Optik最新文献

{"title":"Directional bending sensor based on Mach-Zehnder interferometer formed by side-polished multimode fiber","authors":"Siti Mahfuza Saimon ,&nbsp;Asrul Izam Azmi ,&nbsp;Mohammed Salih Mohammed Gismalla ,&nbsp;Nadiatulhuda Zulkifli ,&nbsp;Mohd Rashidi Salim ,&nbsp;Nurul Ashikin Daud ,&nbsp;Mohd Haniff Ibrahim ,&nbsp;Muhammad Yusof Mohd Noor","doi":"10.1016/j.ijleo.2024.171934","DOIUrl":"https://doi.org/10.1016/j.ijleo.2024.171934","url":null,"abstract":"<div><p>This work proposes a fiber bending sensor based on the Mach-Zehnder interferometer (MZI) constructed using a side-polished multimode fiber (MMF) with bending direction recognition. The sensor is fabricated by directly fusing a section of side-polished MMF sandwiched between two no-core fibers (NCFs) to an input and output single-mode fibers (SMFs). As the applied curvature varies from 0 m⁻¹ to 1.64 m⁻¹, the transmission spectra of the sensor exhibit distinct and linear wavelength shift in opposite directions. The maximum sensitivity observed in 0° and 180° bending is 3.252 nm/m⁻¹ and −1.146 nm/m⁻¹, respectively. The maximum temperature sensitivity is 0.0621 nm/°C and this effect can be compensated by using the sensitivity matrix. The advantages of the proposed sensor include its ability to accurately quantify the direction and magnitude of bending, temperature crosstalk elimination, and cost-effectiveness. These features make the sensor highly desirable for a wide range of practical directional bending applications, such as medical wearable devices for human joint range of motion monitoring.</p></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141582403","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":"Annealing of bismuth telluride-based thick films by laser irradiation","authors":"Matteo d’Angelo,&nbsp;Dario Crimella,&nbsp;Carmen Galassi,&nbsp;Nora Lecis,&nbsp;Ali Gökhan Demir","doi":"10.1016/j.ijleo.2024.171930","DOIUrl":"https://doi.org/10.1016/j.ijleo.2024.171930","url":null,"abstract":"<div><p>Interest towards fabrication and post-processing of thermoelectric micro-sized devices has increased in recent years. The coupling of inexpensive deposition technologies and fast laser treatments on “as-deposited” films is an attractive solution for industrial scalability. In this work, we propose an approach never reported before in literature: the utilization of a ns-pulsed active fibre laser to directly densify p-type bismuth telluride-based thick films deposited on silicon. A feasibility study was conducted on the material to determine optimal laser parameters: the treated products were characterized, and it was concluded that a value of laser fluence as low as 4.5 mJ cm⁻² is sufficient for densification. The material resulted cracked after the laser treatment, and it was demonstrated by SEM and profilometric analyses that shrinking occurs and sintering necks are formed; further, the arising of second phases after annealing was excluded by means of XRD analysis. Envisioning an industrial large area process with linear diode arrays source, a prediction of the laser power requirements to irradiate 1 mm² films in selected conditions is presented. More extensive studies will be performed to determine a narrower parameters window and determine a relationship between the film thickness and laser parameters for future applications to as-deposited films.</p></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0030402624003292/pdfft?md5=c5c35a5a705acec09b364551df837722&pid=1-s2.0-S0030402624003292-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141484097","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Efficient prediction of optical properties in hexagonal PCF using machine learning models","authors":"","doi":"10.1016/j.ijleo.2024.171929","DOIUrl":"10.1016/j.ijleo.2024.171929","url":null,"abstract":"<div><p>This research explores the use of machine learning (ML) models to forecast optical characteristics in photonic crystal fibers (PCF). Specifically, we focus on a solid core index-guided PCF with a hexagonal cladding arrangement. The primary challenges to PCF propagation