We prepared the non-doped and Tb: Sr3La(PO4)3 (SLaPO) single crystals with Tb concentrations ranging from 0.5 to 10 mol% using the floating zone method and evaluated photoluminescence (PL), dosimetric, and imaging properties. The Tb: SLaPO single crystals exhibited PL and thermally stimulated luminescence (TSL) peaks corresponding to the transitions from the ground state to the excited states of Tb3 + ions. The TSL glow peaks were observed at 80°C for the non-doped SLaPO single crystal and 90°C for Tb: SLaPO single crystals. In the TSL does response function, the 5 mol% Tb: SLaPO sample showed a higher TSL intensity compared to the other samples with a detection limit of 0.01 mGy. Additionally, the 5 mol% Tb: SLaPO single crystal indicated a spatial resolution of 7.10 LP/mm after X-ray irradiation.
{"title":"Investigation of photoluminescence, dosimetric, and imaging properties of Sr3La(PO4)3: Tb","authors":"Haruaki Ezawa, Takumi Kato, Daisuke Nakauchi, Noriaki Kawaguchi, Takayuki Yanagida","doi":"10.1016/j.ijleo.2025.172644","DOIUrl":"10.1016/j.ijleo.2025.172644","url":null,"abstract":"<div><div>We prepared the non-doped and Tb: Sr<sub>3</sub>La(PO<sub>4</sub>)<sub>3</sub> (SLaPO) single crystals with Tb concentrations ranging from 0.5 to 10 mol% using the floating zone method and evaluated photoluminescence (PL), dosimetric, and imaging properties. The Tb: SLaPO single crystals exhibited PL and thermally stimulated luminescence (TSL) peaks corresponding to the transitions from the ground state to the excited states of Tb<sup>3 +</sup> ions. The TSL glow peaks were observed at 80°C for the non-doped SLaPO single crystal and 90°C for Tb: SLaPO single crystals. In the TSL does response function, the 5 mol% Tb: SLaPO sample showed a higher TSL intensity compared to the other samples with a detection limit of 0.01 mGy. Additionally, the 5 mol% Tb: SLaPO single crystal indicated a spatial resolution of 7.10 LP/mm after X-ray irradiation.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"346 ","pages":"Article 172644"},"PeriodicalIF":3.1,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145786663","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}
Laser interaction with matter is one of the fundamental fields of the thermophysics.
The problem of heating an isolated finite homogenous silver sulphide slab induced by a laser pulse is studied. Indeed pulsed laser are used in a variety of material processing applications.
The aim of the study is to evaluate quantitatively the thermal effects induced in the irradiated target. The output results will have essential importance in the field of technological applications.
In the present trial, the parabolic heat conduction equation is solved using Laplace integral transform technique which is one of the powerful methods in the field of mathematical physics. An express for the temperature field within the target is obtained.
The functional dependence of the temperature on the parameters of the laser pulse is clarified.
The computations makes it possible to evaluate the critical time required to initiate damage at the front surface, which is a starting point for medical, military, industrial applications.
An illustrative example on silver sulfide slab is given.
