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!
International companies showcase their innovations at Medical Manufacturing Asia in Singapore
21.06.2016 | IVAM Fachverband für Mikrotechnik
EELICON – Smart shading system
07.06.2016 | Fraunhofer-Institut für Silicatforschung ISC
High resolution rotational spectroscopy reveals an unprecedented number of conformations of an odorant molecule – a new world record!
In a recent publication in the journal Physical Chemistry Chemical Physics, researchers from the Max Planck Institute for the Structure and Dynamics of Matter...
Strands of cow cartilage substitute for ink in a 3D bioprinting process that may one day create cartilage patches for worn out joints, according to a team of engineers. "Our goal is to create tissue that can be used to replace large amounts of worn out tissue or design patches," said Ibrahim T. Ozbolat, associate professor of engineering science and mechanics. "Those who have osteoarthritis in their joints suffer a lot. We need a new alternative treatment for this."
Cartilage is a good tissue to target for scale-up bioprinting because it is made up of only one cell type and has no blood vessels within the tissue. It is...
Physicists in Innsbruck have realized the first quantum simulation of lattice gauge theories, building a bridge between high-energy theory and atomic physics. In the journal Nature, Rainer Blatt‘s and Peter Zoller’s research teams describe how they simulated the creation of elementary particle pairs out of the vacuum by using a quantum computer.
Elementary particles are the fundamental buildings blocks of matter, and their properties are described by the Standard Model of particle physics. The...
A year and a half on the outer wall of the International Space Station ISS in altitude of 400 kilometers is a real challenge. Whether a primordial bacterium...
Researchers at Case Western Reserve University have developed a way to swiftly and precisely control electron spins at room temperature.
09.06.2016 | Event News
24.05.2016 | Event News
20.05.2016 | Event News
27.06.2016 | Agricultural and Forestry Science
27.06.2016 | Physics and Astronomy
27.06.2016 | Life Sciences