Results in Optics最新文献

{"title":"Designing scalable single-mode to seven-mode plasmonic filters utilizing disk and ring-shaped resonators","authors":"Saeed Javid,&nbsp;Farzad Tavakkol Hamedani,&nbsp;Pejman Rezaei,&nbsp;Shiva Khani","doi":"10.1016/j.rio.2025.100919","DOIUrl":"10.1016/j.rio.2025.100919","url":null,"abstract":"<div><div>In this paper, seven surface plasmon-based filters using a single disk resonator (DR) and a DR coupled with one to six ring-shaped resonators (RSRs) are proposed. In these configurations, the resonators are bidirectionally connected to a pair of metal–insulator-metal (MIM) waveguides. The initial filter structure, consisting of only a single DR, functions as a single-mode band-pass filter. By coupling a disk resonator with a ring-shaped resonator (RSR), a dual-mode filter is created. Following this pattern, each additional RSR introduce another mode to the transmission spectrum. Essentially, the innovative method detailed in this work allows for the creation of plasmonic filters capable of operating with one through seven distinct modes. By utilizing a consistent topology, the results for various structural geometries with different numbers of RSRs are achieved, showcasing true scalability. Moreover, the quality factor (Q-factor) of the resulting modes is enhanced by increasing the quantity of RSRs. Consequently, these filters detailed in this study are suitable as foundational designs for optical sensors that require varying levels of sensitivity. The insulator material employed is air, while silver, whose properties are described by the Drude model, is used as the metal. Every result was generated through the finite-difference time-domain method, a technique known for its numerical stability and minimal dispersion error. Due to the remarkable features such as single and multi-mode filtering, tunable resonant frequency, and variable Q-factor, the filter topologies proposed here can find applications in more complex designs, including optical sensors, demultiplexers, splitters, couplers, and so on.</div></div>","PeriodicalId":21151,"journal":{"name":"Results in Optics","volume":"21 ","pages":"Article 100919"},"PeriodicalIF":3.0,"publicationDate":"2025-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145323977","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A symmetric dual-ring cross stub based dual-band THz metamaterial absorber design for permittivity sensing applications","authors":"Ahmed Alqurashi ,&nbsp;Sayeeda Khanam ,&nbsp;Esam Y.O. Zafar ,&nbsp;Ahmed J.A. Al-Gburi","doi":"10.1016/j.rio.2025.100917","DOIUrl":"10.1016/j.rio.2025.100917","url":null,"abstract":"<div><div>This paper presents a novel dual-band terahertz (THz) metamaterial absorber based on a symmetric dual-ring cross-stub (SDR-CS) resonator, designed for high-sensitivity permittivity sensing. The absorber, composed of aluminum resonators and a polyamide substrate, features a compact unit cell of 80 × 80 μm with rotational symmetry. It exhibits two strong absorption peaks at 1.26 THz and 2.29 THz with near-unity absorption. Detailed electromagnetic simulations reveal the physical mechanisms underpinning the dual-band response and confirm polarization insensitivity and angular stability up to 60° incidence under TE and TM polarizations. Crucially, the device demonstrates excellent sensing performance for refractive indices in the range 1.0–3.162, achieving sensitivities of 0.148 THz/RIU (148 GHz/RIU) and 0.28 THz/RIU (280 GHz/RIU) at the lower and higher resonance frequencies, respectively. The quality factors (Q) are 32.3 and 39.3, resulting in figure-of-merits (FOM) of 39.3 and 32.3 RIU–1, outperforming many reported metamaterial sensors with larger sizes or more complex materials. These attributes underscore the absorber’s potential as a compact, efficient, and highly sensitive platform for THz permittivity sensing with applications in biomedical diagnostics, chemical identification, and environmental monitoring.</div></div>","PeriodicalId":21151,"journal":{"name":"Results in Optics","volume":"21 ","pages":"Article 100917"},"PeriodicalIF":3.0,"publicationDate":"2025-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145360991","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Wideband 1 × 2 tree-shaped fractal antenna array with gain enhancement and sidelobe level reduction for sub-6 GHz 5G applications","authors":"Rania Hamdy Elabd ,&nbsp;Ahmed J.A. Al-Gburi ,&nbsp;Amany A. Megahed","doi":"10.1016/j.rio.2025.100918","DOIUrl":"10.1016/j.rio.2025.100918","url":null,"abstract":"<div><div>This research presents a wideband (WB) 1 × 2 tree-shaped fractal antenna (TFA) array designed for sub-6 GHz 5G applications, featuring sidelobe level (SLL) reduction and gain enhancement. The array consists of two linearly arranged TFAs combined with a Wilkinson power divider (WPD) using a single-feed configuration. The WPD is selected due to its wide bandwidth, strong