{"title":"Analytical modeling of heating effects induced in a finite silver sulfide (Ag2S) slab by a time dependent laser pulse using Laplace integral transform technique","authors":"M.K. El-Adawi, S.A. Shalaby, S.S. Mostafa, S.A. Antar","doi":"10.1016/j.ijleo.2025.172601","DOIUrl":"10.1016/j.ijleo.2025.172601","url":null,"abstract":"<div><div>Laser interaction with matter is one of the fundamental fields of the thermophysics.</div><div>The problem of heating an isolated finite homogenous silver sulphide <span><math><mrow><mfenced><mrow><mspace></mspace><mi>A</mi><msub><mrow><mi>g</mi></mrow><mrow><mn>2</mn></mrow></msub><mi>S</mi></mrow></mfenced></mrow></math></span> slab induced by a laser pulse is studied. Indeed pulsed laser are used in a variety of material processing applications.</div><div>The aim of the study is to evaluate quantitatively the thermal effects induced in the irradiated target. The output results will have essential importance in the field of technological applications.</div><div>In the present trial, the parabolic heat conduction equation is solved using Laplace integral transform technique which is one of the powerful methods in the field of mathematical physics. An express for the temperature field within the target is obtained.</div><div>The functional dependence of the temperature on the parameters of the laser pulse is clarified.</div><div>The computations makes it possible to evaluate the critical time required to initiate damage at the front surface, which is a starting point for medical, military, industrial applications.</div><div>An illustrative example on silver sulfide slab is given.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"346 ","pages":"Article 172601"},"PeriodicalIF":3.1,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145584383","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 : 2026-03-01Epub Date: 2025-12-02DOI: 10.1016/j.ijleo.2025.172633
Min Li, Ruixin Ren, Jie Yang, Lingyu Du, Rubing Bai, Aimin Cong, Xiaowei Li
A highly sensitive bullet-shaped fiber-optic Michelson temperature sensing probe with a wide measurement range is proposed in this paper, and it is fabricated using fiber fusion tapering technology and ultraviolet curing technology. First, a section of fiber taper is fused at the center of a multimode fiber (MMF) with a flat-cut end. The length and diameter of the fiber taper are 52 μm and 52 μm, respectively. Then, the fiber taper is completely encapsulated by SU-8 photoresist. The fiber taper and SU-8 photoresist form microcavity 1 and microcavity 2, respectively. The two microcavities are arranged in parallel at the end of the MMF, and a bullet-shaped fiber sensing probe is formed. The optical paths of two microcavities are close. According to the theory of the Vernier effect, a Vernier envelope appears in the interference spectrum of the proposed fiber-optic sensing probe. However, the Vernier envelope is not directly observed in the interference spectrum due to the presence of a microcavity 3. Microcavity 3 is formed by the superposition of microcavity 1 and microcavity 2. The distinct Vernier envelope can be observed by filtering out the interference spectrum of microcavity 3. The shifts of the Vernier envelope and the high-frequency peak with temperature are monitored. The sensitivity of this probe reaches 2.2627 nm/°C within the temperature range of −10 °C to 62 °C. The proposed sensing probe features a ultra-compact structure, a wide temperature measurement range and high sensitivity, making it a promising breakthrough in the field of temperature monitoring.
{"title":"Highly sensitive bullet-shaped fiber-optic Michelson temperature sensing probe based on Vernier effect","authors":"Min Li, Ruixin Ren, Jie Yang, Lingyu Du, Rubing Bai, Aimin Cong, Xiaowei Li","doi":"10.1016/j.ijleo.2025.172633","DOIUrl":"10.1016/j.ijleo.2025.172633","url":null,"abstract":"<div><div>A highly sensitive bullet-shaped fiber-optic Michelson temperature sensing probe with a wide measurement range is proposed in this paper, and it is fabricated using fiber fusion tapering technology and ultraviolet curing technology. First, a section of fiber taper is fused at the center of a multimode fiber (MMF) with a flat-cut end. The length and diameter of the fiber taper are 52 μm and 52 μm, respectively. Then, the fiber taper is completely encapsulated by SU-8 photoresist. The fiber taper and SU-8 photoresist form microcavity 1 and microcavity 2, respectively. The two microcavities are arranged in parallel at the end of the MMF, and a bullet-shaped fiber sensing probe is formed. The optical paths of two microcavities are close. According to the theory of the Vernier effect, a Vernier envelope appears in the interference spectrum of the proposed fiber-optic sensing probe. However, the Vernier envelope is not directly observed in the interference spectrum due to the presence of a microcavity 3. Microcavity 3 is formed by the superposition of microcavity 1 and microcavity 2. The distinct Vernier envelope can be observed by filtering out the interference spectrum of microcavity 3. The shifts of the Vernier envelope and the high-frequency peak with temperature are monitored. The sensitivity of this probe reaches 2.2627 nm/°C within the temperature range of −10 °C to 62 °C. The proposed sensing probe features a ultra-compact structure, a wide temperature measurement range and high sensitivity, making it a promising breakthrough in the field of temperature monitoring.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"346 ","pages":"Article 172633"},"PeriodicalIF":3.1,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145682230","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 : 2026-03-01Epub Date: 2025-11-24DOI: 10.1016/j.ijleo.2025.172620
