Optik最新文献

{"title":"Halvorsen chaotic system based microwave absorber modelling for fighter jet stealth technologies","authors":"Berker Colak ,&nbsp;Muharrem Karaaslan ,&nbsp;Fatih Ozkan Alkurt ,&nbsp;Mehmet Bakir ,&nbsp;Volkan Akdogan ,&nbsp;Mertcan Oral ,&nbsp;Ahmet Sertol Koksal","doi":"10.1016/j.ijleo.2024.172075","DOIUrl":"10.1016/j.ijleo.2024.172075","url":null,"abstract":"<div><div>This study focuses on the development and detailed analysis of a broadband microwave absorber utilizing Halvorsen chaotic dynamics, that focuses at enhancing stealth capabilities for fighter jets. The investigation begins by exploring the mathematical formulation of the Halvorsen chaotic system and conducting a parametric sweep of its control parameters to generate distinct two-dimensional and three-dimensional chaotic attractor plots. These plots are then post-processed using Julia set theory to develop intricate fractal patterns, which serve as the foundation for the absorber design. Image processing techniques, including filtering and thresholding, are employed to refine the patterns by removing artifacts and noise, ensuring they are suitable for practical implementation. The refined fractal patterns are then imported into a computational electromagnetic simulation environment where they are patterned onto a 0.035 mm thick copper sheet. Moreover, the Magtrex 555 substrate with a thickness of 1.52 mm, is selected for its high permittivity and low-loss characteristics. A comprehensive series of parametric studies are conducted to evaluate the influence of various design parameters such as side length, unit cell geometry, and substrate thickness on the absorber’s electromagnetic performance. Important parameters include the effects of chaotic control parameter optimization and the electromagnetic boundary conditions applied during the simulations. Extensive simulations are performed across the 2–20 GHz frequency range to evaluate absorption efficiency, focusing on key metrics like absorptivity, surface current distribution, and electric field distribution. The final design achieves over 90 % absorption efficiency within the target frequency band when the chaotic control parameters are optimized. Finally, comparative analysis using different commercially available substrates, including FR-4 and Rogers RO3003, reveals that Magtrex 555 offers superior absorption performance. The study concludes with a detailed presentation of the final absorber design, alongside an indepth discussion of the frequency range, parametric variations, and the impact of chaotic system dynamics on the absorption properties. This research provides crucial insights into the design and optimization of chaotic-system-based microwave absorbers, that advances the development of stealth technology in military applications.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"317 ","pages":"Article 172075"},"PeriodicalIF":3.1,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142531585","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":"Guiding properties of Bessel–Gaussian and super-Gaussian pulses in inhomogeneous parabolic plasma channels","authors":"E. Gholipoor ,&nbsp;R. Fallah ,&nbsp;S.M. Khorashadizadeh ,&nbsp;A.R. Niknam","doi":"10.1016/j.ijleo.2024.172071","DOIUrl":"10.1016/j.ijleo.2024.172071","url":null,"abstract":"<div><div>The guidance and stable propagation of laser pulses over many Rayleigh lengths are crucial for the plasma electron acceleration in the laser wakefield accelerators. Using plasma channels with specific characteristics can lead to the proper guidance of the laser pulse. Here, quasi-three-dimensional particle-in-cell (PIC) simulations are performed to investigate the guidance of Bessel–Gaussian pulse (BGP) of zeroth order and super-Gaussian pulse (SGP) of 3rd and 4th orders in an axially and radially inhomogeneous plasma channel. The effects of the channel radius and depth, the laser wavelength and initial spot size, and the plasma channel inhomogeneity on the guidance of the laser pulse are also examined. The results indicate that the guidance of a laser pulse in the plasma channel depends on the pulse profile, and under certain conditions, the pulses can be guided with the least variation of spot size in the inhomogeneous plasma channel. It is shown that the channel depth and the initial laser spot size are very effective in pulse guiding, as the values of these parameters increase, the pulse guidance is done better. In addition, the results show that the guidance of laser pulse is dependent on the type of plasma inhomogeneity represented by three different kinds of initial conditions, as considering the nonlinear-axial inhomogeneity in the parabolic plasma channel can lead to more convergence than the axially homogeneous and linear-axially plasma density profiles.