High-Power Lasers for Materials Processing

A special issue of Micromachines (ISSN 2072-666X). This special issue belongs to the section "D:Materials and Processing".

Deadline for manuscript submissions: closed (31 December 2022) | Viewed by 12441

Special Issue Editor

Centre National de la Recherche Scientifique (CNRS), Franche-Comté Electronique Mécanique Thermique Optique Sciences et Technologies (FEMTO-ST) Institute, Université de Franche-Comté (UFC), 25000 Besançon, France
Interests: optoelectronic oscillators; optical resonators; instrumentation; Brillouin light scattering
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Power lasers have been around for a long time. Many lasers are available from different laser manufacturers. Lasers of high average power have multiple applications for working materials (drilling, sanding, hardening, welding, or cutting, etc.). The principle of laser welding is based on the fusion of a point of the material on which the beam will concentrate thanks to the optical system. After focusing, its illumination can reach more than 1 MW/cm². Lasers can be used for surface treatments. They can also be used to characterize the nature of materials by interacting with the medium, for example to form phononic waves in the material and allow the material to respond. Accordingly, this Special Issue seeks to showcase research papers, communications, and review articles that focus on the efforts made to solve problems, cut and treat surfaces, characterize materials, or any other application of these lasers.

Dr. Patrice Salzenstein
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Micromachines is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • high-power lasers
  • materials processing
  • laser drilling
  • laser sanding
  • laser hardening
  • laser welding
  • laser cutting
  • surface treatments

Related Special Issue

Published Papers (8 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Editorial

Jump to: Research

2 pages, 172 KiB  
Editorial
Editorial for the Special Issue on High-Power Lasers for Materials Processing
by Patrice Salzenstein
Micromachines 2023, 14(5), 1041; https://0-doi-org.brum.beds.ac.uk/10.3390/mi14051041 - 12 May 2023
Viewed by 721
Abstract
Power lasers have been around for a long time [...] Full article
(This article belongs to the Special Issue High-Power Lasers for Materials Processing)

Research

Jump to: Editorial

8 pages, 7015 KiB  
Article
A 3.7-kW Oscillating-Amplifying Integrated Fiber Laser Featuring a Compact Oval-Shaped Cylinder Package
by Donglin Yan, Ruoyu Liao, Chao Guo, Pengfei Zhao, Qiang Shu, Honghuan Lin, Jianjun Wang and Rumao Tao
Micromachines 2023, 14(2), 264; https://0-doi-org.brum.beds.ac.uk/10.3390/mi14020264 - 20 Jan 2023
Cited by 2 | Viewed by 1560
Abstract
Combining the advantages of high efficiency, environmental robustness, and anti-reflection behavior, oscillating-amplifying integrated fiber lasers have become popular for use in high-power laser structures in industrial applications, wherein the size of the laser source matters. Here, an oscillating-amplifying integrated fiber laser in an [...] Read more.
Combining the advantages of high efficiency, environmental robustness, and anti-reflection behavior, oscillating-amplifying integrated fiber lasers have become popular for use in high-power laser structures in industrial applications, wherein the size of the laser source matters. Here, an oscillating-amplifying integrated fiber laser in an oval-shaped cylinder package has been proposed and demonstrated, the footprint for which only occupies an area of 0.024 m2 apart from the pump diode, which is much smaller than in traditional planar fiber laser packages. Numerical simulations have been carried out, which have revealed that an oval-shaped cylinder package can effectively suppress the high-order mode in large mode area fiber setups and thereby benefit the integration of fusion points and the unpackaged elements at the same time. Over 3.7 kW of transverse mode instability (TMI)-free output power has been obtained, with a slope efficiency higher than 80%. With a custom-made chirped and tilted fiber Bragg grating (CTFBG), the Raman suppression ratio is improved to reach 38 dB at peak output power. The oval-shaped design has been verified to assist with the realization of TMI suppression and improve the integration of high-power fiber lasers. To the best of our knowledge, this fiber laser has among the smallest footprints of the various fiber sources at such high-power operating levels. Full article
(This article belongs to the Special Issue High-Power Lasers for Materials Processing)
Show Figures

