Optik最新文献

{"title":"MoS2 and TiN surface plasmon polaritons: A new frontier for PIN photodetector design, compared to gold and silver, and their temperature response","authors":"Hagar Marouf ,&nbsp;Nariman Abdel-Salam ,&nbsp;El-Sayed M. El-Rabaie ,&nbsp;Ahmed Nabih Zaki Rashed ,&nbsp;Khalil M. ElKhamisy","doi":"10.1016/j.ijleo.2026.172687","DOIUrl":"10.1016/j.ijleo.2026.172687","url":null,"abstract":"<div><div>This paper examines the spectral performance of Surface Plasmon Polariton (SPP)-enhanced photodetector arrays based on Germanium (Ge), Silicon (Si), Indium Phosphide (InP), and Gallium Arsenide (GaAs) substrates. The performance of devices using gold (Au) and silver (Ag) as reference plasmonic materials is systematically compared with proposed alternatives, including molybdenum disulfide (MoS₂) and titanium nitride (TiN). Across all semiconductor platforms, Au-based SPP arrays demonstrated significantly better performance in both peak current density and responsivity than their Ag, MoS₂, and TiN counterparts, often by factors of 1.5 to over 2. The proposed materials generally showed silver as the next highest performer, followed by MoS₂ and TiN. While alternative plasmonic materials, such as MoS₂ and TiN, may offer benefits like lower cost or easier integration compared to silver, the absolute current generation and responsivity are notably lower than those of silver in the studied configurations. The highest performance was observed in the Ge-pin photodetector, which achieved 25 mA/cm² with gold, compared to 13 mA/cm² with silver, 12.5 mA/cm² with MoS₂, and 12 mA/cm² with TiN. Its peak responsivity reaches approximately 250 A/W with gold, 130 A/W with silver, 125 A/W with MoS₂, and 115 A/W with TiN. Results showed that Ge outperformed all other tested photodetectors, while the Silver SPP performed similarly to MoS₂ and TiN. Our study explores the effect of temperature on our proposed materials and SPPs. The findings demonstrate that higher temperatures negatively impact the efficiency of these plasmonic devices, likely due to increased carrier scattering and reduced semiconductor performance.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"348 ","pages":"Article 172687"},"PeriodicalIF":3.1,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146190270","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}

{"title":"Photonic generation of dual-band dual-chirp microwave signal with quadrupled frequency based on sideband-selective modulation","authors":"Xie Siwei,&nbsp;Yuan Jin,&nbsp;Cui Jinyi,&nbsp;Liu Jinbo,&nbsp;Li Zengrui","doi":"10.1016/j.ijleo.2026.172688","DOIUrl":"10.1016/j.ijleo.2026.172688","url":null,"abstract":"<div><div>A photonic architecture for generating dual-band dual-chirp microwave waveforms is proposed and demonstrated, leveraging non-reciprocity in a Sagnac loop configuration for sideband-selective modulation. In the first stage, two parallel dual-parallel Mach-Zehnder modulators (DP-MZMs), driven by independent RF signals, produce optical sidebands that are subsequently separated and polarized orthogonally. The optical signal processed in the first stage is injected into the Sagnac loop, where it undergoes selective secondary modulation via an embedded dual-electrode Mach-Zehnder modulator (MZM). Finally, the multiplexed output is subjected to polarization conditioning and detected by a balanced photodetector (BPD), generating a dual-band dual-chirp microwave waveform centered at 32 GHz and 50 GHz (quadruple the frequency of the driven signal) with a bandwidth of 4 GHz and a 1 <em>μs</em> duration. Moreover, the proposed architecture offers reconfigurability, facilitating the generation of not only dual-band dual-chirp signals but also single-band dual-chirp and quad-band chirp signals through flexible parameter tuning.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"348 ","pages":"Article 172688"},"PeriodicalIF":3.1,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146190268","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}