analysis and predictions are accuracy, computational error, and time constraints. To address these difficulties, we have specially used ML ensemble models including Decision Tree Regressor (DTR), Random Forest Regressor (RFR), Gradient Boosting Regressor (GBR), eXtreme Gradient Boosting Regression (XGBR), and Bagging Regressor (BR). Model performance is assessed using metrics like Mean Squared Error (MSE) and R-squared (R2) through 10-fold cross-validation. Our key findings show that the GBR model outperforms other models and shows extremely low MSE and outstanding R2 values in predicting effective refractive index (Neff), effective mode area (Aeff), confinement loss, and dispersion. In addition, the study compares the performance of ML models with that of previous works using Artificial Neural Network (ANN), demonstrating improved efficiency in predicting optical characteristics for hexagonal PCFs.</p></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141884573","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":"Exploring the fascinating world of combinational photonic devices: A review","authors":"Haripriya Noonepalle ,&nbsp;Venkatrao Palacharla ,&nbsp;Shashank Kumar Dubey ,&nbsp;Anjani Kumar Singh ,&nbsp;Sandip Swarnakar","doi":"10.1016/j.ijleo.2024.171923","DOIUrl":"https://doi.org/10.1016/j.ijleo.2024.171923","url":null,"abstract":"<div><p>In the present paper, several literature studies on various combinational photonic devices (PDs) using silicon based photonic crystals (PhC) have been studied. On considering various PhC structures, waveguides (WGs) and ring resonators (RRs) have been preferred because of their quality factor (QF), high transmission efficiency (TE), as well as stability in tuning the structures resonant wavelengths, as opposed to other designs. The articles have been classified based on the type of the material used, during the design manufacture and have been further divided according to the operation of the structure. The designed and performance parameters obtained in the collected articles like Contrast Ratio (CR), Bit Rates (BR), Response Times (RT), transmission time etc., have been summarized in this paper. The combinational photonic devices have been preferred because of their immense applications in calculators and computers that enables quick and accurate computations, data processors to execute logical operations, communication systems for smooth data transmission and handle error detection consumer electronics like TVs, smartphones and digital cameras, industrial control systems in automation and managing data, error detection and correction for data transmission and storage, digital signal processing to process and manipulate signals, instruction decoding to decode instructions and perform specific operations. These are seemed to be more advantageous because of their use in high-speed optoelectronic integrated devices and communication systems.</p></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141484096","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 four-port self-multiplexing tunable graphene based dielectric resonator antenna with defective ground structure for high isolation and MIMO capabilities","authors":"","doi":"10.1016/j.ijleo.2024.171924","DOIUrl":"10.1016/j.ijleo.2024.171924","url":null,"abstract":"<div><h3>Objectives and design</h3><p>A novel self-multiplexing terahertz antenna with four tunable ports is proposed in this work. The configuration comprises four rectangular dielectric resonators (DRs) affixed to a substrate, which are excited through L-shaped microstrip-fed slots positioned beneath them. To guarantee efficient isolation among the tunable antenna components, periodic unit cells are introduced into the ground plane, forming a defective ground structure (DGS). Each L-shaped slot element is equipped with a graphene strip to regulate the tunability of each DR element.