Optik最新文献_第3页

Listening to ultrashort laser pulses to determine their characteristics 聆听超短激光脉冲以确定其特性

IF 3.1 3区物理与天体物理

Optik Pub Date : 2025-09-13 DOI: 10.1016/j.ijleo.2025.172528

How-Luen Hsin , Wei-Hong Haung , Xin-Yun Chang , Yen-Chen Ko , Hao-Keng Wei , Zai-Wen Chen , Chih-Wei Luo

{"title":"Listening to ultrashort laser pulses to determine their characteristics","authors":"How-Luen Hsin , Wei-Hong Haung , Xin-Yun Chang , Yen-Chen Ko , Hao-Keng Wei , Zai-Wen Chen , Chih-Wei Luo","doi":"10.1016/j.ijleo.2025.172528","DOIUrl":"10.1016/j.ijleo.2025.172528","url":null,"abstract":"<div><div>Since the physical principle behind Camera Obscura was first described by Mozi during the 5th century BC, stating in Mo Jing (墨經, is an ancient Chinese philosophical and scientific text attributed to the Mohist school): “Light rays travel straight, like arrows; when passing through a small hole, the lower part of an object projects an image upward, and the upper part projects an image downward.” (景光之人煦若射，下者之入也高，高者之入也下。), people believed that light could only be detected by “seeing.” However, this study breaks this philosophy for hundreds of years and demonstrates that light pulse profile can also be detected by “LISTENING.” Here, we use femtosecond laser pulses to generate air plasma and sound waves via the photoacoustic effect. A nonlinear crystal-free sound autocorrelation is developed to detect these acoustic signals. The autocorrelated sound (AS) signals are measured to determine the characteristics of ultrashort laser pulses and air plasma. Potential applications for this laser-induced sound autocorrelation include a method for ultrafast characterization of laser pulses and as a diagnostic technology to determine the dynamic interaction between plasma and electromagnetic (EM) waves.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"339 ","pages":"Article 172528"},"PeriodicalIF":3.1,"publicationDate":"2025-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145105673","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}

引用次数: 0

Secure image encryption using Rubik’s Cube-based scrambling with chaos-driven diffusion and circular shifts 使用基于混沌驱动扩散和圆移位的魔方置乱的安全图像加密

IF 3.1 3区物理与天体物理

Optik Pub Date : 2025-09-13 DOI: 10.1016/j.ijleo.2025.172533

S. Sharmila , R.S. Bhuvaneswaran , Dhandapani Vaithiyanathan

{"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":"2025-09-13","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}

引用次数: 0

Multilayer image authentication using deep search convolution for image integrity protection 基于深度搜索卷积的多层图像认证图像完整性保护

IF 3.1 3区物理与天体物理

Optik Pub Date : 2025-09-13 DOI: 10.1016/j.ijleo.2025.172534

Ferda Ernawan , Afrig Aminuddin , Agit Amrullah , Dhani Ariatmanto , Achraf Daoui

{"title":"Multilayer image authentication using deep search convolution for image integrity protection","authors":"Ferda Ernawan , Afrig Aminuddin , Agit Amrullah , Dhani Ariatmanto , Achraf Daoui","doi":"10.1016/j.ijleo.2025.172534","DOIUrl":"10.1016/j.ijleo.2025.172534","url":null,"abstract":"<div><div>A fragile image watermarking framework can be employed to ascertain any modifications that may have occurred within the image content. This manuscript introduces a deep search convolution for the localization of tampering, utilizing multiple layers of authentication alongside a chaotic map. The proposed approach generates three distinct metrics of scrambled bits through the application of a chaotic map. Each matrix corresponds in size to the cover color image. Subsequently, the watermark data is created using the parity of the seven most significant bits of the image, along with a scrambled bit, and then embedded into the least significant bit of each pixel. The findings illustrate that our scheme is capable of accurately identifying tampered regions in scenarios involving copy-move forgery, removal, additional text, noise, and collage attacks. The proposed scheme attained a remarkable tamper localization accuracy of approximately 0.9995, alongside an average computational time of about 6.5964 s, which is superior to or comparable with existing tamper detection algorithms. Furthermore, the proposed method yielded a PSNR of 51 dB and an SSIM of 0.9992.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"339 ","pages":"Article 172534"},"PeriodicalIF":3.1,"publicationDate":"2025-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145105669","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}

引用次数: 0

Propagation behavior of a modified anomalous vortex beam in fractional Fourier transform 分数阶傅里叶变换中修正反常涡旋光束的传播特性

