A new ultrashort pulse laser source (USP) from Trumpf, designed for industrial use, will significantly expand the range of applications for USP technology.
The Fraunhofer Institute for Laser Technology ILT in Aachen will systematically explore the potential of the beam source with an average output of 1 KW over the coming months.
Among other things, experiments are planned to optimize processes in battery and fuel cell production, toolmaking and semiconductor technology, as well as to test various beam guidance strategies. Many of these pilot applications have their origins in the Fraunhofer-internal Cluster of Excellence Advanced Photon Sources (CAPS), to which 21 institutes of the Fraunhofer-Gesellschaft belong.
“In the Fraunhofer CAPS cluster, we want to clarify how high-power beam sources can expand the range of applications for USP technology,” explains Dr. Dennis Haasler, Group Manager Micro- and Nanostructuring at Fraunhofer ILT. His team will systematically get to the bottom of this question over the next few months with appropriate experiments.
The focus will be on a new UKP beam source from Trumpf with an average output of 1 kW. As part of a bilateral cooperation, the company is providing the Fraunhofer ILT with the new TruMicro 9000, which is designed for industrial applications.
With its advance into the kilowatt range, this beam source offers many times the average power of the currently most powerful USP lasers for industry.
Its pulse energy of 10 mJ also significantly exceeds the previous level. With a pulse duration of less than 900 fs, numerous burst options and very high beam quality of M² < 1.3, combined with high flexibility at different operating points and the operating standards familiar from Trumpf industrial lasers, the system has the potential to trigger the productivity boost in USP material processing that many users are waiting for. “For the first time, we have a kilowatt beam source that performs like established USP industrial lasers in the 200 W class,” explains Haasler. He and his team will now evaluate how the high-energy laser pulses can be used for industrial manufacturing and finishing processes.
Fraunhofer ILT, Aachen / Ralf Baumgarten
High performance based on a combination of tried and tested technology modules
“By combining tried-and-tested technology components in the amplifier chain, we have succeeded in significantly increasing both the maximum individual pulse energy and the resulting average power,” reports Steffen Rübling, Product Manager for the TruMicro family of USP lasers at Trumpf.
According to Rübling, the fact that the new beam source achieves the typical USP beam quality despite its impressive output is due to the fact that the development team was able to draw on a wealth of experience: Trumpf offers USP lasers of various power classes, each of which is based on different amplifier technologies, including fiber, disk and slab amplifiers. In addition to this technological diversity within the UKP portfolio, the team also benefited from knowledge gained from component development for continuous wave (CW) and short pulse lasers.
For example, the main amplifier of the new TruMicro 9000 – a so-called multi-pass cell – was originally used for the amplification of nanosecond pulses in the power range of 3 KW. The transfer of such tried and tested technology modules to the UKP beam source has ensured that it meets industrial requirements straight away. With this stable source, the Fraunhofer ILT can now explore its application potential.
It will depend on the right process strategies
The focus will be on the question of which process control strategies and system designs can be used to optimally utilize the high average power for processing the respective workpieces. Several test setups are available in the Fraunhofer ILT laboratory for this purpose, which the team can use to direct the high power and energy input of the beam source onto the component surfaces for effective and gentle processing. A key advantage of USP processes comes into play here: although their femtosecond or picosecond pulses bundle a great deal of energy, the thermal load on the material remains minimal thanks to their brevity.
By entering the KW power range and the high pulse energy, beam splitting and beam steering strategies are available that promise greatly increased productivity through the parallelization of machining processes. To prove this, Haasler’s team relies on four system technology approaches: The simplest approach is the burst mode that can be implemented with conventional galvo scanners. Here, the high energy of the femtosecond pulses is distributed over up to eight individual pulses.
The researchers also use special system technology and optical strategies for beam shaping and ultra-fast beam deflection or for the parallelization of machining processes.
“We need the different approaches in order to find out which strategy we can use to achieve the highest productivity for the respective industrial application,” explains Haasler.
For example, a different system technology is required for the selective removal of polymer layers from compound bipolar plates than for the selective removal of active material layers on battery electrodes for their contacting or for the microstructuring of metal surfaces.
Fraunhofer ILT, Aachen
Ultra-fast beam steering or splitting into 900 individual beams
At the Fraunhofer ILT, the team can combine the new kW beam source with a polygon scanner from Moewe, which enables scanning speeds of up to 1000 m/s on a processing area of 700 x 900 mm². A multi-beam system is also available for the tests, which enables various processing strategies with a single beam or beam splitting into 100 or even up to 900 parallelized partial beams on a processing area of 400 x 400 mm². The fourth option available to the team is beam shaping with Spatial Light Modulators (SLM).
This promising approach is currently still under development.
By transforming the beam into optical stamps of almost any design, it could ensure even greater processing efficiency in the future.
“This is especially true in combination with high-power USP lasers,” emphasizes Haasler. The Fraunhofer ILT will now systematically clarify how the power and pulse energy of the new USP beam source can be converted into productivity advantages with the respective beam guidance and process strategies.
The pilot applications come from practical experience. Input is provided by the CAPS cluster, which includes 21 Fraunhofer Institutes.