suppression factor, compact size, simple structure, excellent port isolation, and low insertion loss. A single TFA element, fabricated on a Rogers RT5880 substrate with a relative permittivity of 2.2 and a thickness of 1.57 mm, has dimensions of 38.5 × 49.5 mm². It operates from 2.2 GHz to beyond 5 GHz, achieving a gain of 2.2–4.5 dBi. The proposed 1 × 2 array layout measures 76.5 × 81.36 mm² and employs defected ground structure (DGS) and stub-loading techniques to suppress SLL and enhance gain. The array achieves a reflection coefficient better than –25 dB and an SLL of –13.2 dB. At the resonance frequency of 3.5 GHz, the gain improves significantly, rising from 3.2 dBi (single element) to 7.5 dBi (array). Simulated and experimental results confirm excellent agreement, validating the effectiveness of the proposed design.</div></div>","PeriodicalId":21151,"journal":{"name":"Results in Optics","volume":"21 ","pages":"Article 100918"},"PeriodicalIF":3.0,"publicationDate":"2025-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145360992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Field of view extension in Mueller matrix microscopy for whole-slide imaging of biological samples","authors":"Roman Demczylo ,&nbsp;Diego Silva ,&nbsp;Federico Lecumberry ,&nbsp;Ariel Fernández","doi":"10.1016/j.rio.2025.100916","DOIUrl":"10.1016/j.rio.2025.100916","url":null,"abstract":"<div><div>Quantitative measures of the interaction of polarized light with tissue have been established as a powerful tool for biomedical diagnosis in recent years. In this regard, we implemented a microscopy setup that incorporates a polarized sensor in the imaging plane to obtain Stokes parameters corresponding to a given Field of View (FoV) of a tissue sample. By illuminating with linearly independent States of Polarization in the input, Mueller matrix elements can also be retrieved from the same FoV of the sample. In order to achieve whole-slide imaging the FoV can be extended by stitching multiple images taken after XY displacement. We propose introducing polarimetric features, specifically the Mueller matrix norm for each pixel, into the stitching algorithm. This allows for FoV extension with minimal overlap between neighboring images, substantially reducing the total number of images required for the entire sample. This approach can significantly reduce acquisition time and data storage requirements for whole-slide MM imaging. Validation results for the retrieval of whole-slide MM of tissue samples show <span><math><mrow><mtext>SSIM</mtext><mo>=</mo><mn>0</mn><mo>.</mo><mn>93</mn><mo>±</mo><mn>0</mn><mo>.</mo><mn>04</mn></mrow></math></span> and 100% stitching success from images with overlapping as low as 35%.</div></div>","PeriodicalId":21151,"journal":{"name":"Results in Optics","volume":"21 ","pages":"Article 100916"},"PeriodicalIF":3.0,"publicationDate":"2025-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145324633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multimodal characterization of horsetail-derived carbon quantum dots: from nanostructure to nonlinear optical behavior","authors":"Zahra Khajavi ,&nbsp;Behnam Mahdavi ,&nbsp;Ehsan Koushki ,&nbsp;Esmail Rezaei-Seresht","doi":"10.1016/j.rio.2025.100913","DOIUrl":"10.1016/j.rio.2025.100913","url":null,"abstract":"<div><div>Carbon quantum dots (CQDs) have attracted significant attention due to their potential in various industrial applications. Extensive research has been dedicated to uncovering the complex and enigmatic nature of CQDs from a physicochemical perspective. In the present study, CQDs were synthesized from horsetail plant extract using the hydrothermal method. Iron and cobalt were then loaded onto the CQDs to investigate their adsorption potential. Transmission electron microscopy (TEM), Dynamic Light Scattering (DLS), Fourier transform infrared (FT-IR), ultraviolet–visible (UV–Vis), photoluminescence (PL) spectroscopy, and Z-scan aperture were used to investigate the physical, chemical, and structural properties of the synthesized CQDs. The results revealed changes in the FT-IR spectra of CQDs compared to the metals loaded CQDs. TEM imaging showed that the CQDs had an average size of 5.27 nm. Furthermore, reversed saturation absorption (RSA) and dense diffraction rings patterns were observed in Z-scan experiments, indicating a high nonlinear optical response of CQDs.