Optics & Laser Technology最新文献

{"title":"Coupling effect of dynamic power and oscillation path on butt weld formation and melt flow behavior during aluminum alloys","authors":"Jiangmei Cui, J.P. Oliveira, Bowen Pang, Jiajia Shen, Zhi Zeng","doi":"10.1016/j.optlastec.2024.111687","DOIUrl":"https://doi.org/10.1016/j.optlastec.2024.111687","url":null,"abstract":"The influence of the coupling effect between dynamic power and oscillation path on the formation of weld seams and the fluid behavior of the molten pool during laser welding of 5A06 aluminum alloy was investigated through numerical simulation and experimentation. Three power modes were compared in the experiments: equal power (EP), delayed dynamic power (D-DP), and non-delayed dynamic power (ND-DP). The experimental results show that both D-DP and ND-DP modes are favorable to improve the mechanical properties. Among them, the joints formed under the D-DP mode exhibit the best mechanical properties, with an average tensile strength reaching ≈ 99.1% of the base material, which is an increase of ≈ 35.3% and ≈ 5.6% compared to the EP and ND-DP modes, respectively. Numerical simulation results indicate that the D-DP mode effectively mitigates the average flow velocity of the molten pool, reduces the collision effects between liquid flows, suppresses the impact of fluid on the keyhole walls, and improves the stability of the keyhole and the welding process, thereby enhancing the mechanical properties of the joints.","PeriodicalId":19597,"journal":{"name":"Optics & Laser Technology","volume":"117 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142219934","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Generation of variable light fields by radially polarized chirped circular Airy vortex beams","authors":"Xiaobing Li, Yang Zhang, Mingyu Liu, Jiayan Li, Jiayang Sun, Wenzhi Wu, Degui Kong","doi":"10.1016/j.optlastec.2024.111724","DOIUrl":"https://doi.org/10.1016/j.optlastec.2024.111724","url":null,"abstract":"Based on Richards-Wolf vector diffraction theory, the tight focusing properties of radially polarized chirped circular Airy vortex beams (RP-CCAVBs) are theoretically investigated using a high numerical aperture objective lens in the paper. The results shown that super-resolution scalable optical needles, dark channels, elliptical optical cages, and optical oscillations can be obtained by adjusting the scale factor, exponential attenuation coefficient, main ring radius, and topological charge of optical vortex in the incident RP-CCAVBs. The DOF of optical needle and dark channels is exponent dependent on scaling factor ω of RP-CCAVBs. And the position optical needle and dark channels can be moved by changing chirped parameter of RP-CCAVBs. The size of obtained optical cages can be adjusted by changing the radius of main rings in RP-CCAVBs. The intensity distribution of the obtained optical oscillations is intensely affected by parameter and chirp parameter of RP-CCAVBs.","PeriodicalId":19597,"journal":{"name":"Optics & Laser Technology","volume":"285 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142219929","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Shedding light on and comparing three different mathematical models of the optical conductivity concept","authors":"Gharam A. Alharshan, H.A. Saudi, Shams A.M. Issa, Hesham M.H. Zakaly, Hosam M. Gomaa","doi":"10.1016/j.optlastec.2024.111690","DOIUrl":"https://doi.org/10.1016/j.optlastec.2024.111690","url":null,"abstract":"The optical response in materials offers valuable insights into their properties, especially regarding interband transitions, distinct from direct current responses. By adjusting the frequency of electromagnetic radiation, interband transitions and energy band mappings can be explored, even in materials like graphene. Optical conductivity, which measures a material’s ability to conduct electricity under the influence of light, is pivotal across physics, materials science, and engineering. It quantifies a material’s efficiency in absorbing and transporting electromagnetic energy as photons. Typically described by Drude’s model, optical conductivity has applications in diverse fields, from designing specific optical properties in materials to optimizing solar cells and developing photonic devices. Plasmonics, meta-materials, and renewable energy research also benefit from understanding and controlling optical conductivity. The optical conductivity problem centers on comprehending materials’ electrical interactions with light across the optical spectrum, which is vital for various technologies. Theoretical models, simulations, and experiments address this problem, aiming to develop tunable materials and enhance theoretical models for accurate prediction of optical properties. Mathematical models, such as Maxwell’s equations, the Lorentz-Drude model, and the Hosam-Heba model, elucidate optical conductivity, aiding in understanding light-material interactions and predicting material behavior under