O. Ben hammou , J. El-Hamouchi , A. Fakkahi , M. Jaouane , A. Ed – Dahmouny , H. Azmi , M. Jaafar , A. Mazouz , N. Zeiri , H. El Ghazi , A. Sali
This work presents a detailed investigation of the binding energy of a donor impurity positioned at the center of pyramidal core/shell/shell quantum dots, as well as the corresponding photoionization cross-section, under a Konwent-like confinement potential. The study examines the influence of confinement potential parameters and geometrical dimensions, as well as the combined effects of hydrostatic pressure and temperature. Within the effective mass approximation, the Schrödinger equation is numerically solved using the finite element method (FEM), ensuring high accuracy and computational efficiency. The results reveal that both the impurity binding energy and the photoionization cross-section are strongly influenced by the size of the nanostructure as well as the specific characteristics of the confinement potential. An increase in hydrostatic pressure leads to an enhancement of the donor binding energy, whereas higher temperatures induce a notable decrease. Additionally, the photoionization cross-section exhibits a pronounced peak when the photon energy matches the donor binding energy. Variations in system dimensions, confinement potential parameters, hydrostatic pressure, or temperature cause this resonance peak to shift either toward lower photon energies (red shift) or higher photon energies (blue shift).
{"title":"Donor binding energy and photoionization cross-section in pyramidal core/shell/shell quantum dots under external perturbations","authors":"O. Ben hammou , J. El-Hamouchi , A. Fakkahi , M. Jaouane , A. Ed – Dahmouny , H. Azmi , M. Jaafar , A. Mazouz , N. Zeiri , H. El Ghazi , A. Sali","doi":"10.1016/j.ijleo.2025.172620","DOIUrl":"10.1016/j.ijleo.2025.172620","url":null,"abstract":"<div><div>This work presents a detailed investigation of the binding energy of a donor impurity positioned at the center of pyramidal core/shell/shell quantum dots, as well as the corresponding photoionization cross-section, under a Konwent-like confinement potential. The study examines the influence of confinement potential parameters and geometrical dimensions, as well as the combined effects of hydrostatic pressure and temperature. Within the effective mass approximation, the Schrödinger equation is numerically solved using the finite element method (FEM), ensuring high accuracy and computational efficiency. The results reveal that both the impurity binding energy and the photoionization cross-section are strongly influenced by the size of the nanostructure as well as the specific characteristics of the confinement potential. An increase in hydrostatic pressure leads to an enhancement of the donor binding energy, whereas higher temperatures induce a notable decrease. Additionally, the photoionization cross-section exhibits a pronounced peak when the photon energy matches the donor binding energy. Variations in system dimensions, confinement potential parameters, hydrostatic pressure, or temperature cause this resonance peak to shift either toward lower photon energies (red shift) or higher photon energies (blue shift).</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"346 ","pages":"Article 172620"},"PeriodicalIF":3.1,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145616969","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 study presents a promising approach to synthesizing antimicrobial polypropylene fibers (PP) through thermal-induced grafting of acrylamide (AM) using Fenton's reagent as an initiator. The research achieved a breakthrough grafting percentage of 32 % under relatively mild conditions (80°C), marking a significant improvement over previous methods which typically yielded 3–27 % grafting. Through systematic optimization of reaction parameters (0.85 mol/L AM, 0.03 mol/L Fe (II), 4.26 mol/L H₂O₂, and 1.5 g/L PP fiber), the study established optimal conditions for efficient grafting. Notably, the research introduced an advanced application of the Mach-Zehnder interferometer technique to characterize the optical and structural properties of modified fibers, providing unprecedented insights into the relationship between grafting concentration and molecular organization. The modified fibers demonstrated significant antimicrobial activity against both gram-positive and gram-negative bacteria, as well as fungi. Comprehensive characterization using FT-IR, SEM, and XRD revealed that PP-g-AM (0.85 mol/L) exhibited superior properties, including enhanced crystallinity (CI increase from 38.57 % to 41.27 %) and optimal molecular alignment. This study bridges a critical gap in PP fiber modification technology by combining high grafting efficiency with detailed optical characterization, offering new possibilities for developing advanced antimicrobial textiles with tailored properties.