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"317 ","pages":"Article 172071"},"PeriodicalIF":3.1,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142531587","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":"Enhanced conversion efficiency enabled with natural dyes extracted from Mirabilis flower and Bixa seed revealing prospects of application of co-sensitized DSSC","authors":"Ishwar Chandra Maurya,&nbsp;Shalini Singh,&nbsp;Shubham Sharma,&nbsp;Shiva Prakash Singh Kushwaha,&nbsp;Pankaj Srivastava,&nbsp;Lal Bahadur","doi":"10.1016/j.ijleo.2024.172072","DOIUrl":"10.1016/j.ijleo.2024.172072","url":null,"abstract":"<div><div>In this report, we present the studies on co-sensitization effects of two natural dyes extracted from Mirabilis flower and Bixa seeds on TiO₂-based dye-sensitized solar cells (DSSC). The objective is to extend the spectral sensitivity and light-to-electrical energy conversion efficiency of the selected dyes. UV–visible absorption within the 480–580 nm and 400–500 nm range signify anthocyanin in Mirabilis flower and carotenoid in Bixa seed respectively. Bixa seed and Mirabilis flower extracted mixed natural dye exhibited absorption in 400–600 nm range. The study further established the co-sensitization through computational studies and electrochemical impedance spectroscopy (EIS) studies. With the use of Bixa seed and Mirabilis flower extracted dye, photovoltaic parameter short-circuit current density (<em>J</em>_sc) &amp; conversion efficiency (<em>η</em>) were observed 0.20 mA/cm², 0.44 mA/cm² and 0.09 % 0.38 % respectively. The Bixa seed and Mirabilis flower extracts co-sensitized DSSC revealed enhanced <em>J</em>_sc 0.65 mA/cm² and <em>η</em> 0.40 %.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"317 ","pages":"Article 172072"},"PeriodicalIF":3.1,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142531586","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 novel feature screening algorithm for low-resolution LIBS spectrum elemental quantification","authors":"Yunfeng Bi ,&nbsp;Xiaohan Bai ,&nbsp;Chao Li ,&nbsp;Tao Zhang ,&nbsp;Zhongyi Bao ,&nbsp;Meili Guo ,&nbsp;Man Wang ,&nbsp;Zhengjiang Ding","doi":"10.1016/j.ijleo.2024.172069","DOIUrl":"10.1016/j.ijleo.2024.172069","url":null,"abstract":"<div><div>This study presents an innovative approach that integrates Laser-Induced Breakdown Spectroscopy (LIBS) with chemometrics for the quantitative analysis of Si, Ca, Al, and Mg in geological samples. Given the spectral redundancy in low-resolution LIBS devices, the study employs pre-processing techniques, such as AirPLS, Wavelet Transform (WT), and normalization to mitigate spectral noise. Enhanced feature threshold searching is achieved by incorporating SHapley Additive exPlanations (SHAP) and LightGBM into the Boruta algorithm, substantially improving quantitative analysis models based on Support Vector Regression (SVR) and Partial Least Squares Regression (PLSR). The modified Boruta-SVR model demonstrated remarkable robustness, with <em>R²</em> values of 0.9862, 0.9873, 0.9882, and 0.9916, and <em>RMSE</em> values of 0.8099, 0.324, 0.1378, and 0.2382, respectively, for Si, Ca, Al, and Mg. The results confirm that the Boruta-based feature selection method, when applied to low-resolution LIBS spectra, outperforms traditional methods, capturing unique sample features under mixed spectral peak conditions, thereby enhancing the robustness of quantitative analysis models.