- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Tailoring Properties of Microcavity In-line Mach-Zehnder Interferometer by the Microcavity Enlargement using Femtosecond Laser
摘要： This work presents a theoretical analysis and experimental verification of fine-tuning of the spectral response and refractive index (RI) sensitivity of microcavity in-line Mach-Zehnder interferometer (μIMZI). The μIMZIs were fabricated using femtosecond (fs) laser micromachining in standard single-mode fibers as circular cavities with a diameter of 60 μm. Next, the structures underwent fs laser post-processing, which included fabrication of an additional cavity with the same diameter but shifted by 15 μm or 30 μm against the center of the initial microcavity. Different depths of the additional structures were investigated. The enlargement of the microcavity allows for tailoring the spectral response, i.e., it shifts the interference pattern by more than 200 nm, with no introduction of any additional losses and distortions in the spectrum. As the additional effect, regardless of the size of the extension, the sensitivity of the enlarged μIMZI was improved by 32%.
关键词： Fiber optics sensors,Laser materials processing,Interferometry,Microcavities,Microstructure fabrication
更新于2025-11-28 14:23:57
-
[IEEE 2018 IEEE 7th World Conference on Photovoltaic Energy Conversion (WCPEC) (A Joint Conference of 45th IEEE PVSC, 28th PVSEC & 34th EU PVSEC) - Waikoloa Village, HI, USA (2018.6.10-2018.6.15)] 2018 IEEE 7th World Conference on Photovoltaic Energy Conversion (WCPEC) (A Joint Conference of 45th IEEE PVSC, 28th PVSEC & 34th EU PVSEC) - Plasma Texturing of Silicon Wafers and Finished Solar Cell for Mass Production
摘要： Standard plasma texturing of silicon wafers are not widely introduced within mass production due to several challenges which have to be overcome before implementation i.e. surface contamination, surface near damaging due to ion bombardment, and surface passivation. Within this contribution we will show our current status to overcome these challenges. We will present that the electrical and optical properties of ICP only plasma textured samples are sufficient for solar cell production. Since in ICP processes the ion bombardment is low we also will discuss our current understanding of the plasma process based on experimental results of the self-masking process. Furthermore, a new plasma texturing approach texturing the SiN layer of finished solar cells is introduced for the first time which overcome all problems introduced by the plasma texturing of bare solar wafers.
关键词： Plasma materials processing,silicon,SiN texturing,Plasma texturing,photovoltaic cells
更新于2025-10-22 19:40:53
-
Brazing, Laser, and Electron-Beam Welding of Additively Manufactured GRCop-84 Copper for Phased Array Lower Hybrid Launchers
摘要： Recent advances in selective laser melting 3-D printing technology allow additive manufacturing of lower hybrid current drive (LHCD) RF launchers from a new material, Glenn Research Copper 84 (GRCop-84), a Cr2Nb (8 at. % Cr, 4 at. % Nb) precipitation hardened alloy, in configurations unachievable by conventional machining. Cr2Nb crystals pin grain boundaries within the copper matrix resulting in high tensile strength and resistance to annealing at elevated temperatures. Brazing, laser, and electron-beam welding (EBW) techniques are explored for joining a thin-walled GRCop-84 waveguide with zero porosity and minimal internal surface roughness. GRCop-84 wets well with the silver solder, CuSil, and Cusil-ABA brazes, once the durable surface oxide is mechanically removed. GRCop-84 melt pool size and flow during EBW is reduced compared to oxygen-free copper (OFC). Pulsed laser and e-beam welding maintains the Cr2Nb precipitate size; precipitate coarsening occurs in conduction mode e-beam welding.
关键词： joining processes,fusion reactor design,magnetic confinement,Annealing,tokamaks,copper alloys,melt processing,materials processing,phased arrays,waveguide
更新于2025-09-23 15:21:01
-
[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - PolySi Based Passivating Contacts Enabling Industrial Silicon Solar Cell Efficiencies up to 24%
摘要： An RF argon plasma jet has been explored using high-speed camera imaging at 10 000 frames/s. Small variations of gas ?ow and/or RF power lead to instabilities of the ?lament movement. Two types of instabilities have been observed depending on the interrelated azimuthal velocities of ?laments. In the case of antiparallel ?lament velocities, one ?lament is collapsing and fuses with the other ?lament, while the collapsing ?lament exhibits a striated structure. In the case of parallel velocities, both ?laments establish a symmetric con?guration and rotate with constant velocity in the jet. Spatially and temporally resolved features are visualized with a time-colored stroboscopic image.
关键词： plasma stability,plasma materials processing,Image processing
更新于2025-09-23 15:19:57
-
Recent progress in laser materials processing and synthesis
摘要： Already today, high-power lasers have become indispensable for many areas of material processing such as welding, cutting, engraving or drilling. Without them, many industrial production processes are no longer possible. In the age of Industry 4.0, the integration of intelligent production systems and advanced information technologies, laser-assisted material processing, and synthesis will become even more important. Thanks to their high throughput, great precision, and efficiency as well as the excellent quality of the processed products laser-based technologies are on the way of becoming one of the most important processing and production routes of the future. By changing laser parameters such as wavelength or pulse durations many different types of materials, including metals, polymers, ceramics, and their composites can be processed. The energy required for processing can be provided in a localized volume with negligible heat transfer to the surrounding components. Due to these unique properties of lasers, new applications of the laser as a material processing tool are continuously made available. New process pathways in additive manufacturing, surface structuring, material deposition or nanoparticle synthesis are among the newer application areas of lasers.