IF 3.1 3区物理与天体物理

Optik Pub Date : 2025-09-10 DOI: 10.1016/j.ijleo.2025.172526

Faroq Saad , Halima Benzehoua , Salma Chib , Abdelmajid Belafhal

引用次数: 0

Graphene-based series-fed plasmonic antenna array optimised with metaheuristic algorithm for 6G THz communications 基于元启发式算法优化的石墨烯串联等离子体天线阵列用于6G 太赫兹通信

IF 3.1 3区物理与天体物理

Optik Pub Date : 2025-09-03 DOI: 10.1016/j.ijleo.2025.172514

Kalaiarasan K., Ramesh G. P.

{"title":"Graphene-based series-fed plasmonic antenna array optimised with metaheuristic algorithm for 6G THz communications","authors":"Kalaiarasan K., Ramesh G. P.","doi":"10.1016/j.ijleo.2025.172514","DOIUrl":"10.1016/j.ijleo.2025.172514","url":null,"abstract":"<div><div>This paper presents the modelling and optimisation of a compact series-fed plasmonic antenna array operating in the terahertz (THz) frequency range from 1 THz to 1.8 THz, suitable for 6 G communication applications. The proposed antenna is designed using graphene over a polyimide substrate, taking advantage of graphene’s tunable plasmonic properties and the substrate’s mechanical flexibility. The antenna elements are configured using a single resonator structure, comprising a rhombus-shaped resonator and an octagonal resonator, connected via a central cross dipole to ensure broadband impedance matching and stable radiation characteristics. Firefly Algorithm (FFA) is employed for optimisation, improving the antenna’s performance parameters. A series-fed configuration is adopted to achieve compact integration with directional gain. The design is extended to a two-element multiple-input multiple-output (MIMO) system for improved data throughput. The array occupies a physical size of 125 × 28 µm, corresponding to 0.417λ × 0.093λ at 1 THz, and achieves a fractional bandwidth of 55.5 %. The realized gain of the antenna is greater than 7.8 dBi and a total efficiency above 80 % across the entire operational band. Key MIMO performance indicators—envelope correlation coefficient (ECC), diversity gain (DG), total active reflection coefficient (TARC), and channel capacity loss (CCL)—are evaluated and presented, demonstrating strong isolation and diversity performance. Simulation results confirm that the optimized antenna array, using FFA, is a promising candidate for integration into compact THz front-end modules for 6 G communication systems.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"339 ","pages":"Article 172514"},"PeriodicalIF":3.1,"publicationDate":"2025-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144996216","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}

引用次数: 0

Designing enhanced two-terminal tandem photovoltaic devices with AgSb2(SxSe1−x)3 absorbers 利用AgSb2(SxSe1−x)3吸收剂设计增强型双端串联光伏器件

IF 3.1 3区物理与天体物理

Optik Pub Date : 2025-09-03 DOI: 10.1016/j.ijleo.2025.172515

Sanghyun Lee , Kent J. Price

{"title":"Designing enhanced two-terminal tandem photovoltaic devices with AgSb2(SxSe1−x)3 absorbers","authors":"Sanghyun Lee , Kent J. Price","doi":"10.1016/j.ijleo.2025.172515","DOIUrl":"10.1016/j.ijleo.2025.172515","url":null,"abstract":"<div><div>Integrating silver (Ag) into antimony sulfide selenide Sb(S<sub><em>x</em></sub>Se<sub>1<em>−x</em></sub>)<sub>3</sub> thin films has recently highlighted their potential as efficient light-absorbing layers in thin-film solar cells. In this work, we have designed and analyzed two-terminal monolithic tandem solar cells with AgSb(S<sub>x</sub>Se<sub>1−x</sub>)<sub>3</sub> and Sb<sub>2</sub>S<sub>3</sub>. The novel tandem device is configured with a AgSb(S<sub>x</sub>Se<sub>1−x</sub>)<sub>3</sub> bottom subcell with and a top subcell with a Sb<sub>2</sub>Se<sub>3</sub> photovoltaic device with different bandgaps, enabling the selective absorption of targeted photon energy. The upper absorber layer's thickness is carefully calibrated according to the sulfur concentration optimized at x<sub><em>sulfur</em></sub> = 0.2 of the AgSb(S<sub>x</sub>Se<sub>1−x</sub>)<sub>3</sub> layer to enhance the performance. The bandgap energies for the AgSb(S<sub>0<em>.</em>2</sub>Se<sub>0<em>.</em>8</sub>)<sub>3</sub> bottom and the Sb<sub>2</sub>Se<sub>3</sub> top subcells are optimized at 1.19 eV and 1.7 eV, respectively. After employing spectral filtering and current matching methodologies, tandem devices demonstrate open-circuit voltage (Voc) of 1.63 V, short-circuit current density (Jsc) of 17.04 mA/cm<sup>2</sup>, and fill factor (FF) of 62.94 %. These tandem devices could be promising candidates for future photovoltaic devices. The power conversion efficiency is 17.48 %, which shows a promising candidate for high-performing tandem solar cells.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"338 ","pages":"Article 172515"},"PeriodicalIF":3.1,"publicationDate":"2025-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144988584","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}

