Pub Date : 2025-11-01Epub Date: 2025-08-25DOI: 10.1016/j.ijleo.2025.172511
Leila Mehraban, Mojtaba Sadeghi, Zahra Adelpour
A high-performance plasmonic sensor featuring a graphene-coated triangular array is presented that achieves an exceptional combination of spectral sharpness and sensitivity. The sensor design demonstrates an ultra-narrow full width half maximum (FWHM) of 0.52 nm, enabled by strong plasmonic field confinement from the triangular array’s sharp vertices, suppressing radiative losses and graphene’s unique damping of plasmon decay via its high charge-carrier mobility and conductivity. The finite element method (FEM) simulations yield a record Q-factor of 1211 and figure of merit (FOM) of 769 RIU⁻¹ while maintaining 400 nm/RIU sensitivity across a broad refractive index range (1.0–2.0). The optimized geometry (400 nm periodicity, 5 nm Au thickness) efficiently excites surface plasmons in the visible-NIR (400–800 nm). Graphene-enhanced charge-density oscillations, combined with the array’s field confinement, enable a resolution of 1.3 × 10⁻5 RIU (at SNR=100), establishing this platform for sub-nanometer spectral resolution in molecular sensing.
{"title":"Ultra-sharp plasmonic resonance in graphene-coated triangular arrays for high-precision sensing","authors":"Leila Mehraban, Mojtaba Sadeghi, Zahra Adelpour","doi":"10.1016/j.ijleo.2025.172511","DOIUrl":"10.1016/j.ijleo.2025.172511","url":null,"abstract":"<div><div>A high-performance plasmonic sensor featuring a graphene-coated triangular array is presented that achieves an exceptional combination of spectral sharpness and sensitivity. The sensor design demonstrates an ultra-narrow full width half maximum (<em>FWHM</em>) of 0.52 nm, enabled by strong plasmonic field confinement from the triangular array’s sharp vertices, suppressing radiative losses and graphene’s unique damping of plasmon decay via its high charge-carrier mobility and conductivity. The finite element method (FEM) simulations yield a record <em>Q</em>-factor of 1211 and figure of merit (<em>FOM</em>) of 769 RIU⁻<sup>¹</sup> while maintaining 400 nm/RIU sensitivity across a broad refractive index range (1.0–2.0). The optimized geometry (400 nm periodicity, 5 nm Au thickness) efficiently excites surface plasmons in the visible-NIR (400–800 nm). Graphene-enhanced charge-density oscillations, combined with the array’s field confinement, enable a resolution of 1.3 × 10⁻<sup>5</sup> RIU (at <em>SNR</em>=100), establishing this platform for sub-nanometer spectral resolution in molecular sensing.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"339 ","pages":"Article 172511"},"PeriodicalIF":3.1,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144904064","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-01Epub Date: 2025-10-14DOI: 10.1016/j.ijleo.2025.172567
Pankaj Kumar Ray, Suman Ranjan
In this paper, a compact micron-sized triple unsymmetrical microring resonator (TUMRR) using the Vernier effect based optical filter and highly sensitive refractive index (RI) based biosensor for cancer cells detection has been demonstrated. The simulation analysis of dual-function TUMRR as an optical filter is done using MATLAB, and the sensitivity results for cancer cell detection using the refractive index change technique have been obtained in OptiFDTD software. The proposed structure may act as a 1 × 3 input-output optical filter to address high FSR and Q-value. Mathematical modeling to obtain the transfer function for filter analysis is done using delay line signal processing, where a unit delay is modeled as . The obtained FSRs for are 315 THz, 615 THz, and 835 THz, and the Q-factors are 842, 1338, and 2200, respectively. The reported sensitivity range of the proposed sensor structure is from 150.3 to 167 nm/ RIU.
