Pub Date : 2024-10-21DOI: 10.1016/j.ijleo.2024.172091
R.A. Ganeev , G.S. Boltaev , A.S. Alnaser
We demonstrate high-order harmonic generation in carbon plasma using linearly, radially, and azimuthally polarized beams from a femtosecond laser (1030 nm, 40 fs, 50 kHz). The conditions for carbon plasma formation during laser ablation were optimized by adjusting the heating pulse energy in the cases of the single-color (1030 nm) and two-color (1030 nm + 515 nm) pump schemes to generate harmonics up to the 39th order. The application of radial and azimuthally polarized annular single-color (1030 nm) beams at optimal conditions of plasma formation allowed the demonstration of the spectral division and inclination of the vector harmonics. An asymmetric distribution of harmonics was obtained using the vortex beam generated during the propagation of laser radiation through the quarter-wave plate and S-waveplate.
{"title":"Spectral analysis of high-order harmonic generation in carbon plasma using linearly, radially, and azimuthally polarized femtosecond pulses","authors":"R.A. Ganeev , G.S. Boltaev , A.S. Alnaser","doi":"10.1016/j.ijleo.2024.172091","DOIUrl":"10.1016/j.ijleo.2024.172091","url":null,"abstract":"<div><div>We demonstrate high-order harmonic generation in carbon plasma using linearly, radially, and azimuthally polarized beams from a femtosecond laser (1030 nm, 40 fs, 50 kHz). The conditions for carbon plasma formation during laser ablation were optimized by adjusting the heating pulse energy in the cases of the single-color (1030 nm) and two-color (1030 nm + 515 nm) pump schemes to generate harmonics up to the 39th order. The application of radial and azimuthally polarized annular single-color (1030 nm) beams at optimal conditions of plasma formation allowed the demonstration of the spectral division and inclination of the vector harmonics. An asymmetric distribution of harmonics was obtained using the vortex beam generated during the propagation of laser radiation through the quarter-wave plate and S-waveplate.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"318 ","pages":"Article 172091"},"PeriodicalIF":3.1,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142553855","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}
Pub Date : 2024-10-19DOI: 10.1016/j.ijleo.2024.172074
Islam Arafa, Hassan Mostafa, Yasmine Elogail
A safe 3-D lidar sensor for autonomous vehicle creates a high demand on 1550 nm SPADs detectors. Due to the limitation of the energy band gab and absorption coefficient of Si and Ge, their photodetectors have low efficiency at the 1550 nm wavelength. Doping Ge with Sn reduces its bandgap and enables higher efficiency in this range while adding Bragg reflector represents a smart way to increase absorption area effective thickness. Here a simulation model for Ge(1-x)Snx SACM SPAD is proposed to work as a 1550 nm laser detector. Two Bragg reflectors are built using SiSiGe and SiSiGeSn layers. Results show a significant enhancement on detector optical properties. PDP reaches 38 % at room temperature and the increase in Pdp due to Bragg reflector reaches 66 %. Although DCR also increases, it can be handled with proper dead time configuration.
