plus the method of Jost function (JFM), which is one of modern theories to handle bound and unbound continuum states in a unified manner. We have calculated the CN cross-section for a thermal neutron scattering (En = 25.3 meV) by about 300 stable targets. The enhancements in the CN cross section at the specific mass number region, A ∼ 10, 50 and 160, which are well-known results in the previous optical model analyses, are reproduced by the present calculation. The JFM calculation is applied to investigate the origin of the enhanced CN cross-section, and the poles in the scattering matrices (S-matrices) are systematically explored in the complex momentum plane. In JFM, the S-matrix poles representing the virtual states, which are different from the usual resonances described by the Breit-Wigner formula, appear around the origin (zero energy) in the momentum plane at the mass region with the enhanced CN cross-section. The present analysis of the S-matrix means that the virtual state strongly enhances the CN cross-section. We also discuss the present results in connection to giant resonances and compound nuclear resonances, which were regarded as the established theories to understand the enhanced absorption of the thermal neutron in the previous studies.

Accurate Layer-Number Determination of Hexagonal Boron Nitride Using Optical Characterization.

Precise determination of the layer number (N) of hexagonal boron nitride (hBN) is crucial for its integration with other layered materials in applications such as ferroelectric devices and moiré potential modulation. We present a nondestructive method to accurately identify N, combining optical contrast analysis with second harmonic generation (SHG) measurements. By studying the flakes on 90 nm thick SiO2/Si substrates, we demonstrate that red-filtered optical images provide a clear contrast step in N with an uncertainty of ±1 layer, while SHG measurements further reduce the error by distinguishing even and odd layers. We also introduce a real-time detection technique to identify monolayer and few-layer hBN, improving flake identification efficiency. Given the growing interest in twisted hBN interfaces and their integration in van der Waals heterostructures, this method offers a practical approach for future studies.

First on-sky interference fringes at 810 nm with the CHARA Array using servo controlled hectometric outdoor fibre links

Abstract In the framework of the ALOHA (Astronomical Light Optical Hybrid Analysis) project, we have implemented a fibre-linked interferometer connecting two telescopes of the CHARA Array to the recombination beam facility using servo controlled hectometric outdoor fibres (240m). During two consecutive nights, on-sky fringes at 810nm were recorded on the star Vega (mag 0), with servo control of the fibre lengths. The optical path difference (OPD) was set close to zero using internal fringes found before the on-sky observations. The repeatability of the delay line position offset between internal and on-sky fringes was less than 0.2mm. The efficiency of the servo control systems has been demonstrated, leading to an enhancement of the signal-to-noise ratio from 68.9 with the servo off to 91.6 with the servo on. This result is a cornerstone for the ALOHA project goal of interferometry at 3.5μm and a seminal step for the future kilometric infrared fibre-linked interferometer at CHARA.

Complex quadrupled-power-law nonlinearity form of Radhakrishnan-Kundu-Lakshmanan equation: novel optical soliton analysis

Complex quadrupled-power-law nonlinearity form of Radhakrishnan-Kundu-Lakshmanan equation: novel optical soliton analysis

Low thickness effect on the properties of Mn-doped ZnO thin films synthesized by sol-gel spin coating technique

In this study, 7% manganese-doped zinc oxide (MZO) thin films with varying low thicknesses were synthesized using the spin coating method. The structural, optical, and morphological properties of MZO films with different film thickness, were systematically investigated. The crystallite structure, superficial morphology, and optical characteristics were analyzed using X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM), and ultraviolet–visible spectroscopy (UV-Vis). Structural analysis confirmed that all films exhibit a hexagonal wurtzite phase with a pronounced peak along the c-axis, and slight variation in low thickness significantly affected the structural parameters. The surface morphology demonstrated good uniformity, characterized by rounded grain shapes in the plane, while surface roughness was found to be increased with increasing film thickness. Optical analysis revealed that as the number of coatings increased, both transmittance and band gap energy decreased, accompanied by a redshift in the absorption edge across all samples. This behavior is attributed to light scattering, as well as an increase in the refractive index and dielectric function with visible light energy, influenced by the number of layers and corresponding crystallite size.