Figure 1

11 pages, 2803 KiB  
Article
A Calibration Method for the Resolution of 2D TPP Laser Direct Writing
by Yu Xie, Yixiong Chen, Hang Xu and Jianxiong Chen
Micromachines 2023, 14(1), 212; https://0-doi-org.brum.beds.ac.uk/10.3390/mi14010212 - 14 Jan 2023
Cited by 2 | Viewed by 1429
Abstract
To improve the fabrication efficiency of the two-photon polymerization (TPP) laser direct writing, the TPP exposure process was set to complete by a single-line scan, which was named 2D TPP. The voxel of the 2D TPP should be large enough to cross the [...] Read more.
To improve the fabrication efficiency of the two-photon polymerization (TPP) laser direct writing, the TPP exposure process was set to complete by a single-line scan, which was named 2D TPP. The voxel of the 2D TPP should be large enough to cross the photoresist and the underlayer. To explore the resolution limit of the 2D TPP considering the thickness of the photoresist, a new method named the 45° scanning method was proposed. Meanwhile, a two-photon micro-nano fabrication platform was developed. A group of experiments based on the orthogonal decomposition method was carried out to analyze the width and length of the voxel on the S1805 photoresist under different laser power and processing speed. To confirm whether the resolution of the micro-nano structures fabricated by 2D TPP is consistent with the width of the voxel, aluminum wire grids were fabricated through the 2D TPP and the metal lift-off process. A second-order regression equation of the machining resolution and input parameters of the 2D TPP is deduced. The correlation coefficient between the width of the voxel and the aluminum wire grids is 0.961, which means a significant positive correlation between them. Finally, the second-order regression model derived from the fabrication resolution of the 2D TPP was validated by experiments. Full 2D grids were fabricated using 2D TPP and mental lift-off process. This paper provides a convenient, low-cost, and high-efficiency method for calibrating the fabrication resolution of 2D TPP on various photoresists. Full article
(This article belongs to the Special Issue High-Power Lasers for Materials Processing)
Show Figures

Figure 1

15 pages, 11776 KiB  
Article
Algorithms for Weld Depth Measurement in Laser Welding of Copper with Scanning Optical Coherence Tomography
by Thomas Will, Eduardo Massieu Garcia, Claudio Hoelbling, Christian Goth and Michael Schmidt
Micromachines 2022, 13(12), 2243; https://0-doi-org.brum.beds.ac.uk/10.3390/mi13122243 - 16 Dec 2022
Cited by 1 | Viewed by 1535
Abstract
In-process monitoring of weld penetration depth is possible with optical coherence tomography (OCT). The weld depth can be identified with OCT by statistical signal processing of the raw OCT signal and keyhole mapping. This approach is only applicable to stable welding processes and [...] Read more.
In-process monitoring of weld penetration depth is possible with optical coherence tomography (OCT). The weld depth can be identified with OCT by statistical signal processing of the raw OCT signal and keyhole mapping. This approach is only applicable to stable welding processes and requires a time-consuming keyhole mapping to identify the optimal placement of a singular OCT measuring beam. In this work, we use an OCT measurement line for the identification of the weld depth. This approach shows the advantage that the calibration effort can be reduced as the measurement line requires only calibration in one dimension. As current literature focuses on weld depth measurement with a singular measurement point in the keyhole, no optimal algorithm exists for weld depth measurement with an OCT measurement line. We developed seven different weld depth processing pipelines and tested these algorithms under different weld conditions, such as stable deep penetration welding, unstable deep penetration welding, and heat conduction welding. We analyzed the accuracy of the weld depth processing algorithms by comparing the measured weld depth with metallographic weld depths. The intensity accumulation approach is identified as the most accurate algorithm for successful weld depth measurement with a scanning OCT measurement line. Full article
(This article belongs to the Special Issue High-Power Lasers for Materials Processing)
Show Figures

