Very high power is needed to cut or weld using a laser beam. But this creates its own problem: the beam’s energy deforms the mirrors that are focusing it to a point. When this happens, the beam expands and loses intensity. A new type of mirror can deform itself so as to correct this unwanted deformation. It will be presented at the Optatec trade fair in Frankfurt from May 20 to 22 (hall 3, booth D50).
Lasers are used in manufacturing to cut materials or weld components together. Laser light is focused to a point using various lenses and mirrors; the smaller the focal point and the higher the energy, the more accurately operators can work with the laser. So, turn up the power and off you go, right?
It is not that simple because when laser power increases, the mirror heats up accordingly, causing it to deform. A deformed mirror cannot effectively focus the laser; the focal point gets bigger and laser power falls away.
Precisely correcting unwanted deformation
Scientists are working on ways of making the mirrors more temperature-resistant and getting rid of the deformation. However, this difficult undertaking only works up to a point. Researchers at the Fraunhofer Institute for Applied Optics and Precision Engineering IOF in Jena are pursuing a completely different approach. “We’ve developed a mirror that doesn’t prevent deformation by the laser, but corrects it,” explains Dr. Claudia Reinlein, from Fraunhofer IOF. “By deliberately heating up the mirror to a precisely controlled level, we balance out the unwanted deformation by the laser.”
Working with colleagues from Fraunhofer IKTS and Ilmenau University of Technology, the scientist designed a ceramic mirror with a copper layer on the front and built-in temperature sensors and filaments. When a laser beam heats up the mirror, the sensors detect the change. Software calculates how strongly the mirror is deforming from the heat and sends a corresponding current of electrical power through the filaments. These heat up accordingly and balance out the unwanted deformation.
On the back of the mirror, the researchers have fitted a piezoelectric layer that can also deform the mirror and correct all further errors that could disrupt the laser beam. The scientists have already developed a prototype of the mirror and are presenting it at the Optatec trade fair in Frankfurt am Main from May 20 to 22 (hall 3, booth D50). Currently the researchers still have to control the system manually, but the mirror should be able to correct deformations automatically in future.
Lasers as “guardian angels” for satellites
power laser is directed at the dust particle, the beam can push the particle outward and change its path to avoid collision with the satellite.
However, one problem is that atmospheric turbulence can alter the laser beam; which is where the deformable mirror can come to the rescue. First the researchers send a beam from a separate laser into the atmosphere and analyze how the turbulence changes it. Based on this data, they can then deform the mirror using the filaments and a piezoelectric layer such that the laser beam hits the dust particle with just the right focus.
Kevin Füchsel | Eurek Alert!
OLED production facility from a single source
29.03.2017 | Fraunhofer-Institut für Angewandte Polymerforschung IAP
High Resolution Laser Structuring of Thin Films at LOPEC 2017
21.03.2017 | Fraunhofer-Institut für Lasertechnik ILT
The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.
To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
30.03.2017 | Health and Medicine
30.03.2017 | Health and Medicine
30.03.2017 | Medical Engineering