{"title":"Refined thermal-induced grafting of acrylamide onto polypropylene fibers: Optimization, optical characterization, and antimicrobial enhancement","authors":"G.M. Abo-Lila , T.Z.N. Sokkar , E.A. Seisa , E.Z. Omar , M.M. Metwally","doi":"10.1016/j.ijleo.2025.172636","DOIUrl":"10.1016/j.ijleo.2025.172636","url":null,"abstract":"<div><div>This study presents a promising approach to synthesizing antimicrobial polypropylene fibers (PP) through thermal-induced grafting of acrylamide (AM) using Fenton's reagent as an initiator. The research achieved a breakthrough grafting percentage of 32 % under relatively mild conditions (80°C), marking a significant improvement over previous methods which typically yielded 3–27 % grafting. Through systematic optimization of reaction parameters (0.85 mol/L AM, 0.03 mol/L Fe (II), 4.26 mol/L H₂O₂, and 1.5 g/L PP fiber), the study established optimal conditions for efficient grafting. Notably, the research introduced an advanced application of the Mach-Zehnder interferometer technique to characterize the optical and structural properties of modified fibers, providing unprecedented insights into the relationship between grafting concentration and molecular organization. The modified fibers demonstrated significant antimicrobial activity against both gram-positive and gram-negative bacteria, as well as fungi. Comprehensive characterization using FT-IR, SEM, and XRD revealed that PP-g-AM (0.85 mol/L) exhibited superior properties, including enhanced crystallinity (CI increase from 38.57 % to 41.27 %) and optimal molecular alignment. This study bridges a critical gap in PP fiber modification technology by combining high grafting efficiency with detailed optical characterization, offering new possibilities for developing advanced antimicrobial textiles with tailored properties.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"346 ","pages":"Article 172636"},"PeriodicalIF":3.1,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145682229","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 : 2026-03-01Epub Date: 2025-11-20DOI: 10.1016/j.ijleo.2025.172607
J. Arriaga Hernández , B. Cuevas Otahola , A. Diaz Nayotl , A. Jaramillo Núñez , A. Pérez Villegas , O. Valenzuela
We apply new machine learning (ML) technologies to optimize the Hartmann test (HT) and Bi-Ronchi test (BRT) regarding the recognition, identification, and localization of the centroids in experimental Hartmanngrams and Bi-Ronchigrams. We replace the conventional rigid Hartmann screen (Hartmann mask, HM) with structured apertures implemented via a spatial light modulator (SLM), which enables the generation of multiple patterns with different aperture geometries. Based on the classical HM with circular apertures, we build square apertures for the Bi-Ronchi mask (BRM). We designed an experimental setup based on an SLM with a laser illumination system and implemented an unsupervised Centroid Clustering Algorithm (uCCA), based on the ML algorithm -means, to identify the geometries of the centroids, followed by their segmentation and localization by clustering. We compare the experimental and theoretical Bi-Ronchigrams (or Hartmanngrams) to obtain a point cloud of transverse aberrations (). We apply the point cloud method (PCM) to obtain an integrable surface from the points in . Finally, we replace the numerical integration of with transverse aberrations () and a directional derivative approach based on the Eikonal equation, solved using Gaussian quadrature to obtain the wavefront. We compare our results with the Zernike aberration polynomials for sensing optical elements from the aberrations of the system by means of the aberrations of its wavefront .