Hydrothermally synthesized hierarchical Pom-Pom-like gadolinium modified tungsten oxide reinforced with rGO for annihilation of acetylsalicylic acid and crystal violet

Herein, novel hierarchical Gd@WO3 pom-pom-like microstructures have been prepared through the hydrothermal method and combined with RGO sheets (denoted as RGO/Gd@WO3). The synthesized materials, along with their analogs, were characterized through X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), Fourier transform infrared (FT-IR), Mott-Schottky, current-voltage (I-V), electrochemical impedance spectroscopy (EIS), and optical analyses. The unique morphology of pom-pom-like microstructures allowed better interaction with pollutant molecules. Rare earth element (Gd3+) ions act as trapping species for photo-generated electrons and prolong the life span of reactive oxygen species (ROS). The high conductivity and flexible nature of RGO sheets provided fast transport of active species and provided stability to the photocatalytic material. To test the photocatalytic efficiency of RGO/Gd@WO3, crystal violet (CV) and acetylsalicylic acid (ASA) were used as model pollutants. Under a mimetic light source, RGO/Gd@WO3 exhibited maximum photodegradation of 98.8 % and 84 % for CV and ASA within 120 min of irradiation, respectively. Photocurrent, Mott-Schottky, and EIS experiments proved the production, effective separation, and transmission of photo-active species in the presence of RGO/Gd@WO3 as compared to Gd@WO3 and WO3. Given the electrochemical testing and optical analysis, the photocatalytic mechanism is anticipated for the high photocatalytic activity of RGO/Gd@WO3. The novel RGO/Gd@WO3 photocatalyst proved to be a superior photocatalytic material for the photodegradation of organic pollutants.

Achieving Luminous Efficiency Enhancement and Near‐Infrared Emission in Moisture‐Stable 0D Zinc‐Based Halides

AbstractZero‐dimensional (0D) metal halides are attractive due to their structure‐dependent and tunable photoluminescence properties. Herein, a new 0D organic–inorganic hybrid Zn‐based halide, (C4H12N2)ZnBr4, featuring a long‐term stable crystal structure and moisture‐stable PL emission under various extreme conditions is reported. A strong electron–phonon coupling effect enables the Zn‐based halide to display highly efficient blue light at 472 nm with a large Stokes shift of 7385 cm−1. Intriguingly, heterovalent substitution of Cu+‐Zn2+ further enhances the photoluminescence quantum efficiency to 60% as the introduction of Cu+ effectively suppresses the nonradiative recombination process. Besides, the formation of twisted [SbBr4]− tetrahedra via Sb3+‐Zn2+ substitution help to achieve a broadband near‐infrared (NIR) emission (760 nm) with full width at half maxima (FWHM) of 203 nm, enabling the potential applications in night‐vision and nondestructive fruit damage inspection. Detailed structural and optical analyses are used to investigate the photophysical processes of different self‐trapped exciton (STE) emission for pristine and Cu+/Sb3+‐doped 0D metal halides. These findings advance the understanding of spectral regulation mechanism via heterovalent substitution and initiate more exploitation of luminescent metal halides for emerging applications.

In Situ Optical Observation of Lithium Dendrite Pattern in Solid Polymer Electrolytes.

Solid polymer electrolytes (SPEs) have been treated as a viable solution to build high-performance solid-state lithium metal batteries (SSLMBs) at the industrial level, bypassing the safety and energy density dilemmas experienced by today's lithium-ion battery technology. To promote a wider application of SPEs-based SSLMBs, the chemical and electrochemical characteristics of lithium metal (Li°) electrode in SPEs have to be clearly elucidated. In this work, the morphological evolution of Li° electrode in the SPEs-based SSLMBs is comprehensively investigated, via a customized electrochemical cell allowing optical microscopic analyses. The results demonstrate that differing from inorganic solid electrolytes, the elastic feature of SPEs eliminates the "memory effect" of the dendrite formation, in which the previously formed dendrites can be dissolved and the resulting space can be simultaneously occupied by electrolyte components, instead of leaving for a second-round growth of Li° dendrites. Furthermore, the largely increased electronic conductivities of the as-formed interphases between Li° electrode and SPEs are found to be responsible for the notoriously soft short-circuit behavior observed during cycling. These findings bring a fresh understanding of the formation and evolution of lithium dendrites in SPE-based cells, which are vital for improving the long-term stability of SSLMBs and other related high-energy battery systems.

