Optik最新文献

{"title":"Atomic state preparation as an effective control tool for engineering the EIT based slow light","authors":"Zahra Heydarinasab,&nbsp;Mohammad Karami,&nbsp;Farrokh Sarreshtedari","doi":"10.1016/j.ijleo.2025.172456","DOIUrl":"10.1016/j.ijleo.2025.172456","url":null,"abstract":"<div><div>The influence of the initial state preparation on electromagnetically induced transparency (EIT) and slow light propagation in ⁸⁷Rb is theoretically investigated. By solving the Liouville equation for an 8 × 8 density matrix, we demonstrate that using special polarized optical beams for state preparation and engineering the population distribution among Zeeman sublevels, a significant reduction in group velocity could be achieved. The results interestingly show that the group velocity of slow light can be reduced by more than 20 dB through initial pumping of the atomic sample with balanced right- and left-circularly polarized resonant light.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"336 ","pages":"Article 172456"},"PeriodicalIF":3.1,"publicationDate":"2025-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144290515","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":"Low-profile four-port MIMO antenna realizing penta-band notches for UWB systems","authors":"Vanka Saritha ,&nbsp;V.N. Koteswara Rao Devana ,&nbsp;M. Bhagya Lakshmi ,&nbsp;Md. Ahsan Halimi ,&nbsp;GS K.Gayatri Devi ,&nbsp;Nageswara Rao Lavuri ,&nbsp;Ahmed J.A. Al-Gburi","doi":"10.1016/j.ijleo.2025.172454","DOIUrl":"10.1016/j.ijleo.2025.172454","url":null,"abstract":"<div><div>This paper presents a low-profile, four-port Ultra-Wideband (UWB) Multiple-Input Multiple-Output (MIMO) antenna with integrated penta-band notch functionality to suppress interference from coexisting narrowband systems. The antenna employs a combination of mushroom-type Electromagnetic Bandgap (EBG) structures and inverted L-shaped slots to realize five distinct notched bands at 3.5, 4.1, 5.0, 6.7, and 7.8 GHz, each exhibiting rejection levels better than −4 dB. This effectively mitigates interference from WiMAX, INSAT, Wi-Fi (5 G), Wi-Fi-6E (6 G), and X-band uplink services. The four antenna elements are arranged face-to-face to minimize mutual coupling and ensure improved isolation. Notching is achieved using two square mushroom EBG structures, a spiral-slot EBG near the feedline, and three inverted L-shaped slots on the radiating surface. To enhance compactness further, a spiral-shaped defect is incorporated into one of the EBGs. Additionally, two square EBGs placed symmetrically beside the feedline enable the 5.5 GHz notch. The antenna occupies a compact footprint of 45.3 × 69.8 × 1.6 mm³ and demonstrates excellent diversity performance, with Envelope Correlation Coefficient (ECC) values below 0.02 and Diversity Gain (DG) near 10 dB. Performance validation includes frequency response, surface current analysis, ECC, DG, and radiation patterns, confirming the design’s suitability for compact UWB wireless devices requiring multi-band interference suppression.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"336 ","pages":"Article 172454"},"PeriodicalIF":3.1,"publicationDate":"2025-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144262740","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":"Probing the effect of annealing on the structural and optical properties of CdS thin films: Combining experimental and first-principles study","authors":"Bo Yue ,&nbsp;Qigui Yang ,&nbsp;Xuemei Li ,&nbsp;Rui Cui ,&nbsp;Yongbo Zhang ,&nbsp;Shanshan Li ,&nbsp;Rengang Zhang ,&nbsp;Peng Zhang ,&nbsp;Runsheng Yu ,&nbsp;Xingzhong Cao","doi":"10.1016/j.ijleo.2025.172450","DOIUrl":"10.1016/j.ijleo.2025.172450","url":null,"abstract":"<div><div>Defects play a pivotal role in determining the performance of semiconductor materials, and their influence can be effectively adjusted through processing techniques. In this study, CdS thin films were prepared using a novel sputtering-evaporation-sputtering (SES) method with metal target followed with annealing. The effects of annealing temperature on the structural and optical properties of CdS film were thoroughly investigated by combining various experimental techniques with first-principles calculations. The results showed that the unannealed precursor of CdS film has poor