{"title":"Machine learning K-means algorithm applied to wavefront sensing in Bi-Ronchi/Hartmann tests with SLM","authors":"J. Arriaga Hernández , B. Cuevas Otahola , A. Diaz Nayotl , A. Jaramillo Núñez , A. Pérez Villegas , O. Valenzuela","doi":"10.1016/j.ijleo.2025.172607","DOIUrl":"10.1016/j.ijleo.2025.172607","url":null,"abstract":"<div><div>We apply new machine learning (ML) technologies to optimize the Hartmann test (HT) and Bi-Ronchi test (BRT) regarding the recognition, identification, and localization of the centroids in experimental Hartmanngrams and Bi-Ronchigrams. We replace the conventional rigid Hartmann screen (Hartmann mask, HM) with structured apertures implemented via a spatial light modulator (SLM), which enables the generation of multiple patterns with different aperture geometries. Based on the classical HM with circular apertures, we build square apertures for the Bi-Ronchi mask (BRM). We designed an experimental setup based on an SLM with a laser illumination system and implemented an unsupervised Centroid Clustering Algorithm (uCCA), based on the ML algorithm <span><math><mi>K</mi></math></span>-means, to identify the geometries of the centroids, followed by their segmentation and localization by clustering. We compare the experimental and theoretical Bi-Ronchigrams (or Hartmanngrams) to obtain a point cloud of transverse aberrations (<span><math><mi>P</mi><msub><mi>C</mi><mrow><mi>T</mi><mi>A</mi></mrow></msub></math></span>). We apply the point cloud method (PCM) to obtain an integrable surface from the points in <span><math><mi>P</mi><msub><mi>C</mi><mrow><mi>T</mi><mi>A</mi></mrow></msub></math></span>. Finally, we replace the numerical integration of <span><math><mrow><mi>P</mi><msub><mi>C</mi><mrow><mi>T</mi><mi>A</mi></mrow></msub></mrow></math></span> with transverse aberrations (<span><math><mi>T</mi><mi>A</mi></math></span>) and a directional derivative approach based on the Eikonal equation, solved using Gaussian quadrature to obtain the wavefront. We compare our results with the Zernike aberration polynomials for sensing optical elements from the aberrations of the system by means of the aberrations of its wavefront <span><math><mrow><mrow><mi>W</mi></mrow></mrow><mo>(</mo><mrow><mi>ρ</mi></mrow><mo>,</mo><mrow><mi>θ</mi></mrow><mo>)</mo></math></span>.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"346 ","pages":"Article 172607"},"PeriodicalIF":3.1,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145616970","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 : 2026-03-01Epub Date: 2025-12-12DOI: 10.1016/j.ijleo.2025.172640
P.S. Vinayagam , S. Mahendran , S. Thaarini , P. Sabeenadevi
In this work, we investigate an integrable nonlocal cubic–quintic nonlinear Schrödinger (NLS) equation that incorporates both nonlocal cubic and nonlocal quintic interactions, a model that is physically relevant for describing beam propagation in highly nonlinear nonlocal optical media as well as matter-wave dynamics in Bose–Einstein condensates (BECs) with long-range interactions and engineered -symmetric potentials. Using a modified Darboux transformation and a nontrivial plane-wave seed, we derive a more general class of soliton solutions that enables us to uncover two key dynamical features that have not been reported for higher-order nonlocal integrable systems. First, we show that the evolution of the field exhibits an exact -symmetric mirror reflection in its conjugate mode for all soliton families—Bright–Bright, Dark–Dark, Bright–Dark, and Dark–Bright—demonstrating that the full soliton dynamics respects the intrinsic nonlocal symmetry of the model. Second, we provide physical insight into the mechanism by showing that the spectral parameter governs the phase and velocity structure of individual solitons, while the cubic–quintic nonlocal terms generate an effective -symmetric nonlocal potential that constrains one soliton while allowing the other to undergo rotation. For mixed bound states, the inherent asymmetry of the bright and dark backgrounds limits the achievable rotation angle, resulting in a less flexible dynamical response. The combined observation of -symmetric reflection and controllable trajectory rotation demonstrates the richness of nonlinear wave propagation in this integrable nonlocal model. These results offer potential applications in nonlinear optics, such as all-optical switching, trajectory-controlled soliton routing, and beam steering in -symmetric photonic structures, as well as in BEC systems where nonlocal interactions and symmetry-engineered potentials play a major role in manipulating matter-wave solitons.