Within the cluster, they can access the specific laser expertise of the Fraunhofer ILT and the two Fraunhofer Institutes for Applied Optics and Precision Engineering IOF in Jena and for Material and Beam Technology IWS in Dresden for their own project ideas and applications for their industrial partners. Other USP applications that the team will be evaluating have their origins in various collaborative research projects in which the Fraunhofer ILT is working with industrial partners to find new process solutions for the production of batteries, fuel cells or electrolyzers.
In addition, there are many applications in toolmaking, medical and environmental technology, semiconductor production and printed electronics in which USP material processing promises quality advantages. However, widespread industrial use has so far failed due to insufficient productivity levels. This could now change thanks to the performance boost of these USP beam sources.
Broad demand for reliable, highly productive UKP processes
With the new UKP beam source from Trumpf, the Fraunhofer team will now clarify in detail how the KW power can be used in material processing practice – and how the high power level affects the process quality, the workpieces and the optics used. “Ten millijoules of pulse energy require high-quality, precisely designed optical components,” explains Haasler. Practical issues such as the heat input into the component or the possible development of dirt as a result of the increased material removal also need to be clarified. It is also questionable to what extent the combination of high ablation and repetition rates can lead to unwanted shielding of the laser beam at certain points or whether there is a risk of interaction between the ablated material and the surrounding partial beams during multi-beam processing.
Other questions concern the service life and contamination of the optical elements in the process chamber and radiation protection. Last but not least, there is the question of whether 1 KW is enough or whether even more powerful lasers are needed to exploit the industrial potential of USP technology. According to Trumpf Product Manager Rübling, the modular architecture of the TruMicro 9000 makes this possible: “In addition to further increasing the average power, it is also possible to convert the wavelength or extend or reduce the pulse duration,” he explains.
In preparation for the tests with the current system, the Fraunhofer ILT has theoretically approached various applications in micro- and nanostructuring and calculated the required laser power based on the required material removal volumes and rates. The spectrum of these applications includes the targeted structuring of graphite layers on the electrodes of lithium-ion batteries to increase their power density and fast-charging capability, the selective ablation and selective roughening of bipolar plates for fuel cells and electrolysers, the laser structuring of printing rollers and specific applications in printed electronics.
Other promising fields of application include ultra-fast nano-polishing, micro-drilling in water filters and cutting wafers into individual chips. According to Haasler, high-performance UVP processes also hold great potential for targeted surface functionalization, for example with regard to anti-reflective properties or self-cleaning effects or friction minimization and flow optimization. The aerospace industry also has a need. For example, USP processes are suitable for producing highly emissive aluminum surfaces for heat dissipation from satellites.
Fraunhofer ILT, Aachen / Ralf Baumgarten
USP lasers fuel the development of secondary sources
“The quality of USP processes has already been proven in many of the fields of application mentioned. The important thing now is to increase productivity to industrial levels,” explains Haasler. In order for high-performance USP processes to actually be able to refine more and more products in the future, they would have to meet the cycle times of existing process chains and the cost framework.
Another possible application is the use as a secondary source for generating X-rays, which the Fraunhofer ILT is exploring together with Trumpf and other industrial partners in the current BMBF-funded XProLas research project.
USP lasers serve as an upstream beam source when generating X-rays. Their high-intensity pulses are compressed to less than 50 femtoseconds and hit the so-called target – a metal such as gallium, indium or tin – with a strong focus. Depending on the respective target, different plasmas are created that emit part of their energy as extremely short-wave light. The project plans to develop highly compact, excellent X-ray sources that will provide insights into ongoing battery charging and discharging processes in the future.
Important sustainability impulses
Based on theoretical assumptions for a wide range of applications and materials, the team will now begin practical trials. The aim is to verify the assumed productivity benefits. Whether selectively removing the polymer layers of compound bipolar plates or roughening the stainless steel surfaces of metallic bipolar plates: The team will systematically get to the bottom of the potential of the new 1 kW beam source.
Wherever surface enlargement and modification, polishing, the exposure of contacting zones or nano- and microstructuring are required, USP processes can demonstrate their specific advantages in conjunction with the corresponding beam splitting and beam directing strategies. Their potential ranges from significantly more productive material processing to the substitution of a wide range of chemical processes.
As a result, USP technology will also make substantial contributions to sustainability: whether it is drilling billions of tiny, bacteria-impermeable pores into water filters using the multi-beam process, providing aircraft wings and rotor blades of wind turbines with flow-optimizing microstructures, or optimizing the performance of batteries, fuel cells and electrolysers through nano- and microstructuring and selective material removal, the benefits for environmental and climate protection are obvious.
And so the ultra-short, energy-charged pulses of light provide new impetus for the upcoming transformation towards a sustainable society.
Save the date! 8th UKP Workshop Ultrafast Laser Technology
The 8th UKP Workshop on 8. and In addition to the basics of USP technology, the conference on April 9, 2025 will address current developments in the field of USP beam sources and the necessary system technology. The spectrum of topics ranges from the basics of USP technology and the latest trends in beam shaping and laser beam sources to applications in electronics, energy storage, glass processing and microelectronics. At the congress, experts will also present the initial results of the test series with the TruMicro 9000.
