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[IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Ultrasensitive refractive index sensor based on Cascaded tilted fiber Bragg grating
摘要： An ultrasensitive refractive index sensor based on cascaded tilted fiber Bragg grating (CTFBG) is proposed and simulated. On the basis of TFBG theory, CTFBG is theoretically deduced by the transmission matrix method. The spectral characteristics of CTFBG under different surrounding refractive indexes are simulated and analyzed. The results show that the small changes of surrounding refractive index has little effect on the core mode, but has great influence on the cladding mode. The high-order cladding mode near 1557.67nm is extremely sensitive to the surrounding refractive index, and when the surrounding refractive index increases from 1.44322 to 1.44330, the sensitivity of CTFBG refractive index sensor is 9.39×105 dB/RIU, which is nearly double that of TFBG.
关键词： surrounding refractive index,high-order cladding mode,CTFBG
更新于2025-09-16 10:30:52
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[Laser Institute of America ICALEO? 2016: 35th International Congress on Applications of Lasers & Electro-Optics - San Diego, California, USA (October 16–20, 2016)] International Congress on Applications of Lasers & Electro-Optics - Rapid prototyping based on laser cladding of cp-Ti
摘要： Commercially pure titanium (cp-Ti) and titanium alloys are successful metallic biomaterials for implants because of their biocompatibility, corrosion resistance, fatigue strength, and a relatively low elastic modulus to minimize “stress shielding” and osteopenia. Nowadays, titanium components are manufactured by conventional subtractive methods, which show a set of inconveniences: titanium has low machinability, loss of high cost material during machining, and the geometrical limitation for the shapes achieved by subtractive methods. Rapid Prototyping based on Laser Cladding is an Additive Manufacturing (AM) technique that can be applied to any material which can be melted. It can be found under different names and acronyms: Laser Consolidation (LC), Direct Laser Deposition (DLD), Laser Metal Deposition (LMD), Laser Engineering Net Shaping (LENS), etc. Rapid Prototyping based on Laser Cladding can become a solution to manufacture advanced pure titanium components customized for the final user, with new geometries and/or with enhanced microstructures and mechanical properties for a better performance. In this research work, Laser Additive Manufacturing was employed to obtain simple parts made out of commercially pure titanium. Generated parts were analyzed by Optical Microscopy (OM), Optical Profilometry (OP), Scanning Electron Microscopy (SEM), and Energy Dispersive X-Ray Spectroscopy (EDS) to study morphology, microstructure, and composition.
关键词： Titanium,cp-Ti,Additive Manufacturing,Rapid Prototyping,Laser Cladding
更新于2025-09-16 10:30:52
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Lasing and Gain Properties of Multicomponent Optical Fibers with Heavily Er-Doped Phosphate Core and Silica Cladding
摘要： The most common Er-doped fibres being used today are silica-based. However solubility limit of erbium ions in silica glass restrict shortening of the gain medium in fibre light sources and that way, it limits improving single-frequency fibre lasers, amplifiers and pulsed fibre lasers characteristics. Shortening of a fibre gain medium might be successfully realised by using high-concentration Er-doped phosphate glasses. It was shown that such type of glass allows getting rare-earth ions concentration an order of magnitude higher in comparison with silica glasses without ions clusterization [1]. But significant drawbacks of phosphate fibres are their low corrosion resistance and high losses of its fusion splices with standard silica fibres [2]. The main purpose of our work was an investigation of fibre light sources based on novel multicomponent fibre with 3wt.% Er-doped phosphate core and silica cladding, which take advantages of both phosphate and silica glasses.
关键词： phosphate core,Er-doped fibres,silica cladding,multicomponent fibre,fibre light sources
更新于2025-09-16 10:30:52
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Analysis of the Source Type Influence on the Structure Forming during Aluminum Wire-Feed Laser Deposition
摘要： Most of the enterprises around the world engaged in various industrial sectors appreciated the potential of additive technologies. One such technology is direct laser deposition. The technology of direct laser deposition is most relevant for the manufacture and restoration of parts due to lower time and resource costs compared to traditional technologies. The use of wire instead of powder can reduce the consumption of filler material and improve production efficiency. The article presents the results of the study of the additive technology of direct deposition from aluminum wire using various energy sources - laser, arc, and combined laser-arc. Also presented grown samples obtained by each method. Metallographic studies were carried out to study the structure of grown samples from the aluminum alloy AlMg6Zr. Experimental work was carried out on a technological complex based on an ytterbium fiber laser with a power of up to 16 kW (LS-16) and an arc source for MIG welding.
关键词： high power laser,microstructure aluminum based alloys,laser cladding
更新于2025-09-16 10:30:52
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Modeling of the Formation Process of the Coherent Intermetallides in Nickel Alloys during Laser Treatment
摘要： A solution for new phase inclusion growth is suggested for the case of the Ni-based alloys. This solution takes into account a chemical composition of the alloy and conditions of the laser treatment process. A method for calculation of the chemical reaction rate constant is also suggested for the Ni3Al formation in the Ni-Al alloy. Modeling is fulfilled for the laser cladding process. Time dependences for the reacting component concentration is obtained as well as for intermetallic inclusion growth and thermal cycle.