{"title":"Reflecting solitons and their rotation of trajectories in PT-symmetry nonlinear Schrödinger equation with nonlocal cubic-quintic interaction","authors":"P.S. Vinayagam , S. Mahendran , S. Thaarini , P. Sabeenadevi","doi":"10.1016/j.ijleo.2025.172640","DOIUrl":"10.1016/j.ijleo.2025.172640","url":null,"abstract":"<div><div>In this work, we investigate an integrable nonlocal cubic–quintic nonlinear Schrödinger (NLS) equation that incorporates both nonlocal cubic and nonlocal quintic interactions, a model that is physically relevant for describing beam propagation in highly nonlinear nonlocal optical media as well as matter-wave dynamics in Bose–Einstein condensates (BECs) with long-range interactions and engineered <span><math><mrow><mi>P</mi><mi>T</mi></mrow></math></span>-symmetric potentials. Using a modified Darboux transformation and a nontrivial plane-wave seed, we derive a more general class of soliton solutions that enables us to uncover two key dynamical features that have not been reported for higher-order nonlocal integrable systems. First, we show that the evolution of the field <span><math><mi>Q</mi><mo>(</mo><mi>x</mi><mo>,</mo><mi>t</mi><mo>)</mo></math></span> exhibits an exact <span><math><mrow><mi>P</mi><mi>T</mi></mrow></math></span>-symmetric mirror reflection in its conjugate mode <span><math><msup><mi>Q</mi><mrow><mo>∗</mo></mrow></msup><mo>(</mo><mo>−</mo><mi>x</mi><mo>,</mo><mi>t</mi><mo>)</mo></math></span> for all soliton families—Bright–Bright, Dark–Dark, Bright–Dark, and Dark–Bright—demonstrating that the full soliton dynamics respects the intrinsic nonlocal <span><math><mrow><mi>P</mi><mi>T</mi></mrow></math></span> symmetry of the model. Second, we provide physical insight into the mechanism by showing that the spectral parameter governs the phase and velocity structure of individual solitons, while the cubic–quintic nonlocal terms generate an effective <span><math><mrow><mi>P</mi><mi>T</mi></mrow></math></span>-symmetric nonlocal potential that constrains one soliton while allowing the other to undergo rotation. For mixed bound states, the inherent asymmetry of the bright and dark backgrounds limits the achievable rotation angle, resulting in a less flexible dynamical response. The combined observation of <span><math><mrow><mi>P</mi><mi>T</mi></mrow></math></span>-symmetric reflection and controllable trajectory rotation demonstrates the richness of nonlinear wave propagation in this integrable nonlocal model. These results offer potential applications in nonlinear optics, such as all-optical switching, trajectory-controlled soliton routing, and beam steering in <span><math><mrow><mi>P</mi><mi>T</mi></mrow></math></span>-symmetric photonic structures, as well as in BEC systems where nonlocal interactions and symmetry-engineered potentials play a major role in manipulating matter-wave solitons.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"346 ","pages":"Article 172640"},"PeriodicalIF":3.1,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145786602","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 : 2026-02-01Epub Date: 2025-11-17DOI: 10.1016/j.ijleo.2025.172603
Kishore Kumar Venkatesan , Sathiyan Samikannu
The design, fabrication, and development of smart sensors are among the ultimate challenges faced by researchers nowadays in intelligent and real-time monitoring systems. A system for monitoring human breath holds exceptional promise in harsh environments, healthcare, sports, and remote monitoring. Translating this into the real world will be quite challenging as it requires developing unobtrusive and comfortable systems while maintaining high metrological performance. The potential solution for this has been derived from fiber optic sensors due to their compact size, ability to handle multiple inputs, chemical stability, and immunity to electromagnetic (EM) interference. Inclusive of this, a 2D nanomaterial is coated on an optical fiber and used as a sensing medium which detects changes in the breath composition and provides valuable information about the respiratory system because of its high surface-to-volume ratio, high carrier mobility, tunable band gaps, and strong light-matter interactions. This approach can potentially revolutionize the field of breath monitoring, enabling early detection of respiratory diseases and improving patient outcomes. Thus, this system will provide a pathway for exploring new possibilities in the emerging 2D material-based sensing platform. Here, we overview recent developments for monitoring human breath with fiber optic sensors and nanomaterial-based FOS along with various methods of respiratory monitoring and their benefits in real-time monitoring. Also, we summarize the challenges and future perspectives of 2D layered nanomaterial-based fiber optic sensors for human breath monitoring applications.