Figure 1

7 pages, 1919 KiB  
Article
Highly Integrated Cladding Mode Stripper Array for Compact High-Power Industrial Fiber Laser
by Yu Liu, Wenjie Wu, Pengfei Zhao, Shan Huang, Yuwei Li, Yue Li, Min Li, Rumao Tao, Honghuan Lin and Jianjun Wang
Micromachines 2022, 13(12), 2226; https://0-doi-org.brum.beds.ac.uk/10.3390/mi13122226 - 15 Dec 2022
Cited by 1 | Viewed by 1288
Abstract
A design integrating multiple cladding mode strippers used in fiber laser architectures into a single device is proposed. This approach can increase the compactness of fiber lasers, thus contributing to industrial laser processing applications. By offset-placing the most intense light-stripping parts, for instance, [...] Read more.
A design integrating multiple cladding mode strippers used in fiber laser architectures into a single device is proposed. This approach can increase the compactness of fiber lasers, thus contributing to industrial laser processing applications. By offset-placing the most intense light-stripping parts, for instance, by inversing the laser injection directions or by displacing the beginning of etched sections, multiple cladding mode strippers bundled together into a single housing can have the hottest regions separated and can operate at full power simultaneously, with no evident cross-influence on each other. Two and three cladding-mode-stripper arrays have been implemented, and validation tests have been conducted with ~500-W cladding power being injected into each input port. For both arrayed devices, compared to the scenario in which only a single cladding mode stripper is working, no greater than a 2.1 °C temperature increment is generated when all components are operating concurrently, which demonstrates the effectiveness of the integration method. In this way, one half and two thirds of space/weight reduction can be realized, respectively, for the two and three cladding-mode-stripper arrays, which is meaningful, since cladding mode strippers are among the most bulky and hottest components in fiber lasers. Moreover, this integration provides a valuable reference for the miniaturization of other components, and thus, could contribute to the development fiber lasers with higher power-to-volume ratios, which would be more economical for industrial applications. Full article
(This article belongs to the Special Issue High-Power Lasers for Materials Processing)
Show Figures

Figure 1

14 pages, 8282 KiB  
Article
Quasi-Continuous Wave Pulsed Laser Welding of Copper Lap Joints Using Spatial Beam Oscillation
by Amirhossein Sadeghian, Subhasisa Nath, Yuze Huang, Ranveer S. Matharu, Noppawee Wadee, Nicolas Pembrey and David G. Waugh
Micromachines 2022, 13(12), 2092; https://0-doi-org.brum.beds.ac.uk/10.3390/mi13122092 - 27 Nov 2022
Cited by 1 | Viewed by 2012
Abstract
Laser beam welding of copper (Cu) using near-infrared radiation is extremely challenging due to its high thermal conductivity and large laser reflectivity. In the present study, the challenges and benefits of using spatial beam oscillation during quasi-continuous wave (QCW) pulsed laser beam welding [...] Read more.
Laser beam welding of copper (Cu) using near-infrared radiation is extremely challenging due to its high thermal conductivity and large laser reflectivity. In the present study, the challenges and benefits of using spatial beam oscillation during quasi-continuous wave (QCW) pulsed laser beam welding of 0.4 mm Cu to 1 mm Cu in lap joint configuration are presented. This work demonstrates how laser beam oscillating parameters can be used to control the laser weld quality and laser weld dimensions for Cu-Cu joining. Compared to a non-oscillated laser beam, welds made using laser beam oscillation showed fewer spatters, porosities, and better surface quality. Four levels of oscillating amplitudes (0.2 mm, 0.4 mm, 0.6 mm, and 0.8 mm) and oscillating frequencies (100 Hz, 200 Hz, 300 Hz, and 400 Hz) were compared to reveal the effect of beam oscillation parameters. The weld width was mainly controlled by oscillating amplitude, while weld penetration was affected by both oscillating amplitude and frequency. As the oscillating amplitude increased, the weld width increased while the weld penetration decreased. Increasing the oscillating frequency reduced the weld penetration but had a negligible effect on the weld width. The maximum tensile force of approximately 1944 N was achieved for the joint with a high width-to-depth ratio with an oscillating amplitude of 0.8 mm and an oscillating frequency of 200 Hz. Full article
(This article belongs to the Special Issue High-Power Lasers for Materials Processing)
Show Figures