Comparative Analysis of Structural, Optical, and Electronic Properties of Nickel Oxide and Potassium‐Doped Nickel Oxide Nanocrystals

ABSTRACTMetal oxide semiconductors, known for their exceptional optical transparency, high carrier mobility, and stability, have found extensive use in emerging technologies such as optoelectronics and energy storage devices. Among all metal oxide semiconductors, nickel oxide (NiO) stands out as a highly favorable candidate due to its p‐type conductivity along with its substantial band gap (3.5–4 eV) for the broad range of applications, including gas sensors, high‐rate Lithium‐ion batteries, high‐performance supercapacitors, and photovoltaic devices. In light of these versatile applications, our current study presents a comprehensive comparative analysis of the structural and optoelectronic properties of NiO and potassium (K)‐doped NiO nanocrystals. The nanocrystals were synthesized using the co‐precipitation route and subsequently annealed at 500°C under ambient conditions. The effect of K doping on the structural and optoelectronic characteristics was systematically examined using various techniques, including x‐ray diffraction, UV–visible spectroscopy, Raman spectroscopy, and Hall effect measurements. To explore the structural characteristics, XRD measurements were performed, which confirm the FCC structure of nanocrystals. The optical property analysis suggested that the formation of the energy level can contribute to reduction of the band gap. A sharp peak at 397 cm−1 is associated with NiO bond in FTIR spectra which verifies the formation of nanocrystals. Moreover, the incorporation of K increases the intensity of the Raman peaks, which provides evidence for the higher degree of crystallinity in doped samples. These results of Raman scattering are in good agreement with XRD outcomes. In addition, the resistivity of NiO nanocrystals decreases monotonically with the increasing K concentration. The results of temperature‐dependent resistivity further demonstrate that electrons required more energy to jump from one polaron state to another in the case of x = 0.01 M and 0.03 M doped Ni0.5‐xKxO samples. The combination of a diminished band gap and enhanced conductivity makes these materials exceptionally promising for applications in optoelectronics and energy storage.

Ellagic acid/Fe nanocomposite thin film with high power conversion efficiency for photovoltaic devices

This study synthesizes and characterizes an ellagic acid/Fe nanocomposite thin film ([Ellag-A/Fe.6H2O]NCTF) to enhance photovoltaic device efficiency, achieving a notable power conversion efficiency of 14.5%. Using FT-IR, TGA, XRD, SEM, and optical analyses, the nanocomposite's structural, thermal, and optical properties were investigated, revealing a polycrystalline structure with improved thermal stability over pure ellagic acid. Density Functional Theory (DFT) calculations show a large energy gap of 1.08 eV, indicating stability and high excitation energies. The combination of organic ellagic acid with iron nanoparticles makes ([Ellag-A/Fe.6H2O]NCTF a promising material for photovoltaic applications.

Pioneering diabetes screening tool: machine learning driven optical vascular signal analysis

The escalating prevalence of diabetes mellitus underscores the critical need for non-invasive screening tools capable of early disease detection. Present diagnostic techniques depend on invasive procedures, which highlights the need for advancement of non-invasive alternatives for initial disease detection. Machine learning in integration with the optical sensing technology can effectively analyze the signal patterns associated with diabetes. The objective of this research is to develop and evaluate a non-invasive optical-based method combined with machine learning algorithms for the classification of individuals into normal, prediabetic, and diabetic categories. A novel device was engineered to capture real-time optical vascular signals from participants representing the three glycemic states. The signals were then subjected to quality assessment and preprocessing to ensure data reliability. Subsequently, feature extraction was performed using time-domain analysis and wavelet scattering techniques to derive meaningful characteristics from the optical signals. The extracted features were subsequently employed to train and validate a suite of machine learning algorithms. An ensemble bagged trees classifier with wavelet scattering features and random forest classifier with time-domain features demonstrated superior performance, achieving an overall accuracy of 86.6% and 80.0% in differentiating between normal, prediabetic, and diabetic individuals based on the optical vascular signals. The proposed non-invasive optical-based approach, coupled with advanced machine learning techniques, holds promise as a potential screening tool for diabetes mellitus. The classification accuracy achieved in this study warrants further investigation and validation in larger and more diverse populations.

