Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Deformable mirror corrects errors

15.05.2014

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).


Thermic-piezoelectric deformable mirror to be used in high power laser systems.

© Fraunhofer IOF

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!
Further information:
http://www.fraunhofer.de/en/press/research-news/2014/may/optatec-2014-deformable-mirror-corrects-errors.html

Further reports about: Engineering IOF Precision atmosphere copper errors filaments laser mirror piezoelectric

More articles from Trade Fair News:

nachricht SAB on the Fair "Innotrans": Railway cables acc. to DIN EN 45545-2
07.08.2014 | SAB Bröckskes GmbH & Co. KG

nachricht Targeted Infrared – Matched to the Task
05.08.2014 | Heraeus Noblelight GmbH

All articles from Trade Fair News >>>

The most recent press releases about innovation >>>

Anzeige

Anzeige

Event News

MEDICA EDUCATION CONFERENCE: Bessere Behandlung dank Biomarker

21.08.2014 | Event News

Mathematics and Computer Science - Key Disciplines in Developing Countries as well?

20.08.2014 | Event News

5th Technical Conference "Subsoil Analysis, Ground Improvement and Wind Turbine Foundations"

13.08.2014 | Event News

 
Latest News

Siemens receives order for 67 wind turbines for Dudgeon offshore wind power plant

21.08.2014 | Press release

How Lizards Regenerate Their Tails: Researchers Discover Genetic ‘Recipe’

21.08.2014 | Life Sciences

500 million year reset for the immune system

21.08.2014 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>