{"title":"Dual-function analysis of triple unsymmetrical microring resonators for biosensor and optical filter applications","authors":"Pankaj Kumar Ray, Suman Ranjan","doi":"10.1016/j.ijleo.2025.172567","DOIUrl":"10.1016/j.ijleo.2025.172567","url":null,"abstract":"<div><div>In this paper, a compact micron-sized triple unsymmetrical microring resonator (TUMRR) using the Vernier effect based optical filter and highly sensitive refractive index (RI) based biosensor for cancer cells detection has been demonstrated. The simulation analysis of dual-function TUMRR as an optical filter is done using MATLAB, and the sensitivity results for cancer cell detection using the refractive index change technique have been obtained in OptiFDTD software. The proposed structure may act as a 1 × 3 input-output optical filter to address high FSR and Q-value. Mathematical modeling to obtain the transfer function for filter analysis is done using delay line signal processing, where a unit delay is modeled as <span><math><msup><mrow><mi>z</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></math></span>. The obtained FSRs for <span><math><mrow><msub><mrow><mi>Tf</mi></mrow><mrow><mn>1</mn></mrow></msub><mo>,</mo><mspace></mspace><msub><mrow><mi>Tf</mi></mrow><mrow><mn>2</mn></mrow></msub><mo>,</mo><mi>and</mi><msub><mrow><mi>Tf</mi></mrow><mrow><mn>3</mn></mrow></msub></mrow></math></span> are 315 THz, 615 THz, and 835 THz, and the Q-factors are 842, 1338, and 2200, respectively. The reported sensitivity range of the proposed sensor structure is from 150.3 to 167 nm/ RIU.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"340 ","pages":"Article 172567"},"PeriodicalIF":3.1,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145334365","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper presents a new investigation into the evolution properties of a modified anomalous vortex beam (MAVB) within a fractional Fourier transform (FRFT). Analytical formulas for the MAVB as it propagates through both apertured and unapertured FRFT are derived by applying the Collins formula and expanding the hard aperture function into a finite series of Gaussian functions. Numerical simulations produce graphical representations that show the variations in intensity at the receiving plane. These illustrations indicate that initial beam parameters, such as topological charge, beam order, modification parameters, and FRFT parameters like fractional order and truncation parameter, significantly impact the beam's intensity distribution. The intensity evolution of the beam within the FRFT system demonstrates a periodic dependence on the fractional order. Our findings offer a convenient method for laser beam shaping.
{"title":"Propagation behavior of a modified anomalous vortex beam in fractional Fourier transform","authors":"Faroq Saad , Halima Benzehoua , Salma Chib , Abdelmajid Belafhal","doi":"10.1016/j.ijleo.2025.172526","DOIUrl":"10.1016/j.ijleo.2025.172526","url":null,"abstract":"<div><div>This paper presents a new investigation into the evolution properties of a modified anomalous vortex beam (MAVB) within a fractional Fourier transform (FRFT). Analytical formulas for the MAVB as it propagates through both apertured and unapertured FRFT are derived by applying the Collins formula and expanding the hard aperture function into a finite series of Gaussian functions. Numerical simulations produce graphical representations that show the variations in intensity at the receiving plane. These illustrations indicate that initial beam parameters, such as topological charge, beam order, modification parameters, and FRFT parameters like fractional order and truncation parameter, significantly impact the beam's intensity distribution. The intensity evolution of the beam within the FRFT system demonstrates a periodic dependence on the fractional order. Our findings offer a convenient method for laser beam shaping.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"339 ","pages":"Article 172526"},"PeriodicalIF":3.1,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145045934","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-01Epub Date: 2025-09-22DOI: 10.1016/j.ijleo.2025.172531
Shamshad Alam , Mohd Mansoor Khan , Ramesh Kumar Sonkar
The presented work examines the detection of multiple biological analytes associated with various diseases in humans using an optical ring resonator-based refractive index sensor. The suggested sensor has great potential in the healthcare domain for early disease diagnosis. The sensor system, utilizing a C-band (1550 nm) optical source, has been designed and numerically analyzed to detect sickle cell anemia (SCA), breast cancer cells, glucose concentrations, and tuberculosis. The time-efficient finite different time domain (FDTD) method has been employed to optimize the performance metrics of the sensor enhancing the sensitivity (), figure of merit (), and quality factor (). Apparently, the designed sensor can detect multiple analytes with nanometer/Refractive Index Unit (nm/RIU), RIU-1, and , respectively. The obtained results further motivates the fabrication of ubiquitous sensing system for multiple disease detection.