{"title":"Simulation model to enhance Bragg reflector assisted GeSn SACM-SPAD performance for 1550 nm LIDAR applications in autonomous vehicles","authors":"Islam Arafa, Hassan Mostafa, Yasmine Elogail","doi":"10.1016/j.ijleo.2024.172074","DOIUrl":"10.1016/j.ijleo.2024.172074","url":null,"abstract":"<div><div>A safe 3-D lidar sensor for autonomous vehicle creates a high demand on 1550 nm SPADs detectors. Due to the limitation of the energy band gab and absorption coefficient of Si and Ge, their photodetectors have low efficiency at the 1550 nm wavelength. Doping Ge with Sn reduces its bandgap and enables higher efficiency in this range while adding Bragg reflector represents a smart way to increase absorption area effective thickness. Here a simulation model for Ge<sub>(1-x)</sub>Sn<sub>x</sub> SACM SPAD is proposed to work as a 1550 nm laser detector. Two Bragg reflectors are built using SiSiGe and SiSiGeSn layers. Results show a significant enhancement on detector optical properties. PDP reaches 38 % at room temperature and the increase in Pdp due to Bragg reflector reaches 66 %. Although DCR also increases, it can be handled with proper dead time configuration.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"317 ","pages":"Article 172074"},"PeriodicalIF":3.1,"publicationDate":"2024-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142531096","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}
Pub Date : 2024-10-18DOI: 10.1016/j.ijleo.2024.172076
Guowei Zhang
The Jimbo–Miwa equation is the second equation in the KP hierarchy of integrable systems. In this paper, this equation is extended and introduced with the stochastic process and fractional derivatives. Firstly, the phase portrait of the Hamiltonian system generated by it is studied to understand its bifurcation behavior. Additionally, non-periodic and periodic perturbation terms are added to this system. Different values are assigned to the parameters in the perturbation terms to analyze its sensitivity and the resulting chaos is obtained. Finally, through integration techniques, the expression of the solution of this equation is obtained. These solutions are related to rational functions, trigonometric functions, exponential functions and Jacobi elliptic functions. To observe the form of the solutions more intuitively, 3D and 2D numerical simulations are conducted on the solutions and the solution images of the stochastic fractional differential equation are given by Matlab software. Compared with the existing literature, the research on the stochastic fractional equation of this equation is relatively rare and the analysis of the phase portrait is even scarcer. Our solution method is quite different from that in the previous literature. Therefore, this paper is novel. The conclusion of this paper will be of great help for the practical application of this equation.
{"title":"The bifurcation, chaotic behavior and exact solutions of the fractional stochastic Jimbo–Miwa equations","authors":"Guowei Zhang","doi":"10.1016/j.ijleo.2024.172076","DOIUrl":"10.1016/j.ijleo.2024.172076","url":null,"abstract":"<div><div>The Jimbo–Miwa equation is the second equation in the KP hierarchy of integrable systems. In this paper, this equation is extended and introduced with the stochastic process and fractional derivatives. Firstly, the phase portrait of the Hamiltonian system generated by it is studied to understand its bifurcation behavior. Additionally, non-periodic and periodic perturbation terms are added to this system. Different values are assigned to the parameters in the perturbation terms to analyze its sensitivity and the resulting chaos is obtained. Finally, through integration techniques, the expression of the solution of this equation is obtained. These solutions are related to rational functions, trigonometric functions, exponential functions and Jacobi elliptic functions. To observe the form of the solutions more intuitively, 3D and 2D numerical simulations are conducted on the solutions and the solution images of the stochastic fractional differential equation are given by Matlab software. Compared with the existing literature, the research on the stochastic fractional equation of this equation is relatively rare and the analysis of the phase portrait is even scarcer. Our solution method is quite different from that in the previous literature. Therefore, this paper is novel. The conclusion of this paper will be of great help for the practical application of this equation.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"317 ","pages":"Article 172076"},"PeriodicalIF":3.1,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142531582","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}
In this work, we introduce a П-shaped LCPV which works with a simple single-axis solar tracking system. The simulation of the П-shaped LCPV was made on COMSOL Multiphysics and output power of the LCPV was modeled and compared with other PV, LCPV systems using predicted optical efficiency at different incidence angles by regression methods such as XGBoost regression, Linear Regression, Support Vector Regression, Decision Tree Regression, Random Forest Regression. The most effective one was XGBoost regression with accuracy of 91.23931 %. The П-shaped LCPV generates 2.2 times more energy than the fixed nine-solar cell panel per a day. Using nine solar cells and the designed optics allows the system to operate well at wider incidence angles using a single-axis solar tracking system which rotates the system only 4 times a day. The П-shaped LCPV is less complex and cheaper than an ordinary Fresnel lens-based LCPV.