{"title":"Comprehensive review on 2D nanomaterial-based fiber optic sensor for human breath monitoring application","authors":"Kishore Kumar Venkatesan , Sathiyan Samikannu","doi":"10.1016/j.ijleo.2025.172603","DOIUrl":"10.1016/j.ijleo.2025.172603","url":null,"abstract":"<div><div>The design, fabrication, and development of smart sensors are among the ultimate challenges faced by researchers nowadays in intelligent and real-time monitoring systems. A system for monitoring human breath holds exceptional promise in harsh environments, healthcare, sports, and remote monitoring. Translating this into the real world will be quite challenging as it requires developing unobtrusive and comfortable systems while maintaining high metrological performance. The potential solution for this has been derived from fiber optic sensors due to their compact size, ability to handle multiple inputs, chemical stability, and immunity to electromagnetic (EM) interference. Inclusive of this, a 2D nanomaterial is coated on an optical fiber and used as a sensing medium which detects changes in the breath composition and provides valuable information about the respiratory system because of its high surface-to-volume ratio, high carrier mobility, tunable band gaps, and strong light-matter interactions. This approach can potentially revolutionize the field of breath monitoring, enabling early detection of respiratory diseases and improving patient outcomes. Thus, this system will provide a pathway for exploring new possibilities in the emerging 2D material-based sensing platform. Here, we overview recent developments for monitoring human breath with fiber optic sensors and nanomaterial-based FOS along with various methods of respiratory monitoring and their benefits in real-time monitoring. Also, we summarize the challenges and future perspectives of 2D layered nanomaterial-based fiber optic sensors for human breath monitoring applications.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"345 ","pages":"Article 172603"},"PeriodicalIF":3.1,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145570773","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 : 2026-02-01Epub Date: 2025-12-08DOI: 10.1016/j.ijleo.2025.172638
Kamiul Islam , Joyonta Das Joy , Md.Shakibur Rahman , Md.Ismail Hossain , Nayem Al Kayed , Rakayet Rafi , M.R. Karim , Jobaida Akhtar , Mohammad Istiaque Reja
This paper presents a novel dispersion-engineered inverse rib waveguide design for ultra-broadband supercontinuum generation (SCG), utilizing an chalcogenide glass core with cladding layers. The proposed structure achieves dispersion flattening over a wide range, enhancing nonlinear interactions for efficient spectral broadening under a 3.6 m pump laser. Optimized waveguide geometry and material composition yield an output spectrum spanning 1.99–16.58 m (3.06 octaves) at 4 kW peak pump power. Even at a reduced pump power of 2 kW, the supercontinuum extends from 4 m to 16 m, covering nearly two octaves, showcasing superior spectral broadening at lower power compared to other designs. The design maintains power stability and near-zero dispersion, which are essential for coherent SCG. The broad spectral range and low-power efficiency make the waveguide suitable for environmental monitoring, gas sensing, chemical analysis, biomedical imaging, and thermal imaging. Integration of cladding enhances mechanical durability and stability.