{"title":"Multiplexed detection of refractive indices among analytes via microfluidics and optical ring resonator: Optical coupling approach","authors":"Shamshad Alam , Mohd Mansoor Khan , Ramesh Kumar Sonkar","doi":"10.1016/j.ijleo.2025.172531","DOIUrl":"10.1016/j.ijleo.2025.172531","url":null,"abstract":"<div><div>The presented work examines the detection of multiple biological analytes associated with various diseases in humans using an optical ring resonator-based refractive index sensor. The suggested sensor has great potential in the healthcare domain for early disease diagnosis. The sensor system, utilizing a C-band (1550 nm) optical source, has been designed and numerically analyzed to detect sickle cell anemia (SCA), breast cancer cells, glucose concentrations, and tuberculosis. The time-efficient finite different time domain (FDTD) method has been employed to optimize the performance metrics of the sensor enhancing the sensitivity (<span><math><mi>S</mi></math></span>), figure of merit (<span><math><mrow><mi>F</mi><mi>O</mi><mi>M</mi></mrow></math></span>), and quality factor (<span><math><mrow><mi>Q</mi><mi>F</mi></mrow></math></span>). Apparently, the designed sensor can detect multiple analytes with <span><math><mrow><mi>S</mi><mo>=</mo><mn>420</mn><mo>.</mo><mn>45</mn></mrow></math></span> nanometer/Refractive Index Unit (nm/RIU), <span><math><mrow><mi>F</mi><mi>O</mi><mi>M</mi><mo>=</mo><mn>289</mn><mo>.</mo><mn>85</mn></mrow></math></span> RIU<sup>-1</sup>, and <span><math><mrow><mi>Q</mi><mi>F</mi><mo>=</mo><mn>1107</mn><mo>.</mo><mn>36</mn></mrow></math></span>, respectively. The obtained results further motivates the fabrication of ubiquitous sensing system for multiple disease detection.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"339 ","pages":"Article 172531"},"PeriodicalIF":3.1,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145157918","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-01Epub Date: 2025-09-13DOI: 10.1016/j.ijleo.2025.172533
S. Sharmila , R.S. Bhuvaneswaran , Dhandapani Vaithiyanathan
The increasing exchange of multimedia content in the digital era demands reliable image encryption techniques to ensure data privacy and security. This paper presents an image encryption method that integrates Rubik’s Cube-inspired scrambling with a chaos-based diffusion process to provide strong security while maintaining computational efficiency. The scrambling stage is implemented using iterative modulo-two operations that determine left or right circular shifts for rows and columns, and these operations are deterministic without the involvement of chaotic sequences in controlling their direction or magnitude. In the diffusion stage, logistic-map-generated keys modify pixel intensity values through XOR operations. Comprehensive security analyses, including entropy, NPCR, UACI, correlation coefficients, SSIM, PSNR, chi-square, and NIST statistical test suite assessments, demonstrate strong cryptographic performance. The proposed method achieves an entropy value of 7.99, an NPCR greater than 0.994, and a UACI greater than 0.32, while the correlation coefficients of the encrypted images approach zero in all orientations. Histogram analysis shows a nearly uniform distribution, and low structural similarity and peak signal-to-noise ratio values confirm strong encryption with accurate decryption. This approach effectively balances implementation simplicity, security strength, and suitability for real-time hardware applications such as FPGA-based systems.