{"title":"Output power analysis of low concentrated solar cells with fresnel lens optics","authors":"Dinara Almen, Ainur Kapparova, Evan Yershov, Sayat Orynbassar, Gulbakhar Dosymbetova, Madiyar Nurgaliyev, Ahmet Saymbetov, Nurzhigit Kuttybay, Batyrbek Zholamanov, Askhat Bolatbek, Nursultan Koshkarbay","doi":"10.1016/j.ijleo.2024.172088","DOIUrl":"10.1016/j.ijleo.2024.172088","url":null,"abstract":"<div><div>In this work, we introduce a П-shaped LCPV which works with a simple single-axis solar tracking system. The simulation of the П-shaped LCPV was made on COMSOL Multiphysics and output power of the LCPV was modeled and compared with other PV, LCPV systems using predicted optical efficiency at different incidence angles by regression methods such as XGBoost regression, Linear Regression, Support Vector Regression, Decision Tree Regression, Random Forest Regression. The most effective one was XGBoost regression with accuracy of 91.23931 %. The П-shaped LCPV generates 2.2 times more energy than the fixed nine-solar cell panel per a day. Using nine solar cells and the designed optics allows the system to operate well at wider incidence angles using a single-axis solar tracking system which rotates the system only 4 times a day. The П-shaped LCPV is less complex and cheaper than an ordinary Fresnel lens-based LCPV.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"317 ","pages":"Article 172088"},"PeriodicalIF":3.1,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142531583","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}
Metalenses represent a paradigm shift in optics, offering unprecedented control over light manipulation. This study focuses on the design optimization of a polarization-insensitive germanium (Ge) metalens operating in the longwave infrared (LWIR) regime. Employing rigorous coupled-wave analysis (RCWA) and finite-difference time-domain (FDTD) simulations, a metalens with 1 mm focal length was designed using nanopillars with 3.5 µm height and radius ranging from 0.55 µm to 1.2 µm. Then, the impact of lattice size and numerical aperture (NA) on lens performance was investigated. The results indicate that smaller lattices allow finer phase control and enhanced transmittance stability across the phase profile if significant coupling effects are not verified. As the NA increases, the focal spot size decreases, albeit with diminishing returns towards the diffraction limit. To the best of our knowledge, it is the first work that shows high focal efficiency (∼80 %) across multiple NA's for a LWIR metalens with a diameter under 1100 µm. The proposed metalens is compatible with complementary metal-oxide-semiconductor (CMOS) technology and supports low-cost manufacturing.
金属透镜代表了光学领域的范式转变，为光操纵提供了前所未有的控制能力。本研究的重点是对工作在长波红外（LWIR）波段的偏振不敏感锗（Ge）金属透镜进行设计优化。利用严格的耦合波分析 (RCWA) 和有限差分时域 (FDTD) 模拟，使用高度为 3.5 µm、半径为 0.55 µm 至 1.2 µm 的纳米柱设计了焦距为 1 mm 的金属膜。然后，研究了晶格尺寸和数值孔径（NA）对透镜性能的影响。结果表明，如果没有验证显著的耦合效应，较小的晶格可以实现更精细的相位控制，并增强整个相位剖面的透射稳定性。随着 NA 的增大，焦斑尺寸也随之减小，但在衍射极限时，焦斑尺寸会逐渐减小。据我们所知，这是第一项工作，显示了直径小于 1100 微米的 LWIR 金属膜在多个 NA 范围内的高聚焦效率（∼80%）。拟议的金属膜与互补金属氧化物半导体（CMOS）技术兼容，支持低成本制造。
{"title":"Germanium metalens for longwave infrared applications","authors":"J.M. Borlido , E.M.F. Vieira , J.H. Correia , J.A. Rodrigues","doi":"10.1016/j.ijleo.2024.172087","DOIUrl":"10.1016/j.ijleo.2024.172087","url":null,"abstract":"<div><div>Metalenses represent a paradigm shift in optics, offering unprecedented control over light manipulation. This study focuses on the design optimization of a polarization-insensitive germanium (Ge) metalens operating in the longwave infrared (LWIR) regime. Employing rigorous coupled-wave analysis (RCWA) and finite-difference time-domain (FDTD) simulations, a metalens with 1 mm focal length was designed using nanopillars with 3.5 µm height and radius ranging from 0.55 µm to 1.2 µm. Then, the impact of lattice size and numerical aperture (NA) on lens performance was investigated. The results indicate that smaller lattices allow finer phase control and enhanced transmittance stability across the phase profile if significant coupling effects are not verified. As the NA increases, the focal spot size decreases, albeit with diminishing returns towards the diffraction limit. To the best of our knowledge, it is the first work that shows high focal efficiency (∼80 %) across multiple NA's for a LWIR metalens with a diameter under 1100 µm. The proposed metalens is compatible with complementary metal-oxide-semiconductor (CMOS) technology and supports low-cost manufacturing.</div></div>","PeriodicalId":19513,"journal":{"name":"Optik","volume":"317 ","pages":"Article 172087"},"PeriodicalIF":3.1,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142531584","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}
Pub Date : 2024-10-11DOI: 10.1016/j.ijleo.2024.172075
Berker Colak , Muharrem Karaaslan , Fatih Ozkan Alkurt , Mehmet Bakir , Volkan Akdogan , Mertcan Oral , Ahmet Sertol Koksal
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.
