Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Significantly more productivity in USP lasers

06.12.2016

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising: Ultrashort pulses vaporize the material so rapidly that hardly any heat remains in the workpiece. At the same time, surfaces are particularly smooth, cuts extremely precise and the process is barely dependent on the used material.


With the hybrid systems composed of freely programmable multi-beam optics and galvo scanners, a laser beam can be split into any number of beamlets.

© Fraunhofer ILT, Aachen, Germany / Volker Lannert.

This has been recognized for a long time, but it is only in the last ten years that complex laser sources have reached a level that permits 24/7 use in industry. Systems with up to 100 watts are now being sold in batches.

These systems have become established in micro-material processing, with calls in the meantime for more productivity and stronger lasers. The development of laser sources with kW power is well advanced, but a simple scaling of processes by increasing the laser power is not immediately possible without losing the high processing quality – process engineering especially beam delivery is now the bottleneck.

Which is faster? Scanners versus multi-beam optics

New USP laser sources offer improved performance through repetition rates into the MHz range or through higher pulse energies. New scanner systems with polygon mirrors show promising results for high repetition rates. In this context, the spot must be moved extremely rapidly on the workpiece to keep too many pulses from overlapping and the accumulated heat from impairing the processing quality.

Scanners enable a high level of flexibility in the contour to be processed, but they move only a single spot on the surface of the workpiece. Large surfaces with repeating patterns can be processed more efficiently with what are known as multi-beam optics.

A multi-beam optic device splits a single laser beam into numerous beamlets. This requires higher laser pulse energies so that every beamlet can also remove material. Micro-optics or diffractive optical elements that generate a set pattern from a laser beam have been tested to date. Adjusted to the application, this might be a line, a special contour or a pattern made of hundreds of single beams.

Dynamic multi-beam optics uses liquid crystals

At present, beam shaping in multi-beam optics is achieved by diffracting the laser beam on solid optical structures. Experts at Fraunhofer ILT in Aachen have now developed a system that allows the diffractive pattern to be switched at a rate of 50 hertz. To this end, they use spatial light modulators (SLM) that generate the required diffraction pattern with liquid crystals.

The researchers optimized the system and tested it together with a galvanometer scanner in an experimental setup. With suitable optics, image errors are corrected so that even large workpieces can be processed with a high degree of precision.

Programmable multi-beam optics enable a significant increase in productivity, especially in USP lasers with higher pulse energies. Applications are envisioned in microelectronics or in the texturing of surfaces, in the consumer goods sector for example.

4th UKP Workshop 2017

Productivity and process engineering when using USP lasers will be important topics at the “UKP Workshop - Ultrafast Laser Technology” on April 26 and 27, 2017 in Aachen, Germany. Specialists from laser development, process engineering and industry will be meeting there for the fourth time to discuss new results and share experience gained from practice. You will find more information on the event at www.ultrakurzpulslaser.de.

Contact

Dipl.-Phys. Patrick Gretzki
Micro and Nano Structuring Group
Telephone +49 241 8906-8078
patrick.gretzki@ilt.fraunhofer.de

Weitere Informationen:

http://www.ilt.fraunhofer.de/en.html
http://www.ultrakurzpulslaser.de/en

Petra Nolis | Fraunhofer-Institut für Lasertechnik ILT

More articles from Physics and Astronomy:

nachricht NASA detects solar flare pulses at Sun and Earth
17.11.2017 | NASA/Goddard Space Flight Center

nachricht Pluto's hydrocarbon haze keeps dwarf planet colder than expected
16.11.2017 | University of California - Santa Cruz

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

Im Focus: Wrinkles give heat a jolt in pillared graphene

Rice University researchers test 3-D carbon nanostructures' thermal transport abilities

Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

NASA detects solar flare pulses at Sun and Earth

17.11.2017 | Physics and Astronomy

NIST scientists discover how to switch liver cancer cell growth from 2-D to 3-D structures

17.11.2017 | Health and Medicine

The importance of biodiversity in forests could increase due to climate change

17.11.2017 | Studies and Analyses

VideoLinks
B2B-VideoLinks
More VideoLinks >>>