{"title":"Secure image encryption using Rubik’s Cube-based scrambling with chaos-driven diffusion and circular shifts","authors":"S. Sharmila , R.S. Bhuvaneswaran , Dhandapani Vaithiyanathan","doi":"10.1016/j.ijleo.2025.172533","DOIUrl":"10.1016/j.ijleo.2025.172533","url":null,"abstract":"<div><div>The increasing exchange of multimedia content in the digital era demands reliable image encryption techniques to ensure data privacy and security. This paper presents an image encryption method that integrates Rubik’s Cube-inspired scrambling with a chaos-based diffusion process to provide strong security while maintaining computational efficiency. The scrambling stage is implemented using iterative modulo-two operations that determine left or right circular shifts for rows and columns, and these operations are deterministic without the involvement of chaotic sequences in controlling their direction or magnitude. In the diffusion stage, logistic-map-generated keys modify pixel intensity values through XOR operations. Comprehensive security analyses, including entropy, NPCR, UACI, correlation coefficients, SSIM, PSNR, chi-square, and NIST statistical test suite assessments, demonstrate strong cryptographic performance. The proposed method achieves an entropy value of 7.99, an NPCR greater than 0.994, and a UACI greater than 0.32, while the correlation coefficients of the encrypted images approach zero in all orientations. Histogram analysis shows a nearly uniform distribution, and low structural similarity and peak signal-to-noise ratio values confirm strong encryption with accurate decryption. This approach effectively balances implementation simplicity, security strength, and suitability for real-time hardware applications such as FPGA-based systems.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"339 ","pages":"Article 172533"},"PeriodicalIF":3.1,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145106092","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-01Epub Date: 2025-09-16DOI: 10.1016/j.ijleo.2025.172541
Svetislav Savović , Konstantinos Aidinis
The influence of mode coupling on two and three spatially multiplexed optical channels in unaltered and D-shaped multimode step-index plastic optical fibers (SI POFs) is analyzed by solving the power flow equation (PFE). The D-shaped technique applies controlled perturbations to suppress high-order modes, thereby improving the fiber’s bandwidth. Our numerical results show that mode coupling significantly limits the fiber length over which space division multiplexing (SDM) can be implemented with minimal crosstalk between adjacent channels. This limitation is especially pronounced when external perturbations, such as D-shaping of the fiber, increase mode coupling, further reducing the fiber’s capacity for SDM. In particular, two and three spatially multiplexed channels exhibit lower crosstalk over longer distances in unaltered SI POFs compared to their D-shaped counterparts. These findings highlight the importance of fiber characterization when designing SDM-based optical transmission systems.
{"title":"Theoretical investigation of space division multiplexing capacity of unaltered and D-shaped multimode step-index POF","authors":"Svetislav Savović , Konstantinos Aidinis","doi":"10.1016/j.ijleo.2025.172541","DOIUrl":"10.1016/j.ijleo.2025.172541","url":null,"abstract":"<div><div>The influence of mode coupling on two and three spatially multiplexed optical channels in unaltered and D-shaped multimode step-index plastic optical fibers (SI POFs) is analyzed by solving the power flow equation (PFE). The D-shaped technique applies controlled perturbations to suppress high-order modes, thereby improving the fiber’s bandwidth. Our numerical results show that mode coupling significantly limits the fiber length over which space division multiplexing (SDM) can be implemented with minimal crosstalk between adjacent channels. This limitation is especially pronounced when external perturbations, such as D-shaping of the fiber, increase mode coupling, further reducing the fiber’s capacity for SDM. In particular, two and three spatially multiplexed channels exhibit lower crosstalk over longer distances in unaltered SI POFs compared to their D-shaped counterparts. These findings highlight the importance of fiber characterization when designing SDM-based optical transmission systems.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"339 ","pages":"Article 172541"},"PeriodicalIF":3.1,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145106091","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-01Epub Date: 2025-09-18DOI: 10.1016/j.ijleo.2025.172532
Li Sun , Jingyu Wang , Cong Xie , Wenli Zhang , Wei Ding
Dent defects in button cell batteries frequently arise during production and transportation, which not only impair their aesthetic appeal but also pose safety risks. The detection of these defects is particularly challenging due to the highly reflective surfaces of the cells and the interference caused by stamped characters. To tackle these issues, an automatic optical imaging system featuring dark field lighting is developed to capture time-series images. By employing shape template matching, relative position calculation, and affine transformation, the character regions were accurately located. The threshold segmentation method is then applied to both the original and Gaussian-filtered images, excluding the character regions, to identify potential defect areas. Defect pixel areas are determined using a 200-pixel threshold. Through comparative analysis, the number of time-series images is optimized to 7, significantly enhancing defect recognition accuracy. Online testing of 150,911 batteries demonstrated a 97.87% accuracy rate for normal batteries and a 99.05% detection rate for defective ones. The proposed algorithm processes each sample in under 300 ms, satisfying the requirements for real-time industrial detection. This study presents an effective solution for the real-time monitoring of dent defects in button cell batteries, contributing to improved quality control and safety assurance in the battery manufacturing industry.