引用次数: 0

A triband graphene-based linear array THz antenna for 6G IoT applications using Spotted Hyena Optimizer 一种基于石墨烯的三波段线性阵列太赫兹天线，用于6G物联网应用，使用斑点鬣狗优化器

IF 3.1 3区物理与天体物理

Optik Pub Date : 2025-08-26 DOI: 10.1016/j.ijleo.2025.172510

Sreekumar K.N. , Ranganathan G. , Lal Raja Singh R. , Bindhu V.

{"title":"A triband graphene-based linear array THz antenna for 6G IoT applications using Spotted Hyena Optimizer","authors":"Sreekumar K.N. , Ranganathan G. , Lal Raja Singh R. , Bindhu V.","doi":"10.1016/j.ijleo.2025.172510","DOIUrl":"10.1016/j.ijleo.2025.172510","url":null,"abstract":"<div><div>This study introduces a novel tri-band terahertz (THz) antenna array designed with graphene on a flexible, low-profile polyimide base, integrated with a SiO₂ layer. The antenna element comprises a hexagonal patch integrated with a cross slot and a cross loop resonator, enabling three distinct resonances at 0.252 THz (sub-THz), 0.493 THz (transition range), and 0.696 THz (THz regime). These bands are realised through geometrical evolution and strong inter-resonator coupling. The structure is optimised using the Spotted Hyena Optimizer (SHO) to achieve fractional bandwidths of 10.7 %, 8.3 %, and 8.05 %, respectively. The design is further extended into a two-element differential-fed array with an element spacing of 0.034λ at 0.252 THz, which ensures excellent isolation above 50 dB across all frequency bands. The proposed array achieves gains of 7.22 dBi, 11.106 dBi, and 11.06 dBi at the three operating bands with corresponding efficiencies of 85 %, 87 %, and 86 %, confirming its high-performance radiation capability. The estimated Multiple Input Multiple Output (MIMO) performance shows an Envelope Correlation Coefficient (ECC) below 0.01, apparent Diversity Gain (DG) close to 10 dB, and a low Total Active Reflection Coefficient (TARC), confirming high diversity performance. The antenna’s compact geometry, superior electromagnetic isolation, and consistent far-field patterns position it as a suitable option for 6 G IoT systems and integrated THz networks.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"338 ","pages":"Article 172510"},"PeriodicalIF":3.1,"publicationDate":"2025-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144923001","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}

引用次数: 0

Convergence of multi-domain hybrid dispersion compensation paradigms for ultra-high-speed optical fiber transmission in spectrally-efficient coherent communication systems 频谱高效相干通信系统中超高速光纤传输多域混合色散补偿范式的收敛性