crystallinity and low transmittance, with unreacted Cd present. Annealing significantly improves crystallinity of CdS films. The transmittance and stoichiometric ratio initially increase with annealing temperature but decrease at higher temperatures. Optimal annealing conditions enable a complete transformation of precursors into CdS films, while excessive temperatures lead to the escape of sulfur and the formation of sulfur vacancies. Sulfur vacancies, confirmed by first-principles calculations and positron annihilation Doppler broadening spectroscopy, significantly contribute to the observed transmittance degradation at elevated temperatures. This research is expected to provide insights into the thermal treatment and vacancy management of CdS thin films.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"336 ","pages":"Article 172450"},"PeriodicalIF":3.1,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144280416","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":"Facile green synthesis of nickel oxide nanoparticles using Citrus medica leaf derivatives, characterization and study of dye degradation activity","authors":"S. Johnson Jeyakumar,&nbsp;R. Piriyadharsini ,&nbsp;M. Jothibas","doi":"10.1016/j.ijleo.2025.172442","DOIUrl":"10.1016/j.ijleo.2025.172442","url":null,"abstract":"<div><div>The nanosized Nickel Oxide is competitive in the solar treatment of textile industry effluent, which is a significant cause of global water pollution. The Nickel Oxide was meticulously prepared to utilize a green synthesis methodology, thereby demonstrating remarkable photon absorption characteristics spanning the substantial solar spectrum, encompassing visible light regions. Subsequent investigations have revealed that the optical band gap of the material under scrutiny is measured to be 3.1 eV. Additionally, the structural analysis of Nickel Oxide nanoparticles has indicated that the average crystallite size is 12.1 nm. Morphological analysis reveals that rod-like Nickel Oxide nanoparticles were grown with a uniform particle distribution. Photoluminescence (PL) examination reveals the consequences of structural defects and oxygen-based deficiencies, which help to extend the life span of charge carriers’ recombination. X-ray Photoelectron Spectroscopy (XPS) - surface chemical state examinations confirmed various oxygen-coordinated molecular species accommodation. The dye degradation percentages of methylene orange and methylene violet organic dyes were observed to be 98 % and 94 %, respectively. These results were obtained by utilizing a bio nano-rod catalyst with a dose of 0.2 g/l during a 60-minute duration under solar light irradiation. According to the observations, it was demonstrated that the photodegradation of Methyl Orange dye solution by Nickel Oxide nanoparticles synthesized under a beneficial pathway using an ecological, benign process under favourable circumstances was successful. Comparatively, the Nickel Oxide was favourable to eliminating the Methyl Orange (MO) dye compositions utilizing the renewable light source under ecological and beneficial pathways.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"336 ","pages":"Article 172442"},"PeriodicalIF":3.1,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144253646","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":"Transparent frequency selective surfaces with high optical transparency and wide bandwidth for 5 G mm-wave spatial filtering applications","authors":"Dat Tien Nguyen,&nbsp;Chang Won Jung","doi":"10.1016/j.ijleo.2025.172440","DOIUrl":"10.1016/j.ijleo.2025.172440","url":null,"abstract":"<div><div>This study presents a design method for a transparent frequency-selective surface (FSS) that combines high optical transparency (OT), enhanced frequency selectivity, and broad bandwidth (BW) performance, specifically for 5 G millimeter-wave spatial filtering applications. Transparent FSSs are designed to function as spatial filters in electromagnetic environments where visibility is required—such as on building windows, vehicle glass, drone surfaces, and radomes. However, most existing research has concentrated on lower frequency bands (e.g., S-band and X-band), with relatively little attention paid to the mm-wave range (K and Ka bands), which is essential for next-generation 5 G