{"title":"Numerical analysis of structured illumination microscopy: Influence of illumination pattern geometry and fringe thickness on resolution enhancement","authors":"Ferhat Hanife ,&nbsp;Yashar Azizian-Kalandaragh","doi":"10.1016/j.ijleo.2026.172672","DOIUrl":"10.1016/j.ijleo.2026.172672","url":null,"abstract":"<div><div>Structured illumination microscopy (SIM) enables optical imaging beyond the diffraction limit by heterodyning high spatial frequencies into the observable passband of a conventional microscope. In this work, a complete numerical framework is developed to investigate how illumination pattern geometry and structural parameters influence image formation and resolution enhancement in two-dimensional SIM. Synthetic samples representing periodic arrays of polymer nanotubes are modeled under multiple illumination families, including sinusoidal, Ronchi, sawtooth, and triangular configurations. Each simulation incorporates realistic photon shot noise, detector readout noise, and the optical transfer function (OTF) of a high-numerical-aperture system. Quantitative metrics such as full width at half maximum (FWHM), intensity dip metric, modulation contrast, edge sharpness, contrast-to-noise ratio (CNR), and high-frequency spectral energy are extracted to evaluate performance as a function of fringe thickness. The results demonstrate that structured illumination significantly narrows the effective point-spread function (PSF), enhances image contrast, and recovers otherwise inaccessible high-frequency details. Non-sinusoidal patterns yield improved resolution due to their richer harmonic content, though with minor side-lobe artifacts. Generally, the proposed simulation framework provides both physical insight and practical guidance for optimizing illumination design and achieving higher fidelity in super-resolution SIM imaging.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"348 ","pages":"Article 172672"},"PeriodicalIF":3.1,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146006823","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}

{"title":"Design and experimental validation of a 1 Gbps VLC transmitter with standard illumination-grade LEDs","authors":"Rania A. Elsayed ,&nbsp;Youssef A. Diab ,&nbsp;Khalid.F.A. Hussein ,&nbsp;Asmaa E. Farahat ,&nbsp;Azhar A. Hamdi","doi":"10.1016/j.ijleo.2026.172689","DOIUrl":"10.1016/j.ijleo.2026.172689","url":null,"abstract":"<div><div>This paper presents the design, implementation, and experimental validation of a high-speed visible light communication (VLC) transmitter based entirely on cost-effective, commercially available components. The main objective is to demonstrate gigabit-class data transmission using standard white LEDs originally intended for general illumination, while simultaneously maintaining practical indoor lighting conditions. To achieve this, a custom high-speed LED driver is developed, featuring a closed-loop proportional–derivative (PD) control architecture that enables precise and dynamic regulation of the LED forward current. This ensures accurate reproduction of high-frequency electrical transitions, minimizes waveform distortion, overshoot, and intersymbol interference, and enables sub-nanosecond rise and fall times. On–Off Keying (OOK) modulation is used for data transmission, while the feedback control maintains stable luminance for consistent indoor illumination. Experimental validation demonstrates reliable operation at 0.5 Gbps and 1 Gbps within a 1m-radius indoor cell, achieving average bit error rates of <span><math><mrow><mn>1</mn><mspace></mspace><mo>×</mo><mn>10</mn><mi>⁻</mi><mi>⁶</mi></mrow></math></span> and <span><math><mrow><mn>1.6</mn><mo>×</mo><mn>10</mn><mi>⁻</mi><mi>⁴</mi></mrow></math></span>, respectively. In addition, the measured end-to-end frequency response of the system, including the driver, LED array, optical channel, and photodetector, indicates a −3 dB bandwidth of approximately 300 MHz, supporting the observed gigabit-class performance. These results confirm that standard illumination-grade LEDs, when combined with a carefully designed high-speed driver, can provide both high-speed optical communication and practical indoor lighting. Overall, the proposed system offers a scalable and feasible solution for integrating VLC into standard lighting infrastructure. It achieves a unique balance between high-speed data transmission and real-world illumination requirements, demonstrating the practicality of gigabit-class VLC using commercially available components for indoor applications.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"348 ","pages":"Article 172689"},"PeriodicalIF":3.1,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146189937","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}

{"title":"Geographic Information System-based road network accessibility modeling using heuristic assisted adaptive temporal convolution network","authors":"Kannadasan B ,&nbsp;Yogeswari K","doi":"10.1016/j.ijleo.2026.172683","DOIUrl":"10.1016/j.ijleo.2026.172683","url":null,"abstract":"<div><div>Due to the rapid development of the country's economy, the utilization of the road network has greatly increased. It improves the facility of accessing educational, health centers, markets, and other essential places. Multiple models are introduced for calculating the accessibility of the road network. However, traditional frameworks struggle to capture dynamic temporal shifts and fail to align selection outcomes with complex, real-world structures. To address these limitations, this work develops a deep learning-based road network accessibility framework to analyze the road network structure to provide sustainable transportation. At first, the required data is gathered from the online resources and subjected to the feature extraction phase. Here, the Aggregate Transportation Score (ATS), Mean Fractal Dimension (MFD), Mean Road Network Density (MRND), and Mean Weighted Accessibility Index (MWAI) features are derived using “connectivity, accessibility, spatial pattern, and network development.” Then, these features are fused and transferred to the detection phase. Here, the road network accessibility modeling is executed using the Adaptive Temporal Convolution Network (ATCN). The modeling performance of the ATCN is enhanced by tuning its parameter using the Random Revised Student Psychology Optimization (RRSPO). Finally, the proposed approach offers an accurate outcome. The experimentation is evaluated to confirm the designed approach’s efficacy. The developed framework achieved MEP of 3.7, and RMSE of 13.77. Thus, the result showed the recommended model had better transportation planning than other models.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"348 ","pages":"Article 172683"},"PeriodicalIF":3.1,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146190269","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}