</div></div>","PeriodicalId":21151,"journal":{"name":"Results in Optics","volume":"21 ","pages":"Article 100913"},"PeriodicalIF":3.0,"publicationDate":"2025-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145324663","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A comparative study of conventional spectroscopic techniques versus a miniaturized lab-on-a-chip platform for captopril analysis","authors":"Basma Saadi Talib ,&nbsp;Mohammad K. Hammood ,&nbsp;Rawaa A. Faris","doi":"10.1016/j.rio.2025.100915","DOIUrl":"10.1016/j.rio.2025.100915","url":null,"abstract":"<div><div>Microfluidic devices have special benefits for developing effective drug tests and screening. The microfluidic platforms may provide a less expensive and faster alternative. Fluid-containing devices are quite large on a micrometer scale. Drug assay levels are modest (milliliters to femtoliters) as a result of this strict constraint. In this study, a carbon dioxide (CO₂) laser machine was used to build a microfluidic chip with micro-channels carved on substrate materials made of acrylic (polymethyl methacrylate, or PMMA). The breadth, depth, and roughness of the chip are influenced by the CO₂ parameters. Low roughness and a regular channel surface are achieved by using the laser power (60 W).permits us to obtain microchannels with a minimum diameter of 450 µm and a depth of 89.4 µm at a scanning speed of 250 m/s. The channels’ depth was 89.4 µm, and their surface roughness was measured with high precision and good surface quality using the Arithmetic Average Roughness Ra = 2.3 (Relative roughness, ̐ = 5 %). To detect extremely low levels of captopril, the drug signal was enhanced using functionalized multi-walled carbon nanotubes (F-MWCNTs). In this study, laser microfluidic sensors outperform the conventional method (UV–VIS) spectrophotometer in terms of captopril detection accuracy. The linear range of the microfluidic sensors is 1–20 ppm, whereas the linear range of the UV–VIS spectrophotometer is 10–90 ppm. The LOD is 1.3 and 0.1, respectively.</div></div>","PeriodicalId":21151,"journal":{"name":"Results in Optics","volume":"21 ","pages":"Article 100915"},"PeriodicalIF":3.0,"publicationDate":"2025-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145324632","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analyses of the dust influence on individual efficiencies of the silicon PV module in Sudano-Sahelian conditions","authors":"Adama Ouedraogo ,&nbsp;Pègdwendé Yves Ouedraogo ,&nbsp;Bruno Korgo ,&nbsp;Ousmane Aly Yabyouré Ouedraogo ,&nbsp;Thierry Sikoudouin Maurice Ky ,&nbsp;Dieudonné Joseph Bathiebo ,&nbsp;Sie Kam","doi":"10.1016/j.rio.2025.100906","DOIUrl":"10.1016/j.rio.2025.100906","url":null,"abstract":"<div><div>The evaluation of degradation caused by dust accumulation on photovoltaic (PV) systems is critical to ensuring optimal energy exploitation in the Sahel region. This study investigates the impact of dust accumulation on the performance of monocrystalline silicon PV modules under a Sudano-Sahelian climate, with a particular emphasis on the physical properties of the dust. Results indicate a significant decrease in extractable electrical power with increasing dust levels, primarily due to a reduction in the fill factor (<span><math><mrow><mi>F</mi><mi>F</mi></mrow></math></span>). This decline stems from the shadowing effect of dust particles that partially block incident solar radiation, thereby reducing the effective illumination of the cell surface. While dust has little effect on light absorption and only marginally affects carrier thermalization, it significantly influences the electrical characteristics by increasing the series resistance-particularly when conductive organic matter is present. Dust samples collected from the site were classified as silt loam, with particle sizes ranging between <span><math><mrow><mn>2</mn><mspace></mspace><mi>μ</mi><mi>m</mi></mrow></math></span> and <span><math><mrow><mn>20</mn><mspace></mspace><mi>μ</mi><mi>m</mi></mrow></math></span>(USDA classification). These sizes, being comparable to the wavelengths of visible light (<span><math><mrow><mn>0</mn><mo>.</mo><mn>4</mn><mspace></mspace><mi>μ</mi><mi>m</mi></mrow></math></span>–<span><math><mrow><mn>0</mn><mo>.</mo><mn>7</mn><mspace></mspace><mi>μ</mi><mi>m</mi></mrow></math></span>), promote scattering and contribute to optical losses. The average dust deposition rate was 39.683 g m<span><math><msup><mrow></mrow><mrow><mo>−</mo><mn>2</mn></mrow></msup></math></span> day<span><math><msup><mrow></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></math></span>, highlighting the need for appropriate mitigation strategies. Maintenance protocols combining periodic blowing and water cleaning can reduce water usage and lower overall maintenance costs.