communications. To address this gap, a double-layer FSS (D-FSS) is proposed, composed of two spatially separated single-layer FSSs (S-FSSs). This configuration substantially improves frequency selectivity and achieves a wide fractional bandwidth of 23.1 %, spanning 24.5–30.9 GHz—covering the n257 and n258 bands used in 5 G mm-wave systems. Each S-FSS consists of narrow, symmetrically arranged metallic lines that provide both excellent optical transparency—84 % for the S-FSS and 70 % for the D-FSS—and strong angular stability. The proposed FSS structures demonstrate significant potential for improving signal coverage and transmission bandwidth in a variety of 5 G mm-wave applications.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"336 ","pages":"Article 172440"},"PeriodicalIF":3.1,"publicationDate":"2025-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144240272","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":"Mach-Zehnder interferometer temperature sensor based on misaligned optical fiber coated with SU-8 photoresist","authors":"Aimin Cong,&nbsp;Yuxin Zheng,&nbsp;Jie Yang,&nbsp;Bowen Yu,&nbsp;Min Li","doi":"10.1016/j.ijleo.2025.172441","DOIUrl":"10.1016/j.ijleo.2025.172441","url":null,"abstract":"<div><div>In this paper, a Mach-Zehnder fiber-optic temperature sensor based on core-offset is proposed. The sensor is prepared using fiber-optic splicing technology and UV curing technology, and the fabrication process is simple. First, the impact of the fiber offset-spliced length and offset-spliced size on spectral quality is studied. Second, the fiber structure with the offset-spliced size of 42 μm and the offset-spliced length of approximately 700 μm is further investigated. The SU-8 photoresist with high thermal expansion coefficient and high thermo-optical coefficient is coated with the offset-spliced area. Finally, a fiber Mach-Zehnder temperature sensor is obtained. Within the temperature range of 30 ℃ to 60 ℃, the temperature characteristics are investigated. The fast Fourier transform is done, and the wavelengths of the interference peak near 1300 nm is measured. Experimental results show that the sensitivity of the proposed sensor reaches 0.72096 nm/℃. Moreover, SU-8 has good acid and alkali resistance, making the proposed fiber-optic temperature sensor promising for applications in biomedicine, chemistry and other fields.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"336 ","pages":"Article 172441"},"PeriodicalIF":3.1,"publicationDate":"2025-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144240271","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":"Tuning WO3 film properties for electrochromic applications via annealing and oxygen pressure","authors":"Smitha G. Prabhu ,&nbsp;Kilari Naveen Kumar ,&nbsp;Kavitha Kamath ,&nbsp;N. Veera Pandi ,&nbsp;S. Nithyashree ,&nbsp;R.Imran Jafri","doi":"10.1016/j.ijleo.2025.172439","DOIUrl":"10.1016/j.ijleo.2025.172439","url":null,"abstract":"<div><div>The objective of this investigation was to examine the intricate relationship between annealing temperature and oxygen partial pressure (PaO₂) in regard to morphological, structural, and electrochemical properties of tungsten trioxide (WO₃) films that were produced through sputtering. The films were deposited under two different PaO₂ values, specifically 0.3 mTorr and 0.5 mTorr, and then underwent annealing at various temperatures: room temperature, 100, 200, 300, and 400 degrees Celsius. X-ray diffraction (XRD) analysis revealed a temperature-dependent transition from an amorphous to a crystalline phase. Morphological analyses conducted with scanning electron microscopy (SEM) indicated a trend towards a smoother surface as both the annealing temperature and PaO₂ rose. At 400 °C, the films exhibited a granular surface finish. Significantly, the film fabricated at 0.3 mTorr and subjected to room temperature (RT) annealing showed cracks, indicating inherent stress in the film. Electrochemical evaluations revealed that the WO₃ film deposited at 0.5 mTorr and annealed later at 200 °C demonstrated enhanced redox performance, better diffusion of ions, and remarkable reversibility. Impressive results were demonstrated in optical studies, attaining 83 % optical modulation, colouration efficiency (CE) up to 30.54 cm²/C, and swift switching durations of 1.17 s for colouration and 0.82 s for decolouration. Moreover, cycling tests showed negligible degradation after 100 cycles for the films deposited at 0.5 mTorr PaO₂ and treated at 200 °C, emphasizing their resilience. This study furnishes a comprehensive knowledge of the consequences of annealing temperature and PaO₂ collectively on WO₃ films, highlighting the novel strategy of enhancing electrochromic efficacy by modifying temperature and meticulously balancing the PaO₂, thus contributing to the progress of energy-efficient smart materials.