{"title":"A self-calibrating registration system for arbitrary-view 3D scanning","authors":"Kelei Wang ,&nbsp;Junpeng Xue ,&nbsp;Shuai Ma ,&nbsp;Hongyang Chen ,&nbsp;Ran Jia ,&nbsp;Ziji Chen","doi":"10.1016/j.ijleo.2026.172679","DOIUrl":"10.1016/j.ijleo.2026.172679","url":null,"abstract":"<div><div>Three-dimensional (3D) measurement technology has been widely applied across various industries, yet the challenge of registering multi-view point clouds into a unified coordinate system persists. In this paper, we propose and mathematically derive a flexible calibration model for an arbitrary-view registration system, which consists of a real Binocular Structured Light Measurement (BSIE) unit and a turntable. When the turntable rotates, one real and multi-virtual measurement units are distributed along a spatial circle. The proposed method first constructs a model describing the positional relationship between the real and virtual units relative to the turntable, with the model parameters calibrated using a single 2D calibration target. Secondly, the data of point clouds of the object surface in different views are measured by BSIE units. After that, the set of point clouds is aligned into the global coordinate system utilizing the calibrated model parameters. So far, the point cloud registration is completed for regular objects with limited texture information. For complex surfaces, ICP is applied as a post-processing step to refine results enabled by accurate calibration. Furthermore, when the positional relationship of the system changes, the calibration parameters will no longer be applicable. In order to improve the convenience of the algorithm, some marker points are set on the turntable to realize the automatic calibration. Experimental results on two objects with regular and complex shapes demonstrate that the proposed method is convenient, fast, and easy to calibrate, with a registration error of less than 0.08 mm.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"348 ","pages":"Article 172679"},"PeriodicalIF":3.1,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146080612","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}

{"title":"Iron phthalocyanine-based saturable absorber for dual-wavelength passive Q-switching in a thulium-doped fiber laser","authors":"Yu Chen ,&nbsp;Zian Cheak Tiu ,&nbsp;Zhan Hong Lip ,&nbsp;Sin Jin Tan ,&nbsp;Xiau San Cheng ,&nbsp;Masruroh ,&nbsp;Sulaiman Wadi Harun","doi":"10.1016/j.ijleo.2026.172686","DOIUrl":"10.1016/j.ijleo.2026.172686","url":null,"abstract":"<div><div>This paper reports on dual-wavelength Q-switched operations in a thulium-doped fiber laser (TDFL) using a saturable absorber (SA) based on iron phthalocyanine (FePc). The SA was fabricated by embedding FePc into a water-soluble polyvinyl alcohol (PVA) polymer matrix at two different concentrations. The performance of these FePc-based SAs in Q-switching operations was evaluated and compared across the spectral, temporal, and frequency domains. The SA with 3.5 mg FePc concentration achieved a maximum repetition rate of 65.47 kHz and a corresponding pulse width of 2.639 µs. The emission spectrum exhibited dual peaks at 1916.841 nm and 1927.097 nm. Notably, the lower FePc concentration results in a smaller non-saturable loss, which enables improved control over pulse formation and supports stable Q-switched operation over a wider pump-power range. In contrast, the higher FePc concentration yields a slightly higher effective modulation depth, reducing the Q-switching threshold pump power, but introduces greater cavity loss, thereby shifting the laser operation toward longer wavelengths where the optical gain is higher. These findings demonstrate that FePc is a promising SA material for generating dual-wavelength laser pulses in the 2 µm region, opening up broad application potential in pulsed laser systems.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"348 ","pages":"Article 172686"},"PeriodicalIF":3.1,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146189939","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}