关键词： reaction rate constant,powder GS6U,laser cladding,Ni3Al intermetallide,new phase inclusion growth
更新于2025-09-16 10:30:52
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Application of Laser Metal Deposition for a New Model of Assembled Camshaft
摘要： This work introduces the invention of an alternative camshaft manufacturing method aimed at improving the efficiency of the process and providing a more flexible product. The innovation consists in the laser metal deposition (LMD) of a profile on the shaft in order to realize a coupling stretch where the cam is fixed by interference. Alternative profile materials (1.4404 steel and Inconel 625 alloy) are deposited on a 1.0421 steel tube at different laser power levels and powder flow rate. The effect of the process parameters on the deposited profile is investigated initially through the evaluation of indirect quality attributes, such as deposit dimensions, hardness values, and microstructure. Then, the coupling force resulting from the press-fit test is evaluated. Finally, the best configuration of this new assembled camshaft is tested with a torsion test rig. Performances of the new assembled camshaft are compared with those of traditional products, leading to the validation of this innovative solution. The preliminary feasibility of the LMD application to the production of an assembled camshaft is demonstrated.
关键词： additive manufacturing,cladding,hardness,testing,laser metal deposition (LMD),dilution
更新于2025-09-16 10:30:52
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[IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Fabrication and sensing characteristics of 2 μm long period fiber grating written in double cladding fiber by CO <sub/>2</sub> laser
摘要： We demonstrate the fabrication of long period fiber gratings (LPFGs) in double cladding fiber in mid-infrared wavelength. The experimental results show that the LPFGs with a resonance dip in mid-infrared wavelength have much higher sensitivity.
关键词： double cladding fiber,fiber sensor,Long-period fiber grating
更新于2025-09-16 10:30:52
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Study on direct laser metal deposition
摘要： In the current economic situation with worldwide trend for developing new products, the importance of time and cost reduction increases day-by-day. To achieve this goal the man-machine-material interaction should be maximized. Direct laser metal deposition (DLMD) is one of the most famous approaches for this. DLMD is one kind of 3D printing technology (Additive Manufacturing) together with laser cladding process. In DLMD, it is possible to fabricate fully functional metallic parts directly from CAD data, which involves a feeding of metal powders through a nozzle into a high power laser beam and creates a melt pool on the surface of the solid substrate upon which a metallic powder is injected. DLMD process are now acknowledged worldwide and is also known to all by several other names such as Laser engineered net shaping (LENS), Direct light fabrication (DLF), Laser deposition welding (LDW) and powder fusion welding (PFW). The role of nozzle in this process is as important as the heart of a human being. There are variety of nozzle configurations namely off-axis, continuous coaxial and discontinuous coaxial powder injection. Comparison of these types of configurations towards specific applications revels very interesting observations which are subsequently reproduced in this article. In DLMD, powder metals are fed through the nozzle onto a metallic substrate. Then, powder melts by the laser heat and creates a metal pool on the solid substrate by fusion bonding. Once the deposition of a layer, the laser head, along with the powder delivery nozzle, move up. The whole process is carried out until final near-net-shape of the metal part or component is achieved with a variety of material applicability and high quality clad track deposition with good mechanical properties. After development of this process in 1995, lot of researchers for several years work on various aspects of high quality deposition with dimensional accuracy such as good clad geometry, clad height, and microstructure study of the mechanical properties. Through this paper on the basis of literature survey an attempt has been made to focus on proper selection of the set up configuration for direct laser metal deposition to fulfill the requirement and helps to achieve high quality deposition.
关键词： 3D printing,Laser cladding,Additive manufacturing
更新于2025-09-16 10:30:52
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[Laser Institute of America ICALEO? 2015: 34th International Congress on Laser Materials Processing, Laser Microprocessing and Nanomanufacturing - Atlanta, Georgia, USA (October 18–22, 2015)] International Congress on Applications of Lasers & Electro-Optics - Hot wire laser cladding for repairing martensite precipitation hardening stainless steel
摘要： Martensite precipitation hardening stainless steel (M-PHSS) is widely used as load-bearing parts because of its excellent overall properties. It is economical and flexible to repair the failure parts instead of changing new ones. However, it is difficult to keep the properties of repaired layer as good as the substrate. Multi-pass layers were cladded on the surface of FV520B by hot wire laser cladding. Response surface methodology (RSM) was used to optimize processing parameters and predict formation quality of multi-pass cladding. Microstructure of the as-cladded layer was non-uniform and divided into quenched and tempered region. For the as-cladded layer, tensile strength was almost equivalent to that of the substrate, while ductility and impact toughness deteriorated much. With using laser scanning, microstructure of the clad layers was tempered to fine martensite uniformly. The ductility and toughness of clad layer were improved to be equivalent to those of the substrate, while the tensile strength was a little lower than that of the substrate. By adding TiC nanoparticles as well as laser scanning, the precipitation strengthening effect was improved and the structure was refined in the clad layer. As a result, the strength, ductility and toughness were all improved further. Finally, high quality clad layers were obtained with equivalent or even superior mechanical properties to the substrate, offering a valuable technique to repair M-PHSS.
关键词： Mechanical properties,Microstructure,Hot wire laser cladding,Martensite precipitation hardening stainless steel,Repair
更新于2025-09-16 10:30:52
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[IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Immunosensor Based On Cladding-etched Excessively Tilted Fiber Grating Coated With Graphene Oxide
摘要： In this work, a bovine serum albumin (BSA) immunosensor based on graphene oxide (GO) modified cladding-etched excessively tilted fiber grating (ExTFG) is proposed, and the basic principle and sensing characteristics of the sensor are analyzed. Refractive index (RI) sensitivity of ExTFG is increased by 77.17% by etching to 80μm. The cladding-etched ExTFG is coated with GO, and then BSA anti-monoclonal antibody (anti-MABs) are immobilized on its surface, so as to realize the special detection for BSA. Experimental results show that the sensitivity is about five times of that of the un-etched GO-coated ExTFG, the limit of detection (LOD) is ~0.165 nM by using optical spectrum analyzer with a resolution of 0.03nm.
关键词： Graphene oxide (GO),Cladding etching,Excessively tilted fiber grating (ExTFG),Immunosensor
更新于2025-09-16 10:30:52