{"title":"Automated optical inspection system for real-time dent defect detection in button cell batteries","authors":"Li Sun , Jingyu Wang , Cong Xie , Wenli Zhang , Wei Ding","doi":"10.1016/j.ijleo.2025.172532","DOIUrl":"10.1016/j.ijleo.2025.172532","url":null,"abstract":"<div><div>Dent defects in button cell batteries frequently arise during production and transportation, which not only impair their aesthetic appeal but also pose safety risks. The detection of these defects is particularly challenging due to the highly reflective surfaces of the cells and the interference caused by stamped characters. To tackle these issues, an automatic optical imaging system featuring dark field lighting is developed to capture time-series images. By employing shape template matching, relative position calculation, and affine transformation, the character regions were accurately located. The threshold segmentation method is then applied to both the original and Gaussian-filtered images, excluding the character regions, to identify potential defect areas. Defect pixel areas are determined using a 200-pixel threshold. Through comparative analysis, the number of time-series images is optimized to 7, significantly enhancing defect recognition accuracy. Online testing of 150,911 batteries demonstrated a 97.87% accuracy rate for normal batteries and a 99.05% detection rate for defective ones. The proposed algorithm processes each sample in under 300 ms, satisfying the requirements for real-time industrial detection. This study presents an effective solution for the real-time monitoring of dent defects in button cell batteries, contributing to improved quality control and safety assurance in the battery manufacturing industry.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"339 ","pages":"Article 172532"},"PeriodicalIF":3.1,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145109701","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A comprehensive detailed theoretical investigation into structural, optical, and optoelectronic properties of caesium indium titanate (CsInTiO₄) quantum dots (QDs), modelled with a unit cell size of approximately 15 Å. As a structural analogy of CsAlTiO₄, CsInTiO₄ crystallizes in a monoclinic phase with space group , as confirmed by X-ray diffraction (XRD) analysis. The material exhibits a wide optical band gap , classifying it as a robust wide-band-gap insulator. Optical dispersion behavior was analyzed using the Wemple-DiDomenico model, yielding a high single-oscillator energy () and oscillator strength of (), indicative of strong ionic character and electronic stability. Furthermore, nonlinear optical (NLO) characterization revealed a significant third-order susceptibility () and a high nonlinear refractive index (), highlighting the material’s strong nonlinear response. Such insights, supported by both theoretical simulations and XRD data, represent the 1st detailed exploration of CsInTiO₄-QDs, laying the ground for upcoming experiments. These numerical benchmarks not only establish CsInTiO₄-QDs as a wide-band-gap insulator but also underscore their exceptional potential for UV optoelectronic and nonlinear optical applications.