Optical and Radio Analysis of Systematically Classified Broad-lined Type Ic Supernovae from the Zwicky Transient Facility

We study a magnitude-limited sample of 36 broad-lined type Ic supernovae (SNe Ic-BL) from the Zwicky Transient Facility Bright Transient Survey (detected between 2018 March and 2021 August), which is the largest systematic study of SNe Ic-BL done in literature thus far. We present the light curves (LCs) for each of the SNe and analyze the shape of the LCs to derive empirical parameters, along with the explosion epochs for every event. The sample has an average absolute peak magnitude in the r band of M¯r,max=−18.51±0.15 mag. Using spectra obtained around peak light, we compute expansion velocities from the Fe ii 5169 Å line for each event with high enough signal-to-noise ratio spectra, and find an average value of vph¯=16,100±1100 km s−1. We also compute bolometric LCs, study the blackbody temperature and radii evolution over time, and derive the explosion properties of the SNe. The explosion properties of the sample have average values of M¯Ni=0.37−0.06+0.08M⊙ , M¯ej=2.45−0.41+0.47M⊙ , and E¯K=(4.02−1.00+1.37)×1051 erg. Thirteen events have radio observations from the Very Large Array, with eight detections and five non-detections. We find that the populations that have radio detections and radio non-detections are indistinct from one another with respect to their optically inferred explosion properties, and there are no statistically significant correlations present between the events’ radio luminosities and optically inferred explosion properties. This provides evidence that the explosion properties derived from optical data alone cannot give inferences about the radio properties of SNe Ic-BL and likely their relativistic jet formation mechanisms.

Random Forest Model-based Aerosol Optical Depth Inversion and Variation Analysis in China

Random Forest Model-based Aerosol Optical Depth Inversion and Variation Analysis in China

An investigation of n-type semiconductors based on optical and photoluminescence of pure and Al doped Pr:123 compound

With ZnO comparison, we report here an investigation of n-type semiconductors in terms of optical and photoluminescence (PL) analysis based on PrBa2Cu3-3xAl3xOy (AlPr:123) compound with (0.00 ≤ x ≤ 1.00). The structure is tetragonal of the samples with x ≤ 0.30 and changes to orthorhombic for x > 0.30, whereas it is wurtizite (hexagonal) for ZnO. As x increases to 1.00, the grain size is decreased, while the crystallite size and porosity are increased, but they are comparable with those obtained for ZnO. The Debye temperature, Young’s modulus and energy gap are drastically decreased by increasing x until reach to their maximum values of 623.14 K, 952 GPa and 3.45 eV for x = 1.00 (650.39 K, 17 GPa and 3.28 eV for ZnO). The x = 0.05 has increased the carrier density to 8.06 × 10 19 (cm−3), which is about 8-times higher than of ZnO (1.07 × 10 19 (cm −3). The highest value of q-factor (3.5 × 10 5) is obtained for x = 0.00, which is about 10-tims higher than of ZnO (3 × 10 4). As x increases above 0.30, the optical conductivity is significantly increased to be greater than that of ZnO. The PL intensity of the visible emission peaks was gradually increases against x until becomes higher than that of ZnO when x = 1.00. A slight UV shift is obtained for x ≤ 0.30 samples, but it changed to blue for x ≥ 0.60, which is typically similar to ZnO. As compared to ZnO, the present samples are strongly recommended for plastic deformation, solar cell, light emission, super-capacitor and high-power operation. To the best of our knowledge, the present work has never been done elsewhere.

A DFT-based computational study on a highly and lead-free inorganic new fluoroperovskite of Mg3PF3

Inorganic fluoroperovskite materials are increasingly important in solar technology due to their exceptional structural, optical, electronic, and mechanical properties. This study uses DFT calculations to investigate the properties of Mg3PF3 fluoroperovskite. Our results show a crystal structure and lattice parameter of (a = 4.64 Å) which align with previous theoretical and experimental findings, confirming the accuracy of our calculations. Mechanical analysis reveals that Mg3PF3 is naturally ductile, elastically anisotropic, and stable according to established criteria. The band structure and PDOS indicate that it is a semiconductor with direct bandgap of 3.88 eV at the Γ point, making it suitable for electronic applications. Electron charge density mapping suggests a predominantly ionic bonding nature. Optical property analysis shows significant dielectric constant peaks in the photon energy range favorable for solar cells. Overall, these findings position Mg3PF3 as a promising candidate for solar cell technology, highlighting its potential for enhancing renewable energy solutions.