</div></div>","PeriodicalId":21151,"journal":{"name":"Results in Optics","volume":"21 ","pages":"Article 100906"},"PeriodicalIF":3.0,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145324300","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Micropatterning of high-speed steel surface with femtosecond lasers: a comprehensive study on laser parameter effects","authors":"Máté Sepsi,&nbsp;Zsolt Könyves,&nbsp;Dániel Koncz-Horváth,&nbsp;Valéria Mertinger","doi":"10.1016/j.rio.2025.100914","DOIUrl":"10.1016/j.rio.2025.100914","url":null,"abstract":"<div><div>Laser surface processing provides several benefits in engineering applications, such as non-contact operation, absence of tool wear, and rapid processing speed. Ultra-short pulse lasers enable the modification of surface patterns across a broad spectrum, from nanometres to micrometres, without inducing surface burn-in or heat-affected zones. This benefits various applications, including adhesion issues, wetting, and alterations in lubrication conditions, in ways unattainable through traditional machining techniques. Altering the laser parameters significantly modifies the laser-material interaction, leading to variations in the geometric attributes of the surface pattern. This benefit simultaneously constitutes a drawback of the method, as there are no pre-existing formulas for generating specific surface patterns. We employed a femtosecond laser to fabricate line geometries measuring several tens of micrometres on the surface of high-speed steel. The effect of laser power, frequency, energy, and scanning repetition and the influence of the geometric relationships of the resultant patterns are investigated. A collection of parameters appropriate for generating intricate surface patterns is also provided, contributing to surface machining without cracking, remelting, or extensive heat-affected zones.</div></div>","PeriodicalId":21151,"journal":{"name":"Results in Optics","volume":"21 ","pages":"Article 100914"},"PeriodicalIF":3.0,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145324665","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bipartite mechanical systems of a laser-driven optomechanical cavity","authors":"Edris Salih,&nbsp;Misrak Getahun","doi":"10.1016/j.rio.2025.100909","DOIUrl":"10.1016/j.rio.2025.100909","url":null,"abstract":"<div><div>We investigate the correlation of mechanical systems of nondegenerate three-level laser with parametric oscillator in optomechanical cavity coupled to a two-mode squeezed vacuum reservoir. The quantum properties of the mechanical systems as a result of the correlation have been analyzed using the expectation values of mechanical mode variables at steady state and the eigenvalues of the reduced covariance matrix of the two sub-mechanical systems. The logarithmic negativity, steerability, and quantum discord criterion for entanglement, steerability, and quantum discord, respectively confirm that bipartite sub-mechanical systems are correlated. The results show that the bipartite sub-mechanical systems exhibit entanglement two-way steering and non-classical correlation or quantum discord. Moreover, the sub-mechanical system exhibits squeezing in the minus quadrature or momentum. The correlation properties of sub-mechanical systems are depend on the reservoir but the cavity laser has no effect on the quantum correlation of the sub-mechanical systems.</div></div>","PeriodicalId":21151,"journal":{"name":"Results in Optics","volume":"21 ","pages":"Article 100909"},"PeriodicalIF":3.0,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145324666","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gain spectrum engineering for temperature-insensitive 980 nm VCSEL performance using heterogeneous quantum wells","authors":"Wei Miao ,&nbsp;Hui Li ,&nbsp;Jian Feng ,&nbsp;Cai Liu ,&nbsp;Gaomin Li ,&nbsp;Haoxin Yan ,&nbsp;Tiejun Huang ,&nbsp;Shupeng Deng ,&nbsp;Chuyu Zhong ,&nbsp;Shihao Ding ,&nbsp;Jinglong Lu ,&nbsp;Nannan Li","doi":"10.1016/j.rio.2025.100912","DOIUrl":"10.1016/j.rio.2025.100912","url":null,"abstract":"<div><div>Lasers with stable temperature-dependent performance are increasingly demanded in high-speed optical interconnects. We present a temperature stable 980-nm wavelength vertical-cavity surface-emitting lasers featuring an asymmetric quantum wells active region engineered. This design broadened the gain spectrum and significantly reduced the temperature sensitivity of the modulation bandwidth under constant bias current. Through comprehensive simulations and experimental analysis, we demonstrated that the proposed asymmetric quantum well structures outperformed conventional symmetric quantum well structure across the range of 298 K – 358 K. Key improvements included a 41.75 % reduction in threshold current variation rate over the range of 298 K <strong>–</strong> 358 K, alongside decreases in modulation bandwidth variation of 53.98 %, 62.47 %, and 55.18 % at bias currents of 3 mA, 4 mA, and 5 mA respectively. Experimentally, by photoluminescence measurements, heterogenous quantum well structures demonstrated significant spectrum broadening and multi-wavelength photon emission at both room temperature and low temperatures (1.7 K <strong>–</strong> 150 K). This design is particularly suitable for data centers and 5G networks, where thermal stability is critical.</div></div>","PeriodicalId":21151,"journal":{"name":"Results in Optics","volume":"21 ","pages":"Article 100912"},"PeriodicalIF":3.0,"publicationDate":"2025-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145265258","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}