{"title":"Ultra-broadband three-octave supercontinuum generation in a dispersion-engineered chalcogenide inverse rib waveguide","authors":"Kamiul Islam , Joyonta Das Joy , Md.Shakibur Rahman , Md.Ismail Hossain , Nayem Al Kayed , Rakayet Rafi , M.R. Karim , Jobaida Akhtar , Mohammad Istiaque Reja","doi":"10.1016/j.ijleo.2025.172638","DOIUrl":"10.1016/j.ijleo.2025.172638","url":null,"abstract":"<div><div>This paper presents a novel dispersion-engineered inverse rib waveguide design for ultra-broadband supercontinuum generation (SCG), utilizing an <span><math><msub><mrow><mtext>As</mtext></mrow><mn>2</mn></msub><msub><mrow><mtext>Se</mtext></mrow><mn>3</mn></msub></math></span> chalcogenide glass core with <span><math><mrow><mtext>GeAsS</mtext></mrow><mrow><mo>/</mo></mrow><msub><mrow><mtext>MgF</mtext></mrow><mn>2</mn></msub></math></span> cladding layers. The proposed structure achieves dispersion flattening over a wide range, enhancing nonlinear interactions for efficient spectral broadening under a 3.6 <span><math><mrow><mtext>μ</mtext></mrow></math></span>m pump laser. Optimized waveguide geometry and material composition yield an output spectrum spanning 1.99–16.58 <span><math><mrow><mtext>μ</mtext></mrow></math></span>m (3.06 octaves) at 4 kW peak pump power. Even at a reduced pump power of 2 kW, the supercontinuum extends from 4 <span><math><mrow><mtext>μ</mtext></mrow></math></span>m to 16 <span><math><mrow><mtext>μ</mtext></mrow></math></span>m, covering nearly two octaves, showcasing superior spectral broadening at lower power compared to other designs. The design maintains power stability and near-zero dispersion, which are essential for coherent SCG. The broad spectral range and low-power efficiency make the waveguide suitable for environmental monitoring, gas sensing, chemical analysis, biomedical imaging, and thermal imaging. Integration of <span><math><msub><mrow><mtext>MgF</mtext></mrow><mn>2</mn></msub></math></span> cladding enhances mechanical durability and stability.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"345 ","pages":"Article 172638"},"PeriodicalIF":3.1,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145733038","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 study presents a terahertz (THz) metal–insulator–metal (MIM) metamaterial absorber designed for high-sensitivity biochemical sensing through two sequential design mechanisms. The first mechanism establishes a periodic hexagonal resonant structure—consisting of a solid hexagon and a hexagonal shape formed by rectangular metal bars—that creates a hexagonal-edge unit cell capable of strong field confinement and enhanced sensitivity compared with conventional geometries. Building on this primary structure, the second mechanism introduces a targeted etching process applied to the dielectric layer. Straight and sloped etching profiles are used to progressively expose the resonant surfaces, thereby increasing the direct interaction between the electromagnetic fields and the surrounding analyte. With this combined structural and processing approach, the hexagonal bar pattern achieves ultra-high sensitivity, increasing from 72 to 378 GHz/RIU at a straight dielectric-layer etch depth of 2.0 µm, corresponding to a figure of merit (FOM) of 11.8 RIU⁻¹ and a quality factor (Q-factor) of 86. These results demonstrate that integrating a hexagonal-edge resonant structure with a controlled dielectric etching process offers an effective route to achieving ultra-high sensitivity in THz metamaterial absorbers for diverse sensing applications.
{"title":"Advancements in terahertz metamaterial absorber sensor design: Dielectric-etched hexagonal architectures for enhanced biochemical sensing","authors":"Patharakorn Rattanawan, Asmar Sathukarn, Nutthamon Limsuwan, Khwanchai Tantiwanichapan","doi":"10.1016/j.ijleo.2025.172637","DOIUrl":"10.1016/j.ijleo.2025.172637","url":null,"abstract":"<div><div>This study presents a terahertz (THz) metal–insulator–metal (MIM) metamaterial absorber designed for high-sensitivity biochemical sensing through two sequential design mechanisms. The first mechanism establishes a periodic hexagonal resonant structure—consisting of a solid hexagon and a hexagonal shape formed by rectangular metal bars—that creates a hexagonal-edge unit cell capable of strong field confinement and enhanced sensitivity compared with conventional geometries. Building on this primary structure, the second mechanism introduces a targeted etching process applied to the dielectric layer. Straight and sloped etching profiles are used to progressively expose the resonant surfaces, thereby increasing the direct interaction between the electromagnetic fields and the surrounding analyte. With this combined structural and processing approach, the hexagonal bar pattern achieves ultra-high sensitivity, increasing from 72 to 378 GHz/RIU at a straight dielectric-layer etch depth of 2.0 µm, corresponding to a figure of merit (FOM) of 11.8 RIU⁻¹ and a quality factor (Q-factor) of 86. These results demonstrate that integrating a hexagonal-edge resonant structure with a controlled dielectric etching process offers an effective route to achieving ultra-high sensitivity in THz metamaterial absorbers for diverse sensing applications.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"345 ","pages":"Article 172637"},"PeriodicalIF":3.1,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145733039","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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