{"title":"Polymer whispering gallery mode sensor for simultaneous measurements of temperature and refractive index","authors":"Huda Zain ,&nbsp;Khurram Qureshi","doi":"10.1016/j.ijleo.2026.172684","DOIUrl":"10.1016/j.ijleo.2026.172684","url":null,"abstract":"<div><div>This work presents a Polymethyl Methacrylate (PMMA) whispering gallery mode (WGM) resonator for simultaneous measurements of refractive index and temperature. A single PMMA resonator coupled with a silica waveguide was used to build the sensor and offered multimodal WGM resonance. The coupling gaps and coupling states for the resonator’s modes, along with their minimum transmission/extinction ratios (ER), were investigated. Heatmap barcodes combined with cross-correlation analysis provided insights into the sensor’s performance for single measurands. Lastly, the sensor was analyzed as a dual-analyte sensor. The refractive index sensitivity reached 86 nm/RIU and 60 nm/RIU for the two modes. The temperature responses were 0.131 nm/<span><math><msup><mspace></mspace><mrow><mo>∘</mo></mrow></msup></math></span>C and 0.122 nm/<span><math><msup><mspace></mspace><mrow><mo>∘</mo></mrow></msup></math></span>C. The characteristic matrix demonstrates the sensor’s potential for simultaneous temperature and refractive index sensing.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"348 ","pages":"Article 172684"},"PeriodicalIF":3.1,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146190247","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}

{"title":"Three-dimensional nondiffracting Weber beams","authors":"ZhengPing Yang ,&nbsp;Wei-Ping Zhong ,&nbsp;Milivoj Belić ,&nbsp;WenYe Zhong","doi":"10.1016/j.ijleo.2026.172678","DOIUrl":"10.1016/j.ijleo.2026.172678","url":null,"abstract":"<div><div>Controlling the shape of higher-dimensional nondiffracting beams is one of the important research topics in current beam propagation theory and engineering practice. This article investigates the three-dimensional Helmholtz equation and derives its exact beam solution, which incorporates Weber functions and a single control parameter. Building upon the nondiffracting beam solution obtained, we analyze the excited states of Weber beams for different values of the control parameter, including the fundamental state, the first excited state, and even- and odd-order Weber beams. Our findings reveal that the fundamental state of Weber beams exhibits a pancake-like shape, while the first excited state forms a tube-like shape. Odd-order beams display toroidal shapes, whereas even-order beams combine toroidal and ellipsoidal shapes. Typically, the toroidal structures exhibit vortex-type energy distributions, with higher intensities appearing at the edges of tubes, while the ellipsoidal structures display Gaussian-type energy distributions, with higher energies concentrated at the center of pancake-like regions. The method proposed in this study for constructing higher-dimensional exact solutions of the Helmholtz equation using a novel coordinate transformation can be extended to other higher-dimensional models.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"348 ","pages":"Article 172678"},"PeriodicalIF":3.1,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146080610","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}

{"title":"Multifaceted encryption for secure and efficient image transmission: The ARTE approach","authors":"Poonam Yadav ,&nbsp;Hukum Singh ,&nbsp;Kavita Khanna","doi":"10.1016/j.ijleo.2026.172681","DOIUrl":"10.1016/j.ijleo.2026.172681","url":null,"abstract":"<div><div>Ensuring secure and effective image transmission is a significant task in the modern world. Images can be protected using encryption algorithms, but each algorithm has advantages and disadvantages of its own. To address this, we proposed the Advanced Real-Time Encryption (ARTE) system, which combines various encryption algorithms to strike a compromise between security and efficiency. The ARTE system includes a key vault that holds information on several masks and encryption methods, each of which has a unique key. Each input image is given a random algorithm from the key vault and randomly selected masks, which are then used to encrypt it. An identifier key is then attached to the encrypted image. The system identifies the encryption algorithm that was used to encrypt the image at the other end, gets the algorithm's specifics, and decrypts the image according to those specifications. The proposed system ups the encryption challenge by including more encryption methods to increase security. The suggested cryptosystem is challenging to crack and can withstand the majority of current attacks due to the real-time encryption algorithm's unpredictable encryption technique for each input image. This ARTE system key vault that holds details of various transforms and masks is developed using.NET, and all transforms and masks are developed in MATLAB (2019a). Our tests support the suggested advanced real-time encryption system's viability and effectiveness. This project's goal is to develop a more secure image encryption solution with acceptable computing complexity, as evidenced by performance measurements and outcomes.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"348 ","pages":"Article 172681"},"PeriodicalIF":3.1,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146189938","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}