High-Power Fibre Lasers – Application Potentials for Welding of Steel and Aluminium Sheet Material

2005 ◽  
Vol 6-8 ◽  
pp. 171-178 ◽  
Author(s):  
Claus Thomy ◽  
Thomas Seefeld ◽  
Frank Vollertsen
Keyword(s):  
High Power ◽  
Welding Speed ◽  
Beam Quality ◽  
Sheet Material ◽  
Laser Source ◽  
Fibre Laser ◽  
Energetic Efficiency ◽  
Fibre Lasers ◽  
Aluminium Sheet ◽  
Compact Size

Latest developments in laser physics have enabled the production of high-power fibre lasers with beam powers up to 10 kW at excellent beam quality. Adding to these properties their high energetic efficiency, their considerable estimated lifetime and their compact size, they might well be considered to be a viable alternative to both conventional lamp- or diode-pumped Nd:YAGas well as to CO2-Lasers. However, due to the novelty of the system, very few experiences on their usability for materials processing and in special for welding of steel and aluminium sheet material are existing. To help this situation, a 7 kW high-power fibre laser system was tested at the Bremer Institut fuer angewandte Strahltechnik, and its potentials for welding steel and aluminium sheets have been assessed. By these results, of which a selection is presented here, it could indeed be demonstrated that it is possible to remarkably enhance process limitations considering welding speed and sheet thickness previously regarded to be inevitable when welding with solid-state lasers. Consequently, in July 2004 the first high-power fibre laser with a beam power exceeding 10 kW at a BPP of less than 12.5 mm*mmrad was tested in cooperation with SLV M-V Rostock. This laser source is currently used for developing mainly welding, but also cutting and cladding applications for a variety of industries. Within these studies, it was e. g. demonstrated that it is possible to achieve a penetration of 10 mm in EN-AW 6082 at a welding speed of 3 m/min.

scholarly journals High power narrowband 589nm frequency doubled fibre laser source

2009 ◽  
Vol 17 (17) ◽  
pp. 14687 ◽  
Author(s):  
Luke Taylor ◽  
Yan Feng ◽  
Domenico Bonaccini Calia
Keyword(s):  
High Power ◽  
Laser Source ◽  
Fibre Laser

scholarly journals Towards high-power mid-IR light source tunable from 3.8 to 4.5 µm by HBr-filled hollow-core silica fibres

2022 ◽  
Vol 11 (1) ◽  
Author(s):  
Zhiyue Zhou ◽  
Zefeng Wang ◽  
Wei Huang ◽  
Yulong Cui ◽  
Hao Li ◽  
...  
Keyword(s):  
High Power ◽  
Continuous Wave ◽  
Transmission Loss ◽  
Coupling Efficiency ◽  
Fibre Length ◽  
Fibre Laser ◽  
Hollow Core ◽  
Fibre Lasers ◽  
Fibre Amplifier ◽  
Ir Emission

AbstractFibre lasers operating at the mid-IR have attracted enormous interest due to the plethora of applications in defence, security, medicine, and so on. However, no continuous-wave (CW) fibre lasers beyond 4 μm based on rare-earth-doped fibres have been demonstrated thus far. Here, we report efficient mid-IR laser emission from HBr-filled silica hollow-core fibres (HCFs) for the first time. By pumping with a self-developed thulium-doped fibre amplifier seeded by several diode lasers over the range of 1940–1983 nm, narrow linewidth mid-IR emission from 3810 to 4496 nm has been achieved with a maximum laser power of about 500 mW and a slope efficiency of approximately 18%. To the best of our knowledge, the wavelength of 4496 nm with strong absorption in silica-based fibres is the longest emission wavelength from a CW fibre laser, and the span of 686 nm is also the largest tuning range achieved to date for any CW fibre laser. By further reducing the HCF transmission loss, increasing the pump power, improving the coupling efficiency, and optimizing the fibre length together with the pressure, the laser efficiency and output power are expected to increase significantly. This work opens new opportunities for broadly tunable high-power mid-IR fibre lasers, especially beyond 4 μm.