electromagnetic radiation. Each model offers a unique perspective on optical conductivity, with different theoretical foundations and mathematical formulations that can be applied depending on the specific properties of the material being studied. Understanding and manipulating optical conductivity is foundational to utilizing light across various technological applications.","PeriodicalId":19597,"journal":{"name":"Optics & Laser Technology","volume":"60 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142219930","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical simulation and experimental research of molten pool flow field and temperature field by hollow-laser direct energy deposition","authors":"Gangxian Zhu, Lele Zhao, Jiaqin Luo, Jiaqiang Li, Xing Zhang","doi":"10.1016/j.optlastec.2024.111732","DOIUrl":"https://doi.org/10.1016/j.optlastec.2024.111732","url":null,"abstract":"Hollow-laser Direct Energy Deposition (HL-DED) significantly surpasses traditional Laser Directed Energy Deposition (L-DED) methods, marked by its superior adjustability of energy density, exacting control of energy distribution, and versatility in creating cladding layers of varied geometries. This novel technique ensures a markedly uniform and stable melt path. In this paper, the HL-DED process was systematically analyzed by combining numerical simulation and experimental research. A novel three-dimensional transient computational fluid dynamics (CFD) simulation model is established based on the Flow 3D software to study the flow and heat and mass transfer behaviors. At the optimized processing parameters, the single-track and multi-track cladding layer processes were carried out respectively. Results show that the model can well predict and explain the flow of the molten pool and the morphology of the cladding layer in the HL-DED process. In the initial stage of single-track cladding, the molten pool exhibits a symmetrical bimodal distribution configuration characterized by the peak flow rate of 0.09 m/s, with temperatures being higher at the periphery and lower at the center. In the stabilization phase, the dynamics of the molten pool are primarily influenced by gas-powder momentum transfer, showing increased peak flow rates up to 0.26 m/s. Concurrently, the peripheral temperatures rise from 2001 K to 2122 K (0.06 % increase), but central temperatures ascend from 1400 K to 1800 K (0.29 % increase). The flow and temperature distribution patterns in multi-track cladding closely mirror those observed in single-track layers, maintaining a symmetrical bimodal temperature distribution with peak flow rates reaching 0.105 m/s. The temperature distribution evolves from a unimodal to a bimodal pattern, with the left peak approximately 100 K higher than the right, before reverting to a unimodal configuration. Simulation outcomes closely align with experimental findings, offering valuable insights for refining the experimental adjustment of the internal optical coaxial powder feeding process.","PeriodicalId":19597,"journal":{"name":"Optics & Laser Technology","volume":"27 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142219931","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improving the beam pointing and intensity stability of the third harmonic generated in air filament","authors":"Fukang Yin, Yaoxiang Liu, Tie-Jun Wang, Yingxia Wei, Juan Long, Hengyi Zheng, Chengpu Liu, Yuxin Leng","doi":"10.1016/j.optlastec.2024.111717","DOIUrl":"https://doi.org/10.1016/j.optlastec.2024.111717","url":null,"abstract":"Third harmonic generation (THG) by laser filamentation in gases is immune to the damage threshold and phase matching limit for UV and EUV pulse generation. Here, we report on the jitter measurements of the beam pointing and the intensity of the THG through filamentation with different repetition rates in air. The THG jitters are stronger at the high repetition rates (1 kHz) filaments. A technique of applying an external DC electric field on the filament was found to suppress the jitters. The beam pointing and intensity jitters of the 1 kHz THG from laser filament in air were reduced by about 1 fold with the extreme external electric field electric field applied on the filament. This technique provides a way to generate a stable, high repetition rate UV and EUV sources.","PeriodicalId":19597,"journal":{"name":"Optics & Laser Technology","volume":"27 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142219932","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Real-time estimation of blood oxygenation parameters from human foot sole during leg elevation: A preliminary study with diffuse reflectance spectroscopy","authors":"Ajay Kumar, Viney Lohchab, Dnyandeo Pawar, Vimal Someshwar, Vikas Mathe, Sudhir Husale, Rajesh Kanawade","doi":"10.1016/j.optlastec.2024.111706","DOIUrl":"https://doi.org/10.1016/j.optlastec.2024.111706","url":null,"abstract":"This study investigated the applicability of diffuse reflectance spectroscopy (DRS) for real-time