Dynamics of optical solitons and sensitivity analysis in fiber optics

The nonlinear Schrödinger equation (NLSE) and its various forms have significant applications in the field of soliton theory. The Fokas-Lenells (FL) equation stands as a cornerstone in deepening our understanding of nonlinear wave dynamics within optical systems, particularly concerning the behavior of ultrashort pulses across different media. Its significance lies in providing a comprehensive framework to study and analyze complex phenomena, ultimately contributing to advancements in optical technology and applications. The FL equation is an integrable extension of the NLSE that provides a description of the nonlinear propagation of pulses in optical fiber. This paper seeks to discover optical soliton solutions for the FL equation by employing a modified sub-equation method. Additionally, the sensitivity analysis is described by using the various initial conditions. The main novelty of this paper lies in conducting a sensitivity analysis of the FL equation by examining the effects of various initial conditions, providing deeper insights into how these conditions influence the behavior of soliton solutions. For the physical behavior of the models, some solutions are graphically shown in 2D, 3D, and contour graphs by assigning specific values to the parameters under the provided situation at each solution. As a result, we discovered several new families of exact traveling wave solutions, such as bright solitons, dark solitons, and combined bright and dark solitons. This research opens numerous avenues for further exploration in the field of nonlinear wave dynamics and optical soliton theory. The discovery of exact soliton solutions for the FL equation through a modified sub-equation method paves the way for deeper investigations for newcomer researchers. The results of this study will contribute further to the field of mathematical physics, particularly in enhancing the understanding of nonlinear wave propagation and soliton theory in optical and other physical systems.

Evaluation of the potentially toxic elements and radionuclides in the soil sample of Novaya Zemlya in the Arctic Circle

The study presented here elucidate the concentrations of radionuclides and potentially toxic elements in the soil samples around the Novaya Zemlya in the Russian Arctic zone, determined using HPGe gamma spectrometry, inductively coupled plasma optical emission spectrometry and direct mercury analyzer. The average detected concentrations for 226Ra, 232Th, 40K, 235U and 137Cs were 36.40, 46.06, 768, 2.06 and 4.71 Bq/kg, respectively. At many sampling sites, the concentrations of potentially toxic elements (Zn, Cu, Pb, Cd, Ni, and Cr) were higher than the natural levels. Positive Matrix Factorization analysis revealed the contribution of oil dumps (32%), natural sources (16%), bird colonies (32%) and atmospheric deposition (20%) for elevated elements content. In the case of radionuclides, the natural occurring contamination (38%) was primary source followed by dumped material (32%) and bird colonies (30%). The radiological risk from radionuclides was relatively high, yet still under permissible levels. For potentially toxic elements, Fe was predominant non-carcinogenic pollutant and Ni emerged as major carcinogenic contaminant. Keeping in view the high content of some elements, future studies are required to keep the human and ecological risk low, and to establish scientific grounds for the contribution of settled bird species. The findings of the study advance the present knowledge about the contamination of the study area and lays the path for further effort.

Puck 3D-based modeling and validation of progressive failure in instrumented glass fiber-reinforced polypropylene via the split-disk test

This study analyzes the mechanical behavior and damage progression of filament-wound thermoplastic composite rings, focusing on the effects of embedded fiber optic (FO) sensors. Utilizing a split-disk test, the study evaluates both experimental and numerical approaches to examine the impact of FO sensors in glass fiber-reinforced polypropylene composite rings. The split-disk test is employed to measure key mechanical properties such as hoop tensile strength, stiffness and failure strain using strain gauges and 3D Digital Image Correlation (DIC). The research specifically examines two extreme configurations of FO sensor placement: parallel and perpendicular to the reinforced fibers. The objective is to propose sensor integration that minimizes potential negative effects on the material's properties. Both instrumented and non-instrumented samples are analyzed numerically and experimentally. The experimental phase involves detailed mechanical characterization using the split-disk test, while the numerical approach uses a developed UMAT finite element model based on the 3D Puck failure criterion and an element weakening method for progressive failure analysis. The numerical models adopt real microstructural details according to optical microscopic analysis. The study concludes that parallel embedded FO sensors are preferable as they enhance the ultimate strength to failure and avoid creating resin-rich zones near the sensor, thereby improving the overall mechanical performance of the composite rings. The 3D Puck failure criterion combined with the element weakening method provides accurate predictions of fiber failure initiation and growth in the composite rings.