关键词： nanoparticle synthesis,laser materials processing,laser synthesis,additive manufacturing,high-power lasers
更新于2025-09-23 15:19:57
-
Tandem laser-gas metal arc welding joining of 20a??mm thick super duplex stainless steel: An experimental and numerical study
摘要： The present work covers the topic of strains and stresses prediction in case of welded steel structures. Steel sheets of 20 mm thickness made in URTM2507Cu are welded using a laser and gas metal arc welding processes combination. The focused laser beam leads the arc in a Y-shape chamfer geometry. Both sources are 20 mm apart from each other in order to avoid any synergic effect with each other. In order to predict residual strain, a 3D unsteady numerical simulation has been developed in COMSOL finite element software. A volume heat source has been identified based on the temperature measurements made by 10 K-type thermocouples, implanted inside the workpiece. The 50 mm deep holes are drilled in the workpiece using dye-sinking Electrical Discharge Machining (EDM) machine. Before the implantation in the hole, each thermocouple is surrounded by Inconel sheathing. Hot junctions of the thermocouples are positioned in a way to feel two advancing molten pools. The equivalent heat source is composed of three sources. First one is a Goldak source that represents the molten pool induced by gas metal arc welding. The second one is a cylinder with an elliptic cross-section that represents the focused laser beam penetrating into the workpiece. The third one is a surface Gaussian source that represents energy radiated by arc and blocked by workpiece surface. Concerning mechanical simulation, an elasto-plastic behavior with isotropic hardening is implemented. A weak coupling is established between equations governing heat transfer and mechanics thanks to the temperature dependent coefficient of linear expansion. This numerical simulation made with some simplifying assumptions predicts an angular distortion and a longitudinal shrinkage of the welded structure. The numerical results are consistent with the displacements measured by digital image correlation method.
关键词： welding,simulation,Finite element method,materials processing,laser-gas metal arc welding,thermomechanics
更新于2025-09-23 15:19:57
-
[IEEE 2019 IEEE Pulsed Power & Plasma Science (PPPS) - Orlando, FL, USA (2019.6.23-2019.6.29)] 2019 IEEE Pulsed Power & Plasma Science (PPPS) - Electro-Optical Measurement of Electric Fields for Pulsed Power Systems
摘要： An RF argon plasma jet has been explored using high-speed camera imaging at 10 000 frames/s. Small variations of gas ?ow and/or RF power lead to instabilities of the ?lament movement. Two types of instabilities have been observed depending on the interrelated azimuthal velocities of ?laments. In the case of antiparallel ?lament velocities, one ?lament is collapsing and fuses with the other ?lament, while the collapsing ?lament exhibits a striated structure. In the case of parallel velocities, both ?laments establish a symmetric con?guration and rotate with constant velocity in the jet. Spatially and temporally resolved features are visualized with a time-colored stroboscopic image.
关键词： plasma stability,Image processing,plasma materials processing
更新于2025-09-19 17:13:59
-
Optimal Cleaning Scheduling for Photovoltaic Systems in the Field Based on Electricity Generation and Dust Deposition Forecasting
摘要： An RF argon plasma jet has been explored using high-speed camera imaging at 10 000 frames/s. Small variations of gas ?ow and/or RF power lead to instabilities of the ?lament movement. Two types of instabilities have been observed depending on the interrelated azimuthal velocities of ?laments. In the case of antiparallel ?lament velocities, one ?lament is collapsing and fuses with the other ?lament, while the collapsing ?lament exhibits a striated structure. In the case of parallel velocities, both ?laments establish a symmetric con?guration and rotate with constant velocity in the jet. Spatially and temporally resolved features are visualized with a time-colored stroboscopic image.
关键词： plasma materials processing,plasma stability,Image processing
更新于2025-09-19 17:13:59
-
Multi-Objective Optimization of High Power Diode Laser Surface Hardening Process of AISI 410 by means of RSM and Desirability Approach
摘要： In this research, laser surface hardening of AISI 410 was carried out by a high power diode laser based on Response Surface Method (RSM). Laser power, scanning speed, and focal plane position were evaluated as input process changeable while geometry dimensions of hardened zone (i.e., Depth and width of hardness), maximum hardness, Microhardness deviation (MHD) from base material in depth, and ferrite phase percentage in the microstructure were evaluated as process output Results. The effect of input parameters on the response variations were studied by statistical investigation. Results indicated that by increasing the laser power and decreasing other parameters, higher surface hardness with significant penetration, and least ferrite percentage would be reached by means of the desirability function approach. By using experimental tests, validation of optimized results was performed. In this research in the optimum conditions, the maximum hardness, maximum depth of hardness and minimum ferrite percentage were achieved 670 Vickers, 2.2 mm and 0.45%, respectively.
关键词： Laser Surface Hardening,High Power Diode Laser,Design of Experiments,Laser Materials Processing,Optimization
更新于2025-09-19 17:13:59
-
[IEEE IGARSS 2019 - 2019 IEEE International Geoscience and Remote Sensing Symposium - Yokohama, Japan (2019.7.28-2019.8.2)] IGARSS 2019 - 2019 IEEE International Geoscience and Remote Sensing Symposium - First Results from Laser-Based Spectral Characterization of Landsat 9 Operational Land Imager-2
摘要： An RF argon plasma jet has been explored using high-speed camera imaging at 10 000 frames/s. Small variations of gas ?ow and/or RF power lead to instabilities of the ?lament movement. Two types of instabilities have been observed depending on the interrelated azimuthal velocities of ?laments. In the case of antiparallel ?lament velocities, one ?lament is collapsing and fuses with the other ?lament, while the collapsing ?lament exhibits a striated structure. In the case of parallel velocities, both ?laments establish a symmetric con?guration and rotate with constant velocity in the jet. Spatially and temporally resolved features are visualized with a time-colored stroboscopic image.
关键词： plasma stability,Image processing,plasma materials processing
更新于2025-09-16 10:30:52