and non-invasive measurement of blood oxygenation parameters (BOPs) such as reduced hemoglobin (RHb), oxyhemoglobin (HbO), and oxygen saturation (SO) from human foot sole during leg elevation. Seventeen (17) healthy male subjects aged between 21 to 39 years were included in this study. Diffuse reflectance spectra were recorded from measurement sites namely the 5th metatarsal, ball of great joint, calcaneum, and great toe of the human foot sole w.r.t. leg elevation angles such as 0, 15, 30, 45, and 60, respectively. The localized BOPs were derived from the recorded spectra. In addition, blood hemodynamic parameters (BHPs) such as heart rate (HR), SO, perfusion index (PI), systolic blood pressure (SBP), and diastolic blood pressure (DBP) were also measured for each elevating angle. To study and assess the changes in BOPs and BHPs w.r.t. leg elevation, a One-way ANOVA test followed by a Tukey HSD post-hoc test was performed. We observed a statistically significant increase in RHb (p < 0.001) and a decrease in HbO (p < 0.001) after 45° of leg elevation, however, there was no statistically significant difference in SO (p = 0.74) and HR (p = 0.84) for each measurement site w.r.t. leg elevation, respectively. Furthermore, PI (p < 0.01), ankle SBP (p < 0.001) and DBP (p < 0.001) were decreased w.r.t. leg elevation. The obtained results are in agreement with the literature. The preliminary results suggest that DRS has the potential for real-time estimation of BOPs from the local sites of healthy human foot soles during leg elevation. Thus, it opens the possibility of DRS to monitor and evaluate the diagnosis and treatment of ischemia and edema during leg elevation of patients through BOPs measurement.","PeriodicalId":19597,"journal":{"name":"Optics & Laser Technology","volume":"171 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142219933","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Regulating thermal management by a CsPbClBr2/Ag hybrid microcavity for stable room temperature blue lasing with low threshold","authors":"Shulei Li, Zhenxu Lin, Quantong Deng, Fu Deng, Mingcheng Panmai, Junying Chen, Yuheng Mao, Shimei Liu, Jun Dai, Yunbao Zheng, Rui Huang, Sheng Lan","doi":"10.1016/j.optlastec.2024.111723","DOIUrl":"https://doi.org/10.1016/j.optlastec.2024.111723","url":null,"abstract":"Realization of long-term stable lasing from all-inorganic perovskite supercrystals is highly desirable for practical applications in optoelectronic devices. However, lasing from perovskite supercrystals excited by continuous wave laser light remains a challenge due to the photoluminescence degradation induced by thermal accumulation. Here, we report highly stable lasing with low threshold fom a CsPbClBr supercrystal placed on a thin Ag film, which form a CsPbClBr/Ag microcavity, by managing the thermal distribution inside the CsPbClBr supercrystal. Combined numerical simulations and lifetime measurements, the localized electric field in such a hybrid microcavity leads to a spatially localized temperature distribution, which plays a crucial role in suppressing the thermal accumulation on the surface and in eliminating non-radiative recombination defects. The effective thermal management in the hybrid microcavity renders highly stable lasing with low threshold under the irradiation of continuouw wave laser light. Our findings provide a feasible and universal approach to the development of long-term stable perovskite laser.","PeriodicalId":19597,"journal":{"name":"Optics & Laser Technology","volume":"145 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142219974","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Broadband multiple resonant metasurface for mixture surface-enhanced infrared absorption based on polarization-sensitive folded nanoantennas","authors":"Si Luo, Yunlian Ding, Meiyan Pan, Rujun Zhou, Haichao Han, Zijun Liao, Daru Chen","doi":"10.1016/j.optlastec.2024.111685","DOIUrl":"https://doi.org/10.1016/j.optlastec.2024.111685","url":null,"abstract":"Multiple resonant metasurfaces for mixture component detection by surface-enhanced infrared absorption in a broadband spectrum region are still highly desirable. This paper presents a polarization-sensitive multi-resonant broadband metasurface in the mid-infrared (MIR) region based on an odd symmetric folded antenna array. Six major resonant modes are effectively excited in 6–15 μm covering the absorption peak of multiple gases and biomolecules. In addition, the calculation indicates the maximum electric field intensity enhancement reaches 3607 and the average electric enhancement factors are dominantly amplified to a maximum of 75.08. The excited multiple hotspots provide more spatial overlap with analytes and would be beneficial for label-free detection. Moreover, owing to the contributions of the intrinsic phonons and polaritons in the ENZ material, the spectroscopy features are relatively stable when changing the geometry parameters and the incident angles, allowing more fabrication