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"317 ","pages":"Article 172069"},"PeriodicalIF":3.1,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142442039","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":"Effect of current spreading layer on Internal Quantum efficiency and optical power of flip chip gallium nitride LEDs with circular contacts","authors":"Y. Prasamsha ,&nbsp;N. Mohankumar ,&nbsp;M. Arun Kumar ,&nbsp;P. Sriramani ,&nbsp;H. Maity ,&nbsp;Nitin Rakesh","doi":"10.1016/j.ijleo.2024.172073","DOIUrl":"10.1016/j.ijleo.2024.172073","url":null,"abstract":"<div><div>The unique properties of the Indium Tin Oxide (ITO) make it an excellent choice as a current spreading layer in Flip Chip Light Emitting Diodes (FCLEDs) and other optoelectronic devices. Herein, the performance of FCLEDs is analyzed by a precise mathematical model for the current spreading length (L_s) produced by the ITO layer under circular-shaped contacts. The expressions are formulated without approximations using ABC-model for extracting the Internal Quantum Efficiency (IQE, <span><math><msub><mrow><mi>η</mi></mrow><mrow><mi>int</mi></mrow></msub></math></span>), optical power (P_int) and Emission Intensity (EI). The thickness <span><math><mrow><mo>(</mo><msub><mrow><mi>t</mi></mrow><mrow><mi>I</mi><mi>T</mi><mi>O</mi></mrow></msub><mo>)</mo></mrow></math></span> and resistivity <span><math><mrow><mo>(</mo><msub><mrow><mi>ρ</mi></mrow><mrow><mi>I</mi><mi>T</mi><mi>O</mi></mrow></msub><mo>)</mo></mrow></math></span> of the ITO layer are varied for different current densities, and their adverse effects on IQE are determined. At lower current densities, IQE increases with thickness and decreases for high resistivity of the ITO layer. At higher current densities, there is a gradual decrease in IQE irrespective of the ITO layer presence due to “Efficiency Droop”. The IQE in the proposed work is 82 % at a thickness of 50–200 nm and current density of 8 A/cm², and the optical power is around 40 mW, showing good agreement with the experimental data, making it feasible for future high-performance FCLEDs.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"317 ","pages":"Article 172073"},"PeriodicalIF":3.1,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142445024","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":"Flat mirrors, virtual rear-view cameras, and camera-mirror calibration","authors":"Rigoberto Juarez-Salazar","doi":"10.1016/j.ijleo.2024.172067","DOIUrl":"10.1016/j.ijleo.2024.172067","url":null,"abstract":"<div><div>Flat mirrors are useful to generate virtual cameras and capture a scene from multiple viewpoints. However, the resultant camera-mirror setup is cumbersome to calibrate because of the mirror image reversion. The typical calibration flaws are omitting the checkerboard symmetry and assuming that virtual cameras are front-view. This paper explains the rear-view abstraction and its usefulness in calibrating a camera-mirror setup to obtain the equivalent mirrorless configuration. The underlying theory is reviewed, including camera imaging, the calibration process, and the laws of reflection. The proposed approach is illustrated by calibrating a camera-mirror setup and then using the calibrated camera to generate mirror images synthetically. This work offers a practical insight into calibrating more sophisticated systems such as mirrored camera-projector profilometers.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"317 ","pages":"Article 172067"},"PeriodicalIF":3.1,"publicationDate":"2024-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142428355","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":"Novel carboxylic-MWCNTs photoresist for fabricating sub-diffraction polymer nanowires via STED lithography","authors":"Fei Xie ,&nbsp;Lili Liang ,&nbsp;Qingbin Zhou ,&nbsp;Ziwei Feng ,&nbsp;Jian Xu ,&nbsp;Xiangping Li ,&nbsp;Yaoyu Cao","doi":"10.1016/j.ijleo.2024.172070","DOIUrl":"10.1016/j.ijleo.2024.172070","url":null,"abstract":"<div><div>A novel composite photoresist, derived from acrylates and carboxylic-functionalized multi-walled carbon nanotubes (MWNTs-COOH), has been developed for the fabrication of sub-diffraction-sized polymer nanowires using STED-inspired lithography. The MWNTs-COOH dispersed in highly cross-linking acrylate monomers benefits to a reduced inhibition laser power for improving lithography. With the MWNTs-COOH, the inhibition laser power is decreased from 5 mW to 3 mW, while the achievable minimum feature size is increased from 121 nm to 48 nm. This innovative approach holds significant promise for the development of sub-diffraction MWCNTs/polymer composite-based devices in the fields of Micro-Electro-Mechanical Systems (MEMS) and Nano-Electro-Mechanical Systems (NEMS).