</p></div><div><h3>Results and applications</h3><p>This antenna can operate in various modes with resonant frequencies at 4.01, 4.23, 4.37, and 4.57 THz. It holds potential for future terahertz wireless applications that require the utilization of adjacent channels with distinct communication frequencies. Furthermore, a four-port antenna design is implemented, offering tunable MIMO capabilities with self-quadruplexing ability. The MIMO parameters, specifically the envelope correlation coefficient (ECC) and diversity gain (DG), have been assessed and found to fall within acceptable limits across the operating frequency bands. Additionally, an equivalent circuit model (ECM) is analysed to shed light on the antenna's working principle and verify the obtained results.</p></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141770764","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":"Diffraction of laser light by a Ferrocell and ferrofluid layers: A comparison","authors":"Vishakha Dave,&nbsp;R.V. Mehta","doi":"10.1016/j.ijleo.2024.171925","DOIUrl":"https://doi.org/10.1016/j.ijleo.2024.171925","url":null,"abstract":"<div><p>In a previous study, we conducted a comparative analysis of laser light extinction using both a Ferrocell and ferrofluid layers. Specifically, we examined the diffraction of laser light by these devices. The Ferrocell was positioned between an electromagnet and a He-Ne-laser beam, and diffraction patterns were recorded with and without the application of a magnetic field. Subsequently, the experiment was replicated using a glass cuvette filled with a ferrofluid. We investigated the power spectra of these diffraction patterns and analyzed temperature variations. Our findings reveal significant distinctions between the diffraction patterns produced by the ferrofluid and the Ferrocell. Further investigations into these differences are currently underway.</p></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141484081","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":"Indium selenide for mode-locked pulse generation in a Mid-infrared Er:ZBLAN fiber laser","authors":"Linyan Wang ,&nbsp;Yushuo Bao ,&nbsp;Xinhao Zhou ,&nbsp;Huanhuan Li ,&nbsp;Can Li ,&nbsp;Junjie Zhang ,&nbsp;Shiqing Xu","doi":"10.1016/j.ijleo.2024.171928","DOIUrl":"https://doi.org/10.1016/j.ijleo.2024.171928","url":null,"abstract":"<div><p>Two-dimensional materials are increasingly recognized for their distinctive nonlinear optical properties. Indium selenide (InSe), a notable optoelectronic material, demonstrates unique advantages in terms of nonlinear absorption behavior, making it a promising candidate in mid-infrared mode-locked lasers. By preparing a InSe saturable absorber (SA) and applying it in a Er: ZBLAN fiber laser, we demonstrate a stable mode-locked mid-infrared fiber laser at 2.8 μm. The obtained mode-locked pulses have a repetition frequency and pulse duration of 29.875 MHz and 13.6 ps, respectively. The obtained maximum value of pulse energy is 4.3 nJ. The signal-to-noise ratio (SNR) is 55 dB, indicating the high stability of the laser system. Our experimental results validate that InSe is a promising SA in the near 3 μm band. This work paves the way for further investigations and applications of InSe-based devices in nonlinear optics and mode-locked laser systems.</p></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141484079","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":"First-principles calculation of structural, electronic, optical and thermoelectric properties of Li3TrAs2 (Tr = Al, Ga)","authors":"A. Vijay,&nbsp;R.D. Eithiraj","doi":"10.1016/j.ijleo.2024.171926","DOIUrl":"https://doi.org/10.1016/j.ijleo.2024.171926","url":null,"abstract":"<div><p>Computational analysis of the materials Li₃TrAs₂ (Tr = Al, Ga) through first principles DFT approach using WIEN2k code was done to evaluate the feasibility of the materials for several applications. The study comprises structural, electronic, optical and thermoelectric parameters. Structural parameters for the orthorhombic compounds with c/a variation in accordance to ground state energy is in well agreement with experimental data. From the electronic properties, direct bandgap semiconducting behavior of both compounds has been observed. Optical studies such as absorption coefficient and its direct bandgap nature implying the materials capability in utilizing in optoelectronic devices. Higher figure of merit (ZT) at ambient conditions implies the material to be good contender in thermoelectric devices such as waste heat recovery systems at room temperature. Based on the exciton binding energy from excitonic study reveals the weak or Mott-Wannier type exciton within both the material.