{"title":"Unveiling CsInTiO₄ quantum dots: A novel wide-band-gap material with exceptional nonlinear optical properties","authors":"M.A.M. El-Mansy , M.S. El-Bana , Ashwani Kumar , Pankaj Sharma","doi":"10.1016/j.ijleo.2025.172544","DOIUrl":"10.1016/j.ijleo.2025.172544","url":null,"abstract":"<div><div>A comprehensive detailed theoretical investigation into structural, optical, and optoelectronic properties of <sub>caesium</sub> indium titanate (CsInTiO₄) quantum dots (QDs), modelled with a unit cell size of approximately 15 Å. As a structural analogy of CsAlTiO₄, CsInTiO₄ crystallizes in a monoclinic phase with space group <span><math><mrow><mo>(</mo><mi>P</mi><mn>21</mn><mo>/</mo><mi>N</mi><mo>)</mo></mrow></math></span>, as confirmed by X-ray diffraction (XRD) analysis. The material exhibits a wide optical band gap <span><math><mrow><mo>(</mo><mn>5.33</mn><mspace></mspace><mi>eV</mi><mo>)</mo></mrow></math></span>, classifying it as a robust wide-band-gap insulator. Optical dispersion behavior was analyzed using the Wemple-DiDomenico model, yielding a high single-oscillator energy (<span><math><mrow><mi>E</mi><mi>₀</mi><mspace></mspace><mo>=</mo><mspace></mspace><mn>7.68</mn><mspace></mspace><mi>eV</mi></mrow></math></span>) and oscillator strength of (<span><math><mrow><mi>f</mi><mo>=</mo><mn>35.8</mn><mspace></mspace><mi>eV²</mi></mrow></math></span>), indicative of strong ionic character and electronic stability. Furthermore, nonlinear optical (NLO) characterization revealed a significant third-order susceptibility (<span><math><msup><mrow><mi>χ</mi></mrow><mrow><mo>(</mo><mn>3</mn><mo>)</mo></mrow></msup></math></span>) and a high nonlinear refractive index (<span><math><msub><mrow><mi>n</mi></mrow><mrow><mn>2</mn></mrow></msub></math></span>), highlighting the material’s strong nonlinear response. Such insights, supported by both theoretical simulations and XRD data, represent the 1st detailed exploration of CsInTiO₄-QDs, laying the ground for upcoming experiments. These numerical benchmarks not only establish CsInTiO₄-QDs as a wide-band-gap insulator but also underscore their exceptional potential for UV optoelectronic and nonlinear optical applications.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"339 ","pages":"Article 172544"},"PeriodicalIF":3.1,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145118085","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-01Epub Date: 2025-09-15DOI: 10.1016/j.ijleo.2025.172536
Chinky , Pankaj Kumar
In this paper, an analysis on the stability of zinc oxide (ZnO) nanoparticles (NPs) induced homeotropic alignment (HA) of dichroic dye doped nematic liquid crystal (NLC) at varying temperatures has been carried out. Three sample cells, namely conventional PI coated homeotropically aligned liquid crystal (HALC) (S1), NPs induced HALC (S2), and dye doped NPs induced HALC (S3) were prepared. Further, their morphological and electro-optical (E-O) characteristics were determined between temperature ranges from 20 °C to 60 °C. Findings illustrate that there are no observable textural changes in terms of background consistency, phase transitions, and uniformity in coloration across all the cells. Also, with increasing electric field, the liquid crystal (LC) molecules exhibit uniform switching behavior up to 60 °C, confirming that the performance of the HALC device remains unaffected under elevated thermal conditions. Comparatively, cell S1 shows larger threshold and operating voltages, whereas cell S3 exhibits the most thermally stable alignment with low threshold and operating voltages with highest contrast ratio (CR) at all temperatures. Thus, NPs induced dichroic dye doped HALC cells have potential to contribute to the development of thermally reliable LC based devices.