Fibre laser cutting: Beam absorption characteristics and gas-free remote cutting

2009 ◽  
Vol 224 (5) ◽  
pp. 1007-1018 ◽  
Author(s):  
A Mahrle ◽  
M Lütke ◽  
E Beyer
Keyword(s):  
Laser Cutting ◽  
Beam Quality ◽  
Sheet Thickness ◽  
Practical Experience ◽  
Fibre Laser ◽  
Experimental Fact ◽  
Attractive Alternative ◽  
Fibre Lasers ◽  
Laser Systems ◽  
Absorption Characteristics

Laser cutting is still the most common industrial application of CO 2 laser systems but currently available high-power fibre lasers seem to be an attractive alternative to the established CO 2 laser sources for several cutting tasks. Practical experience has shown that fibre lasers enable significantly increased travel rates in the case of inert-gas fusion cutting. This advantage in achieving higher cutting speeds in comparison to CO 2 laser cutting is however a clear function of the sheet thickness to be cut. In the first part of this article, possible reasons for this experimental fact are derived from a thermodynamic analysis of the process with consideration of the specific beam absorption characteristics under cutting conditions. After that, in the second part, a quite new laser cutting variant, namely the gas-free remote cutting process that considerably benefits from the high beam quality of fibre laser systems, is presented.

High-power pump combiners for Tm-doped fibre lasers

2015 ◽  
Vol 23 (4) ◽  
Author(s):  
D. Stachowiak ◽  
P. Kaczmarek ◽  
K.M. Abramski
Keyword(s):  
Pump Power ◽  
Output Power ◽  
High Power ◽  
Fibre Laser ◽  
Power Combiner ◽  
Fibre Lasers ◽  
Transmission Level ◽  
Laser Setup

AbstractIn this paper our results of investigation on a pump power combiner in a configuration of 7×1 are presented. The performed combiner, with pump power of 80–85% transmission level, was successfully applied in a thulium doped fibre laser. The performed all-fibre laser setup reached a total CW output power of 6.42 W, achieving the efficiency on a 32.1% level.

High power, high beam quality laser source with narrow, stable spectra based on truncated-tapered semiconductor amplifier

2013 ◽  
Author(s):  
X. Wang ◽  
G. Erbert ◽  
H. Wenzel ◽  
P. Crump ◽  
B. Eppich ◽  
...  
Keyword(s):  
High Power ◽  
Beam Quality ◽  
Laser Source ◽  
High Beam ◽  
High Beam Quality

The characteristics of high power fibre laser welding

2010 ◽  
Vol 224 (5) ◽  
pp. 1019-1029 ◽  
Author(s):  
A Salminen ◽  
H Piili ◽  
T Purtonen
Keyword(s):  
Laser Welding ◽  
High Power ◽  
Focal Point ◽  
Beam Quality ◽  
Welding Process ◽  
High Energy ◽  
High Energy Density ◽  
Fibre Laser ◽  
Line Energy ◽  
Laser Welding Process

Laser welding has an ever growing role in manufacturing technology. Keyhole laser welding is the most important laser welding process in metal industry when exceeding the 1 mm weld penetration. This process uses efficiently the high energy density of a laser beam to vaporize and melt materials, thus producing a keyhole in the material via which the energy is brought to it. The requirements from customer side and the development of new materials have been giving justification for the development of new laser types suitable for material processing with ever higher power values. In contrast, the development of laser technologies has made it possible to build more powerful lasers with excellent beam properties and good electrical efficiency. New laser sources with good absorption and beam quality make the laser welding even more efficient when throughput and efficiency are considered. They show their ability to produce narrower welds with lower line energy. However, the validation of actual keyhole shape, size, and behaviour against the models is still lacking because of the difficulties in performing the measurements of the actual dimensions. It has been shown that the better the beam quality the higher the welding speed. When welding with high power, good beam quality, and wavelength close to 1000 nm, there are some obstacles to overcome, which are caused by high absorption and power density. Typically, problems, such as thermal lensing, can be avoided with proper parameter and tool selection. Typically, the size of the keyhole is according to the focal point size, and the stability of the keyhole plays a major role when considering the ability of the laser welding process to produce high quality welds.