tolerance and experiment flexibility. Furthermore, the multiple resonant metasurface is also effectively enabled under orthogonal circular polarizations. Finally, the sensing abilities of the designed metasurface for polyethylene terephthalate and isopropanol molecules have been computationally validated. These results indicate the potential for nanophotonic detection and mixture spectroscopy analysis.","PeriodicalId":19597,"journal":{"name":"Optics & Laser Technology","volume":"21 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142219976","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Research on accurate analysis of coal quality using NIRS-XRF fusion spectroscopy in complex coal type scenarios","authors":"Jiaxuan Li, Rui Gao, Yan Zhang, Lei Zhang, Lei Dong, Weiguang Ma, Wangbao Yin, Suotang Jia","doi":"10.1016/j.optlastec.2024.111734","DOIUrl":"https://doi.org/10.1016/j.optlastec.2024.111734","url":null,"abstract":"Coking coal in coal chemical enterprises presents a challenge due to its diverse types, wide sources, and variable quality, influenced by varying degrees of metamorphism and physicochemical properties. These differences not only impact coal quality but also hinder accurate analysis. Rapid and precise coal quality detection amidst diverse coal types is crucial for maintaining stable production and ensuring coke quality. This study employs near-infrared spectroscopy (NIRS) and X-ray fluorescence spectroscopy (XRF) fusion spectroscopy analysis, along with Principal Component Analysis (PCA) and t-Distributed Stochastic Neighbor Embedding (t-SNE), for data dimensionality reduction and visualization to devise a coal sample classification strategy. Subsequently, Support Vector Machine (SVM) is employed for automatic coal sample classification based on this strategy. Finally, Partial Least Squares Regression (PLSR) is used to establish regression models and evaluate their performance in predicting coal quality. Results show that classified regression model achieves values of 0.9987, 0.9955, and 0.9997 for ash content, volatile matter, and sulfur content, with corresponding root mean square error for prediction () of 0.31 %, 1.34 %, and 0.05 %, and the mean absolute relative error for prediction () of 2.48 %, 3.58 %, and 3.57 %, respectively. Compared to the unclassified model, there is a significant enhancement in prediction accuracy. The classification and modeling method proposed herein effectively improve the accuracy of coal quality analysis in complex coal type scenarios, crucial for industries like coal chemical engineering to enhance production efficiency and optimize coal resource utilization.","PeriodicalId":19597,"journal":{"name":"Optics & Laser Technology","volume":"18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142219972","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Generation of atto-zeptosecond X-rays through cross-collision between relativistic electron and tightly focused intense laser pulse","authors":"Qingyu Yang, Youwei Tian, Yizhang Li, Yubo Wang","doi":"10.1016/j.optlastec.2024.111719","DOIUrl":"https://doi.org/10.1016/j.optlastec.2024.111719","url":null,"abstract":"The generation of ultrashort pulses is a hot topic in ultrafast physics. In the framework of classical electrodynamics, the process of nonlinear cross Thomson scattering which involves sideways radiation generation by a high-energy single electron cross-colliding with a tightly focused circularly polarized intense laser pulse is investigated through numerical simulation. For spatial limited tightly focused laser pulses, the laser delay time determines the position the electron interacts with, so precise control of the laser delay time to ensure the electron collides with the laser center is the key to obtaining high-power radiation. Through the research on the time evolution of electron radiation, it is found that the nonlinear cross Thomson scattering power is related to the coupling of electron velocity and its acceleration, where the increase of the electron velocity is critical to obtaining higher-power radiation. For off-axis electrons, the increase in deviation distance mainly leads to a decrease in radiation power, rather than pulse width and central photon energy. For low initial energy electrons, the asymmetry brought about by cross-collisions will improve the spatial collimation. For high-energy electrons, the asymmetry is weakened but the spatial collimation is enhanced. Using a single electron with an initial energy of 100 MeV and a laser pulse with an intensity of about , hard -rays can be generated. This study reveals part of the mechanism of nonlinear cross Thomson scattering and provides the theoretical basis and parameter suggestions for the design of the next generation ultrashort high-energy pulse generator.","PeriodicalId":19597,"journal":{"name":"Optics & Laser Technology","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142219975","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}