{"title":"Halvorsen chaotic system based microwave absorber modelling for fighter jet stealth technologies","authors":"Berker Colak , Muharrem Karaaslan , Fatih Ozkan Alkurt , Mehmet Bakir , Volkan Akdogan , Mertcan Oral , 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}
Pub Date : 2024-10-10DOI: 10.1016/j.ijleo.2024.172071
E. Gholipoor , R. Fallah , S.M. Khorashadizadeh , A.R. Niknam
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.
{"title":"Guiding properties of Bessel–Gaussian and super-Gaussian pulses in inhomogeneous parabolic plasma channels","authors":"E. Gholipoor , R. Fallah , S.M. Khorashadizadeh , 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}
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 (Jsc) & conversion efficiency (η) 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 Jsc 0.65 mA/cm2 and η 0.40 %.
{"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, Shalini Singh, Shubham Sharma, Shiva Prakash Singh Kushwaha, Pankaj Srivastava, 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 TiO<sub>2</sub>-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><sub>sc</sub>) & conversion efficiency (<em>η</em>) were observed 0.20 mA/cm<sup>2</sup>, 0.44 mA/cm<sup>2</sup> and 0.09 % 0.38 % respectively. The Bixa seed and Mirabilis flower extracts co-sensitized DSSC revealed enhanced <em>J</em><sub>sc</sub> 0.65 mA/cm<sup>2</sup> 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}
Pub Date : 2024-10-09DOI: 10.1016/j.ijleo.2024.172069
Yunfeng Bi , Xiaohan Bai , Chao Li , Tao Zhang , Zhongyi Bao , Meili Guo , Man Wang , Zhengjiang Ding
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 R2 values of 0.9862, 0.9873, 0.9882, and 0.9916, and RMSE 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.
{"title":"A novel feature screening algorithm for low-resolution LIBS spectrum elemental quantification","authors":"Yunfeng Bi , Xiaohan Bai , Chao Li , Tao Zhang , Zhongyi Bao , Meili Guo , Man Wang , 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>R<sup>2</sup></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}
Pub Date : 2024-10-09DOI: 10.1016/j.ijleo.2024.172073
Y. Prasamsha , N. Mohankumar , M. Arun Kumar , P. Sriramani , H. Maity , Nitin Rakesh
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 (Ls) 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, ), optical power (Pint) and Emission Intensity (EI). The thickness and resistivity 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.
氧化铟锡（ITO）的独特性质使其成为倒装芯片发光二极管（FCLED）和其他光电设备中电流扩散层的绝佳选择。本文通过一个精确的数学模型来分析 FCLED 的性能，即在圆形触点下 ITO 层产生的电流扩散长度 (Ls)。在提取内部量子效率 (IQE,ηint)、光功率 (Pint) 和发射强度 (EI) 时，使用 ABC 模型无近似地列出了表达式。在不同的电流密度下，改变 ITO 层的厚度（tITO）和电阻率（ρITO），并确定它们对 IQE 的不利影响。在电流密度较低时，IQE 随厚度增加而增加，而在 ITO 层电阻率较高时，IQE 则随厚度增加而减少。在较高的电流密度下，由于 "效率下降 "的原因，无论是否存在 ITO 层，IQE 都会逐渐下降。在厚度为 50-200 nm、电流密度为 8 A/cm2 的情况下，所提出的工作的 IQE 为 82%，光功率约为 40 mW，与实验数据显示出良好的一致性，使其成为未来高性能 FCLED 的可行方案。
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