</p></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141484095","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":"Rhodamine B degradation over visible light promoted Bi2WO6/Bi2W0.75Mo0.25O6 and Bi2MoO6/Bi2W0.75Mo0.25O6 heterostructures: DFT and photocatalytic studies","authors":"Bandi Ashok ,&nbsp;K. Ramesh ,&nbsp;Ashok Bhogi ,&nbsp;G. Upender","doi":"10.1016/j.ijleo.2024.171927","DOIUrl":"https://doi.org/10.1016/j.ijleo.2024.171927","url":null,"abstract":"<div><p>In the recent past, the dye degradation through semiconductor photocatalysis under visible light has drawn the widespread attention. In this view, visible active (1-x)Bi₂WO₆/xBi₂W_0.75Mo_0.25O₆ and (1-x)Bi₂MoO₆/xBi₂W_0.75Mo_0.25O₆ (commonly 0.05 ≤ x ≤ 0.20 wt%) heterostructures prepared through a one-step hydrothermal process. These compounds were analyzed by XRD, FE-SEM, HRTEM, XPS, FT-IR, DFT, UV-Vis DRS and photoluminescence. In (1-x)Bi₂WO₆/xBi₂W_0.75Mo_0.25O₆, the 0.90Bi₂WO₆/0.10Bi₂W_0.75Mo_0.25O₆ heterostructure showed the highest photocatalytic activity in comparison with Bi₂WO₆ and Bi₂W_0.75Mo_0.25O₆. On contrary, all (1-x)Bi₂MoO₆/xBi₂W_0.75Mo_0.25O₆ heterostructures exhibited the less photocatalytic activity than that of Bi₂MoO₆. The analysis carried out on both heterostructures clearly demonstrated that (1-x)Bi₂WO₆/xBi₂W_0.75Mo_0.25O₆ is more active in comparison to (1-x)Bi₂MoO₆/xBi₂W_0.75Mo_0.25O_6. The radical trapping test was conducted for 0.90Bi₂WO₆/ 0.10Bi₂W_0.75Mo_0.25O₆ heterostructure, asserted that <span><math><msubsup><mrow><mi>O</mi></mrow><mrow><mn>2</mn></mrow><mrow><mo>∙</mo><mspace></mspace><mo>−</mo></mrow></msubsup></math></span> and <span><math><msup><mrow><mi>h</mi></mrow><mrow><mo>+</mo><mspace></mspace></mrow></msup></math></span>radicals were dominant species responsible for Rhodamine B (Rh B) photo-degradation. The estimated redox potentials of Bi₂WO₆, Bi₂W_0.75Mo_0.25O₆ establish the fact that the charge (e^-/h⁺) migration between Bi₂WO₆ and Bi₂W_0.75Mo_0.25O₆ via Z scheme is accountable for the aggressive photocatalytic activity of Bi₂WO₆/Bi₂W_0.75Mo_0.25O₆ heterostructure. The plausible Z scheme mechanism of the generation of electron-hole pairs, charge transfer and also visible light-induced degradation of Rh B was proposed.</p></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141484098","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":"Tunable mode-locked holmium-doped fiber laser based on GIMF-SIMF-GIMF structure at 2.09 µm","authors":"Harith Ahmad ,&nbsp;Khalil Kamaruzzaman ,&nbsp;Muhamad Zharif Samion ,&nbsp;Shufeng Sun","doi":"10.1016/j.ijleo.2024.171922","DOIUrl":"https://doi.org/10.1016/j.ijleo.2024.171922","url":null,"abstract":"<div><p>In this study, a structure of graded-index multimode fiber-step index multimode fiber-graded index multimode fiber (GIMF-SIMF-GIMF) was used as a saturable absorber (SA) to generate mode-locking in a holmium-doped fiber laser (HDFL). The HDFL was pumped with a compact in-house thulium-doped fiber laser (TDFL) operating at 1943 nm with a maximum output power of 2.1 W. Mode-locked pulses with a pulse duration of 1.61 ps were successfully generated at the center wavelength of 2091.1 nm. The pulse had a repetition rate of 12.79 MHz with a bit of fluctuation of 2.09 %, indicating stable pulses. The mode-locked pulses were also tunable with a range from 2086.5 nm to 2091.1 nm by stretching the GIMF part of the SA. This first report demonstrated mode-locking using nonlinear multimode interference (NL-MMI) using GIMF-SIMF-GIMF structure as a saturable absorber in HDFL operating near 2.1 µm wavelength.</p></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141484082","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}