{"title":"Analysis on nanoparticles induced alignment stability of dye doped liquid crystal at varying temperatures","authors":"Chinky , Pankaj Kumar","doi":"10.1016/j.ijleo.2025.172536","DOIUrl":"10.1016/j.ijleo.2025.172536","url":null,"abstract":"<div><div>In this paper, an analysis on the stability of zinc oxide (ZnO) nanoparticles (NPs) induced homeotropic alignment (HA) of dichroic dye doped nematic liquid crystal (NLC) at varying temperatures has been carried out. Three sample cells, namely conventional PI coated homeotropically aligned liquid crystal (HALC) (S1), NPs induced HALC (S2), and dye doped NPs induced HALC (S3) were prepared. Further, their morphological and electro-optical (E-O) characteristics were determined between temperature ranges from 20 °C to 60 °C. Findings illustrate that there are no observable textural changes in terms of background consistency, phase transitions, and uniformity in coloration across all the cells. Also, with increasing electric field, the liquid crystal (LC) molecules exhibit uniform switching behavior up to 60 °C, confirming that the performance of the HALC device remains unaffected under elevated thermal conditions. Comparatively, cell S1 shows larger threshold and operating voltages, whereas cell S3 exhibits the most thermally stable alignment with low threshold and operating voltages with highest contrast ratio (CR) at all temperatures. Thus, NPs induced dichroic dye doped HALC cells have potential to contribute to the development of thermally reliable LC based devices.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"339 ","pages":"Article 172536"},"PeriodicalIF":3.1,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145105674","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this work, we developed a silicon/CH3NH3PbI3 (MAPbI3) heterojunction-based photodetector under ambient conditions using the antisolvent treatment method. To achieve the best morphology and coverage in the perovskite thin film, we investigated the antisolvent dripping time by tracking the turbid point during the spin coating of the perovskite precursor solution on the substrate. By introducing the antisolvent in the processing window just before reaching the turbid point, we successfully obtained a dense MAPbI3 film with improved surface coverage, exhibiting elevated absorption within the wavelength range of 300–550 nm. The performance of silicon/MAPbI3 heterojunction-based photodetectors is also influenced by the antisolvent dripping times relative to the turbid point. The dark current of the champion device is suppressed by about ten orders of magnitude when the antisolvent treatment is applied a second before the turbid point. The optimal device demonstrates a responsivity of 30 mA/W and a specific detectivity exceeding 10 ¹ ⁰ Jones at -9V under 25 mW/cm² light illumination at 530 nm.
{"title":"Effect of antisolvent dripping time on the photodetection performance of silicon/MAPbI3 heterojunction","authors":"Zeinab PourMohammadi, Fatemeh Dehghan Nayeri, Rouhollah Azimirad","doi":"10.1016/j.ijleo.2025.172537","DOIUrl":"10.1016/j.ijleo.2025.172537","url":null,"abstract":"<div><div>In this work, we developed a silicon/CH<sub>3</sub>NH<sub>3</sub>PbI<sub>3</sub> (MAPbI<sub>3</sub>) heterojunction-based photodetector under ambient conditions using the antisolvent treatment method. To achieve the best morphology and coverage in the perovskite thin film, we investigated the antisolvent dripping time by tracking the turbid point during the spin coating of the perovskite precursor solution on the substrate. By introducing the antisolvent in the processing window just before reaching the turbid point, we successfully obtained a dense MAPbI<sub>3</sub> film with improved surface coverage, exhibiting elevated absorption within the wavelength range of 300–550 nm. The performance of silicon/MAPbI<sub>3</sub> heterojunction-based photodetectors is also influenced by the antisolvent dripping times relative to the turbid point. The dark current of the champion device is suppressed by about ten orders of magnitude when the antisolvent treatment is applied a second before the turbid point. The optimal device demonstrates a responsivity of 30 mA/W and a specific detectivity exceeding 10 ¹ ⁰ Jones at -9V under 25 mW/cm² light illumination at 530 nm.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"339 ","pages":"Article 172537"},"PeriodicalIF":3.1,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145105671","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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