Figure 1

11 pages, 1996 KiB  
Article
In-Process Analysis of Melt Pool Fluctuations with Scanning Optical Coherence Tomography for Laser Welding of Copper for Quality Monitoring
by Thomas Will, Tobias Jeron, Claudio Hoelbling, Lars Müller and Michael Schmidt
Micromachines 2022, 13(11), 1937; https://0-doi-org.brum.beds.ac.uk/10.3390/mi13111937 - 09 Nov 2022
Cited by 5 | Viewed by 1712
Abstract
Optical coherence tomography (OCT) is an inline process monitoring technology for laser welding with various applications in the pre-, in-, and post-process. In-process monitoring with OCT focuses on the measurement of weld depth by the placement of a singular measurement beam into the [...] Read more.
Optical coherence tomography (OCT) is an inline process monitoring technology for laser welding with various applications in the pre-, in-, and post-process. In-process monitoring with OCT focuses on the measurement of weld depth by the placement of a singular measurement beam into the keyhole. A laterally scanned measurement beam gives the opportunity to measure the keyhole and melt pool width. The processing region can be identified by separating higher signal intensities on the workpiece surface from lower signal intensities from the keyhole and the melt pool. In this work, we apply a scanned measurement beam for the identification of keyhole fluctuations. Different laser processing parameters are varied for laser welding of copper to evoke welds in the heat conduction regime, stable deep penetration welding, and unstable deep penetration welding. As keyhole instabilities can be related to the generation of spatter and other defects, we identified a feature for the classification of different weld statuses. In consequence, feedback can be given about possible defects which are originated in keyhole fluctuations (e.g., spatter). Full article
(This article belongs to the Special Issue High-Power Lasers for Materials Processing)
Show Figures

Figure 1

14 pages, 6753 KiB  
Article
Developing a Real-Time Working Method That Improves Process Efficiency in High-Power Fiber Laser Systems
by Uğur Yalçın and Uğur Karanfil
Micromachines 2022, 13(9), 1552; https://0-doi-org.brum.beds.ac.uk/10.3390/mi13091552 - 19 Sep 2022
Cited by 1 | Viewed by 1333
Abstract
The need for studies on new simulation and monitoring methods for interactions occurring during material processing in high-power fiber laser systems has increased. In this manuscript, a structure that can intervene in real time and improved solutions that demonstrate the potential of photodiode-based [...] Read more.
The need for studies on new simulation and monitoring methods for interactions occurring during material processing in high-power fiber laser systems has increased. In this manuscript, a structure that can intervene in real time and improved solutions that demonstrate the potential of photodiode-based monitoring are presented. By processing the signals instantly received during material processing with InGaAs and Si photodiodes integrated into the cutting head in algorithms, the method that intervenes in the process by detecting the last stage of the piercing process and the problems that may occur during cutting are explained. The stability of the proposed system has been tested on the most used materials in the industry such as St37, stainless steel, and aluminum at laser powers of 6, 8, and 10 kW, respectively. In this article, it is shown that there is a relationship between the signals observed in the infrared (IR) and visible (VIS) spectrum and the characteristics of the cut quality and scenario. Analysis results of photo-diode tracking signals obtained according to material, power, and gas type are presented. Among the innovations added by the method are related application process improvements, material analysis, and cutting and piercing parameter improvements. Full article
(This article belongs to the Special Issue High-Power Lasers for Materials Processing)
Show Figures

Figure 1

Back to TopTop