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"336 ","pages":"Article 172439"},"PeriodicalIF":3.1,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144221031","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":"Third-order optical properties of Ag nanocubes and Ag@Au hollow nanostructures investigated by femtosecond Z-Scan measurements","authors":"Claudevan A. Sousa ,&nbsp;Antonio F.A.A. Melo ,&nbsp;Nefe J.B. Silva ,&nbsp;Tânia Patrícia Silva e Silva ,&nbsp;Bartolomeu C. Viana ,&nbsp;Francisco Eroni P. Santos ,&nbsp;Hans Garcia","doi":"10.1016/j.ijleo.2025.172430","DOIUrl":"10.1016/j.ijleo.2025.172430","url":null,"abstract":"<div><div>We investigate the third-order nonlinear optical properties of silver nanocubes (Ag-NCs) and Ag@Au hollow nanostructures using femtosecond Z-scan measurements at 1040 nm. Both systems exhibit negative nonlinear refraction (<em>n₂∼10⁻¹⁶</em> cm²/W) attributed to hot-electron generation under ultrafast excitation. In contrast, saturable absorption (SA) is uniquely observed in Ag@Au nanoboxes, with SA intensity tunable via Au content. Ag@Au hollow nanostructures exhibit an order-of-magnitude enhancement in nonlinear refractive index (<em>n₂</em>) and saturable absorption (SA) performance compared to monometallic Ag nanocubes, highlighting morphology and composition as key design parameters. These results demonstrate the promise of Ag@Au hollow nanostructures for applications in ultrafast all‑optical switching and nonlinear photonic devices.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"336 ","pages":"Article 172430"},"PeriodicalIF":3.1,"publicationDate":"2025-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144280417","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":"Retraction notice to “An intrusion identification and prevention for cloud computing: From the perspective of deep learning” [Optik 270 (2022) 170044]","authors":"Anil Kumar ,&nbsp;Rajabov Sherzod Umurzoqovich ,&nbsp;Nguyen Duc Duong ,&nbsp;Pratik Kanani ,&nbsp;Arulmani Kuppusamy ,&nbsp;M. Praneesh ,&nbsp;Minh Ngyen Hieu","doi":"10.1016/j.ijleo.2025.172386","DOIUrl":"10.1016/j.ijleo.2025.172386","url":null,"abstract":"","PeriodicalId":19513,"journal":{"name":"Optik","volume":"335 ","pages":"Article 172386"},"PeriodicalIF":3.1,"publicationDate":"2025-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144242722","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":"Laser-induced nonlinear far-field diffraction patterns of disperse azo dyes","authors":"M.Y. Shubar,&nbsp;H.L. Saadon,&nbsp;M.A. Rahma","doi":"10.1016/j.ijleo.2025.172422","DOIUrl":"10.1016/j.ijleo.2025.172422","url":null,"abstract":"<div><div>The nonlinear optical properties of the dispersed azo dyes (orange 3, orange 13 and orange 25) were investigated using laser field-induced spatial self-phase modulation (SSPM) with continuous wave laser of 532 nm. The research of disperse azo dyes at different concentrations and incoming laser power produced diffraction ring patterns. The results of the experiment showed a large nonlinear refractive index n₂ and a large thermo-optical coefficient dn/dT. The effect of excitation laser input and time evolution on shape diffraction pattern shape was investigated. We therefore explain the collapse effect of the diffraction circle model. The results show that the type of laser input is responsible for the variation of the number of diffraction circles. The results indicated that the dispersed azo dyes are a good candidate for use as an optical limiter.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"335 ","pages":"Article 172422"},"PeriodicalIF":3.1,"publicationDate":"2025-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144138914","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}