</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"317 ","pages":"Article 172070"},"PeriodicalIF":3.1,"publicationDate":"2024-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142428359","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":"Improving multi-wavelength overlay measurement time by the development of color-mixing light source","authors":"Hung-Chih Hsieh,&nbsp;Yi-Xian Peng,&nbsp;Liang-Rong Chen","doi":"10.1016/j.ijleo.2024.172066","DOIUrl":"10.1016/j.ijleo.2024.172066","url":null,"abstract":"<div><div>This paper introduces an innovative approach to streamline the time-consuming process of multiple-wavelength measurement in semiconductor overlay metrology. To achieve this, a color-mixing light source was developed, which employed light sources of different wavelengths, each modulated with different sine wave frequencies. By aligning these sources and directing them simultaneously onto the test sample, we mixed all wavelength information into a single test signal. Leveraging the known modulation frequencies, we can accurately extract the amplitudes of each wavelength using a three-parameter sine wave fitting method. These amplitudes effectively represent the sought-after signal for each wavelength. A 4-wavelength mixed light source was developed to demonstrate this method's feasibility. Compared with the intensities received independently for each wavelength, the reconstructed amplitude error was below 5 %. Finally, in the test of multiple-wavelength overlay measurement, the overlay difference between this and traditional methods was only 0.078 nm. The experimental results confirm that this method enables a reduction in the measurement time for multiple wavelengths from 0.8 sec to 0.2 sec, i.e., a 75 % reduction).</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"316 ","pages":"Article 172066"},"PeriodicalIF":3.1,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142421020","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 high-resolution spectroscopic technique for the analysis of the external quantum efficiency of a multimode semiconductor laser","authors":"Watheq Al-Basheer ,&nbsp;Taofeek O. Adigun ,&nbsp;Abdulaziz Aljalal ,&nbsp;Khaled Gasmi","doi":"10.1016/j.ijleo.2024.172068","DOIUrl":"10.1016/j.ijleo.2024.172068","url":null,"abstract":"<div><div>The high-resolution emission spectra of a GaN-based semiconductor laser were utilized to investigate the external differential quantum efficiency variation with temperature and stability over an extended period of continuous operation time. Moreover, the dynamics and evolution of the optical gain and longitudinal modes emitted both below and above threshold current were also reported. Upon studying the L-I curves over the full range of operating current and temperature, three distinct temperature regimes of the quantum efficiency were identified, with the regime of the temperature range 285–301 K yielding the highest stability. The thermal stability of the laser was also assessed by monitoring the variation of threshold current with temperature.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"316 ","pages":"Article 172068"},"PeriodicalIF":3.1,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142421058","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":"Breather–breather interactions, rational and semi-rational solutions of an integrable spin system in optical fibers","authors":"Qin-Ling Liu ,&nbsp;Yan-Nan Zhao ,&nbsp;Hui-Qin Hao","doi":"10.1016/j.ijleo.2024.172064","DOIUrl":"10.1016/j.ijleo.2024.172064","url":null,"abstract":"<div><div>This paper investigates an integrable spin system (or Heisenberg ferromagnet-type equation or Nurshuak-IIA equation) which is an integrable generalization of the Heisenberg ferromagnet equation that raises from magneto-optical devices. The <span><math><mi>N</mi></math></span>-fold Darboux transformation of the Nurshuak-IIA equation will be constructed. With the selection of several parameters, a variety of the solutions will be produced, including breather–breather interactions, higher-order rogue waves and semi-rational solutions.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"316 ","pages":"Article 172064"},"PeriodicalIF":3.1,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142421021","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}