Beam Shaping Technology for High Power Diode Laser Source

2014 ◽  
Vol 915-916 ◽  
pp. 385-389
Author(s):  
Yuan Yuan Gu ◽  
Guo Xing Wu ◽  
Hui Lu ◽  
Jian Lin
Keyword(s):  
Conversion Efficiency ◽  
High Power ◽  
Beam Quality ◽  
Diode Lasers ◽  
Beam Shaping ◽  
Laser Source ◽  
Beam Parameter ◽  
Beam Combination ◽  
Continuous Output ◽  
Wall Plug Efficiency

Direct diode lasers have some of the most attractive features of any laser. They are very efficient, compact, wavelength versatile, low cost, and highly reliable. However, the full utilization of direct diode lasers has yet to be realized. This is mainly due their poor output beam quality. Because of this, direct diode lasers are typically used to pump other lasers such as bulk solid-state (rod and thin disk) and fiber lasers. An improvement of the wall-plug efficiency and Power density necessary can be achieved by beam shaping and beam combination such as polarization coupling. In this paper, using the beam shaping technology realize good beam quality and high wall-plug efficiency. Base on bars rated to 60 W and 57% conversion efficiency, vertically stacked arrays (twenty bars) of such configuration are demonstrated with rated to about 1200W. The beam quality of high-power high brightness 880 nm laser diode source is improved with beam shaping. Beam parameter product of 79. 3 mm mrad ×81. 2 mm mrad, electro-optical conversion efficiency of more than 45.8% and continuous output power of 1 kW are demonstrated. This laser can be directly applied to cladding, surface hardening and other fields.

scholarly journals Towards Ultimate High-power Scaling: Coherent Beam Combing of Fiber Lasers

2021 ◽  
Author(s):  
Hossein Fathi ◽  
Mikko Närhi ◽  
Regina Gumenyuk
Keyword(s):  
Fiber Laser ◽  
High Power ◽  
Fiber Lasers ◽  
Continuous Wave ◽  
Beam Quality ◽  
Coherent Beam ◽  
Laser Source ◽  
Coherent Beam Combining ◽  
Beam Combining ◽  
Wide Range

Fiber laser technology has been demonstrated as a versatile and reliable approach for laser source manufacturing with a wide range of applicability in various fields ranging from science to industry. The power/energy scaling of single fiber laser systems has faced several fundamental limitations. To overcome them and to boost the power/energy level even further, combining the output powers of multiple lasers has become the primary approach. Among various combining techniques, the coherent beam combining of fiber amplification channels is the most promising approach, instrumenting ultra-high power/energy lasers with near-diffraction-limited beam quality. This paper provides a comprehensive review of the progress of coherent beam combining for both continuous-wave and ultrafast fiber lasers. The concept of coherent beam combining from basic notions to specific details of methods, requirements, and challenges are discussed, along with reporting some practical architectures for both continuous and ultrafast fiber lasers.

scholarly journals Characterization of Absorption Losses and Transient Thermo-Optic Effects in a High-Power Laser System

Photonics ◽  
2020 ◽  
Vol 7 (4) ◽  
pp. 94
Author(s):  
Lukasz Gorajek ◽  
Przemyslaw Gontar ◽  
Jan Jabczynski ◽  
Jozef Firak ◽  
Marek Stefaniak ◽  
...  
Keyword(s):  
High Power ◽  
Continuous Wave ◽  
Beam Quality ◽  
Laser System ◽  
Infrared Camera ◽  
High Energy ◽  
Laser Source ◽  
Transient Temperature ◽  
Temperature Profiles ◽  
Beam Diameter

(1) Background: The modeling, characterization, and mitigation of transient lasers, thermal stress, and thermo-optic effects (TOEs) occurring inside high energy lasers have become hot research topics in laser physics over the past few decades. The physical sources of TOEs are the un-avoidable residual absorption and scattering in the volume and on the surface of passive and active laser elements. Therefore, it is necessary to characterize and mitigate these effects in real laser systems under high-power operations. (2) Methods: The laboratory setup comprised a 10-kW continuous wave laser source with a changeable beam diameter, and dynamic registration of the transient temperature profiles was applied using an infrared camera. Modeling using COMSOL Multiphysics enabled matching of the surface and volume absorption coefficients to the experimental data of the temperature profiles. The beam quality was estimated from the known optical path differences (OPDs) occurring within the examined sample. (3) Results: The absorption loss coefficients of dielectric coatings were determined for the evaluation of several coating technologies. Additionally, OPDs for typical transmissive and reflective elements were determined. (4) Conclusions: The idea of dynamic self-compensation of transient TOEs using a tailored design of the considered transmissive and reflecting elements is proposed.

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