IF 3.1 3区物理与天体物理

Optik Pub Date : 2025-08-23 DOI: 10.1016/j.ijleo.2025.172509

Noor J. Jihad, Ahmed H. Abbas, Shayma W. Nourildean, Murooj A. Abd Almuhsan

{"title":"Convergence of multi-domain hybrid dispersion compensation paradigms for ultra-high-speed optical fiber transmission in spectrally-efficient coherent communication systems","authors":"Noor J. Jihad, Ahmed H. Abbas, Shayma W. Nourildean, Murooj A. Abd Almuhsan","doi":"10.1016/j.ijleo.2025.172509","DOIUrl":"10.1016/j.ijleo.2025.172509","url":null,"abstract":"<div><div>As global data traffic accelerates, the challenge of chromatic dispersion in high-speed long-haul optical fiber systems has become increasingly critical. This study explores advanced hybrid dispersion compensation techniques designed to mitigate dispersion effects and enhance transmission fidelity in 100 Gbps optical networks. A comprehensive simulation framework was implemented using Opti System and MATLAB to analyze the performance of individual and hybrid compensation methods, including Dispersion Compensating Fiber (DCF), Fiber Bragg Grating (FBG), Electronic Dispersion Compensation (EDC), and Optical Phase Conjugation (OPC). Results indicate that while DCF and FBG offer notable improvements individually, their performance is significantly enhanced when integrated with EDC. The DCF+EDC configuration achieved a Bit Error Rate (BER) of <span><math><msup><mrow><mspace></mspace><mn>10</mn></mrow><mrow><mo>−</mo><mn>7</mn></mrow></msup></math></span>, while FBG and EDC further reduced BER to 5 ×<span><math><msup><mrow><mspace></mspace><mn>10</mn></mrow><mrow><mo>−</mo><mn>8</mn></mrow></msup></math></span> The OPC with DCF scheme demonstrated superior performance with BER approaching 1 ×<span><math><msup><mrow><mspace></mspace><mn>10</mn></mrow><mrow><mo>−</mo><mn>9</mn></mrow></msup></math></span>and a corresponding Q-factor of approximately 21 dB. Eye diagram analysis revealed substantial improvements in signal integrity, with minimal inter-symbol interference and restored pulse symmetry. These results confirm the efficacy of hybrid compensation schemes in extending transmission reach, maintaining signal quality, and supporting ultra-high-speed optical communication over long distances.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"338 ","pages":"Article 172509"},"PeriodicalIF":3.1,"publicationDate":"2025-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144923000","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}

引用次数: 0

Enhanced empirical relations for higher-order dispersions modeling in holey fibers 多孔纤维中高阶色散建模的增强经验关系

IF 3.1 3区物理与天体物理

Optik Pub Date : 2025-08-21 DOI: 10.1016/j.ijleo.2025.172504

Ashkan Ghanbari

引用次数: 0

Band gap engineering and optoelectronic properties of europium-doped cesium tin chloride (Eu-doped CsSnCl3) perovskite using a DFT based first-principles GGA+U+SOC approach for PC-LED applications 基于DFT第一性原理GGA+U+SOC方法的掺铕氯化铯锡钙钛矿带隙工程和光电子特性研究

IF 3.1 3区物理与天体物理

Optik Pub Date : 2025-08-18 DOI: 10.1016/j.ijleo.2025.172506

Salman Ahmad , Amin Ur Rahman , Sikander Azam , Muhammad Asif Hasham , Asiya Zaman Khan

{"title":"Band gap engineering and optoelectronic properties of europium-doped cesium tin chloride (Eu-doped CsSnCl3) perovskite using a DFT based first-principles GGA+U+SOC approach for PC-LED applications","authors":"Salman Ahmad , Amin Ur Rahman , Sikander Azam , Muhammad Asif Hasham , Asiya Zaman Khan","doi":"10.1016/j.ijleo.2025.172506","DOIUrl":"10.1016/j.ijleo.2025.172506","url":null,"abstract":"<div><div>This research investigates the potential of europium-doped cesium tin chloride perovskite (Eu-doped CsSnCl₃) as phosphor material for LED applications. We conducted computational analysis using first-principles calculations, specifically implementing the GGA+<em>U</em>+SOC methodology through WIEN2k software, to evaluate how europium (Eu) substitutional doping affects the material's electronic and optical behavior. The study compared pure CsSnCl₃ with two europium doping concentrations: a single-atom case Eu-CsSnCl₃ (2.5 %) and a double-atom scenario of 2Eu-CsSnCl₃ (5 %). Our findings demonstrate that Eu incorporation significantly alters the electronic band structure, with the band gap decreasing from 3.2 eV in pristine CsSnCl₃ to 1.009 eV and 0.967 eV for the 2.5 % and 5 % europium concentrations, respectively. This modification occurs through the formation of additional electronic states within both the valence and conduction bands. The research revealed that the 2.5 % europium concentration yielded optimal optical characteristics, particularly within visible light wavelengths, exhibiting improved absorption coefficients and more pronounced optical features compared to both the pristine material and the 5 % Eu variant. Through examination of dielectric properties, optical conductivity, and energy loss patterns, we determined that europium incorporation creates optimal conditions for light absorption and emission processes. These results indicate that precisely controlled Eu doping of CsSnCl₃ represents a viable approach for developing advanced phosphor materials with adjustable color properties and enhanced performance for future LED applications.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"338 ","pages":"Article 172506"},"PeriodicalIF":3.1,"publicationDate":"2025-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144893213","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}

引用次数: 0